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Alternanthera philoxeroides (Amaranthaceae), commonly known as alligator weed, is a globally invasive and detrimental perennial weed. Agasicles hygrophila serves as an important biocontrol agent for alligator weeds. However, during mid-summer, when temperatures increase, A. hygrophila populations experience a significant decline, leading to ineffective weed control. This study has examined the impact of periodic heat events on the reproduction and survival of A. hygrophila females and males using various mating combinations and durations of temperature treatments. The results demonstrated significant effects on all of the studied parameters across mating combinations when compared with the control. Under the same temperature combination, the fecundity and survival rates of females, as well as the egg-hatching rate, decreased significantly with increasing repeated heat exposure. Furthermore, the egg-hatching rate varied significantly among different temperatures and time-interval combinations. In addition, the females displayed greater sensitivity to heat stress than males in terms of fecundity. These findings enhance our understanding of A. hygrophila population dynamics during summer and provide insights into the release of biocontrol agents in diverse regions with varying climates. [ABSTRACT FROM AUTHOR]

Ferritins are conserved iron-binding proteins that exist in most living organisms and play an essential role in the maintenance of cellular iron homeostasis. Although ferritin has been studied in many species, little is known about its role in the whitefly, Bemisia tabaci. In this study, we identified an iron-binding protein from B. tabaci and named it BtabFer1. The full-length cDNA of BtabFer1 is 1,043 bp and encodes a protein consisting of 224 amino acids with a deduced molecular weight of 25.26 kDa, and phylogenetic analysis shows that BtabFer1 is conserved among Hemiptera insects. The expression levels of BtabFer1 in different developmental stages and tissues were analyzed by real-time PCR, and results showed that BtabFer1 was ubiquitously expressed at all developmental stages and in all examined tissues. The RNAi-mediated knockdown of BtabFer1 caused a significant reduction in survival rate, egg production, and egg hatching rate of whiteflies. Knockdown of BtabFer1 also inhibited the transcription of genes in the juvenile hormone signal transduction pathway. Taken together, these results suggest that BtabFer1 plays a critical role in the development and reproduction of whiteflies. This study can broaden our understanding of ferritin in insect fecundity and development, as well as provide baseline data for future studies. [ABSTRACT FROM AUTHOR]

Hepatocyte nuclear factor 4 (HNF4) is essential for glucose homeostasis and lipid metabolism in insects. However, little is known about the role of HNF4 in whiteflies. In the present study, we identified a hepatocyte nuclear factor protein from Bemsia tabaci (Diptera: Drosophilidae) and named it BtabHNF4. The full-length of BtabHNF4 was 3,006 bp, encoding a sequence of 434 amino acids that contains a conserved zinc-finger DNA-binding domain (DBD) and a well-conserved ligand-binding domain (LBD). The temporal and spatial expression showed that BtabHNF4 was highly expressed in the female adult stage and abdominal tissues of B. tabaci. A leaf-mediated RNA interference method was used to explore the function of BtabHNF4 in whiteflies. Our results showed that the knockdown of BtabHNF4 influences the desiccation tolerance, egg production, and egg hatching rate of whiteflies. Additionally, BtabHNF4 silencing significantly inhibited the expression level of vitellogenin. These results expand the function of HNF4 and pave the way for understanding the molecular mechanisms of HNF4 in regulating multiple physiological processes. [ABSTRACT FROM AUTHOR]

Imidacloprid is a widely used insecticide for controlling piercing-sucking pests. However, its impact on nontarget insects must not be ignored. In this study, we assessed the effects of sublethal dose of imidacloprid on Sclerodermus alternatusi (Hymenoptera: Bethylidae), which is an important predator of many pests. The data indicate that imidacloprid at LD10 (0.1468 ng active ingredient per insect) and LD30 (0.2376 ng active ingredient per insect) significantly reduced the longevity and fecundity of the F0 generation of S. alternatusi. However, the adult female longevity of the F1 generation of the LD10 dose group showed a significant increase, and the LD30 dose group showed a nonsignificant increase. The study found that as the imidacloprid dose increased, the intrinsic rate of increase (r) decreased, while the mean generation time (T) increased. The imidacloprid groups also showed a decrease in age-stage specific survival rate (Sxj) and age-specific survival rate (lx). However, the female age-specific survival rate (fx4) showed an increasing and then decreasing trend for all treatments. The study found that imidacloprid had an impact on the longevity of S. alternatusi in the F0 generation and extended the mean generation time (T) in the F1 generation. However, it had negative effects on population growth parameters. These findings can be used as a basis for developing integrated pest management strategies., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

The western flower thrips (WFT), Frankliniella occidentalis (Pergande) is one of the most harmful pests of crops in greenhouses and fields. Considering the need for studies that introduce new insecticides for control of the WFT, the leaf dip method was carried out to study the acute toxicity of Proteus, matrine, and pyridalyl to adult thrips, and life tables were constructed to assess the impacts of sublethal concentrations (LC25) of these insecticides on the development and reproduction of the F1 generation. Bioassays showed that the toxicity of matrine (LC50: 45.9 µl ml–1) and Proteus (LC50: 54.5 µl ml–1) was higher than pyridalyl (LC50: 176.5 µl ml–1). At LC25 concentration, both Proteus and matrine prolonged the development period and reduced the survival rate of eggs, larval stages, and pupae in the F1 generation. Also, the adults' longevity, oviposition duration, and the cumulative number of eggs laid per female (fecundity) were decreased significantly. Sublethal concentrations of Proteus and matrine inhibited the population growth rate relative to the control based on the predicted number of offspring. The lowest net reproductive rate (R 0), intrinsic rate of increase (r), and finite rate of increase (λ) were estimated for Proteus (7.02 offspring/individual, 0. 0838 d–1, and 1. 08 d–1, respectively). In contrast, the WFT F1 generation that resulted from parent adults treated with pyridalyl was neither affected in their developmental time, nor fecundity, or the intrinsic rate of increase. According to our findings, all tested insecticides, especially Proteus, showed good potential for use in integrated pest management strategies against F. occidentalis. [ABSTRACT FROM AUTHOR]

Trogoderma granarium Everts, the Khapra beetle, is a major pest of stored products, especially grains. In this study, fumigant toxicity and sublethal effects of Eucalyptus camaldulensis Dehnh. (Myrtaceae) and Mentha piperita L. (Lamiaceae) essential oils (EOs) were investigated against different growth stages of T. granarium. To assess the sublethal effects, insects were exposed to an LC20 or LC50 concentration of each essential oil, and the ability of these oils to deter feeding, oviposition, and damage to wheat seeds and overall mass were surveyed. At LC50 concentrations, M. piperita EO showed higher fumigant toxicity than E. camaldulensis EO against eggs, 2nd instar larvae, 4th instar larvae, and adults of T. granarium. Furthermore, the adults were more sensitive to the tested EOs than immatures. In free-choice tests, both larvae and adults showed a preference for control-treated wheat seeds than for seeds treated with an LC20 or LC50 concentration of EOs from E. camaldulensis or M. piperita. In a no-choice test, adult females exposed to EOs showed lower fecundity and fertility in comparison to control females not exposed to EOs. Treatment of wheat seeds with E. camaldulensis or M. piperita EOs resulted in a dose-specific reduction in the number of damaged seeds and seed weight loss when compared to control. According to our results, both tested EOs, especially EOs extracted from M. piperita , showed good potential for use in integrated pest management strategies against T. granarium. [ABSTRACT FROM AUTHOR]

The migratory fall armyworm, Spodoptera frugiperda (Smith), has become a worldwide agricultural pest. In this study, the effects of photoregime on the development, reproduction, and flight performance of fall armyworm were assessed based on two-sex life tables, ovarian and testis anatomy, and flight mill tests. The results indicated that photoregime had a significant effect on developmental duration of fall armyworm individuals, pupal survival and emergence, and adult fecundity. Among seven photoregimes tested, the 16:8 (L:D) h photoregime was the most suitable for fall armyworm fitness with the shortest pre-oviposition period and mean generation period (T), highest mating frequency and mating rate of female moths, largest intrinsic rate of natural increase (r m) and finite rate of increase (λ), and highest net reproduction rate (R 0). Population growth for seven different photoregimes in decreasing order was 16:8 (L:D) h > 8:16 (L:D) h > 12:12 (L:D) h > 10:14 (L:D) h > 14:10 (L:D) h > 0:24 (L:D) h > 24:0 (L:D) h. The ovarian development level, mating frequency, and testis size did not significantly differ between long (16:8 (L:D) h) and short (10:14 (L:D) h) illumination. Photoregime had a significant effect on mass loss during flight of adults, but not on flight velocity, flight duration, and flight distance. These findings can be used to refine laboratory rearing protocols, accurately predict seasonal changes in population dynamics and should help improve regional forecasts and management of the fall armyworm. [ABSTRACT FROM AUTHOR]

Delayed mating is an effective strategy that can decrease the fecundity of a pest by reducing the time that females have to mate. This disruption does not completely inhibit mating and may lead to multiple matings. The effects of delayed mating with multiple partners on different indexes of mating in female and male Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) were determined in this study. The delay in mating significantly decreased the number of matings and the mating success of both sexes and the male contribution to reproduction. Compared with the effect on female fecundity, the delayed mating with multiple partners had a greater effect on the male mate contribution to fecundity. The longevity of females and males increased significantly with a 72 h delay in mating. Linear regression analysis showed negative relationships between delayed mating and fecundity and number of matings in both sexes. Thus, delayed mating with multiple partners can disrupt the mating and reproductive potential of S. litura. [ABSTRACT FROM AUTHOR]

The golden twin-spot moth or tomato looper, Chrysodeixis chalcites (Esper), is a polyphagous and worldwide pest that causes important aesthetic damages to banana fruits in the Canary Islands. The life history parameters of C. chalcites were determined under laboratory conditions in base on the age-stage, two-sex life table at 15, 20, 25, 30, and 35°C, 65% relative humidity (RH), and a photoperiod of 16:8 (L:D) h, when it was reared on a semi-synthetic diet. The results show that C. chalcites was able to develop and survive from 15 to 30°C, but no development occurred at 35°C. Developmental threshold temperatures of the egg, larval, pupal, and total preoviposition stages were 10.42, 11.73, 11.22, and 9.42°C, respectively, and their effective accumulated temperatures were 58.31, 265.96, 118.57, and 562.39 degree-days, respectively. The adult longevity was reduced with increasing temperature, which ranged between 16.27 and 34.85 d for females and between 14.27 and 35.21 d for males. The highest values of net reproductive rate (R 0 ) and fecundity were observed at 25°C, with 232.70 offspring and 1,224.74 eggs, respectively. Both the intrinsic rate of increase (r) and finite rate of increase (λ) increased significantly and mean generation time (T) decreased significantly with increasing temperature. These results provide useful information that will allow predicting the impact of climate change on the distribution and population dynamics of C. chalcites and developing successful integrated management programs. [ABSTRACT FROM AUTHOR]

Insect herbivores, especially sap-feeders, are sensitive to host-plant nitrogen quantity. However, past studies present contradicting results on sap-feeder life history traits influenced by plant nitrogen supplementation. This study analyzed the bottom-up effects of below-recommended nitrogen fertilization rates (0, 0.021, 0.048, and 0.091 g N/liter) on life history and total protein and lipid contents of a significant pest species, Phenacoccus madeirensis Green (the Madeira mealybug) (Hemiptera: Pseudococcidae). Developmental durations and survivorship from egg to adulthood of male and female mealybugs were similar across nitrogen fertilization levels. Females reared on plants fertilized at 0.021, 0.048, and 0.091 g N/liter produced, respectively, 152, 142, and 67% more eggs than females reared on unfertilized plants. Finite and intrinsic rates of increase and net reproductive rates of females were similar among the nitrogen fertilization levels, whereas the generation times of females from fertilized plants were significantly shorter than those from the unfertilized plants. Lipid contents of adult females and eggs, and average adult female protein content were similar across the nitrogen treatments. Average egg protein content increased with increasing host-plant fertilization rate. These results suggest that the response of the female Madeira mealybug to nitrogen fertilization is complex and may involve trade-offs and nutrient re-allocation. [ABSTRACT FROM AUTHOR]

The Russian wheat aphid, Diuraphis noxia (Kurdjumov), is one of the most important pests of wheat and barley in most wheat-producing countries. Rapid cold hardiness (RCH) is a capacity of insects to develop, within hours, protection against subfreezing temperatures that plays an important role in aphid survival in response to sudden decreases in air temperature. In this research, we investigated the duration and rate of cooling on the induction of RCH of D. noxia and the costs of RCH on aphid development and fecundity. By transferring aphids directly from 20 °C to a range of subzero temperatures for 2 h, the lower lethal temperature for 80% mortality (LT80) was determined to be - 11.9 °C. Preconditioning the aphids at 0 °C for 1-3 h prior to exposure at (LT80) (- 11.9 °C) resulted in a sharp increase in survival, with little change with longer durations of preconditioning. The slowest cooling rate (0.05 °C/min) increased survival fourfold, whereas rates from 0.1 to 1 °C/min increased survival twofold compared with a direct transfer to 0 °C, regardless of aphid stage used. Deleterious effects of RCH were not observed on aphid development, longevity, or fecundity. The present study indicates that RCH is induced in D. noxia in just a few hours in response to sudden lowering of temperatures to freezing, with little or no cost in reproductive capacity. [ABSTRACT FROM AUTHOR]

Glassy-winged sharpshooters must feed as adults to produce mature eggs. Cowpea and sunflower are both readily accepted by the glassy-winged sharpshooter for feeding, but egg production on sunflower was reported to be lower than egg production on cowpea. To better understand the role of adult diet in egg production, effects of xylem-sap chemistry on glassy-winged sharpshooter egg maturation was compared for females confined to cowpea and sunflower. Females confined to cowpea consumed more xylem-sap than females held on sunflower. In response, females held on cowpea produced more eggs, had heavier bodies, and greater lipid content than females held on sunflower. Analysis of cowpea and sunflower xylem-sap found that 17 of 19 amino acids were more concentrated in cowpea xylem-sap than in sunflower xylem-sap. Thus, decreased consumption of sunflower xylem-sap was likely owing to perceived lower quality, with decreased egg production owing to a combination of decreased feeding and lower return per unit volume of xylem-sap consumed. Examination of pairwise correlation coefficients among amino acids indicated that concentrations of several amino acids within a plant species were correlated. Principal component analyses identified latent variables describing amino acid composition of xylem-sap. For females held on cowpea, egg maturation was affected by test date, volume of excreta produced, and principal components describing amino acid composition of xylemsap. Principal component analyses aided in identifying amino acids that were positively or negatively associated with egg production, although determining causality with respect to key nutritional requirements for glassy-winged sharpshooter egg production will require additional testing. [ABSTRACT FROM AUTHOR]

The combined effect of temperature and age on development, survival, attack rate, and oviposition of the parasitoid Spalangia cameroni (Perkins) (Hymenoptera: Pteromalidae) exploiting house fly pupae was investigated by conducting life-table experiments at 15, 20, 25, 30 and 35°C. Temperature had a pronounced effect on survival and development of the immature stages. Survival was highest at 25°C, where 88.5% of the parasitized host pupae resulted in adult parasitoids, and lowest at 35°C when only 3.78% emerged. Females constituted between 50% (at 20°C) and 100% (at 35°C) of the surviving immatures. Males developed faster than females, with the shortest developmental times at 30°C (18.18d for males and 19.41d for females). Longevity of adult females decreased with temperature from 80d at 15°C to 18 d at 35°C. Total attack rate of female parasitoids was highest at 20°C (106 hosts per female), and life-time reproduction highest at 20°C and 25°C (about 60 offspring per female). Sex ratio was female biased (65% females). A generic model was used to estimate and predict the temperature effect on the intrinsic rate of increase (rm), the net reproduction rate (R0), and the generation time (G). The model predicted that rm peaks at 33.5°C (rm=0.182d-1), that maximum R0 is reached at 27.2°C (R0=50.2), and that the shortest generation time occurs at 34.5°C (G=21.1d). Doubling time was 4.19 d at 33°C. In the temperature range between 20°C and 30°C, S. cameroni has the potential to be an efficient control agent against nuisance flies. [ABSTRACT FROM AUTHOR]

The oriental fruit moth Grapholita molesta (Busck) is a globally important insect pest. In some parts of its geographic range, the oriental fruit moth shifts its attack from peach orchards to pear orchards late in the growing season. The phenological effects of host plants on the performance of the moth were evaluated by examining the development and fecundity of the moth reared on peach (Prunus persica variety "Shahong") and pear (Pyrus bretshneideri variety "Dangshan Su") collected at various times of the growing season under laboratory conditions. Results showed that the moth developed faster on shoots and fruits of peach than on those of pear. The preimaginal survival rate was the highest on peach shoots, and the moth could not survive on pear fruit collected on May 10. For both peach and pear, the boring rates of neonatal larvae were significantly higher on shoots than on fruits, and the pupal mass of females was significantly higher on fruits than on shoots. The boring rate increased with pear fruits growing during later days. Fecundity was significantly less on pear shoots than on the other plant materials. The results of this study suggest a possible host adaptation process in oriental fruit moth. [ABSTRACT FROM AUTHOR]

Patterns of body size evolution are of particular interest because body size can affect virtually all the physiological and life history traits of an organism. Sexual size dimorphism (SSD), a difference in body size between males and females, is a widespread phenomenon in insects. Much of the variation in SSD is genetically based and likely due to differential selection acting on males and females. The importance of environmental variables and evolutionary processes affecting phenotypeic variation in both sexes may be useful to gain insights into insect ecology and evolution. Dichroplus elongatus Giglio-Tos is a South American grasshopper widely distributed throughout Argentina, Uruguay, most of Chile, and southern Brazil. In this study, we analyzed 122 adult females of D. elongatus collected in eight natural populations from central-east Argentina. Females show large body size variation among the analyzed populations and this variation exhibits a strong relationship with fecundity. Our results have shown that larger females were more fecund than smaller ones. We found that ovariole number varied along a latitudinal gradient, with higher ovariole numbers in populations from warmer locations. A considerable female-biased SSD was detected. SSD for three analyzed morphometric traits scaled isometrically. However, SSD for thorax length displayed a considerable variation across the studied area, indicating a larger relative increase in female size than in male size in warmer environmental conditions. [ABSTRACT FROM AUTHOR]

Temperature-related studies were conducted on Drosophila suzukii Matsumura (Diptera: Drosophilidae: Drosophilini). From 10-28°C, temperature had a significant impact on blueberries, Vaccinium corymbosum L. (Ericales: Ericaceae), and cherries, Prunus avium (L.) L. 1755 (Rosales: Rosaceae), important commercial hosts of D. suzukii. Temperature had a significant influence on D. suzukii developmental period, survival, and fecundity, with decreasing developmental periods as temperatures increased to 28°C. At 30°C, the highest temperature tested, development periods increased, indicating that above this temperature the developmental extremes for the species were approached. D. suzukii reared on blueberries had lower fecundity than reared on cherries at all temperatures where reproduction occurred. The highest net reproductive rate (Ro) and intrinsic rate of population increase (rm) were recorded on cherries at 22°C and was 195.1 and 0.22, respectively. Estimations using linear and nonlinear fit for the minimum, optimal, and maximum temperatures where development can take place were respectively, 7.2, 28.1, and 42.1°C. The rm values were minimal, optimal, and maximal at 13.4, 21.0, and 29.3°C, respectively. Our laboratory cultures of D. suzukii displayed high rates of infection for Wolbachia spp. (Rickettsiales: Rickettsiaceae), and this infection may have impacted fecundity found in this study. A temperature-dependent matrix population estimation model using fecundity and survival data were run to determine whether these data could predict D. suzukii pressure based on environmental conditions. The model was applied to compare the 2011 and 2012 crop seasons in an important cherry production region. Population estimates using the model explained different risk levels during the key cherry harvest period between these seasons. [ABSTRACT FROM AUTHOR]

The diamondback moth, Plutella xylostella (L.), is an oligophagous insect that primarily feeds on members of the family Cruciferae. The development, survival, and reproductive potential of P. xylostella were studied on eight wild cruciferous species: Rorippa indica (L.) Hiern, Cardamine hirsuta L., Descurainia sophia (L.) Webb ex Prantl, Capsella bursa-pastoris (L.) Medic, Cardamine leucantha (Tausch) O. E. Schulz, Orychophragmus violaceus (L.) O. E. Schulz, Thlaspi arvense L., and Cardamine macrophylla Willd. Developmental durations of immatures from egg to adult emergence differed significantly among the plant species, with the longest period recorded on C macrophylla (20.8 d) and the shortest on R. indica (15.8 d). The female pupae of P. xylostella reared on C leucantha and T. arvense were lighter (4.2 and 4.3mg/pupa) than those reared on other hosts (5.2-6.5 mg/pupa), and the male pupae from T. arvense were the lightest (3.1 mg/pupa) among all colonies. Survival from egg to adult emergence ranged from 95.7% on R. indica to 48.8% on T. arvense. The longevity (10.1 d) of P. xylostella female and the oviposition period (7.7 d) were the longest when larvae fed R. indica than those that fed on other wild hosts. Female adults of P. xylostella from O. violaceus, C macrophylla, and Ca. bursa-pastoris had higher fecundity (305-351 eggs/female) than from other wild host plants, whereas that from R. indica had the lowest fecundity (134 eggs/female). C hirsuta was the best wild host plant for P. xylostella because of the highest intrinsic rates of increase (rm = 0.2402), whereas T. arvense was the least favorable hosts with the lowest intrinsic rates of increase (rm = 0.1577). The results from this study will be useful for interpretation of the performance and population dynamics of P. xylostella on wild hosts and cultivated cruciferous vegetables. [ABSTRACT FROM AUTHOR]

Lady beetles such as Coleomegilla maculata DeGeer and Hippodamia convergens Guerin-Meneville have been categorized as income breeders because egg maturation depends on resources available during reproduction. However, capital resources acquired during larval feeding influence reproductive success via effects on adult body size and other traits. We produced three sizes of beetles by varying larval access to food and subjected mated females to alternating periods of food surplus and deficit. Both species exhibited temporal variation in clutch size that reflected changes in income, the amplitude of fluctuations being greater in H. convergens. Egg mass in C. nuzculata appeared to increase as a fixed function of oviposition sequence but also was affected by maternal body size, whereas H. convergens egg mass fluctuated more in response to food supply. Fertility was largely unaffected by income fluctuation but appeared constrained by capital, especially in H. convergens. Dynamic changes in reproductive effort (daily mass of eggs/female mass at emergence) mirrored changes in clutch size, the amplitude of fluctuations being greater in H. convergens, the species with higher reproductive effort. Generally, large females compensated for income fluctuations better than small females, likely because of their greater capital and possibly an ability to consume larger meals when food was available. The greater sensitivity to income observed in H. convergens likely reflects a higher degree of aphid-specificity compared with the more generalist C. maculata because effective exploitation of ephemeral aphid outbreaks would favor rapid reproductive responses to changes in food supply. [ABSTRACT FROM AUTHOR]

The life history ofBrontispa longissima (Gestro) (Coleoptera: Hispidae), reared under laboratory conditions on leaves of coconut (Cocos nucifera L.), royal palm [Roystonea regia (Kunth) O.F.Cook], bottle palm [Hyophorbe lagenicaulis (L. Bailey) H.E.Moore], and fishtail palm (Caryota ochlandra Hance) was analyzed using age-stage, two-sex life table. Means and standard errors of population growth parameters were calculated using the jackknife method. Moreover, survival rate and fecundity data were applied to project the population for revealing the different stage structure. The mean intrinsic rates of population growth when reared on each respective leaf type were 0.032, 0.031, 0.019, and 0.044. Individuals reared on C. nucifera achieved the highest net reproduction rate at 114.5 offspring per female. The mean generation times ofB. longissima ranged from 93.2 d (reared on C. ochlandrai) to 161.5 d (reared on H. lagenicaulis). Projections from survival rate and fecundity data indicated that B. longissima populations can row considerably faster on C. ochlandra than on the other three host plants. The results validate the two-stage life history approach taken, providing an essential tool for developing and testing future control strategies. [ABSTRACT FROM AUTHOR]

A biological control program has been initiated against the European swallow-worts Vincetoxicum nigrum (L.) Moench and V. rossicum (Kleopow) Barbar. (Family Apocynaceae) that have become invasive in North America. The leaf-feeding moth, Hypena opulenta Christoph (Lepidoptera: Erebidae), originating from eastern Europe, has been under measurement as a potential biological control agent of swallow-worts since 2006. In this study we measured the host range of H. opulenta by screening 82 potential host plant species for larval development under no-choice conditions. In addition, we also monitored female fecundity, longevity, and oviposition preference among suitable larval hosts. Successful larval development occurs only on Vincetoxicum spp. Partial larval development by one larva was observed on Boehmeria cyclindrica (L.) Sw. (Urticaceae) to the final instar, but this individual failed to pupate. Exploratory feeding occurred on Gonolobus stephanotrichus Griseb. (Apocynaceae) and Urtica dioica L. (Urticaceae), but all larvae failed to develop past the first and second instar, respectively. Additional testing with mature larvae on a subset of the plant species demonstrates that no species outside the genus Vincetoxicum are suitable for complete larval development of//. opulenta. The longevity and fecundity of females raised on each target weed are similar and gravid females do not display an oviposition preference among Vincetoxicum spp. Hypena opulenta does not present a risk to any native plant species or species of economic importance in North America. Petitions have been submitted for experimental open-field releases ofH. opulenta in the United States and Canada. [ABSTRACT FROM AUTHOR]

Studies were designed to examine the effects of host plants (apricot, Prunus armeniaca L.; plum, Prunus salicina L.; peach, Prunus persica L.; jujube, Zizyphus jujuba Will.; apple, Malus domestica Mill.; and pear, Pyrus sorotina Will) on the development and life table parameters of the peach fruit moth, Carposina sasakii Matsumura (Lepidoptera: Carposinidae) under laboratory conditions. Peach fruit moth developed faster (12.48 d) and had the highest preimaginal survival rate (50.54%) on plum compared with the other host plants. Adult longevity was significantly longer on jujube for both female and male moths. Adult females from larvae reared on jujube and peach laid significantly greater numbers of eggs (214.50 and 197.94 eggs per female, respectively) compared with those reared on the other four host plants. Life-table parameters were calculated for each host plant and compared by jackknife procedures. The intrinsic rate of natural increase (rm) was significantly greatest on plum (0.1294 eggs per female per d), followed by jujube and apricot (0.1201 and 0.1128 eggs per female per d), respectively. Implications of the various measures of population performance are discussed. [ABSTRACT FROM AUTHOR]

We assessed the life history parameters and temperature requirement of a Korean population of the endoparasitoid Aphelinus asychis Walker (Hymenoptera: Aphelinidae), using Aphis gossypii Glover (Hemiptera: Aphididae) as a host. We first measured the time from egg to mummification (i.e., pupation) and mummification to adult emergence (i.e., pupal period) at 25°C. The pupal period was significantly longer than the egg to pupation period in both genders, unlike in other regional populations of the species. Females produced an average of 342.9 mummies, the highest reported fecundity among the various regional populations of this species. Age-specific realized fecundity peaked between the 4th and 7th day (23.3-24.8 mummies a day). The intrinsic rate of increase (rm) was 0.255 offspring per female per day. The parasitoids were then reared at eight constant temperatures between 15 and 32.5°C. The developmental time from egg to adult emergence decreased from 27.8 to 9.8 d. The lower developmental thresholds (T0), estimated by linear regression, for the egg to mummy, mummy to adult, and egg to adult stages were 6.7, 6.8 and 6.7, respectively. The thermal constants for each of the three periods were 115, 126, and 243 DD. We compared these parameters with published data of A. asychis from other regions reared on different hosts and representative species of aphid parasitoids in Aphidiinae (Braconidae) reared on hosts including A. gossypii. The T0's of A. asychis were higher than those of Aphidius colemani and Aphidius matricariae when using A. gossypii. [ABSTRACT FROM AUTHOR]

Little is known about the potential cumulative long-term effects of transgenic crops on nontarget organisms. In the present laboratory study, the potential cumulative effects of transgenic Bacillus thuringiensis (Bt) rice on parasitoids in successive generations were observed for an egg parasitoid, Anagrus nilaparvatae parasitizing eggs of Nilaparvata lugens (Stål) (Hemiptera: Deiphacidae) feeding on Bt rice. Enzyme-linked immunosorbent assay test confirmed that CrylAb insecticidal protein could be detected in newly eclosed parasitoid adults. However, no significant effect on the fecundity of Anagrus nilaparvatae Pang et Wang (Hymenoptera: Mymaridae) was observed between Bt and non-Bt rice. Developmental times of both genders of A. nilaparvatae parasitizing host eggs laid in Bt (KMD1 and KMD2) rice lines were significantly prolonged from first generation to second generation, but not always prolonged from third generation to 11th generation as compared with the control rice line. Furthermore, the sex ratio of A. nilaparvatae progeny from the first generation to 11th generation in three rice lines was not significantly different. In general, our results suggested that the effect of Bt rice on this parasitoid could be negligible. [ABSTRACT FROM AUTHOR]

The lesser cornstalk borer, Elasmopalpus lignosellus (Zeller) (Lepidoptera: Pyralidae) is an important pest of sugarcane (a complex hybrid of Saccharum spp.) in southern Florida. Reproductive and life table parameters for E. lignosellus were examined at nine constant temperatures from 13 to 36°C with sugarcane as the larval food source. The pre- and postoviposition periods decreased with increasing temperatures and reached their minimums at 33 and 36°C, respectively. The oviposition period was longest at 27°C. The mean fecundity, stage-specific survival, stage-specific fecundity, intrinsic rate of increase, and finite rate of increase were greatest at 30°C and decreased with increasing or decreasing temperature. The net reproductive rate was greatest at 27°C. The Logan-6 model best described the relationship between temperature and intrinsic rate of increase, The generation and population doubling times were longest at 13 and shortest at 33 and 30°C, respectively. The most favorable temperatures for E. lignosellus population growth were between 27 and 33°C. Life table parameters for E. lignosellus reared on sugarcane were greater than for the Mexican rice borer [Eoreunma loftini (Dyar) (Lepidoptera: Crambidae) ] reared on an artificial diet at 30°C. The intrinsic rates of increase for the sugarcane borer [Diatraea saccharalis (F.) (Lepidoptera: Crambidae)] reared on sugarcane or corn were the same as for E. lignosellus reared on sugarcane at 27°C, but the net reproductive rate was four times higher for the former than the latter borer species. [ABSTRACT FROM AUTHOR]

The effect of temperature on the development, survivorship, fecundity, and life table parameters of Octodonta nipae ( Maulik) ( Coleoptera: Chrysomelidae ), was studied at seven constant temperatures of 17.5, 20, 22.5, 25, 27.5, 30, and 32.5°C. Preliminary experiments showed that no development was observed at 15 and 35°C. All individuals completed development and females laid eggs from 20 to 30°C. There was a significant decrease in male and female longevity with increasing temperatures from 20 to 30°C. The longest and shortest longevity were 203.5 and 73.7 d for males, and 178.7 and 57.6 d for females, respectively. Females produced on average 62.7, 88.9,b116.8, 70.0, and 47.3 eggs and the life expectancy for a newborn egg was 171.6, 148.7, 114.9, 89.2, and 94.8 d at 20, 22.5, 25, 27.5 and 30°C, respectively. Life history data were analyzed by using an age-stage, two-sex life table. The intrinsic rate of increase (r) and the finite rate of increase (λ) of O. nipae increased with increasing temperatures from 20 to 30°C, while the mean generation time (T) decreased within this temperature range. The r was 0.0155, 0.0249, 0.0339, 0.0361, and 0.0383 d-1 at 20, 22.5, 25, 27.5, and 30°C, respectively. The net reproductive rate (Ro) weis highest at 25°C (35.0 offspring), and lowest at 20°C (17.0 offspring). T was shortest at 30°C (76.4 d). The results showed that temperature greatly affected the fecundity and life table parameters of O. nipae, and a suitable temperature for population development and fecundity was at 25°C. The life table data can be used for the projection of population growth and evaluation of control programs. [ABSTRACT FROM AUTHOR]

Ophraella communa (Coleoptera: Chrysomelidae) is a leafbeetle that is unintentionally introduced in China. It is a potential biological control agent against common ragweed, Ambrosia artemisiifolia (Asterales: Asteraceae). The effects of temperature on the development and fecundity of 0. communa were studied at eight constant temperature regimens (15, 20, 22, 25, 28, 30, 32, 36°C) in the laboratory. The results showed that the developmental periods for egg, larva, pupa, and entire immature stages decreased in response to the increasing temperature, with the exception of 30°C. The survival rates at different developmental stages were higher at 25 and 28°C than at other temperatures. Ovipositional period and longevity of female shortened with the increasing temperature. The highest fecundity of female was observed to be 2,712.3 eggs/female at 28°C. Life table of 0. communa was constructed based on the data at 20 -32°C. The innate capacity for increase (rm), the net reproductive rate (R0),and the finite rate of increase (λ) reached the maximum at 28°C, with values of 0.247, 1,773.0, and 1,280, respectively. The shortest period of a generation (T) was 24.6 d at 32°C, whereas the longest T value was recorded as 79.3 d at 20°C. These results offer valuable insight on the establishment potential of 0. communa in new environments with diverse temperature regimens and on its massrearing techniques in laboratory. [ABSTRACT FROM AUTHOR]

We investigated effects of temperature, at 70% RH, on the reproductive parameters of the parthenogenetic psocid Lepinotus reticulatus Enderlein (Psocoptera: Trogiidae). The lowest fecundity (21) was at 35°C and the highest (41) at 27.5°C. At 22.5, 25, and 27.5°C, peak oviposition rates (eggs/female/week) occurred in week 3 and were 4.7, 6.6, and 7.8, respectively; also 51, 57, and 62%, respectively, of all eggs were laid in the first 4 wk. At 30, 32.5, and 35°C, peak oviposition rates occurred in week 2 and were 8.2, 9.0, and 7.4, respectively; 80, 85, and 98%, respectively, of all eggs were laid in the first 4 wk. The longest preoviposition period (4.4 d) was at 22.5 and 25°C, and the longest postoviposition period (13,1 d) was at 22.5°C. Oviposition period and longevity decreased with increasing temperature; at 22.5°C, these parameters were 66 and 83 d, respectively, and at 35°C, they were 18 and 24 d, respectively. Mean weekly oviposition rate increased with temperature and was highest at 32.5°C (5.8 eggs/female/week). At 22.5, 25, 27.5, 30, 32.5, and 35°C, it took 29, 20, 12, 11, 8, and 6 wk, respectively, for all females to die. Intrinsic rate of population increase increased with temperature until 32.5°C (0.128) and then declined. We have developed temperature-dependent equations for preoviposition period, postoviposition period, oviposition period, oviposition rate, and longevity. Reproductive parameters affect population dynamics, and information on these parameters can be used in simulation models to predict L. reticulatus population dynamics to aid in developing effective management strategies. [ABSTRACT FROM AUTHOR]

Because mating may be costly, sexually active males or females are predicted to be in relatively good physiological condition and may preferentially direct their mating behavior toward relatively high-quality mates. We tested this hypothesis in Japanese beetles (Popilliajaponica Newman), a pest species in which males and females may be either isolated or in aggregations while feeding on host plants. We examined male size and lipid content and female size and egg load with respect to both their pairing status and whether they were isolated or in aggregations. Males that were paired had the highest lipid levels, and single, isolated males had the lowest. Paired females had the highest egg loads and single, isolated females had the lowest. Neither male nor female size was related to pairing status. Females captured during the times of relatively high pairing frequency (i.e., morning and evening) had higher egg loads than females captured at times of lower pairing frequency (i.e., afternoon). These results suggest that mating and aggregative behaviors in Japanese beetles are dependent on the physiological status of males and the reproductive condition of females. [ABSTRACT FROM AUTHOR]

We studied a population of Liriomyza sativae Blanchard (Diptera Agromyzidae) identified by morphological and molecular techniques from the semiarid region of the Brazilian northeast. The influence of temperature and relative humidity on the survival and reproductive parameters of L. sativae in cowpeas ( Vigna unguiculata L. Waip.) (Fabales: Fabaceae) was evaluated. We used temperatures of 18, 20, 22, 25, 28, 30, and 32 ± 1°C (50 ± 10% RH) and relative humidity values of 30, 50,70, and 90± 10% (25 ± 1°C) under a 14 L:10 D photoperiod. Adult longevity decreased as temperature and relative humidity increased and was greater, in general, for females. The preovi-position and oviposition periods also decreased as temperature increased, whereas relative humidity only caused reductions in the oviposition period at higher levels. Fecundity was similar in the range from 18 to 30°C but decreased at 32°C with respect to relative humidity; the best performances of L. sativae occurred at lower levels. The pattern of oviposition rate changed with temperature and relative humidity. Regardless of temperature and relative humidity, L. sativae laid between 75 and 92% of its eggs on the adaxial surface of the cowpea leaves. This information will be highly useful to design a leafminer production system aimed at the multiplication of natural enemies, as well as for pest management in the field. [ABSTRACT FROM AUTHOR]

The elm spanworm, Ennomos subsignarius Hubner (Lepidoptera: Geometridae), is an eruptive herbivore that feeds on numerous tree species in forests throughout its range. An unprec- edented outbreak in an urban environment in St. John's, Newfoundland, Canada, caused severe levels of defoliation to a number of native and exotic hardwood tree species, some of which represent novel hosts for this insect. Increased insect performance on these novels hosts was hypothesized as having contributed to the outbreak. To assess this, percentage larval survival and pupal weight were measured for larvae reared on foliage from six different tree species in a no-choice laboratory bioassay. Adult longevity and fecundity (no. eggs laid per female) were assessed for laboratory-reared individuals, as well as for pupae collected from eight different host tree species from the field. A survey to assess feeding occurrence measured defoliation on eight tree species. During this urban outbreak, sycamore maple, Acer pseudoplatanus, a tree species not native to North America, experienced the highest levels of defoliation. Performance of E. subsignartus (pupal weight, female longevity, and fecundity) on this host was comparable with the known host of elm (Ulmus spp.). Despite the fact that E. subsignaria performed well on several introduced hosts, fecundity levels were much lower than previously published reports, suggesting that the current outbreak is not caused by increased fecundity on these novel hosts in contrast to the hypothesis. [ABSTRACT FROM AUTHOR]

The development, survivorship, and fecundity of the potato psyllid, Bactevicera cockerelli (Sulc), fed on eggplant (Solanum melongena L., variety Special Hibush) and bell pepper (Capsicum annuum L., variety Capsitrano) were studied in the laboratory at 26.7 ± 2°C, 70 ± 5% RH, and at a photoperiod of 14:10 (L:D) h. Immature B. cockerelli developed faster (24.1 d) when fed on eggplant than on bell pepper (26.2 d). Survival rates of immature stages from egg to adult emergence were higher on eggplant (50.2%) than on bell pepper (34.6%). The longevity of B. cockerelli female adults fed on bell pepper was similar to that of females fed on eggplant (62.2 versus 55.0 d), but the male adults fed on eggplant lived shorter lives (39.4 d) than those fed on bell pepper (53.9 d). However, the preoviposition and oviposition periods, fecundity, and sex ratio of B. cockerelli fed on eggplant were not different from those fed on bell pepper. The rm value and the finite rate of increase (A) of B. cockerelli were higher on eggplant (0.1099 and 1.116, respectively) than on bell pepper (0.0884 and 1.0924, respectively). Mean generation time and doubling time of B. cockerelli were shorter on eggplant (40.4 and 6.3 d, respectively) than on bell pepper (46.1 and 7.8 d, respectively). In contrast, lifetime fecundity of B. cockerelli was greater on bell pepper (227.3 offspring) than on eggplant (186.5 offspring). Based on these life history parameters, we concluded that B. cockerelli performed better on eggplant than on bell pepper. [ABSTRACT FROM AUTHOR]

Atmospheric levels of carbon dioxide (CO2) have been increasing steadily over the last century. Plants grown under elevated CO2 experience physiological changes that influence their suitability as food. Previous studies have found increased insect herbivory on plants grown under elevated CO2. To determine effects of consuming foliage of soybean (Glycine max) grown under elevated CO2 on adult survivorship and fecundity, Japanese beetles (Popillia japonica Newman) were fed for the duration of their adult lives leaves grown under elevated CO2 (550 μmol/mol), under ambient atmosphere (370 μmol/mol), or grown under ambient atmosphere but supplemented with a solution of sugars. To determine effects of a diet of foliage grown under elevated ozone (O3), another anthropogenic gaseous pollutant, beetles in the laboratory were fed soybean leaves grown under elevated CO2, elevated O3, or a combination of both elevated gases. Leaf tissue was also analyzed for longevity-enhancing antioxidants, because increases in dietary antioxidants can increase lifespan. Lifespan of Japanese beetles was prolonged by 8-25% when fed foliage developed under elevated CO2, but consuming foliage that had taken up sugars to approximately the same level as foliage grown under elevated CO2 had no effect on fecundity or longevity. Females consuming elevated CO2 foliage laid approximately twice as many eggs as females fed foliage grown under ambient conditions. Consuming foliage grown under elevated O3 had no effect on fecundity. No significant differences in total antioxidant content of foliage from ambient and elevated CO2 conditions were detected. Although the precise mechanism is unclear, by altering components of leaf chemistry other than sugar content, elevated CO2 may increase populations of Japanese beetles and their impact on crop productivity. [ABSTRACT FROM AUTHOR]

Greenbug, Schizaphis graminum (Rondani) (Hemiptera: Aphididae), was first discovered damaging seashore paspalum (Paspalum vaginatum Swartz) turfgrass in November 2003 at Belle Glade, FL. Inquiries to several golf courses with seashore paspalum turf across southern Florida indicated infestation was wide spread by April 2004. Damage symptoms progress from water soaked lesions surrounding feeding sites within 24 h to chlorosis and necrosis of leaf tips within 96 h. Problems caused by greenbug feeding were initially misdiagnosed as fertilizer, disease, other insects, or water management problems because aphids were not previously found on warm season turfgrasses. Greenbug development and fecundity studies were conducted on six seashore paspalum varieties: `Aloha,' `SeaDwarf,' `SeaGreen,' `SeaIsle,' `SeaWay,' and `SeaWolf.' Greenbug did not survive on `SeaWolf.' Development rates (mean ± SEM) ranged from 7.6 ± 0.2 to 8.2 ± 0.2 d on the remaining varieties. Greenbug longevity and fecundity on `Aloha' were significantly less than on the other varieties. The estimated intrinsic rate of natural increase (rm) for greenbug ranged from 0.24 to 0.26 across tested varieties. Values for net reproductive rate (Ro) ranged from 12.3 on `Aloha' to 40.4 on `SeaWay.' In feeding trials on indicator plants, the Florida isolate of greenbug exhibited a unique biotypic profile most commonly found on noncultivated grass hosts. It was virulent on the wheat variety GRS1201 that is resistant to the principal agricultural biotypes attacking small grains and to all currently available resistant sorghum varieties. [ABSTRACT FROM AUTHOR]

Pyrrhalta viburni Paykull, a new landscape pest in the United States, feeds in both the larval and adult stages on foliage of plants in the genus Viburnum. We measured lifetime oviposition capacity of mated and unmated females reared in the laboratory versus field-collected females, as well as ovipositional response to physical characteristics of the host plant. Both mated and unmated females produced eggs, but at different rates. Field-collected females and mated females reared in the laboratory laid similar numbers of egg masses containing similar numbers of eggs, but unmated females laid approximately one half as many eggs, the result primarily of smaller clutch size. Mated females reared in the laboratory had a preovipositional period of 11.4 ± 1.7 versus 29 +11.7 d for unmated females, and unmated females lived significantly longer than mated females. The angle and diameter of stems of V. trilobum, a very susceptible host, both greatly influenced oviposition; females laid most eggs on vertically oriented stems, and those of smallest diameter; when these factors were combined, stem diameter predominated. Females also had a very strong geotactic response, preferring to lay eggs on portions of stems toward gravity, even when stems were at fairly shallow angles. [ABSTRACT FROM AUTHOR]

Development times and survivorship of immature shore flies and longevity and reproduction of adult shore flies, Scatella tenuicosta Collin, reared on algae-infested filter paper, were studied at three temperatures (constant 20, 26, and 28.5°C) through life table analysis. The development time for each individual life stage and the total time from egg to adult decreased with increasing temperature. Duration of the third (ultimate) larval instar ranged from 3.3 ± 0.09 d at 20°C to 1.4 ± 0.04 d at 28.5°C and was 1.7-1.9 times longer than the approximately equal first and second instars. Development of male and female shore flies from egg to adult needed an average of 14.5 ± 0.13, 8.2 ± 0.05, and 7.0 ± 0.04 d at 20, 26, and 28.5°C, respectively, and needed an estimated 154.4 ± 1.2 thermal units (degree days). At these respective temperatures, adult females lived 21.8 ± 2.2, 19.9 ± 2.4, and 15.0 ± 1.4 d and produced 379 ± 62, 710 ± 119, and 477 ± 83 eggs during oviposition periods of 14.3 ± 2.1, 15.0 ± 2.2, and 10.8 ± 1.4 d; daily lifetime egg production averaged 16.3 ± 2.3,33.5 ± 3.8, and 29.7 ± 3.5. Developmental stage-specific mortality was relatively low for all life stages at all temperatures, with maximum percent mortalities of 5.7% occurring in both the egg stage and in the third instar. The highest net reproductive rate (Ro) was obtained for insects reared at 26°C and was 329.6. The intrinsic rate of natural increase (rm) was highest at 28.5°C and was 0.430. Generation time and doubling time of the population were shortest at 28.5°C and were 12.4 and 1.6 d, respectively. Results suggested that 26°C was near optimum for reproduction. [ABSTRACT FROM AUTHOR]

Saissetia oleae (Olivier) (Hemiptera: Coccidae) populations were studied and compared in citrus (Citrus spp.) and olive (Olea europaea L.) groves to determine the number of generations, crawler emergence periods and changes in population density during the year. Ten citrus and four olive groves were sampled regularly between March 2003 and December 2005 in eastern Spain, covering an area of 10,000 km2. Each sample consisted of 16 branches and 64 leaves. Saissetia oleae populations presented a similar trend in both crops during the three years of study. Populations peaked in July, when crawlers emerged after the egg-laying period, and decreased during several months due to mortality of first instars in summer. A second crawler emergence period, with lower numbers and more variability from year to year, occurred between October and March. Populations did not increase during this period, probably because most eggs and crawlers perished during the winter and also because females that gave rise to this fall-winter generation were half as big and fecund as spring females. No differences were found between the size of mature females that had developed on citrus and on olives during the spring. Considering this population pattern, the best seasonal period to apply pesticides to control S. oleae would be at the end of July, when populations are synchronous, all crawlers have already emerged, and first instars predominate. [ABSTRACT FROM AUTHOR]