The subfamily Scarabaeinae has been traditionally divided into tribes on the basis of morphological similarity between groups of genera or, even, dissimilarity shown by a single genus. Although various tribal units have been described over the past 220 years, they had been recently reduced to a maximum of only 12 through synonymies within some tribes. However, following the advent of morphological and molecular cladistic systematics, it is clear that there are many discrepancies between phylogeny and phenetic tribal classification. As a result the number of tribes has now been expanded to 20 by revalidating some tribes or describing new groupings although this revision is incomplete. Thus, this study provides a comprehensive review of the current status of dung beetle tribal classification with regards to validity in terms of monophyly versus polyphyly or paraphyly. We discuss the systematic position of tribes among Scarabaeinae and provide a summary of the generic and species structure for each tribe. Given the enduring polyphyly or paraphyly in several tribes, it is clear that further tribal units will need to be described or revalidated to resolve the discrepancies. Therefore, we discuss how to use multiple lines of evidence (molecular, morphological, biogeographical, and paleontological) to build the tree of life for dung beetles and consequently provide stability in the tribal classification of the lineage.

Climate change has facilitated the introduction, establishment, and movement of invasive species in northern regions, enabling the colonization of previously unsuitable areas. While the responses of insects to these changes have been increasingly studied, our understanding of how such alterations impact trophic interactions still requires further research to make reliable predictions about the spread of diseases in a warming world. Phytoplasmas, a group of obligate parasitic unculturable Mollicutes, primarily rely on leafhoppers (Hemiptera: Cicadellidae) for transmission, spread, and survival. Phytoplasmas are associated with over 600 diseases affecting more than 1,000 plant species, including berries, grapevines, and other small fruits. In North America, diseases such as grapevine yellows, blueberry stunt, and strawberry green petal diseases have been linked to phytoplasma strains transmitted by known leafhopper species. However, the number of phytoplasma diseases has significantly increased in North America over the past decade, suggesting the presence of unidentified vectors or an abundance of leafhopper vectors. This short review provides an overview of the current knowledge on leafhoppers as vectors of phytoplasmas to berries, focusing on the last decade's research in Canada. This paper also explores the potential implications of climate change on this pathosystem, including the anticipated range expansion of leafhopper species, changes in phytoplasma acquisition and transmission, and the risk of new leafhopper-transmitted plant-pathogen introductions through the arrival of new leafhopper species.

Little is known about the ecology of early instars of most aquatic insects, particularly their associations with microhabitat (<1 m²) features, such as sediment size distributions, other abiotic parameters, and the overall invertebrate community. This study sought to explore correlations between various biotic and abiotic parameters of a southern Colorado stream and the presence of early instars of Epeorus longimanus (Eaton) (Ephemeroptera: Heptageniidae). A total of 18 samples collected in 2007 and 2013 using a Hess sampler in riffle habitats were used to correlate the size of individuals with biological and abiotic characteristics of the stream, including sediment size, periphyton biomass, entrained organic matter, and the remainder of the benthic invertebrate community, all of which were measured using material from within the sampler. Results from both years showed that early instars of E. longimanus were more likely to be found in areas with smaller sediment sizes, higher live periphyton biomass (but lower overall organic matter), and lower densities of invertebrate predators.

The water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae), shows a clinal variation for 3 Robertsonian translocation (centric fusion) polymorphisms in the southern extreme of its wide geographical distribution. It is a Neotropical semiaquatic grasshopper that lives, feeds, and lays eggs exclusively on floating plants of the family Pontederiaceae, or water-hyacinths, between 23° N (Southern Mexico) and 35° S (Central Argentina and Uruguay). Given the invasive-species status of Pontederia (formerly Eichhornia) crassipes and the voraciousness of these grasshoppers, they were considered as a potential biological control agent in addition to other natural enemies. We already described the association of the rearrangements with geographical and climatic variables, phenotypic variation, trivalent orientation, effects on recombination, and relationship with microsatellite variability. Here we analyze the distribution of constitutive heterochromatin in 2 populations of C. aquaticum in order to (i) provide consistent markers for a better distinction between all chromosomes, those which are involved in the centric fusions, and those which are not, and (ii) describe possible polymorphisms for C-positive supernumerary segments, given that, on conventional staining analysis, it was frequent to find heteromorphic autosomal bivalents. The cytogenetic analysis allowed us to get a detailed characterization of the constitutive heterochromatin distribution, providing unmistakable chromosome markers of the large, fusion-bearing chromosomes as well as the C-positive, polymorphic supernumerary segments.

The Northern Barrens tiger beetle (Cicindela patruela patruela, Dejean 1825) (Coleoptera: Carabidae) is globally rare and endangered in Canada. We know very little about this species' behavioral ecology and despite there being only 2 remaining populations in Canada, we know very little about either's demography. Here, we use capture–mark–recapture methods to estimate population size and movement of individuals on Île-aux-Allumettes (Quebec, Canada). We found that the population on Île-aux-Allumettes is small—approximately 102 individuals—but this appears to be typical for this species and tiger beetles in general. Beetles on Île-aux-Allumettes traveled approximately 33 m per day with no observed difference between the sexes in mobility. We did not find any morphological correlates of mobility, but we did find that females are significantly wider, but not longer, than males. Because the number of C. p. patruela on Île-aux-Allumettes is small and the population is isolated, we recommend that managers continue to monitor the population and consider translocations to augment population numbers and to reduce the negative consequences of demographic and genetic stochasticity, such as inbreeding.

The tobacco budworm, Chloridea virescens (F.), and corn earworm, Helicoverpa zea (Boddie) (heliothines), have had a long-intertwined relationship with respect to their importance as pests in agricultural production systems. Previous studies have examined the impacts of early-season wild host plants on local population density and distribution of these 2 insects on cultivated crops such as cotton, Gossypium hirsutum L., and soybean, Glycine max L. Additional studies have examined the importance of wild host plants, which act as a refuge of nonexposed populations of C. virescens and H. zea to insecticidal toxins from the soil bacterium, Bacillus thuringiensis (Bt) Berliner. The current study examined hophornbeam copperleaf, Acalypha ostryifolia Riddell, as a host plant for mid-late season populations of C. virescens and H. zea. Patches of A. ostryifolia were sampled along roadsides and the edges of fields from 2014 to 2020 in Mississippi, USA, to examine larval density, species composition, and parasitism of heliothines on this wild host plant. Insects were collected from the end of June through October. The largest densities (based on the number of caterpillars per sweep) of heliothines were over one larva per sweep. Overall, 49.5% of the collected caterpillars were determined to be tobacco budworms, while 50.5% were corn earworms. Parasitism rates ranged from approximately 1–30%, increasing throughout the season. In general, densities of heliothines encountered on A. ostryifolia were greater than densities reported for other wild host plants. Hophornbeam copperleaf is an important natural refuge for both heliothines from Bt toxins and synthetic insecticide applications.

Ants (Hymenoptera: Formicidae) have great potential to exert influence over the morphological evolution of their obligate mutualist partners. Obligately myrmecophilic mealybugs are noted for their unusual morphology, and while this is often attributed to their relationship with ants, a quantitative assessment of this link is lacking. We address this need by evaluating morphological change among mealybugs as a function of ant association. This study considers the associates of 2 independent ant clades—Acropyga Roger, 1862 ants associated with root mealybugs from the families Xenococcidae and Rhizoecidae and herdsmen ants from the Dolichoderus cuspidatus (Smith, F., 1857) species-group associated with mealybugs from the tribe Allomyrmococcini (Pseudococcidae)—and compares them to free-living or potentially myrmecophilic species sampled from among the mealybugs and root mealybugs. We use a combination of geometric morphometric and linear datasets to evaluate characteristics of body shape, body size, leg metrics, and ostiole development. Obligate myrmecophily significantly influences both body shape and size. Myrmecophilous mealybugs are smaller than their free-living counterparts and are either pyriform or rotund in shape rather than oval. Ant-associates from Rhizoecidae also have significantly reduced anterior pairs of ostioles compared to free-living species. Ostioles are involved in defense against natural enemies and mutualist ants typically protect their partners, presumably supplanting the need for structures like ostioles among myrmecophilous species. We discuss the influence ants have on the evolution of their associates in the context of domestication and offer avenues for future exploration.

Philornis downsi (Dodge & Aitken), the avian vampire fly, is the main threat to land bird conservation in the Galapagos Islands. However, very little is known about the reproductive morphology, physiology, and behavior of P. downsi adults impeding progress on developing effective methods for its control. Here, we provide the first preliminary description of the female and male reproductive systems of a Philornis species and compare the activity of lab-reared and wild flies. In mature females, the accessory glands are connected from the common oviduct toward the ovaries, and there are 3 spermathecae (1 double and 1 singlet). For males, we found 2 peanut-shaped testes, one possible accessory gland, an apodeme, and an aedeagus. Both wild and lab-reared individuals had similar patterns of movement, although lab-reared adults were more mobile at dusk. We observed higher locomotion in the morning and dusk with a lull at midday, and increased activity as flies aged from 1 to 10 days. Females became more active during the morning at 10 days of age compared to males. Knowledge on the morphology of P. downsi's reproductive system will give us a better understanding of its reproductive physiology and will aid in efforts at establishing a self-reproducing colony. Mobility trials can be used as an easy and practical quality control method, as well as providing essential information on peak activity times, which may be related to foraging in the morning for females and sexual activity and host searching at dusk.

Graphical abstract