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A new species of the genus Leptus, L. (L.) brevitarsus sp. n., is described and illustrated from ectoparasitic larvae collected from grasshoppers (Orthoptera: Acrididae) in Australia. The new species belongs to the phalangii species group and torresianus species subgroup. An updated key to species of torresianus species subgroup is presented. [ABSTRACT FROM AUTHOR]

Animal populations must be able to acquire an adequate amount of nutrients to persist regardless of what environment they are in. In highly variable environments, such as drylands where food sources are limited, this potential mismatch between physiological demands and what is available in the environment is accentuated. For herbivores, the balance of macronutrients (protein and carbohydrate) is particularly important and both nutrients are highly variable in plants both spatially and temporally. Whereas it is known that many herbivores will forage multiple plants to achieve an optimal nutritional ratio (termed the intake target), it is less known how herbivores with different life history strategies address this in variable environments. In this study, we measured the intake targets of three grasshopper species with differing life history strategies, two migratory and one non‐migratory, at three locations in New South Wales, Australia. We measured nutrient variation in plants spatially and temporally by sampling three different locations and repeated the measurement twice for one of these locations. At all three locations and both times, host plant protein differed substantially but carbohydrate content remained constant. The non‐migratory grasshopper species shifted their intake target, presumably to redress nutrient imbalances. On the other hand, the two migratory grasshopper species largely maintained the same intake target, even when in a nutritionally suboptimal environment. These results suggest that non‐migratory species are likely more limited in their capacity to forage for optimal diets and may rely more on digestion to survive in nutritionally suboptimal locations. In contrast, migratory grasshoppers may migrate to obtain the nutrients they need instead of redressing imbalances locally. Therefore, a strong metapopulation structure may aid in the persistence of migratory species at larger spatial scales. Since herbivores, especially insects, are important from nutrient cycling to food chains, understanding how populations persist in nutritionally variable environments is important to the overall ecosystem functioning. Further research should consider how nutritional demands drive population dynamics and how it changes with life history strategies. [ABSTRACT FROM AUTHOR]

Changes in the physical environment with elevation can influence species distributions and their morphological traits. In mountainous regions, steep temperature gradients can result in patterns of ecological partitioning among species that potentially increases their vulnerability to climate change. We collected data on species distributions, relative abundance and body size for three grasshopper species of the genus Kosciuscola (K. usitatus, K. tristis and K. cognatus) at three locations within the mountainous Kosciuszko National Park in Australia (Thredbo, Guthega and Jagungal). All three species showed differences in their distributions according to elevation, with K. usitatus ranging from 1400 to 2000 m asl, K. tristis from 1600 to 2000 m asl and K. cognatus from 1550 to 1900 m asl. Decreasing relative abundance with increasing elevation was found for K. usitatus, but the opposite pattern was found for K. tristis. The relative abundance of K. cognatus did not change with elevation but was negatively correlated with foliage cover. Body size decreased with elevation in both male and female K. usitatus, which was similarly observed in female K. tristis and male K. cognatus. Our results demonstrate spatial partitioning of species distributions and clines in body size in relation to elevational gradients. Species‐specific sensitivities to climatic gradients may help to predict the persistence of this grasshopper assemblage under climate change. [ABSTRACT FROM AUTHOR]

Swarming locusts present a quintessential example of animal collective motion. Juvenile locusts march and hop across the ground in coordinated groups called hopper bands. Composed of up to millions of insects, hopper bands exhibit aligned motion and various collective structures. These groups are well-documented in the field, but the individual insects themselves are typically studied in much smaller groups in laboratory experiments. We present, to our knowledge, the first trajectory data that detail the movement of individual locusts within a hopper band in a natural setting. Using automated video tracking, we derive our data from footage of four distinct hopper bands of the Australian plague locust, Chortoicetes terminifera . We reconstruct nearly 200 000 individual trajectories composed of over 3.3 million locust positions. We classify these data into three motion states: stationary, walking and hopping. Distributions of relative neighbour positions reveal anisotropies that depend on motion state. Stationary locusts have high-density areas distributed around them apparently at random. Walking locusts have a low-density area in front of them. Hopping locusts have low-density areas in front and behind them. Our results suggest novel insect interactions, namely that locusts change their motion to avoid colliding with neighbours in front of them.

Widespread species that exhibit both high gene flow and the capacity to occupy heterogeneous environments make excellent models for examining local selection processes along environmental gradients. Here we evaluate the influence of temperature and landscape variables on genetic connectivity and signatures of local adaptation in Phaulacridium vittatum, a widespread agricultural pest grasshopper, endemic to Australia. With sampling across a 900‐km latitudinal gradient, we genotyped 185 P. vittatum from 19 sites at 11,408 single nucleotide polymorphisms (SNPs) using ddRAD sequencing. Despite high gene flow across sites (pairwise FST = 0.0003–0.08), landscape genetic resistance modelling identified a positive nonlinear effect of mean annual temperature on genetic connectivity. Urban areas and water bodies had a greater influence on genetic distance among sites than pasture, agricultural areas and forest. Together, FST outlier tests and environmental association analysis (EAA) detected 242 unique SNPs under putative selection, with the highest numbers associated with latitude, mean annual temperature and body size. A combination of landscape genetic connectivity analysis together with EAA identified mean annual temperature as a key driver of both neutral gene flow and environmental selection processes. Gene annotation of putatively adaptive SNPs matched with gene functions for olfaction, metabolic detoxification and ultraviolet light shielding. Our results imply that this widespread agricultural pest has the potential to spread and adapt under shifting temperature regimes and land cover change. [ABSTRACT FROM AUTHOR]

Background Mountain landscapes are topographically complex, creating discontinuous 'islands' of alpine and sub-alpine habitat with a dynamic history. Changing climatic conditions drive their expansion and contraction, leaving signatures on the genetic structure of their flora and fauna. Australia's high country covers a small, highly fragmented area. Although the area is thought to have experienced periods of relative continuity during Pleistocene glacial periods, smallscale studies suggest deep lineage divergence across low-elevation gaps. Using both DNA sequence data and microsatellite markers, we tested the hypothesis that genetic partitioning reflects observable geographic structuring across Australia's mainland high country, in the widespread alpine grasshopper Kosciuscola tristis (Sjösted). Results We found broadly congruent patterns of regional structure between the DNA sequence and microsatellite datasets, corresponding to strong divergence among isolated mountain regions. Small and isolated mountains in the south of the range were particularly distinct, with wellsupported divergence corresponding to climate cycles during the late Pliocene and Pleistocene. We found mixed support, however, for divergence among other mountain regions. Interestingly, within areas of largely contiguous alpine and sub-alpine habitat around Mt Kosciuszko, microsatellite data suggested significant population structure, accompanied by a strong signature of isolation-by-distance. Conclusions Consistent patterns of strong lineage divergence among different molecular datasets indicate genetic breaks between populations inhabiting geographically distinct mountain regions. Three primary phylogeographic groups were evident in the highly fragmented Victorian high country, while within-region structure detected with microsatellites may reflect more recent population isolation. Despite the small area of Australia's alpine and sub-alpine habitats, their low topographic relief and lack of extensive glaciation, divergence among populations was on the same scale as that detected in much more extensive Northern hemisphere mountain systems. The processes driving divergence in the Australian mountains might therefore differ from their Northern hemisphere counterparts. [ABSTRACT FROM AUTHOR]

A set of polymorphic loci was characterised using an enrichment library for the Australian alpine specialist, the chameleon grasshopper (Kosciuscola tristis), an atypical grasshopper known for its remarkable temperature-controlled colour change. The number of alleles per locus ranged from three to 20 and observed heterozygosity from 0.16 to 0.76. These are the first microsatellite markers for a non-endangered Australian alpine animal and will inform questions of gene flow across the sky islands of this unique and threatened region. [ABSTRACT FROM AUTHOR]

Aim We explore geographic variation in body size within the wingless grasshopper, Phaulacridium vittatum, along a latitudinal gradient, and ask whether melanism can help explain the existence of clinal variation. We test the hypotheses that both male and female grasshoppers will be larger and lighter in colour at lower latitudes, and that reflectance and size will be positively correlated, as predicted by biophysical theory. We then test the hypothesis that variability in size and reflectance is thermally driven, by assessing correlations with temperature and other climatic variables. Location Sixty-one populations were sampled along the east coast of Australia between latitudes 27.63° S and 43.10° S, at elevations ranging from 10 to 2000 m a.s.l. Methods Average reflectance was used as a measure of melanism and femur length as an index of body size for 198 adult grasshoppers. Climate variables were generated by BIOCLIM for each collection locality. Hierarchical partitioning was used to identify those variables with the most independent influence on grasshopper size and reflectance. Results Overall, there was no simple relationship between size and latitude in P. vittatum. Female body size decreased significantly with latitude, while male body size was largest at intermediate latitudes. Rainfall was the most important climatic variable associated with body size of both males and females. Female body size was also associated with radiation seasonality and male body size with reflectance. The reflectance of females was not correlated with latitude or body size, while male reflectance was significantly higher at intermediate latitudes and positively correlated with body size. Analyses of climate variables showed no significant association with male reflectance, while female reflectance was significantly related to the mean temperature of the driest quarter. Main conclusions Geographic variation in the body size of the wingless grasshopper is best explained in terms of rainfall and radiation seasonality, rather than temperature. However, melanism is also a significant influence on body size in male grasshoppers, suggesting that thermal fitness does play a role in determining adaptive responses to local conditions in this sex. [ABSTRACT FROM AUTHOR]

Abstract: Rapid, reversible colour change is unusual in animals, but is a feature of male chameleon grasshoppers (Kosciuscola tristis). Understanding what triggers this colour change is paramount to developing hypotheses explaining its evolutionary significance. In a series of manipulative experiments the author quantified the effects of temperature, and time of day, as well as internal body temperature, on the colour of male K. tristis. The results suggest that male chameleon grasshoppers change colour primarily in response to temperature and that the rate of colour change varies considerably, with the change from black to turquoise occurring up to 10 times faster than the reverse. Body temperature changed quickly (within 10min) in response to changes in ambient temperature, but colour change did not match this speed and thus colour is decoupled from internal temperature. This indicates that male colour change is driven primarily by ambient temperature but that their colour does not necessarily reflect current internal temperature. I propose several functional hypotheses for male colour change in K. tristis. [Copyright &y& Elsevier]

Recent theoretical developments have led to a renewed interest in the potential role of chromosomal rearrangements in speciation. Australian morabine grasshoppers (genus Vandiemenella, viatica species group) provide an excellent study system to test this potential role of chromosomal rearrangements because they show extensive chromosomal variation and formed the basis of a classic chromosomal speciation model. There are three chromosomal races, viatica19, viatica17, and P24(XY), on Kangaroo Island, South Australia, forming five parapatric populations with four putative contact zones among them. We investigate the extent to which chromosomal variation among these populations may be associated with barriers to gene flow. Population genetic and phylogeographical analyses using 15 variable allozyme loci and the elongation factor-1α ( EF-1α) gene indicate that the three races represent genetically distinct taxa. In contrast, analyses of the mitochondrial cytochrome c oxidase subunit I ( COI) gene show the presence of three distinctive and geographically localized groups that do not correspond with the distribution of the chromosomal races. These discordant population genetic patterns are likely to result from introgressive hybridization between the chromosomal races and range expansions/contractions. Overall, these results suggest that reduction of nuclear gene flow may be associated with chromosomal variation, or underlying genetic variation linked with chromosomal variation, whereas mitochondrial gene flow appears to be independent of this variation in these morabine grasshoppers. The identification of an intact contact zone between P24(XY) and viatica17 offers considerable potential for further investigation of molecular mechanisms that maintain distinct nuclear genomes among the chromosomal races. [ABSTRACT FROM AUTHOR]

The rarity of parthenogenesis, reproduction without sex, is a major evolutionary puzzle. To understand why sexual genetic systems are so successful in nature, we must understand why parthenogenesis sometimes evolves and persists. Here we use DNA sequence data to test for similarities in the tempo and mode of the evolution of parthenogenesis in a grasshopper and a lizard from the Australian desert. We find spectacular congruence between genetic and geographic patterns of parthenogenesis in these distantly related organisms. In each species, parthenogenesis evolved twice and appears to have expanded in parallel waves across the desert, suggesting a highly general selective force against sex. [ABSTRACT FROM AUTHOR]

Investigates the impact of insect grazing on the establishment of plant populations from seed after bushfires in coastal plain woodland near Perth, Western Australia. Measurement of seedling germination; Observation of individual seedlings to estimate survivorship and causes of mortality; Invasion rates of acridid grasshoppers into both small and large burnt areas; Results discussed in the light of current models of plant succession; Conclusion that fire is not a succession-initiating disturbance in this ecosystem because the long association with fire has allowed the evolution of specific survival and recruitment strategies.

Studies the effects of temperature and photoperiod on the morphology of the egg-pod of the Australian plague locust. Examination of the capability of Chortoicetes terminifera to detect absolute differences of both temperature and photoperiod; Indications showing the effects of photoperiod to override those of temperature when temperature and photoperiod change in opposite directions; Significance of the findings on the understanding of the factors that directly or indirectly affect egg development and survival.

Matchstick grasshoppers are a unique and diverse element of Australia's insect fauna with great potential as a model system for ecological, evolutionary and biogeographical studies. The genus Warramaba comprises four bisexual species. It is of special interest from an evolutionary point of view because two parthenogenetic lineages (the Standard and Boulder-Zanthus phylads of W. virgo) have evolved through hybridization events between two of the sexual species. Despite the extensive genetic and systematic work that has been done on this genus, three of the bisexual species are yet to be formally named (P196, P169 and P125) and no key exists for their identification. Here I formally describe these species, respectively, as W. whitei sp. nov., W. flavolineata sp. nov. and W. grandis sp. nov. and split the parthenogenetic species W. virgo into two distinct species (the addition of W. ngadju sp. nov.). I also provide a photographic guide and key to the identification of all species in the genus.

The Australian Plague Locust Commission (APLC) manages locust populations across 2 million square kilometers of eastern Australia using the aerial application of chemical and biological control agents to protect agricultural production. This occurs via a preventative control strategy involving ultralow-volume spray equipment to distribute small droplets of control agent over a target area. The economic costs of, and potential gains stemming from, locust control are well documented. The application of insecticides, however, to fragile arid and semiarid ecosystems is a task that brings with it both real and perceived environmental issues. The APLC is proactive in addressing these issues through a combination of targeted environmental operational research, an ISO-14001-aligned Environmental Management System (EMS), and links with environmental regulatory and research institutions. Increasing due diligence components within Australian environmental legislation dictate that mere legislative compliance is no longer sufficient for industries to ensure that they meet their environmental obligations. The development of external research links and the formulation of an EMS for locust control have enabled the APLC to identify environmental issues and trends, quantify objective environmental targets and strategies, and facilitate continuous improvement in its environmental performance, while maintaining stakeholder support. This article outlines the environmental issues faced by the APLC, the research programs in place to address these issues, and the procedures in place to incorporate research findings into the organization's operational structure.

Between October 1999 and April 2000, nearly 4000 ha of nymphal bands and adult swarms of Chortoicetes terminifera (Walker) were aerially treated using a ULV oil formulation of strain FI-985 of Metarhizium anisopliae var. acridum. During the mild weather (maxima 22-30 degrees C) of spring (October), there was little change in nymphal bands during the first week but at all doses between 25-100 g (1-4 x 10(12) conidia) ha(-1), the bands rapidly declined 9-12 days after treatment reaching > 90% mortality by 14 days. Metarhizium persisted for some time as there was 50% mortality of locusts fed vegetation collected from the treated blocks seven days after treatment. Persistence was confirmed by the high mortality of bands that invaded from untreated areas and of nymphs that hatched on the plot five to seven days after treatment, though mortality was then delayed until early in the third week. During summer (January), temperatures were high (maxima 36-42 degrees C), and at all doses between 25 and 125 g (1-5 x 10(12) conidia) ha(-1), there was a rapid decline seven to ten days after treatment. By 12-14 days, there was a > 90% decline in numbers in most blocks which was confirmed by helicopter surveys two weeks after treatment that found very few adults within or near treated areas. Mortality was delayed in the high dose where there were blockages of spray equipment during treatment. The clear demonstration that Metarhizium can suppress small local populations of C. terminifera led to the limited operational use of Metarhizium on an organic farm and in a National Park where nearly 2500 ha of bands and swarms were treated. Continued research is needed to develop a commercially viable product so that Metarhizium can form a significant part of a programme of integrated pest management of locusts in Australia.