Austral Entomology最新文献

Developing mass rearing systems for the drone fly, Eristalis tenax, is a crucial step toward its use as a complementary commercial pollinator. To meet the timing of commercial needs for E. tenax, there is significant value to both predicting and managing reproductive output and development within the rearing protocol. To help achieve this, our study focuses on the laboratory manipulation of adult mating and the timing of the development of eggs in E. tenax. To stagger colony cohorts, egg rearing temperatures ranging from 12 to 30°C were found to be suitable for both successful egg development and hatching viability (97 to 28.3 h to first hatch, respectively). The mating window for E. tenax females was established to commence from 2 weeks post eclosion and reached 75 ± 11% mated at 7 weeks. Reproductive output over 12 weeks was assessed in separate cage manipulation trials: (1) varying the sex ratio with 20:40, 30:30 and 40:20 female and male flies respectively per cage and (2) varying the adult density per cage with 15:15, 30:30, 60:60 and 120:120 female and male flies per cage. Female percentage mated and egg cluster size, which averaged 200.6 ± 4.3 eggs per cluster, did not change between treatments in the sex ratio and density trials. Egg cluster output per female was significantly reduced for treatments across both trials, which had more than 30 females in a cage. A stocking rate of 15:15 produced 86% more eggs per female than expected, a percentage well above that of all other treatments. However, the highest stocking density produced the most eggs when assessed at a per cage level. Fly survival was significantly different between the sexes across both trials with males dying earlier in cages stocked with more females than males. Although the fly colonies were held at constant temperatures and light conditions for 6 months, we found evidence of endogenous overwintering behaviours among flies resulting in lower mating rates, egg hatching success and greater longevity among flies studied over winter.

Because of their frequency, abundance, and unique morphological and biological traits, the Dryinidae (pincer wasps) are among the most important parasitoids of nymphs and adults of Hemiptera: Auchenorrhyncha. This contribution offers a summary of the knowledge about the main biological characteristics of the Dryinidae gained over more than 130 years. Among other topics, the information provided covers the interactions with their hosts and other organisms, as well as their development, behaviour, natural enemies and economic importance.

The velvetbean caterpillar Anticarsia gemmatalis (VBC) is widely distributed in the Americas and causes severe damage to soybean foliage. This insect presents high ecological plasticity, a feature that is of great importance to understand its genetic diversity and potential gene flow to assist in resistance management strategies. With this objective, we developed microsatellite markers for VBC and applied them to five populations from Brazil. Nine primers were polymorphic, with high values of polymorphic information content (PIC > 0.5), and 134 alleles were identified in 155 individuals. These primers indicated deviation from the Hardy–Weinberg equilibrium for all populations (observed heterozygosity, Ho = 0.48, expected heterozygosity, He = 0.76), with moderate to high levels of genetic diversity and a moderate fixation index (F_ST = 0.14) among the populations. Analysis of population structure indicated the formation of two principal clusters. The northern one can be divided into the two populations that formed the cluster, with high genetic differentiation between them. The other cluster is formed by three populations, and we found evidence of low gene flow between them in the south–north direction, indicating that these populations may be migratory in certain conditions. These findings indicate that the designed primers were effective in describing the genetic diversity of VBC, with major implications for integrated pest management. Given the little gene flow and the high genetic diversity of populations, they present great potential to become resistant to control practices, which can lead to increased management costs.

Australia is inhabited by a very rich and mostly endemic fauna of ladybird beetles (Coccinellidae), with a relatively high proportion of taxa belonging to the tribe Coccidulini. Australian Coccidulini are grouped in 15 genera, of which 11 are endemic. Here, a new distinctive Australian Coccidulini genus and species is described—Euchre australis gen. et sp. nov., which is characterised by compact antennal club, long ventral antennal grooves on head capsule extending to anterior margin of prosternum, and presence of chin piece partially covering mouthparts in repose. Its relationship with other Australian Coccidulini genera is discussed.

Taxonomic investigations of the Eirmocides helenita (Semper, 1879) complex from north-eastern Australia and mainland New Guinea based on adult morphology (male genitalia and wing colour pattern elements), together with a phylogenetic hypothesis of the genus (18 or 69% of the recognised species) based on molecular data (1 mitochondrial and 12 nuclear genes), and examination of type material, indicate that there are five species within this monophyletic lineage, here referred to as the E. helenita species-group. Four of the species, previously classified under the name Eirmocides helenita (Semper, 1879) sensu lato and characterised by iridescent turquoise dorsal colouration in the male, are predominantly allopatric, as follows: Eirmocides callainus Braby & Müller, sp. nov., is endemic to the Wet Tropics biome of north-eastern Queensland; Eirmocides helenita (Semper, 1879) sensu stricto is restricted to Cape York Peninsula of northern Queensland; Eirmocides rouku Braby & Müller, sp. nov., is endemic to the Western Province of southern Papua New Guinea; and Eirmocides dimorphus (Röber, 1886), stat. rev., occurs more widely throughout mainland New Guinea and its adjacent islands. The fifth member of the group, Eirmocides cupreus (Röber, 1886), is sympatric with E. dimorphus on mainland New Guinea. The taxonomic revision brings to 26 the total number of species recognised in Eirmocides and within the tribe Candalidini to 40 species. Lectotypes are designated for Plebeius dimorphus Röber, 1886, Plebeius dimorphus var. cupreus Röber, 1886, and Holochila subargentea Grose-Smith & Kirby, 1896.

The Gondwanan genus Chilepyris Evans, 1964 (Scleroderminae) is studied and revised. A new species from Oceanian region (New Caledonia) is described and illustrated, Chilepyris kanak sp. nov., and compared with the other two species of this genus, C. herbsti Evans, 1964 from Chile and C. platythelys Sorg & Walker, 1989 from New Zealand, based on an integrative taxonomic approach, combining morphological characters and molecular analyses. An emended diagnosis and a deep discussion about the morphological diagnostic characters of this genus and comments about the Gondwana distribution of Chilepyris are also presented. Additionally, a taxonomic key to the three species is provided.

No abstract is available for this article.

Since its accidental introduction into New Zealand in 1916, the invasive eucalypt leaf beetle Paropsis charybdis remains a pest of economic significance to Eucalyptus forestry. For this reason, the braconid parasitoid Eadya daenerys has been approved for release as a classical biological control agent. To aid in field monitoring using hand netting of biocontrol releases and laboratory rearing protocols, the flight activity over 6 a year field research program of E. daenerys and the relationships between the parasitoid and the size of its beetle hosts were evaluated in the country of origin. Wasps were observed flying over 32 days from mid-November to mid-December in Tasmania. E. daenerys was found to exhibit a morning-based scramble competition mating system. Females flying in the early morning had lower mature egg loads (134.2 ± 27.6) than at other times of the day. In the first half of the season, male flight was most often seen in the early morning, whereas in the second half of the season, there was a 4.5-fold decrease in any wasps flying. Female flight activity significantly increased to 70% female in the evening hours from 5:00 pm to 8:00 pm, which by the second half of the season was almost exclusively female. Wasps were caught flying across a wide range of air temperatures (10.7–23.8°C), humidity and light levels, but even light winds reduced flight when average wind speed exceeded 0.27 m/s for males and 0.73 m/s for females. Beetle prepupal weight was a predictor of E. daenerys parasitism success with mean beetle prepupal weights significantly higher for stung but unsuccessfully parasitised larva (62.09 mg) than those successfully parasitised (52.94 mg). The chance of an emerged wasp larva spinning a pupal cocoon was found to increase by 5% with every 1-mg increase in its beetle prepupal weight. Heavier beetle prepupae produced bigger parasitoids. Field-collected adult E. daenerys had larger (12%) head capsule widths (mean of 1.42 mm) than those reared in the laboratory (mean of 1.27 mm), suggesting that improving host nutrition and laboratory rearing conditions for increasing host size may help optimise E. daenerys rearing success.

Sonchus oleraceus is an annual species native to Eurasia and Northern Africa that has become a major weed of cultivated fields and ruderal areas in Australia. Populations are difficult to manage in cropping systems because of the development of resistance to common herbicides. Biological control is being investigated as an additional tactic for managing the weed. A literature review was conducted to identify the phytophagous arthropod species already associated with the species in Australia to guide such a biological control programme. To identify opportunities for biological control agents to aid in management, we undertook field surveys across Queensland and South Australia in different environments. We also investigated factors that may influence their performance in Australia. Both the literature review and field surveys identified 21 arthropod species associated with S. oleraceus in Australia, most of them being generalist species and pests of exotic origin. Capitula were the most damaged plant part while stems were relatively free from insects, except aphids. The field surveys recorded an unexpected new interaction between S. oleraceus and the gall midge, Contarinia jongi (Diptera: Cecidomyiidae). This association was surprising as the midge, only known to develop on Alstroemeria (Liliales: Alstroemeriaceae), a very distant relative to S. oleraceus (Asterales: Asteraceae), was reported in Australia only a few years ago under greenhouse conditions. The midge and the moth Eublemma cochylioides (Lepidoptera: Erebidae) were the two species that occurred most frequently in developing flower head samples. We considered their infestation rate as a proxy of herbivory and tested whether the environment surrounding the plant may influence herbivory. Both E. cochylioides and C. jongi showed the highest infestations in ruderal sites compared with the sites located in conventional farming areas. We discuss the implications of our results in the context of selecting and releasing candidates for the biological control of the weed, especially in agricultural landscapes.