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Perina nuda (Fabricius) (Lepidoptera: Lymantriidae) is an important leaf‐feeding pest of Ficus species. It significantly affects the growth and reproduction of Ficus species, the economic prospects of growers, and the beauty of urban gardens. This study employed the MaxEnt model to predict and analyze the potential distribution of P. nuda in China, utilizing global distribution data and the correlation between the distribution of P. nuda and environmental variables. The results showed that the dominant environmental variables influencing the distribution of P. nuda included the warmest quarterly precipitation, coldest monthly minimum temperature, annual precipitation, and wettest monthly precipitation. The potential distribution area of P. nuda in China under current climatic conditions is 158 × 104 km2, accounting for 16.4% of the total area of the country. According to the SSP5‐8.5 scenario in 2050, the potential distribution area of P. nuda is projected to reach 200 × 104 km2, an increase of 26.5% compared to the current. P. nuda is widespread in China and has a tendency to spread, threatening the growth of Ficus species. This study is important for monitoring and control of P. nuda in areas where it is present, and where it may be present in the future. [ABSTRACT FROM AUTHOR]

Mimicry with warning colors includes Batesian and Müllerian mimicries. If we divide mimicry by sex, there are theoretically four types of mimicry: unimodal, female‐limited, male‐limited and dual mimicry. The latter three cases cause sexual dimorphism in body color and marking pattern but are rarely reported. In this study, we show that the tussock moth Numenes albofascia is possibly a dual mimic. The wing color and marking pattern of male and female N. albofascia are completely different, with the male's pattern resembling that of the smoky moth Pidorus atratus, while the female pattern resembles that of the tiger moth Arctia caja. Body size also differs greatly between the sexes of N. albofascia, matching the mimicry model species of each sex. These moths are distributed sympatrically in Japan, and their adult seasons overlap with each other. According to lizard feeding experiments, N. albofascia is palatable, while both male and female model species are unpalatable. Actograms in the laboratory and the light trapping in the field suggest that females of N. albofascia fly actively from sunset to midnight, while males fly during the twilight period around dawn. Therefore, male and female N. albofascia might be Batesian mimics of diurnally active P. atratus and nocturnally active A. caja, respectively, and the great sexual dimorphism of this moth could be caused by dual mimicry. [ABSTRACT FROM AUTHOR]

Theory on plasticity driving speciation, as applied to insect-plant interactions (the oscillation hypothesis), predicts more species in clades with higher diversity of host use, all else being equal. Previous support comes mainly from specialized herbivores such as butterflies, and plasticity theory suggests that there may be an upper host range limit where host diversity no longer promotes diversification. The tussock moths (Erebidae: Lymantriinae) are known for extreme levels of polyphagy. We demonstrate that this system is also very different from butterflies in terms of phylogenetic signal for polyphagy and for use of specific host orders. Yet we found support for the generality of the oscillation hypothesis, in that clades with higher diversity of host use were found to contain more species. These clades also consistently contained the most polyphagous single species. Comparing host use in Lymantriinae with related taxa shows that the taxon indeed stands out in terms of the frequency of polyphagous species. Comparative evidence suggests that this is most probably due to its nonfeeding adults, with polyphagy being part of a resulting life history syndrome. Our results indicate that even high levels of plasticity can drive diversification, at least when the levels oscillate over time. [ABSTRACT FROM AUTHOR]

The nun moth, Lymantria monacha L., is one of the most important defoliators of Eurasian coniferous forests. Outbreaks during 2011-2015 in the natural/planted larch, and larch-birch mixed forests of the Greater Khingan Range in Inner Mongolia, China, caused tremendous timber losses from severe defoliation and tree mortality. A series of trapping experiments were conducted in these outbreak areas to evaluate the efficacy of a synthetic species-specific pheromone lure based on the female pheromone blend of European nun moth populations. Our results clearly show that the nun moth in Inner Mongolia is highly and specifically attracted to this synthetic pheromone, with few gypsy moths ( Lymantria dispar) captured. Flight activity monitoring of L. monacha male moths using pheromone-baited Unitraps at 2 locations during the summer of 2015 indicated that the flight period started in mid-July, peaking in early August at both locations. Based on male moth captures, there was a strong diurnal rhythm of flight activity throughout the entire scotophase, peaking between 22:00 and 24:00. Unitraps and wing traps had significantly and surprisingly higher catches than the gypsy moth traps. Unitraps fastened to tree trunks 2 m above ground caught significantly more male moths than those at the ground level or at 5 m height. Male L. monacha moths can be attracted to pheromone-baited traps in open areas 150-200 m distant from the infested forest edge. Our data should allow improvement on the performance of pheromone-baited traps for monitoring or mass-trapping to combat outbreaks of this pest in northeastern China. [ABSTRACT FROM AUTHOR]

Anastatus disparis ( Ruschka) ( Hymenoptera: Eupelmidae) is an egg parasitoid and considered a potential biological control agent of the gypsy moth, Lymantria dispar (L.) ( Lepidoptera: Lymantriidae). Only male offspring of A. disparis emerge from single eggs of L. dispar in the laboratory, and A. disparis exhibits low parasitism on L. dispar in the field. We therefore selected several lepidopteran species with various body sizes to evaluate the optimal egg size for hosting A. disparis. In addition, we explored whether the nutritional content of a single L. dispar egg influences the sex of A. disparis offspring and why female offspring can be reared from L. dispar eggs in the field. The results indicated that host egg size decisively influenced the body size and sex ratio of the parasitoid offspring. Therefore, larger hosts, especially the largest eggs of Antheraea pernyi Guérin-Méneville ( Saturniidae), might increase the fitness of A. disparis females. Lymantria dispar eggs concealed in the larger egg shell of A. pernyi produced female A. disparis, suggesting that adult A. disparis should prefer hosts with larger bodies and that the nutritional content of L. dispar eggs did not play a decisive role in the sex allocation of A. disparis. The results also indicated that the egg mass and the fur cover of L. dispar egg masses might be the key factors inducing female A. disparis to lay female offspring in L. dispar eggs. [ABSTRACT FROM AUTHOR]

Larvae of the gypsy moth, Lymantria dispar L. ( Lepidoptera: Lymantriidae), a generalist species, frequently encounter spatial and temporal variations in diet quality. Such variation favoured the evolution of high behavioural and physiological plasticity which, depending on forest stand composition, enables more or less successful exploitation of the environment. Even in mixed oak stands, a suitable habitat, interspecific and intraspecific host quality variation may provoke significant variation in gypsy moth performance and, consequently, defoliation severity. To elucidate the insufficiently explored relationship between gypsy moth and oaks ( Fagaceae), we carried out reciprocal switches between Turkey oaks ( Quercus cerris L.) and less nutritious Hungarian oaks ( Quercus frainetto Ten.) ( TH and HT groups), under controlled laboratory conditions, and compared larval performance between the switched larvae and larvae continuously fed on either Turkey oak ( TT) or Hungarian oak ( HH). We found that larval traits were most strongly affected by among-tree variation in oak quality and identity of the host consumed during the fourth instar. Switching from Turkey to Hungarian oak ( TH) led to a longer period of feeding, decrease of mass gain, growth, and consumption rate, lower efficiency of food use and nutrient conversion, and increase of protease and amylase activities. Larvae exposed to the reverse switch ( HT) attained values of these traits characteristic for TT larvae. It appeared that the lower growth in the TH group than in the TT group was caused by both behavioural (consumption, pre-ingestive) and metabolic (post-digestive) effects from consuming oaks. Multivariate analyses of growth, consumption, and efficiency of food use revealed that early diet experience influenced the sensitivity of the most examined traits to less suitable Hungarian oaks, suggesting the development of behavioural and physiological adjustments. Our results indicate that lower risks of defoliation by gypsy moth might be expected in mixed stands with a higher proportion of Hungarian oak. [ABSTRACT FROM AUTHOR]

There are limitations imposed by current methodologies to detect and quantify insect predation. However, there has been relatively little effort to experimentally document the sources of biases associated with the various methodologies. In this study, we examined how predation estimates in the field using predator exclusion cages may be biased when one fails to account for antipredator behavioral responses. To do this, we did the usual comparison of the number of insects missing from plants where predators were allowed access to the number missing from plants where predators were excluded, but also determined how many of the missing insects reacted to predators by dropping from plants and howmany were actually preyed upon. Our results provide evidence that estimates of insect mortality in the field are significantly reduced if prey antipredator behavior is taken into account. As it is commonly assumed that prey missing in the field are predated, documenting the incidence of predator-mediated 'disappearance' and capturing insect prey before they escape can provide with a relevant estimate of bias. [ABSTRACT FROM AUTHOR]

To understand the evolutionary history of Lymantriinae and test the present higher-level classification, we performed the first broad-scale molecular phylogenetic analysis of the subfamily, based on 154 exemplars representing all recognized tribes and drawn from all major biogeographical regions. We used two mitochondrial genes (cytochrome c oxidase subunit I and 16S ribosomal RNA) and six nuclear genes (elongation factor-1α, carbamoylphosphate synthase domain protein, ribosomal protein S5, cytosolic malate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase and wingless). Data matrices (in total 5424 bp) were analysed by parsimony and model-based evolutionary methods (maximum likelihood and Bayesian inference). Based on the results of the analyses, we present a new phylogenetic classification for Lymantriinae composed of seven well-supported tribes, two of which are proposed here as new: Arctornithini, Leucomini, Lymantriini, Orgyiini, Nygmiini, Daplasini trib. nov. and Locharnini trib. nov. We discuss the internal structure of each of these tribes and address some of the more complex problems with the genus-level classification, particularly within Orgyiini and Nygmiini. [ABSTRACT FROM AUTHOR]

Differences in composition of on-year, off-year and new leaves in Phyllostachys pubescens (moso bamboo) forests will affect the resistance of Pantana phyllostachysae larvae and the parasitic ability of Beauveria bassiana. Pantana phyllostachysae fed on mixed leaves of on-year, off-year and new bamboo leaves. The activities of acetylcholine esterase ( ACh E) and glutathione S-transferase ( GSTs) in P. phyllostachysae larvae fed on mixed leaves were significantly higher, greatly reducing the pathogenicity of B. bassiana to P. phyllostachysae larvae compared with the treatments of off-year and new bamboo leaves. The phenoloxidase ( PO) activity in P. phyllostachysae larvae feeding on mixed leaves varied within three days after parasitization by B. bassiana, which indicated higher and less changeable PO activity compared with treatments of off-year and new bamboo leaves. Inclusion of new leaves differed greatly due to its growth, in which, both ACh E and GSTs activities were higher than the off-year leaf treatment, leading to a lower pathogenicity of B. bassiana to P. phyllostachysae larvae feeding on new leaves compared with off-year leaves. On the contrary, the pathogenicity of B. bassiana to P. phyllostachysae larvae feeding on on-year leaves was lower than other treatments. ACh E and GSTs activities in P. phyllostachysae larvae were lower and PO activity was less changeable, which might be related to the disadvantage of the larval surface structure to B. bassiana infection in the on-year leaf treatment. [ABSTRACT FROM AUTHOR]

A wide known host range in Australia and novel herbivory on native and naturalized species in New Zealand supported the decision to commence a NZ$65 million eradication programme against painted apple moth [ Teia anartoides (Walker) (Lepidoptera: Lymantriidae)] in Auckland (1999-2007)., Laboratory no-choice tests were designed to examine the 'host' status of the associations seen in the field., Laboratory tests investigated 79 native and introduced plant species with 122 provenances. Forty-two percent of plants were capable of supporting larval development to adulthood, with male bias; 30% were defined as potential hosts with female larvae developed through to the pupal stage; > 10% survival indicated probable physiological hosts. Sporadic or more frequent attack of New Zealand native broom, and introduced lemon, apple, sycamore, walnut, cherry and poplar, was likely, with a wider range of hosts supporting male emergence., A few negative laboratory results contradicted field observations of significant damage by large numbers of larvae. The present study highlights the challenge faced with respect to predicting the ecological host range of invasive polyphagous species, whose biology is little known, during the early stages of a first invasion. The implications of a wider host range found in males than females are discussed. [ABSTRACT FROM AUTHOR]

The population densities of the gypsy moth ( Lymantria dispar; Lepidoptera: Lymantriidae) may reach outbreak levels that pose considerable economic and environmental impacts to forests in Europe, Asia, Africa and North America. Compared with the situation in its native European range feeding damage by gypsy moth is often found to be more severe in North America and other parts of the world. Thus, the release from natural enemies can be interpreted as an important cause for high feeding damages. Natural enemies, especially parasitoids, can cause delayed density-dependent mortality, which may be responsible for population cycles. In North America where only few parasitoids have been introduced and the parasitism rates are considerably lower than in Europe, generalist predators play a larger role than in Europe. Many other factors seem to influence the population dynamics of the gypsy moth such as the host plants and weather. Nevertheless, much of the variability in population densities of the gypsy moth may be attributed to interacting effects of weather conditions and attack by natural enemies. In spite of the considerable number of studies on the ecology and population dynamics of the gypsy moth and the impact of their natural enemies, more quantitative information is required to predict the population dynamics of this pest species and to control its economic and ecologic impact. [ABSTRACT FROM AUTHOR]

The behaviour of predators can be an important factor in the transmission success of an insect pathogen. We studied how Calosoma sycophanta influences the interaction between its prey [ Lymantria dispar (L.) (Lepidoptera, Lymantriidae)] and two microsporidian pathogens [ Nosema lymantriae (Microsporidia, Nosematidae) and Vairimorpha disparis (Microsporidia, Burellenidae)] infecting the prey., Using laboratory experiments, C. sycophanta was allowed to forage on infected and uninfected L. dispar larvae and to disseminate microsporidian spores when preying or afterwards with faeces., The beetle disseminated spores of N. lymantriae and V. disparis when preying upon infected larvae, as well as after feeding on such prey. Between 45% and 69% of test larvae became infected when C. sycophanta was allowed to disseminate spores of either microsporidium., Laboratory choice experiments showed that C. sycophanta did not discriminate between Nosema-infected and uninfected gypsy moth larvae . Calosoma sycophanta preferred Vairimorpha-infected over uninfected gypsy moth larvae and significantly influenced transmission., When C. sycophanta was allowed to forage during the latent period on infected and uninfected larvae reared together on caged, potted oak saplings, the percentage of V. disparis infection among test larvae increased by more than 70%. The transmission of N. lymantriae was not affected significantly in these experiments., Beetles never became infected with either microsporidian species after feeding on infected prey., We conclude that the transmission of N. lymantriae is not affected. Because no V. disparis spores are released from living larvae, feeding on infected larvae might enhance transmission by reducing the time to death and therefore the latent period. [ABSTRACT FROM AUTHOR]

The successful establishment of non-native species in new areas can be affected by many factors including the initial size of the founder population. Populations comprised of fewer individuals tend to be subject to stochastic forces and Allee effects (positive-density dependence), which can challenge the ability of small founder populations to establish in a new area. Although the conceptual relationship between initial colony size and establishment success has been previously documented, it is not trivial to estimate precisely the colony size needed to ensure colony persistence. Over the last 40 years, there have been many studies on the probability of mating success of female Lymantria dispar ( L.) ( Lepidoptera: Lymantriidae) in the USA related to background male moth densities. We were motivated by this wealth of data and sought to combine the results from these prior studies with the goal of estimating a robust measure of the male moth density required to achieve varying levels of female mating success. Although the data are specific to L. dispar, the pheromone communication system in L. dispar is not unique and thus the results of this analysis could be broadly applicable to our general understanding of Lepidoptera mating behavior. [ABSTRACT FROM AUTHOR]

1. Ecologists have argued about the commonness and strength of interspecific competition between insect herbivores, but facilitation between herbivores has received much less consideration. We previously found that when two species of folivorous caterpillars co-occurred on a shared host plant, feeding by early season tiger moth caterpillars reduced the growth and reproduction of later season tussock caterpillars. However, densities of tussock caterpillars in summer were positively correlated with densities of tiger moth caterpillars the following spring. 2. In this study, we experimentally manipulated numbers of feeding tussock caterpillars and found that they facilitated tiger moth caterpillars. 3. The depth of the litter layer beneath host lupine bushes was positively correlated with the number of tussock caterpillars feeding on each bush. Experimental additions of litter beneath lupine canopies during summer resulted in increased numbers of tiger moth caterpillars in the following spring, indicating a causal role of litter. Litter potentially provides food, habitat and protection from desiccation and predation. We failed to find evidence that tussock caterpillars facilitated tiger moth caterpillars by mechanisms independent of litter. 4. Our study demonstrates that facilitation may operate between insect herbivores, across life-stages through indirect interactions that are non-trophic. Facilitation operated by a novel mechanism, the accumulation of litter which was a by-product of feeding by one species was valuable to a second species. Facilitation persisted in time and space far beyond the creation of litter by tussock caterpillars which should be considered important ecosystem engineers from the point of view of tiger moths. Facilitations that involve habitat modification may generally connect species that do not interact directly or trophically, and have not previously been considered to affect one another. [ABSTRACT FROM AUTHOR]

1. Some biosecurity systems aimed at reducing the impacts of invasive alien species that employ sentinel trapping systems to detect the presence of unwanted organisms. Once detected, the next challenge is to locate the source population of the invasive species. Tools that can direct search efforts towards the most likely sources of a trapped invasive alien species can improve the chance of rapidly delimiting and eradicating the local population and may help to identify the original introduction pathway. Ground-based detection and delimitation surveys can be very expensive, and methods to focus search efforts to those areas most likely to contain the target organisms can make these efforts more effective and efficient. 2. An individual-based semi-mechanistic model was developed to simulate the spatio-temporal dispersal patterns of an invasive moth. The model combines appetitive and pheromone anemotaxis behaviours in response to wind, temperature and pheromone conditions. The model was trained using data from a series of mark-release-recapture experiments on painted apple moth Teia anartoides. 3. The model was used to create hindcast simulations by reversing the time course of environmental conditions. The ability of the model to encompass the release location was evaluated using individual trap locations as starting points for the hindcast simulations. 4. The hindcast modelling generated a pattern of moth flights that successfully encompassed the origin from 86% of trap locations, representing 95% of the 1464 recaptures observed in the mark-release-recapture experiments. 5. Comparing the guided search area defined using the hindcast model with the area of a simple point-diffusion search strategy revealed an optimized search strategy that combined searching a circle of 1 km radius around the trap followed by the area indicated by hindcast model predictions. 6. Synthesis and applications. Incorporating this novel moth dispersal model into biosecurity sentinel systems will allow incursion managers to direct search effort for the proximal source of the incursion towards those areas most likely to contain a local infestation. Such targeted effort should reduce the costs and time taken to detect the proximal source of an incursion. [ABSTRACT FROM AUTHOR]

1. Leaves possess traits that mediate the preference and performance of herbivores. Most evidence for the importance of leaf traits as defences against herbivory comes from studies of few model plant species. 2. In a phylogenetically explicit comparison, I explain the differences in preference and performance of tussock moth ( Orgyia vetusta Boisduval) larvae on leaves of 27 oak ( Quercus) species using nine putative leaf defences. 3. The preference for an oak species correlated positively with the survival of caterpillars. The correlation between preference and performance did not differ between oak species native to the range of tussock moth versus those from outside the herbivore's range. 4. The first principal component of leaf traits predicted survival of caterpillars on oak leaves but only marginally predicted their preference between oak species. A multiple regression model showed that evergreenness, toughness, and condensed tannin content were the best predictors of caterpillar survival, and leaf toughness was the best predictor of host preference. 5. Generalist caterpillars may accurately assess the value of novel food sources. Moreover, many leaf traits that have been found to affect herbivory within a plant species can also be used to predict the fitness of a generalist herbivore between species. [ABSTRACT FROM AUTHOR]

The advantage of inherited sterility over complete sterility in lepidopteran sterile insect technique programs results from the improvement of mating fitness of male-only releases with wild females, and the resulting large multiplier effect from viable but sterile progeny from every mating. The deleterious effects induced by irradiation are inherited by the F1 generation, but it is very difficult to measure population introgression at that stage, and the alternative has been to await population suppression at the F2 generation. This work, conducted in support of the successful elimination of painted apple moth ( Teia anartoides) in New Zealand, aimed to determine the feasibility of a cytological assessment on the F1 sperm bundles of this species, as a new forensic biosecurity tool providing information for decision support. The technique successfully distinguished the homogeneous nuclei clusters of eupyrene bundles of the normal fertile males from the heterogeneously stained nuclei clusters of the F1 progeny. However, the challenge for the technique involved obtaining good specimens for cytological diagnosis. The percentage of positive staining results was correlated strongly with survival, which was <5 days. Moths that had spent 24 h on a sticky base in a monitoring trap were equivalent to freshly killed specimens, but the efficacy of the technique decreased after that. Some specimens that were 'dead' to the naked eye but potentially alive internally produced reliable results. The technique may be potentially useful as a forensic biosecurity tool in the future when a communicating trap is deployed, ensuring that fresh specimens could be used to monitor the success of inherited sterility in population suppression or eradication. [ABSTRACT FROM AUTHOR]

Painted apple moth Teia anartoides Walker (Lepidoptera: Lymantriidae), a native to Australia, was discovered in Auckland, New Zealand in late 1999 and eradicated by 2006. It was recognised in 2002 that biological control would be the most effective long-term control strategy if eradication was unsuccessful, and a search was initiated for potential biocontrol agents in Australia. In 2003, autumn and spring surveys were undertaken in Victoria, Tasmania and South Australia of the guild of parasitoid natural enemies of T. anartoides. Eggs, larvae and pupae were collected and held to rear out any parasitoids. In addition, localised searches were made in Queensland in late 2003-early 2004 and laboratory-reared juvenile stages of T. anartoides were released for recapture in both Victoria and Queensland. Acacia dealbata Link (Fabales: Fabaceae) was the main plant from which T. anartoides was recovered, followed by apple. Most T. anartoides samples were collected from Victoria and Tasmania. Eighteen species from 13 genera of egg, larval and pupal parasitoids were reared and included Diptera (Tachinidae) and Hymenoptera (Braconidae, Encyrtidae, Eulophidae and Ichneumonidae). Of the seven Hymenopteran genera recovered from the larval stage, the most common in Victoria and Tasmania was a previously unidentified larval parasitoid Cotesia Cameron (Hymenoptera: Braconidae) sp. Echthromorpha intricatoria (Fabricius) (Hymenoptera: Ichneumonidae) was the dominant pupal parasitoid. The survey showed that the parasitoid complex associated with T. anartoides is structurally very similar to that on other pest Lymantriidae in the northern hemisphere such as gypsy moth ( Lymantria dispar L.) (Lepidoptera: Lymantriidae). Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae) was recorded for the first time in Australia. [ABSTRACT FROM AUTHOR]

1. Life table studies have been an essential tool for the comprehension of insect population dynamics, although their use has been methodologically biased by a primary focus on mortality factors, especially natural enemies. Thus, studies in natural populations may relegate important mortality sources to the 'unknown' or 'residual' mortality categories. To overcome this limitation, life tables may be complemented by combining them with other approaches. 2. The aim of the present study was to provide insights into browntail moth Euproctis chrysorrhoea L. (Lepidoptera: Lymantriidae) local outbreaks by combining life table data and statistical modelling. First, E. chrysorrhoea population density, mortality dynamics, net reproductive rate, and reproductive potential were compared in two different Mediterranean habitats (i.e. coastal and inland). Second, we investigated the relationship of reproductive potential as well as residual mortality (i.e. not associated to any specific mortality agent) with several variables likely to play an important role in E. chrysorrhoea population dynamics. As an innovative approach, the relationship was modelled by means of generalised additive modelling (GAM models) in a multi-model inference framework. 3. The present results on E. chrysorrhoea density and life table analyses suggest that local outbreaks are more likely in coastal habitats where higher mortality was compensated by higher reproductive potential. GAMs turned out to be an effective way to gain a deep understanding of this pattern. Residual mortality was positively and non-linearly related to population density, whereas reproductive potential was not significantly related to any of the variables studied. 4. The present study was an attempt to gain a deep understanding of the information derived from descriptive life tables. [ABSTRACT FROM AUTHOR]

The grey-spotted tussock moth, Orgyia ericae Germar (Lepidoptera: Lymantriidae), is an important pest of deciduous trees and woody scrublands in northern China. In a field trapping experiment conducted during the flight of the first generation of 2009, synthetic ( Z)-6-heneicosen-11-one, a common Orgyia spp. sex pheromone component, attracted O. ericae males. Gas chromatography-mass spectrometry analyses (full scan or selected ion-monitoring mode) of pheromone gland extracts from females revealed the presence of a major, a minor, and a trace component, i.e., (6 Z,9 Z)-heneicosa-6,9-diene, (6 Z,9 Z)-tricosa-6,9-diene, and ( Z)-6-heneicosen-11-one, respectively. Field experiments during the flight of the second generation showed that (6 Z,9 Z)-tricosa-6,9-diene, the minor component, was inactive alone or in any combination with the other two components, whereas (6 Z,9 Z)-heneicosa-6,9-diene and ( Z)-6-heneicosen-11-one were weakly attractive when tested individually. However, traps baited with a binary blend of (6 Z,9 Z)-heneicosa-6,9-diene and ( Z)-6-heneicosen-11-one caught seven-fold more moths than any other treatment (except the ternary blend), indicating a strong synergistic interaction between the two components. The analytical and field trapping data suggested that (6 Z,9 Z)-heneicosa-6,9-diene and ( Z)-6-heneicosen-11-one are likely the key sex pheromone components of female O. ericae. This synergistic blend will be useful as an efficient monitoring tool, and possible control tool, to combat this economically and ecologically important forest defoliator. [ABSTRACT FROM AUTHOR]

Several integrated pest management programs rely on the use of mating disruption tactics to control insect pests. Some programs specifically target non-native species, such as the gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae). We evaluated SPLAT® GM, a new sprayable formulation of the gypsy moth sex pheromone disparlure, for its ability to disrupt gypsy moth mating. The study was conducted in 2006, 2007, and 2008 in forested areas in Virginia, USA. Mating success of gypsy moth females was reduced by >99% and male moth catches in pheromone-baited traps by >90%, in plots treated with SPLAT® GM at dosages ranging from 15 to 75 g of active ingredient (a.i.) ha−1. Dosage-response tests conducted in 2008 indicated that SPLAT® GM applied at a dosage of 7.5 g a.i. ha−1 was as effective as a 15 g a.i. ha−1 dosage. [ABSTRACT FROM AUTHOR]

The individual and combined effects of elevated CO2 and O3 on the foliar chemistry of silver birch ( Betula pendula Roth) and on the performance of five potential birch-defoliating insect herbivore species (two geometrid moths, one lymantrid moth and two weevils) were examined. Elevated CO2 decreased the water concentration in both short- and long-shoot leaves, but the effect of CO2 on the concentration of nitrogen and individual phenolic compounds was mediated by O3 treatment, tree genotype and leaf type. Elevated O3 increased the total carbon concentration only in short-shoot leaves. Bioassays showed that elevated CO2 increased the food consumption rate of juvenile Epirrita autumnata and Rheumaptera hastata larvae fed with short- and long-shoot leaves in spring and mid-summer, respectively, but had no effect on the growth of larvae. The contribution of leaf quality variables to the observed CO2 effects indicate that insect compensatory consumption may be related to leaf age. Elevated CO2 increased the food preference of only two tested species: Phyllobius argentatus (CO2 alone) and R. hastata (CO2 combined with O3). The observed stimulus was dependent on tree genotype and the measured leaf quality variables explained only a portion of the stimulus. Elevated O3 decreased the growth of flush-feeding young E. autumnata larvae, irrespective of CO2 concentration, apparently via reductions in general food quality. Therefore, the increasing tropospheric O3 concentration could pose a health risk for juvenile early-season birch folivores in future. In conclusion, the effects of elevated O3 were found to be detrimental to the performance of early-season insect herbivores in birch whereas elevated CO2 had only minor effects on insect performance despite changes in food quality related foliar chemistry. [ABSTRACT FROM AUTHOR]

Modelling moth dispersal in relation to wind direction and strength could greatly enhance the role of pheromone traps in biosecurity and pest management applications. Anemotaxis theory, which describes moth behaviour in the presence of a pheromone plume and is used as a framework for such models. Currently, however, that theory includes only three components: upwind, zigzagging, and sideways casting behaviour. We test anemotaxis theory by analysing the data from a series of mark–release–recapture experiments where the wind direction was known and the insects were trapped using an irregular grid of pheromone traps. The trapping results provide evidence of a downwind component to the flight patterns of the released insects. This active or passive downwind dispersal is likely to be an appetitive behaviour, occurring prior to the elicitation of pheromone-oriented flight patterns (pheromone anemotaxis). Given the potential for significant displacement during downwind dispersal, this component will have impact on final trap captures and should be considered when constructing moth dispersal models. [ABSTRACT FROM AUTHOR]

The movement of humans and goods has facilitated the arrival of non-native insects, some of which successfully establish and cause negative consequences to the composition, services, and functioning of ecosystems. The gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), is currently invading North American forests at variable rates, spreading by local and long-distance movement in a process known as stratified dispersal. Newly arriving colonizers often occur considerably ahead of the population front, and a key question is the degree to which they successfully establish. Prior research has highlighted mate-finding failures in sparse populations as a cause of an Allee effect (positive density dependence). We explored this mechanism by measuring the relationship between female mating success and background male moth densities along the gypsy moth western front in Northern Wisconsin (USA) over 2 years. The mating results were then compared with analogous previous studies in southern Wisconsin, and the southern front in West Virginia and Virginia (USA). Mate-finding failures in low-density populations were consistently observed to be density-dependent across all years and locations. Mate-finding failures in low-density populations have important ramifications to invasive species management, particularly in predicting species invasiveness, preventing successful establishment by small founder populations, and concentrating eradication efforts where they are most likely to succeed. [ABSTRACT FROM AUTHOR]

Synchrony in forest insect outbreaks is important because the resulting regionalized outbreak dilutes the regulating effects of natural enemies, reduces the landscape’s ability to buffer the disturbance, exacerbates the economic burden on individual stakeholders, and overwhelms the logistical abilities of managers to suppress populations and mitigate impacts. Understanding the process of synchronization of dynamics is therefore a crucial aspect of understanding outbreak dynamics. We studied the second-order log-linear (autoregressive) model to ask what patterns of synchronization across invasion fronts may be expected from Moran’s model. Generally, we show that the time to synchronization in the log-linear model is a complex function of a number of parameters of which the overall strength of regulation, the strength of delayed statistical density dependence, and the relaxation time seem to be of particular importance. Interestingly, while environmental correlation is the crucial determinant of the magnitude of asymptotic synchrony, it does not appear to influence the transient process of synchronization. However, synchronization proceeds much more quickly among weakly periodic populations than among populations that are strongly periodic. As a case study, we investigate synchronization following colonization by gypsy moth ( Lymantria dispar) populations located along the species’s expanding invasion front in northeastern USA. Data consisted of more than 100 years of county quarantine records and 30 years of detailed defoliation maps. We found that the dynamics of new populations tended to be initially out of synch with the broadly synchronized outbreaks within the established range. However, the outbreak dynamics of these new populations lock on to the regional patterns very quickly—within 10–15 years of invasion. Focusing on parameters that produce periodicity comparable to that seen in real gypsy moth populations, we discuss how the observed synchronization compares to that predicted by the log-linear model. While our results are equivocal, the synchronization appears to be surprisingly rapid, so more mechanistic models may be needed to explain the synchronization observed in this case study. [ABSTRACT FROM AUTHOR]

The competitive interactions between hatchery and wild juvenile white-spotted charr Salvelinus leucomaenis were examined in enclosure experiments in a natural stream. A total of 24 enclosures (1·0 × 1·0 × 0·7 m height) were arranged in stream in an array for randomized block design with replicates of three treatments (wild fish only, hatchery fish only, wild plus hatchery fish). Three experiments were conducted in 2006, using different densities and sizes for each experimental trial. When densities in enclosures were controlled to be equal among treatments (4 individuals m−2: substitutive design), wild fish in the presence of hatchery fish had significantly higher growth rates than the wild fish alone treatment. When densities in enclosures were controlled to be 4 individuals m−2 hatchery fish only treatment, 4 individuals m−2 wild fish only treatment and 8 individuals m−2 in the hatchery plus wild fish treatment (additive design), wild fish in the presence of hatchery fish had significantly lower growth rate than the wild fish alone treatment. Hatchery fish in the presence of wild fish also grew significantly slower than the hatchery fish alone treatment. When densities in enclosures were controlled to be equal among treatments (4 individuals m−2) but hatchery fish were 1·1 times longer than wild fish, growth of wild fish in the presence of the larger hatchery fish did not differ significantly from growth of the wild fish alone treatment. These results suggested that relative size of hatchery fish in relation to wild fish and increased fish density are two important factors influencing the growth of wild juvenile S. leucomaenis. [ABSTRACT FROM AUTHOR]

We tested for rapid changes in photosynthate transport and partitioning in response to Lymantria dispar (L.) (Lepidoptera: Lymantriidae) (gypsy moth) herbivory in Populus nigra L. (Salicaceae). Transport and partitioning of [11C]-photosynthate from young mature leaves were measured in vivo before and 18 h after leaf chewing by gypsy moth larvae, which were caged on three older leaves. Following herbivory, there was an increase in export speed of recently fixed carbon from younger mature leaves. The increased export speed was due to a quicker transit time of 11C through the leaf, rather than a change in transport speed through the phloem. Additionally, basipetal partitioning of [11C]-photosynthate was increased following herbivory. Neither of these changes was observed in control plants. This enhancement of export occurs even though herbivores are well known to induce increases in carbon allocation to secondary metabolites within leaves. Our results demonstrate that the use of non-destructive imaging of 11C tracer is a powerful tool for examining plant responses to herbivory. Although the mechanisms underlying the rapid increase in carbon flux to stems and roots remain to be elucidated, our results raise the possibility of a coordinated whole plant response to herbivory. Thus, even when the herbivore specializes on only one plant tissue type, a whole plant approach may be key to understanding how plants respond to herbivory. [ABSTRACT FROM AUTHOR]

The study was conducted during 2000, 2001, 2003 and 2004 in forested areas in Virginia, USA to evaluate the 3M™ MEC-GM Sprayable Pheromone® formulation of the gypsy moth sex pheromone, disparlure, for its ability to disrupt mating in gypsy moth, Lymantria dispar (Lep.: Lymantriidae). Both mating success of gypsy moth females and male moth catches in pheromone-baited traps were significantly reduced in plots treated with the 3M™ MEC-GM formulation at dosages ranging from 15 to 75 g of active ingredient/ha. However, the 3M™ MEC-GM formulation reduced trap catch to a lesser extent than did the currently registered Hercon Disrupt® II plastic flakes used as a positive control and applied at similar or lower dosages. Furthermore, the effectiveness of the 3M™ sprayable formulation declined through time, so that by the end of the male flight season, male moth catches in traps were significantly higher than in plots treated with Hercon plastic flakes. Based on the reported results, 3M™ MEC-GM Sprayable Pheromone® formulation was never integrated into the operational treatment projects of USDA Forest Service Cooperative Slow-the-Spread of the Gypsy Moth management programme. [ABSTRACT FROM AUTHOR]

Candan, S., Suludere, Z. and Bayrakdar, F. 2007. Surface morphology of eggs of Euproctis chrysorrhoea (Linnaeus, 1758). — Acta Zoologica (Stockholm) 88: 000–000. Filaments covering the egg batches and chorion structure were studied both by light and scanning electron microscopy in the brown-tailed moth Euproctis chrysorrhoea (Linnaeus, 1758). Females lay eggs in masses on the underside of apple leaves. The egg batches are covered with brown hairs derived from the bodies of the female. Each female lays about 200–400 eggs. The spherical eggs are about 0.84 mm long and 0.47 mm wide. Newly deposited eggs are golden-yellow and darken after the onset of embryonic development. The micropylar area appears somewhat depressed and has a circular outline. The region is surrounded by a rosette of 10–12 petal-shaped primary cells, which are completely surrounded by a series of secondary and tertiary cells. The remainder of the egg is largely smooth, but shows aeropyles. These are located in the corners of ill-defined polygons. [ABSTRACT FROM AUTHOR]

The article presents information on the monitoring of whitemarked tussock moth (WMTM) population using Multipher traps. WMTM is an economic pest in Nova Scotia, Canada, which defoliates Abies balsamea and endangers the balsam fir forests in New Brunswick and the commercial stands in Cape Breton Highlands. Information on the performance of traps under several operational conditions is also provided.

1 The native range of the gypsy moth Lymantria dispar (L.) spans the temperate forests of Eurasia. Across this region, a clinal female flight polymorphism exists; gypsy moth females in eastern Asia are mostly capable of directed flight, those in western and southern Europe are largely incapable of flight and populations distributed across the centre of the distribution exhibit a range of intermediate flight behaviours. 2 Although information exists about the timing and duration of female flight from laboratory and wind tunnel studies, little or no quantitative data are available on average distances flown by Asian gypsy moth females prior to oviposition in the field. This information is critical for estimating risk of contamination at specific ports and transit terminals, as well as for predicting the spread of populations that might someday invade currently uninfested regions of the world. 3 In the present study, an extensive visual survey of gypsy moth egg masses was conducted during a walk through streets and paths in a 3.92 × 5.76 km area in Kanazawa, Japan. This area consisted of a matrix of urban, agricultural and forest land uses. The distribution of egg masses relative to distances from host forests was used to infer the magnitude of pre-ovipositional female flight. 4 A total of 3172 egg masses was recorded from surveys conducted during the search of a path totalling 384 km. Within urban areas, egg masses were most abundant in the area <1 km from the edge of forest land. 5 These results suggest that most female gypsy moth flight is limited to the area within 1 km of host forests. They also suggest that shipping containers and other parcels located >1 km from forests are at a much lower risk of contamination with Asian gypsy moth egg masses. [ABSTRACT FROM AUTHOR]

In forest plots treated aerially with a plastic laminated flake formulation (Disrupt® II) of the gypsy moth sex pheromone disparlure to disrupt gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), mating was monitored the year of treatment and 1–2 years after treatment to determine the effects of the treatment on suppression of trap catch and mating success. In the year of treatment, there was a greater than 95% reduction in trap catch and a greater than 98% reduction in mating success compared to controls. One year after treatment at a dosage of 37.5 g active ingredient (a.i.) ha−1, trap catch was reduced by 46–56% and mating success was reduced by 60–79%. Both trap catch and mating success were significantly reduced compared to controls in plots treated 1 year previously at 15 g a.i. ha−1. Trap catch, but not mating success, was significantly reduced 2 years after treatment at 37.5 g a.i. ha−1. The efficacy of mating disruption (MD) treatments in the Slow-the-Spread of the Gypsy Moth program was significantly reduced 2 years compared to 1 year after treatment. No such reduction was observed in plots treated with aerial applications of Bacillus thuringiensis kurstaki. The higher apparent efficacy of MD treatments 1 year after application may result to some extent from the suppression of moth capture in pheromone traps from the persistent effects of the previous year's treatment. [ABSTRACT FROM AUTHOR]

Asian populations of gypsy moths, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), remain poorly characterized – indeed, they are not presently accorded any formal taxonomic status within the broader species. Their ecology is similarly largely uncharacterized in the literature, except by assumption that it will resemble that of European populations. We developed ecological niche models specific to Asian populations of the species, which can in turn be used to identify a potential geographic distributional area for the species. We demonstrated statistically significant predictivity of distributional patterns within the East Asian range of these populations; projecting the Asian ecological niche model to Europe, correspondence with European distributions was generally good, although some differences may exist; projecting the ecological niche model globally, we characterized a likely potential invasive distribution of this set of populations across the temperate zone of both Northern and Southern Hemisphere. [ABSTRACT FROM AUTHOR]

Carotenoid-based integumental coloration is often associated with individual performance in various animals. This is because the limited amount of the pigment has to be allocated to different vital functions. However, most of the evidence for the carotenoid-based trade-off comes from vertebrate studies, and it is unclear if this principle can be applied to insects. This possibility was investigated in Orgyia antiqua L. (Lepidoptera: Lymantriidae). The larvae of this species are polyphenic in their coloration, varying from a highly conspicuous combination of yellow hair tufts on black background to cryptic appearance with brown hair tufts. The conspicuous larvae are aposematic, advertising their aversive hairiness. The maintenance of different colour morphs in O. antiqua requires explanation, as an aposematic signal is expected to evolve towards monomorphism. Chromatographic analysis showed that the yellow coloration of the hair is based on the carotenoid pigment lutein (α-carotene-3,3’-diol). The colour of hair tufts was dependent on their carotenoid content. This justifies an expectation of carotenoid-based physiological trade-offs between aposematic coloration and individual performance. To test this hypothesis, we monitored life histories of differently coloured larvae reared on various host plants, recording their body sizes, growth rates, and mortalities in each instar. There was a significant but relatively low heritability of tuft coloration, which allowed us to expect environmental effects. We found no phenotypic associations between hair tuft colour and performance indices in O. antiqua larvae, neither did the quality of host plant affect the frequency of colour morphs. However, the frequency of colour morphs differed between larval instars. Our results suggest that carotenoid-mediated physiological trade-offs are not involved in the maintenance of colour morphs in O. antiqua larvae, and factors other than individual condition should be responsible for the observed variability. [ABSTRACT FROM AUTHOR]

As part of an eradication program, field searches were conducted to verify the geographical extent of the painted apple moth (PAM; Teia anartoides Walker: Lepidoptera: Lymantriidae) incursion and to determine which plants were being attacked. Most PAM were found on the wattle species, in particular Paraserianthes lophanta and Acacia mearnsii. Other species with large numbers of PAM included the native Corynocarpus laevigatus (karaka) and Avicennia marina (grey mangrove). The large number of PAM on these New Zealand species would not have been predicted from the known unrelated Australian hosts. The relatively high number of PAM found on inanimate objects demonstrated the mobility of PAM larvae and that plants upon which few larvae were found may not be suitable hosts for PAM. [ABSTRACT FROM AUTHOR]

A portable electroantennogram (EAG) sensor was used to measure relative atmospheric pheromone concentration in forest plots treated with aerial and ground applications of gypsy moth, Lymantria dispar (L.) (Lep., Lymantriidae), mating-disruption formulations. Five treatments (Disrupt II flakes with sticker, Disrupt II flakes without sticker, Disrupt II flakes in a sticker slurry, microcapsules and hand-applied Luretape), all applied at 75 g active ingredient per hectare and an untreated control were evaluated. Gypsy moth male catch in pheromone-baited traps and fertilization of deployed females were suppressed in all treatments, and no females deployed in treated plots produced more than 5% fertile eggs. Relative pheromone concentrations were significantly higher in the two treatments in which flakes were aerially applied with sticker and in the microcapsule treatment. Pheromone concentration measurements in the flakes without sticker and hand-applied treatments were not significantly different from those in the control. Mating success was negatively correlated with relative pheromone concentration. The ability of the EAG to detect differences in pheromone concentration that are correlated with mating success suggests that this could be a useful method for predicting the effectiveness of mating-disruption treatments. [ABSTRACT FROM AUTHOR]

Live female painted apple moths are being used to monitor the distribution of this invasive species in Auckland as part of a major eradication effort, and the goal of this project was to develop a method to minimize the risk of unwanted live insect propagation from the trapping programme as a result of vandalism or ‘eco-terrorism’. Female pupae were irradiated with a range of doses and their egg viability assessed, and also tested to determine the impact of irradiation on male moth catch in the field. Female painted apple moth pupae, irradiated at a range of doses from 100 to 500 Gy, were placed in cages in traps at 10 m spacings from non-irradiated females, near a central release site of irradiated males. Untreated control females alternated along orthogonal transects with irradiated females. The results indicated no significant effect of female irradiation on catch of males. There was no correlation between dose and catch, within the range of exposures tested. There was a very low hatch rate of eggs from females irradiated at all doses tested (100–500 Gy). These results suggest that irradiated females could be used in traps to reduce potential risks of deliberate spread of the unwanted organism by activists, without affecting the effectiveness of monitoring males. [ABSTRACT FROM AUTHOR]

Entomophaga maimaiga Humber, Shimazu, et Soper (Zygomycotina: Entomophthoraceae) is a naturally occurring obligate fungal pathogen specific to gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae) larvae. This fungus is considered the most important natural enemy of this pest insect in North America and Asia. A critically important step for the development of E. maimaiga epizootics is the transmission of propagules to healthy larvae, a process known to require high humidity. Some pathogens are known to manipulate the time of day that hosts die so that propagules are produced to maximize chances of survival and thus enhance transmission. The objective of this study was to assess whether E. maimaiga manipulates L. dispar to die at a certain time of day. Laboratory bioassays were conducted at 15 and 20 °C to record the 24-h activity pattern of death and sporulation exhibited under an L14:D10 photoperiod and 100% r.h. by four isolates of E. maimaiga in its host L. dispar. Events were recorded every 4 h. Our results clearly demonstrate that E. maimaiga-infected L. dispar larvae die mainly in the afternoon and that the fungus sporulates during the night. The rhythm was independent of the fungal isolate tested and type of spores produced after larval death. By raising the temperature from 15 to 20 °C, the peak death time narrowed and sporulation was initiated earlier at night. [ABSTRACT FROM AUTHOR]

In spatially heterogeneous systems, utilizing population models to integrate the effects of multiple population rates can yield powerful insights into the relative importance of the component rates. The relative importance of demographic rates and dispersal in shaping the distribution of the western tussock moth (Orgyia vetusta) among patches of its host plant was explored using stage-structured population models. Tussock moth dispersal occurs passively in first-instar larvae and is poor or absent in all other life stages. Spatial surveys suggested, however, that moth distribution is not well explained by passive dispersal; moth populations were greater on small patches and on isolated ones. Further analysis showed that several local demographic rates varied significantly with patch characteristics. Two mortality factors in particular may. explain the observed patterns. First, crawler mortality both increased with patch size and was density-dependent. A single-patch difference equation model showed mortality related to patch size is strong enough to overcome the homogenizing effect of density dependence; greater equilibrium densities were predicted for smaller patches. Second, although three rates were found to vary with local patch density, only pupal parasitism by a chalcid wasp could potentially account for higher moth abundances on isolated patches. A spatiality explicit simulation model of the multiple-patch system showed that spatial variation in pupal parasitism is indeed strong enough to generate such a pattern. These results demonstrate that habitat spatial structure can affect multiple population processes simultaneously, and even relatively low attack rates imposed on a reproductively valuable life stage of the host can have a dominant effect on population distribution among habitat patches. [ABSTRACT FROM AUTHOR]

Host plant quality is a key determinant of the performance of larvae of herbivorous insects. The effects of nitrogen and dolomite fertilization on the quality of pedunculate oak, Quercus robur L. (Fagaceae) foliage, as a food for gypsy moth, Lymantria dispar L. (Lepidoptera: Lymantriidae) larvae were evaluated. The seedlings were divided into five fertilization treatments (nonfertilized control, commercial nutrient solution, commercial nutrient solution + (NH4)2SO4, commercial nutrient solution + KNO3, and commercial nutrient solution + dolomite). The experiment was performed in Petri dishes, in each of which a fresh leaf from one treatment and one larva were placed. Insect performance assays, survival, development, growth, and food utilization were evaluated for each fertilization treatment. Leaf samples were assayed for nitrogen and other main nutrients, soluble carbohydrates, and phenolic compounds. The fertilizer treatment with added ammonium improved gypsy moth performance, and the amount of food eaten was the lowest in this treatment. Utilization of elements from the food depended on the element and on the fertilization treatment. The insect bodies retained 50–64% of the nitrogen and 55–79% of the phosphorus. The results show that the efficiency of conversion of ingested food (ECI) and the efficiency of conversion of digested food (ECD) differ among the fertilization treatments, but it is not possible to define a general trend. Our results suggest that fertilization (especially ammonium) of host plants can increase herbivore performance, decrease the amount of food needed, and increase its utilization efficiency. [ABSTRACT FROM AUTHOR]

1 Predation by small mammals has previously been shown to be the largest source of mortality in low-density gypsy moth, Lymantria dispar (L.), populations in established populations in north-eastern North America. Fluctuations in predation levels are critical in determining changes in population densities. 2 We compared small mammal communities and levels of predation on gypsy moth pupae among five different oak-dominated forest types along this insect's western expanding population front in Wisconsin. Comparisons of predator impact can provide critical information for predicting variation in susceptibility among forest types. 3 The results indicated that small mammals caused more mortality than did invertebrates. 4 Both abundance of Peromyscus sp. predators and predation levels were lower in urban and xeric forest types than in mesic sites. 5 These results suggest that, because predation pressures will probably be greater in the mesic sites, gypsy moths may be less likely to develop outbreaks in these habitats, and that defoliation will probably be more frequent in urban and xeric oak-dominated sites. [ABSTRACT FROM AUTHOR]

The effect of aerial applications of the pheromone disparlure at varying dosages on mating disruption in low-density gypsy moth,Lymantria dispar(L.) (Lepidoptera: Lymantriidae), populations was determined in field plots in Virginia, USA during 2000 and 2002. Six dosages[0.15, 0.75, 3, 15, 37.5, and 75 g active ingredient (AI)/ha] of disparlure were tested during the 2-year study. A strongly positive dose–response relationship was observed between pheromone dosages and mating disruption, as measured by the reduction in male moth capture in pheromone-baited traps and mating successes of females. Dosages of pheromone 15 g AI/ha (15, 37.5, and 75 g AI/ha) reduced the mating success of females by>99% and significantly reduced male moth catches in pheromone-baited traps compared to untreated plots. Pheromone dosages<15 g AI/ha also reduced trap catch, but to a lesser extent than dosages 15 g AI/ha. Furthermore, the effectiveness of the lower dosage treatments (0.15, 0.75, and 3 g AI/ha) declined over time, so that by the end of the study, male moth catches in traps were significantly lower in plots treated with pheromone dosages 15 g AI/ha. The dosage of 75 g AI/ha was initially replaced by a dosage of 37.5 g AI/ha in the USDA Forest Service Slow-the-Spread (STS) of the Gypsy Moth management program, but the program is currently making the transition to a dosage of 15 g AI/ha. These changes in applied dosages have resulted in a reduction in the cost of gypsy moth mating disruption treatments. [ABSTRACT FROM AUTHOR]

The slow-growth-high-mortality hypothesis proposes that increased development time in arthropods feeding on suboptimal food may result in an increased vulnerability to natural enemies. We measured the development time of the forest caterpillarOrgyia leucostigmaJ.E. Smith (Lepidoptera: Lymantriidae: Orgyiini) on two of its host plants and used a 7-year database on parasitism of this species to test the slow-growth-high-mortality hypothesis. We found that femaleO. leucostigmadeveloped faster when fed on willow (Salix nigraMarsh) than when fed on box elder (Acer negundoL.). However, only one of the parasitoids of the parasitoid community that attack these larvae followed the prediction of the slow-growth-high-mortality hypothesis. Overall parasitism ofO. leucostigmaon willow was greater than in box elder, contradicting the slow-growth-high-mortality hypothesis prediction. This is the first test of the hypothesis to consider parasitism by several species in the parasitoid community attacking a free-feeding herbivore on two distantly related plant species. [ABSTRACT FROM AUTHOR]

Lymantria dispar (L.) (Lepidoptera: Lymantriidae) larvae can be infected in the laboratory with a variety of entomopathogenic microsporidia. In many cases, however, L. dispar is only a semi-permissive host for such infections. In this study, we analyzed changes in the melanization of hemolymph and hemocyte numbers in L. dispar larvae after inoculation with various entomopathogenic microsporidia. We compared the infections produced by microsporidia isolated from L. dispar and infections produced by isolates from other Lepidoptera to which L. dispar is only a semi-permissive host. Microsporidiosis induced a significant activation of the prophenoloxidase system leading to melanization; activation was highest when the pathogen caused heavy infections of the fat body, which was the case with two microsporidia originally isolated from L. dispar. Infection of only the silk glands or light infection of the fat body by two Vairimorpha spp. from other lepidopteran hosts elicited a lower response. Very light infections caused by a microsporidium isolated from Malacosoma americanurn were not accompanied by elevated hemolymph melanization activity. Heavy infections by Endoreticulatus spec. that remained restricted to the gut tissue likewise did not elicit melanization. One Vairimorpha spec. from U dispar induced a significant increase in total hemocyte numbers; the other infections led to temporarily decreased numbers. Microscopic examinations showed that parts of infected tissue were encapsulated by hemocytes. We conclude that measured alterations in hemolymph melanization and hemocyte numbers were likely to be induced by the damaging effects of heavy infections. Observed defense responses did not prevent the progression of infections. [ABSTRACT FROM AUTHOR]

Previous work shows that predation by small mammals is a dominant cause of mortality of low-density gypsy moths in North America and that declines in small mammal density result in increases in gypsy moth density. Here we examined whether predation by small mammals is density dependent by way of a type III functional response, and how predation is influenced by alternative prey. First we showed that the preference of predators for gypsy moth pupae was low compared to other experimental prey items, such as mealworm pupae and sunflower seeds. Predation on gypsy moth pupae was characterized by a type II functional response with percent predation highest at the lowest prey densities, whereas the functional response to sunflower seeds was characterized by a type III functional response in which predation increased with increasing prey density. These results suggest that predation by small mammals is unlikely to stabilize low-density gypsy moth populations. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the applicability of a general optimality model of insect development in the case of lepidopteran larvae. According to the model, larvae moult mainly to increase the size of mouthparts, which is assumed to limit consumption rates. The assumptions of this model being met, one should expect a dependence of growth rates on head capsule size, constancy of absolute growth rates within an instar and higher growth rates in older instars. The validity of these predictions is tested on two species of lymantriid moths. Head capsule size has only a weak effect on growth rates in one of the species, and no effect in the other. Absolute growth rates tend to increase during the development within an instar. Higher growth rates of older instar larvae are explainable by an allometric relationship that extrapolates from growth within the preceding instar. Thus, there is no evidence of an extra increase in growth performance attributable to moulting into the subsequent instar. These results support the idea that growth rates of lepidopteran larvae are limited by nutrient absorption rates rather than by the rates of consumption. There is a considerable cost of moulting in terms of lost growing time: the larvae would double their weights during an instar if they were able to develop without the premoult decrease in growth rates. The investment principle model does not appear to be directly usable to explain moulting strategies in the lepidopteran larvae studied. However, it may well be applicable after some adjustment (i.e. assuming that larvae should moult before consumption rates become limiting). [ABSTRACT FROM AUTHOR]

Abstract The gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), is an introduced defoliator that preferentially feeds on oaks, Quercus spp. (Fagaceae) in the north-eastern USA. As the gypsy moth expands its geographic range, the extensive oak component in forests and urban environments of the USA assure its successful establishment. Given their economic and ecological importance, and the gypsy moth's potential to cause mortality, we evaluated caterpillar preference and performance on various oaks prevalent in the central hardwoods region. Most of the physical and chemical characteristics we measured, from budbreak phenology to foliar chemistry, varied significantly among the oak species tested. Similarly, insect preference and performance varied significantly, though not always in predictable ways. Caterpillar preference was compared for black, Q. velutina Lamarck, burr, Q. macrocarpa Michaux, cherrybark, Q. pagoda Rafinesque, northern red, Q. rubra L., pin, Q. palustris Muenchhausen, swamp white, Q. bicolor Willdenow, white, Q. alba L., and willow, Q. phellos L., oaks. Gypsy moth preference was greatest for black and burr, and least for northern red, pin, and willow oaks. We assessed foliar characteristics and caterpillar performance on foliage from burr, cherrybark, northern red, pin, and willow oaks. Caterpillar preference did not always correlate with performance. Gypsy moth consumption and growth were highest, and development most rapid, on pin oak, which had high nitrogen and tannin levels, and was among the least preferred. Northern red and willow oaks were also among the least preferred and were the least suitable tested, producing caterpillars with moderate to low consumption and growth rates, as well as the longest development. Northern red oak contained the lowest foliar tannins; willow oak foliage was lowest in carbohydrates and nitrogen. Our results suggest that a combination of foliar characteristics may be responsible for gypsy moth... [ABSTRACT FROM AUTHOR]

Studies egg reproduction and the occurrence of adaptive superparasitism in Anaphes nitens, an egg parasitoid of the Eucalyptus snout beetle Gonipterus scutellatus. Occurrence of adaptive superparasitism in relation to competitors' density; Oviposition behavior of females kept alone, in pairs, or in groups of four during patch visits.

1. The western tussock moth (Orgyia vetusta) at the University of California Bodega Marine Reserve (Sonoma County, California, USA) exhibits dense, localized populations in the midst of extensive habitats where variation in host plant quality or predator abundance is unable to explain the restricted extent of the outbreaks. 2. Two primary features suggest that the host patterning is intrinsically generated: (i) female tussock moths are wingless, producing a low effective dispersal distance for the hosts; and (ii) the tussock moth population is attacked by several species of widely dispersing wasp and fly parasitoids. 3. We consider a set of spatially explicit host–parasitoid models to examine whether intrinsically generated patterns are possible within this system. These models include a spatially extended Nicholson–Bailey model to examine general features of pattern formation in host–parasitoid systems, and two system-specific models, an individual-based simulation and a population-level analytic model, to examine the details of this empirical system. 4. Both stable patterning and rapid extinction of the host population are initial-condition dependent outcomes of the general and specific models, implying that an intrinsically generated stable host pattern is feasible within the tussock moth system. 5. Stable patterning is enhanced by a large parasitoid-to-host dispersal ratio, local host resource limitation, and increased parasitism at the host patch’s edge. [ABSTRACT FROM AUTHOR]

An outbreak of acute pruritic rash occurred in Mardi 1990 among 141 residents of a high-rise public housing estate in Bukit Panjang, Singapore. The typical rash consisted of urticarial lesions distributed over the limbs and trunk. The outbreak was associated with a transient increase in tussock moths in the residential estate following an unusual, short dry spell. The aetiology was established when patch tests with crude moth material produced similar eruptions in 5 out of 7 adult volunteers between 40 mm and 12 h. Pharmacological experiments with an aqueous extract of moth hairs in isolated guinea pig ileum elicited a response similar to that induced by histamine. [ABSTRACT FROM AUTHOR]