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Aim: The concept of "island disharmony" has been widely applied to describe the systematic over‐ and under‐representation of taxa on islands compared to mainland regions. Here, we explore an extension of that concept to biological invasions. We compare biogeographical patterns in native and non‐native beetle (Coleoptera) assemblages from around the world to test whether beetle invasions represent a random sample of species or whether some families are more prone to invade than others. Location: Global. Methods: Numbers of non‐native beetle species established in ten regions worldwide were compared with the land area of each region. The distribution of species among families was compared with the distribution among families for all species native to the same region and with the distribution among families for the global pool of all known beetle species. Ordination analysis was used to characterize differences among native and non‐native assemblages based upon the distribution of species among families. Results: We report a total of 1,967 non‐native beetle species across all ten regions, and a classic log–log relationship between numbers of species per region and land area though relationships are generally stronger for native assemblages. Some families (e.g., Dermestidae and Bostrichidae) are over‐represented and others (e.g., Carabidae, Scarabaeidae and Buprestidae) are under‐represented in non‐native assemblages. The distribution of species among families is generally similar among native assemblages with greatest similarities among nearby regions. In contrast, non‐native species assemblages are more similar to each other than to native species assemblages. Main conclusions: Certain families are over‐represented, and others are under‐represented in non‐native beetle assemblages compared to native assemblages, indicating "invasion disharmony" in the global representation of beetle families. Similarities in composition among non‐native assemblages may reflect unobserved associations with invasion pathways and life‐history traits that shape invasion success of different insect groups. [ABSTRACT FROM AUTHOR]

Gonipterus is a genus of defoliating weevils that causes significant impact in commercially grown eucalypts in their native range in southern Australia and as invasive pests in Western Australia and several countries overseas. The diversity of species in this genus is still in the process of discovery, and in subtropical Australia, its diversity and ecological parameters are largely unknown. We surveyed Gonipterus phenology, species composition and trophic associations in South East Queensland, where little has been recorded about this genus. Surveys were conducted once a month in a non‐commercial plantation of native eucalypts, where three species of trees were sampled regularly and others checked on an ad hoc basis. On each sampling occasion, adult weevils, larvae and egg capsules were collected, adults identified, larvae reared and egg capsules individualized in small containers for emergence of larvae and parasitoids. Two peaks of egg‐laying occurred, whereas numbers of adults and larvae had only one peak each. Six species of Gonipterus were collected: two described but in need of revision, two undescribed but previously recognized and two undescribed and hitherto unrecognized, each with a different pattern of host–tree association. Three egg‐parasitoid species, Anaphes nitens, Centrodora damoni and Euderus sp. were reared from egg capsules, varying in prevalence according to the tree species from which the eggs were collected. [ABSTRACT FROM AUTHOR]

The accidental introduction of the eucalypt‐feeding paropsine beetle Paropsisterna cloelia (Paropsisterna variicollis) into New Zealand (NZ) in 2016 prompted investigation of the species complex to which the invasive species belongs. Two mitochondrial gene regions, Cytochrome c oxidase subunit 1 and Cytochrome b, were sequenced from field‐collected specimens superficially resembling P. cloelia collected in Queensland, the Australian Capital Territory, New South Wales, Victoria, South Australia, Tasmania, Western Australia (WA) and NZ. Four distinct Paropsisterna species groups were found, and representatives from each clade were identified with named species using morphology. P. cloelia was confirmed via sequencing and morphology to occur in all sampled geographic regions. The WA and NZ populations showed no diversity at the gene regions studied and hence represent invasive populations. The invasive WA haplotype was shared with both Tasmania and Victoria, whereas the NZ haplotype was unique, but most similar to one shared between WA, Tasmania and Victoria. The melanistic colour variant of P. cloelia was only found in eastern mainland Australian populations and was absent from Tasmania and invasive populations. Implications for pest management, including biological control, are discussed. [ABSTRACT FROM AUTHOR]

Phoracantha longicorn beetles are endemic to Australia, and some species have become significant pests of eucalypts worldwide, yet little is known about their host plant interactions and factors influencing tree susceptibility in Australia. Here, we investigate the host relationships of Phoracantha solida (Blackburn, 1894) on four eucalypt taxa (one pure species and three hybrid families), examining feeding site physical characteristics including phloem thickness, density, and moisture content, and host tree factors such as diameter, height, growth, taper, and survival. We also determine the cardinal and vertical (within-tree) and horizontal (between-tree) spatial distribution of borers. Fewer than 10% of P. solida attacks were recorded from the pure species (Corymbia citriodora subsp. variegate (Hook)), and this taxon also showed the highest survival, phloem thickness, relative growth rate, and bark:wood area. For the two most susceptible taxa, borer severity was negatively correlated with moisture content, and positively related to phloem density. Borers were nonrandomly and nonuniformly distributed within trees, and were statistically aggregated in 32% of plots. More attacks were situated on the northern side of the tree than the other aspects, and most larvae fed within the lower 50 cm of the bole, with attack height positively correlated with severity. Trees with borers had more dead neighbors, and more bored neighbors, than trees without borers, while within plots, borer incidence and severity were positively correlated. Because the more susceptible taxa overlapped with less susceptible taxa for several physical tree factors, the role of primary and secondary chemistries in determining host suitability needs to be investigated. Nevertheless, taxon, moisture content, phloem density, tree size, and mortality of neighboring trees appeared the most important physical characteristics influencing host suitability for P. solida at this site. [ABSTRACT FROM AUTHOR]

The ecology of sexually-transmitted diseases (STDs) is topical in scientific research, and their demography and epidemiology differ from those of classical pathogens and parasites. Transmission of STDs is generally density-independent, occurs via the ‘fittest’ individuals in a population (or, at least, those that achieve the most matings), and reflects differential mating success. STDs can therefore have a major influence on the evolution of host mating systems. We studied the epidemiology of a recently described STD of a chrysomelid beetle in applied and theoretical contexts, exploring the virulence, intensity and prevalence of infection, and using our results to test ecological predictions. Chrysophtharta cloelia is infected with a sexually-transmitted mite (the STD), Parobia captivus. Infection rate over three beetle generations (7 months) was determined and the STD's effects on fertility, fecundity, longevity, mating success and overwintering survival was measured. Throughout the season around 40% of beetles were infected, with approximately one quarter of such hosts carrying infective life stages of the STD at any one time. Infection by P. captivus significantly decreased overwintering survival, but did not impact on other fitness parameters measured, including mate acceptance. However, more female beetles were infected than male beetles, while within both sexes larger beetles were more likely to be infected. Our results concur with theoretical predictions that STDs may be selected for low virulence and low detectability, while the observation of female bias in infection supports hypotheses regarding variable mating success and mating skews, which we discuss. [ABSTRACT FROM AUTHOR]

Intra-specific colour differences in insects may occur as a result of environmental factors such as food type, temperature and humidity, or may be under genetic control. These colour polymorphisms may result in fitness differences through several mechanisms, including mate selection, camouflage from or warning to natural enemies, and heat absorption. Two colour morphs of adult Chrysophtharta agricola (Chapuis) (Coleoptera: Chrysomelidae: Paropsini) are present in the field in mainland Australia and Tasmania: a common green-brown form, and a rare black form. Tasmanian populations were sampled to assess the frequency of each morph at eight localities. The black form represented less than 3% of beetles ( N =1724), with the proportion not significantly different between localities. Crossing tests using the two colour morphs of C. agricola showed that the black form was genetically dominant over the common form. To assess whether colour morphs had any fitness differences, we measured pre-oviposition period, fecundity, longevity, adult size and egg hatch rate, which each showed no significant difference between colour morphs. Field sampling of mating pairs and rearing the offspring of field-collected females showed no evidence of non-random mating. Modelling the population over 100 generations confirmed that for this species, melanism is controlled by a dominant but neutral allele, and, thus, is maintained at a constant low level in the population. [ABSTRACT FROM AUTHOR]

Day-degree developmental requirements and lower temperature thresholds were determined in the laboratory for the immature lifestages and preoviposition periods of Chrysophtharta agricola, a pest of eucalypt plantations in Tasmania and Victoria. These data were used to provide a predictive model for C. agricola's spring-summer phenology under field conditions. The model was validated using field data from two Tasmanian field sites over three seasons. Lower temperature thresholds for immature development ranged from 2.8°C (Liv) to 10.3°C (Li), while the lower temperature threshold for oviposition was 7.4°C for teneral and overwintered adults. Total immature development time (egg-adult) was approximately 400 ± 16 DD above 8 ± 0.41°C. Development time did not differ between males and females, or between offspring of different females. Beetles reared at 25°C were significantly larger than those reared at low temperatures. Day-degree models were usually a good predictor of the appearance of developmental stages in the field. [ABSTRACT FROM AUTHOR]

Parobia husbandi gen. n., sp. n. is described from material collected from the subelytra of the southern eucalyptus leaf beetle, Chrysophtharta agricola (Chapuis), in Tasmania, Australia. Parobia gen. n. is distinguished from other podapolipid genera adult males and females with four pairs of legs and no setae on genua I−IV and femora III−IV, adult females with setae v1 and sc2 < 20 µm, and at least two pairs of coxal setae peg-like, adult males with dorso-terminal genitalia, dorsal shields C-D-E fused, and physogastric larval females with plates C and D entire. A series of morphological plesiomorphies and biological apomorphies link Parobia gen. n. with Chrysomelobia Regenfuss, the most basal genus of Podapolipidae. [ABSTRACT FROM AUTHOR]

Aim Location Method Results Conclusions The Hemiptera is the fifth‐largest insect order but among non‐native insect species is approximately tied with the Coleoptera as the most species‐rich insect order (Hemiptera comprise 20% more species than in world fauna). This over‐representation may result from high propagule pressure or from high species invasiveness. Here, we assess the reasons for over‐representation in this group by analysing geographical, temporal and taxonomic variation in numbers of historical invasions.Global.We assembled lists of historical Hemiptera invasions in 12 world regions, countries or islands (Australia, Chile, Europe, New Zealand, North America, South Africa, South Korea, Japan and the Galapagos, Hawaiian, Okinawa and Ogasawara Islands) and border interception data from nine countries (Australia, Canada, European Union, United Kingdom, Hawaii, Japan, New Zealand, South Korea, USA mainland and South Africa). Using these data, we identified hemipteran superfamilies that are historically over‐represented among established non‐native species, and superfamilies that are over‐represented among arrivals (proxied by interceptions). We also compared temporal patterns of establishments among hemipteran suborders and among regions.Across all regions, patterns of over‐ and under‐representation were similar. The Aphidoidea, Coccoidea, Aleyrodoidea, Cimicoidea and Phylloxeroida were over‐represented among non‐native species. These same superfamilies were not consistently over‐represented among intercepted species indicating that propagule pressure does not completely explain the tendency of some Hemiptera to be over‐represented among invasions. Asexual reproduction is common in most over‐represented superfamilies and this trait may be key to explaining high invasion success in these superfamilies.We conclude that both propagule pressure and species invasiveness are drivers of high invasion success in the Sternorrhyncha suborder (aphids, scales, whiteflies) and this group plays a major role in the exceptional invasion success of Hemiptera in general. The high historical rates of invasion by Sternorrhyncha species provide justification for biosecurity measure focusing on exclusion of this group. [ABSTRACT FROM AUTHOR]