The pear psyllids (Cacopsylla Ossiannilsson; Hemiptera: Psylloidea: Psyllidae) are a taxonomically difficult group of at least 24 species native to the Palaearctic region. One or more species occur in most pear-growing regions, in some cases as invasive introductions. Existing reviews of this group are primarily of taxonomic focus with limited overviews of biology. The earliest biological studies of the pear psyllids centered on a core group of a few western European species. In part, this focus arose because diversity of the pear psyllids was poorly understood. As taxonomic understanding has advanced over the last 3 decades, research has expanded taxonomically. Increasing difficulties in controlling the pear psyllids additionally has contributed to growth in research. Here, we review a now-extensive literature on diversity, biology, and management of the pear psyllids. Three broad observations emerged from this synthesis. First, large gaps in biological understanding of the pear psyllids persist for several geographic faunas, most notably for psyllids of the Eastern Palaearctic region. Second, taxonomic diversity is accompanied by biological diversity. Despite the commonality in host use among the pear psyllids, with each species being limited to development on Pyrus, striking differences exist among species in life cycles, wintering, and other biological traits. Third, many of the tools being used to manage pear psyllids today are in existence because of the long history of basic research which has targeted these pests. These tools include new insecticides of higher selectivity, various cultural and horticultural tactics, and practices that conserve natural enemies in orchards.

Stink bug (Hemiptera: Pentatomidae) development typically requires feeding on a diversity of plant species and various plant tissues. During feeding, stink bugs discharge salivary enzymes with roles in extraoral digestion and countering plant defense responses. Although previous research has described digestive salivary proteins from stink bugs, less is known of the salivary proteins involved in the suppression of plant defenses. We sequenced the transcriptomes of salivary glands dissected from five stink bug species collected from non-crop habitats in Washington: Halyomorpha halys (Stål), Nezara viridula L., Euschistus conspersus (Uhler), Thyanta pallidovirens (Stål), and Chlorochroa ligata (Say). We identified a total of 677 candidate secreted proteins from the salivary glands of the five species. Based on work from other insects, many of the proteins have potential functions in the suppression of plant defense signaling and deactivation of plant defense molecules. We also identified salivary proteins with potential roles in the extraoral digestion of plant tissues, protection from entomopathogens, and deposition of salivary sheaths. This report provides a curation of putative salivary effector genes for further functional analysis.

Nitrogen fixation is often cited as an important nitrogen source for termites. However, the rate of nitrogen fixation between experiments and termite species is highly variable due to termite diversity and sampling limitations. New evidence suggests that subterranean termites (Coptotermes formosanus Shiraki) (Blattodea, Rhinotermitidae) seek alternative dietary nitrogen sources for colony growth and development. This study compares N₂ fixation rates and nitrogenase gene expression rates to a diverse assemblage of feeding groups. It was observed that nitrogenase expression was much higher in one-piece nesting termites from the family Kalotermitidae which lack access to soil. On the other hand, subterranean termites from the family Rhinotermitidae fix nitrogen at much lower rates, not differing from ambient nitrogenase activity in soil.

Both science festivals and insect festivals have increased in frequency in the last few decades. In order to compare insect festivals with science festivals, we modified a validated science festival visitor survey (EvalFest) for Purdue's Bug Bowl, a long-running insect festival. Benchmarking against EvalFest and Collaboration for Ongoing Visitor Experience Studies (COVES) results, we found that Bug Bowl audiences were similar in having high levels of education, a high interest in science, and frequently visiting science venues. In fact, 23% of Bug Bowl survey takers indicated that they were actual scientists themselves. In contrast to EvalFest results, Bug Bowl had a higher rate of returning visitors than new visitors. Bug Bowl visitor motivations were primarily to have fun and bring their children for a learning experience, and they rated their experiences very positively. Ninety-one percent of Bug Bowl attendees surveyed lived in the state of Indiana. We discuss gaps in expected visitor demographics and possible applications for a shared common evaluation within a working group of insect festivals.

Graphical Abstract

Among the richest ecosystems in bioluminescent Coleoptera in Brazil, the Cerrado (savannas) is the most threatened one by agricultural expansion. The Emas (PNE) and Chapada dos Guimarães (PNCG) National parks are 2 of the last main remnants of the original Cerrado ecosystems in Central-west Brazil. During the past 3 decades, we have conducted several expeditions to collect, observe and study bioluminescent beetles occurring in the PNE and surrounding farms. More recently we also started to investigate the PNCG. We recorded a total of 51 bioluminescent species, including fireflies (n = 29), click beetles (n = 11), phengodids (n = 10), and staphylinids (n = 1).The PNE region was the richest one, especially for phengodids (n = 9). Among the habitats that compose the Cerrado physiognomy, the Cerrado and cerradão hosted most of the bioluminescent species, followed by forest, open fields and marshes. Most fireflies inhabiting the Cerrado ecosystem emit yellow-green light, whereas most click beetles emit predominantly green light, and among phengodid species, orange and red-light emission was found in 3 species.The spectacular click beetle Pyrearinus termitilluminans Costa-lodging luminous termite mounds were found in PNE and also reported for the first time at PNCG. In the farms around the PNE, however, a declining number of bioluminescent species was recorded in cerradão areas after the replacement of the surrounding cattle pastures by sugarcane plantations, especially adult phengodid males that were no longer attracted to light traps. Habitat reduction, use of agricultural pesticides and artificial night lighting are thought to be the major causes of such impact on bioluminescent beetle diversity.

The bamboo grasshopper, Ceracris kiangsu Tsai, is a serious pest of bamboo in China and Southeast Asia, and it overwinters as eggs for a period of up to 9 mo. Despite its importance, cold tolerance has not been thoroughly examined in this species. Thus, the present study investigated the low-temperature tolerance of overwintering eggs collected in the field, particularly the effects of rapid cold-hardening (RCH) and cold acclimation (ACC) on egg survival, and changes in the cryoprotectant contents. The supercooling point of overwintering eggs collected from the field was –23.9 °C, and their survival rate after exposure to –22 °C for 6 h was 26.6%, thereby suggesting that the cold tolerance strategy employed by C. kiangsu is freeze avoidance. After exposure to 0 and 4 °C for 12 and 24 h, or 0, 4, and 8 °C for 5 days, the survival rate of eggs subjected to –22 °C increased to approximately 50%, with significant effects of RCH and ACC. The glycerol levels in RCH and ACC treated eggs were also significantly higher than those in the control group, but the protein and trehalose contents were either reduced or not significantly altered. These results indicate that glycerol functions as a low molecular weight cryoprotectant in C. kiangsu eggs, and that RCH and ACC treatment facilitate its accumulation, thereby enhancing cold tolerance. Furthermore, the correlation between RCH and ACC was investigated.

Graphical Abstract