The epidemiologic triad (epi-triad) classically consists of agent, host, and environment. However, with vector-borne diseases (arthropod-transmitted pathogens), the vector plays a vital role, and without the vector there is no sustained pathogen transmission. By not emphasizing the importance of the arthropod vector, the role of the vector is often neglected or underappreciated. The complexities of vector-borne diseases are reviewed by describing the ecology and transmission of the Japanese encephalitis virus (JEV), the causative agent of Japanese encephalitis (JE). JE is a mosquito-borne zoonosis that affects most countries in South and Southeast Asia, and the Western Pacific Rim. It is considered the main cause of viral encephalitis in that region, affecting mainly children up to 14 yr old. The virus is transmitted by mosquitoes, particularly of the Culex genus, and the transmission cycle is complex, involving pigs and ardeid birds as reservoir hosts. Environmental, ecological, and social determinants play a paramount role on the epidemiology of JE and JEV, as well as on its geographical expansion over new territories. JE has no cure; thus, efforts are put forth towards prevention and control by reducing exposure to potentially infected mosquitoes, or vaccination. The sections below cover the most important aspects of JE and JEV, providing a summary of the current body of knowledge and placing the complicated transmission cycle in context of a new epi-triad.

Fire is a major disturbance in ecosystems that generally promotes secondary succession in forests. This study was conducted to track changes in a moth assemblage at a high elevation site before and after fire. A fire destroyed about 2 ha of the conifer and mixed deciduous forest and grassland of Sasa quelpaertensis Nakai, 1933 (Poales: Poaceae) on Mt. Hallasan, Jejudo Island, South Korea. I monitored the moth assemblages of the burned site and three neighboring sites across 5 yr (2011, 2013–2016) using an ultraviolet light trap. There was a decline in species richness and abundance, and increased dissimilarity at the burned site relative to the neighboring sites. However, the moth assemblage at the burned site recovered quickly, within 3 yr of the fire. I also identified three indicator species that characterized the moth assemblage of the burned site: Anaplectoides virens Butler, 1878 (Lepidoptera: Noctuidae), Martania saxea Wileman, 1911 (Lepidoptera: Geometridae), and Catocala dissimilis Bremer, 1861 (Lepidoptera, Erebidae). Host plant information regarding these three species coincided with the early succession of the forest following the fire. In addition, the disappearance of a once dominant species at the burned site, Hydrillodes morosa Butler, 1879 (Lepidoptera: Erebidae), suggested that the fire and succession after the fire changed the interactions between plants and their herbivores. The fire impacted the moth assemblage through changes in species composition; however, the moth assemblage recovered quickly, even in an unfavorable habitats such as a high elevation site.

A spontaneously abortive embryo (SAE) process in field and greenhouse populations of sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae) is described, as well as the occurrence of SAE in populations from Chiapas, Durango, Guanajuato, Nayarit, Michoacán, Querétaro, Sinaloa, and San Luis Potosí states in Mexico. This phenomenon was observed from November 2014 to December 2017 in sugarcane aphid populations grown on Sorghum bicolor (sorghum), Sorghum drummondi (Sudan grass), and Sorghum halepense (Johnson grass). No reports of this phenomenon have been recorded earlier, perhaps due to the small size of the aborted embryos (200–500 μm), the dark color they acquire within few hours of exposure, their frequent drop from the plant, and the crowded populations of aphids. The abortion process, both simple as well as multiple and complex events, are described. Also, embryos in vivo, alcohol-fixed, and mounted individuals are described. Embryogenic stages 13 and 16–19 were identified in the aborted embryos. It is suggested that specific biotic and/or abiotic situations may intervene on the reproductive physiology of these particular populations, most probably, on the hormone balance. However, the presence of a complex symbiotic/pathogenic microbial association is not discarded, according to some observations, which are still to be studied.

Water is a dangerous and often lethal obstacle for small terrestrial animals like insects. However, some ants survive this hazard by efficiently traversing the water surface. Swimming performance (velocity, acceleration, and efficiency) differs dramatically among ant species, yet the factors that affect performance remain unclear. Here, we investigate the relative importance of behavior and morphology to swimming performance using a comparative study of two temperate forest ant species having superficially similar morphology: Camponotus pennsylvanicus (De Geer, 1773) (Hymenoptera: Formicidae) and Formica subsericea (Say, 1836) (Hymenoptera: Formicidae). We also investigated how water surface tension and ant morphology enable some F. subsericea workers to walk across the water surface, whereas others swim partially submerged. Leg ablation experiments demonstrated that both species use their forelegs for propulsion and hind legs as stabilizers, whereas their midlegs effect both propulsion and stabilization during swimming. C. pennsylvanicus workers swam faster than F. subsericea workers, probably reflecting the larger body size and longer relative foreleg length of C. pennsylvanicus workers. F. subsericea workers that walked on water were somewhat smaller than swimming conspecifics, and no workers were able to walk on water when surface tension was reduced with ethanol. Collectively, these results and those of related studies suggest that, within a clade of ants, differences in swimming performance arise mainly from subtle morphological differences. The importance of ant ecology and cuticular chemistry in this context remains to be explored.

Flower flies are one of the most important groups of pollinators worldwide. Unfortunately, little is known about their pollination capacity and the importance of their role for many crops grown commercially, such as cranberries. To address this information gap, 12 cranberry farms were sampled during the blooming periods of 2013 and 2014 in Quebec, Canada, to evaluate hoverfly diversity and pollen load. Moreover, the effects of the following three factors on community structure were investigated: farm management (organic vs conventional), edge mowing (mowed vs non-mowed), and type of adjacent natural habitat (forest vs meadow vs bog). Flower flies were captured using pan-traps and hand-netting once a week for 3 wk. In total 461 specimens of flower flies were captured and 33 species were identified. Among the three factors studied, edge mowing explained most of the variation among communities, followed by farm management. Natural habitat type did not appear to influence hoverfly communities, contrary to our expectations and reports from other studies. Pollen load analyses and interactive connectance plot showed that two flower fly species, Syrphus torvus Osten Sacken and Eristalis tenax L. (Diptera: Syrphidae), transported the most cranberry pollen, both in terms of quantity and proportion.To our knowledge, this study is the first to describe and provide a complete list of flower fly species found in cranberry crops. Our results also highlight the importance of floral resource diversity for these potential cranberry pollinators, since edge mowing was revealed to be the most influential of all factors we considered.

The blue orchard bee, Osmia lignaria (Say) (Hymenoptera: Megachilidae), is an alternative managed pollinator of rosaceous tree-crops, and potentially could be used for blueberry (Ericaceae) pollination. However, the floral preferences of this species for other types of flowers could prevent them from visiting blueberry flowers when alternative forage is available. To evaluate O. lignaria suitability for pollination of commercial blueberries in Michigan, we identified the main pollen sources in scopal loads and brood provisions, and determined the contribution of blueberry pollen to pollen collected by females nesting inside or at the border of a large blueberry field. Across two bloom seasons, we found that blueberry pollen was not the most abundant pollen type in either the scopal loads (≈6%) or the brood provisions (13–20%). Black cherry (Prunus serotina, Rosaceae), white clover (Trifolium repens, Fabaceae), and red clover (Trifolium pratese, Fabaceae) were the most abundant pollen types in the brood provisions. While shelter location (inside or at the border of the field) had an influence on the use of some of these plants, it did not affect the use of blueberry pollen. Our results indicate that in these field conditions, O. lignaria visit other plants rather than blueberries as a pollen source, making it poorly suited as an alternative managed pollinator for this specific crop.

Pupae of numerous Papilionidae and Nymphalidae produce twitter sounds when wriggling in response to mechanical stimulation. The structural basis comprises distinct pairs of sound-producing organs (SPOs) located at intersegmental membranes of the abdomen. They differ—as the twitters do—in sampled taxa of Papilioninae, Epicaliini, and Heliconiini. The opposing sculptured cuticular sound plates (SPs) of each SPO appear structurally the same but are actually mirror-images of each other. Results suggest that sounds are not generated by stridulation (friction of a file and a scraper) but when these inversely sculptured and interlocking surfaces separate during pupal wriggling, representing a stick-slip mechanism. Twitter sounds comprise series of short broadband pulses with the main energy in the frequency range 3–13 kHz; they can be heard by humans but extend into ultrasonic frequencies up to 100 kHz.

The majority of professional STEM (science, technology, engineering, and mathematics) scientists are still male, despite increasing levels of female graduates in those areas. Here, I show that, consistent with this pattern, females are significantly underrepresented in entomology positions in academia and the federal government. In both employment sectors, female share of positions also significantly decreases with increasing rank, while the reverse is true for men. At the highest federal government grade level occupied by entomologists, mean salary for females is significantly lower than for males. These results show that female entomologists, despite representing between 40 and 50% of doctoral graduates in the last 10 y, are employed at levels far below their share of graduates and, as such, are underemployed.

Xenorhabdus nematophila and Photorhabdus luminescens are entomopathogenic bacteria that have mutualistic relationships with their respective nematode hosts, Steinernema carpocapsae Weiser (Rhabditid: Steinernematidae) and Heterorhabditis bacteriophora Poinar (Rhabditidae: Heterorhabditidae). These symbiotic bacteria are delivered into insect hemocoel by nematodes and rapidly activate the immune system of their target species. We show here that both these bacteria influence cellular and humoral defenses in fifth instar larvae of Spodoptera exigua Hübner (Lepidoptera: Noctuidae). Larvae treated with both bacterial species possessed a higher number of hemocytes than either negative controls at initial hour post-injection (hpi) although both the frequency of hemocytes and granulocytes decreased. Results show that at times between 12 and 16 hpi the densities of both fell below the level of the negative control. The hemocyte population also fell below that seen in the negative control in larvae containing heat-killed bacteria, while nodule formation was observed in cases of both live and heat-killed bacterial treatments. We also show that the abilities of live symbiotic bacteria to influence a decrease in nodule formation were higher than was the case for their heat-killed counterparts and that no nodules formed during negative control treatment. Data show that both live and heat-killed symbiotic bacteria initially activated a range of insect defensive enzymes (including protease, phospholipase A₂ [PLA₂], and phenoloxidase [PO]) post-injection compared with the negative control but that their activation levels fluctuated in different ways. The results of this analysis show that attacin, cecropin, and spodoptericin were upregulated by the injection of live symbiotic bacteria; the expression levels of these proteins were higher than in both normal larvae (noninjected) and negative control treatments. We show that attacin and cecropin expression rates due to live P. luminescens treatments were less than was the case for live X. nematophila treatment while the expression of spodoptericin was reversed. Results indicate that the ability of P. luminescens to suppress cellular reactions, including the expression of attacin and cecropin, is higher than is the case for X. nematophila. The results of this study provide new insights into the roles of P. luminescens and X. nematophila in countering insect physiological defenses.