Tiger beetles are a popular, widely studied group of charismatic insects that are a flagship taxon for insect conservation. Five species are currently listed in the United States as Federally Endangered or Threatened, two others have recently been delisted, and many more are listed by individual states. To date, the status of some of these species has been improved or their decline slowed by various conservation strategies. In this article, we review the background and the recent conservation activities for all federally listed tiger beetle species. These species have lost much of their historic habitat and remain at risk because of continuing impacts from vegetation encroachment of native or invasive plants, water-level changes, and other human-related activities. Conservation efforts are limited because for most species there is little or no potential habitat remaining, even following restoration activities. Effective strategies have included long-term monitoring of population size and research activities, acquisition and protection of occupied sites, methods for controlling vegetation encroachment to improve habitat quality, and recent efforts with translocations using beetles from existing populations or from captive rearing. Because tiger beetle life histories are similar, successful management and research methods for any one species can be applicable to others. This presents an opportunity to coordinate taxon-level conservation for all U.S. species through cataloged information and conservation leadership

Small modifications in greenhouse agroenvironments can have a big impact on the success of biological control programs. For instance, the application of supplemental foods during and after the release of natural enemies onto crop plants, could considerably improve their long-term reproductive and population growth prospects. As such, food supplementation represents a valuable biological control supportive strategy, helping to grow natural enemy populations before pest establishment, akin to creating a standing-army to defend crops against future pest invasions. In many places of the world, food supplementation represents a relatively new but growing component or biological control research, with increasingly better resources available to guide producers, IPM practitioners, or researchers wanting to apply or optimize such strategies to their local agents and environments. In this review, we summarize the current stage of knowledge associated with various supplemental food types, which work best to support specific beneficial arthropods as well as some tools and techniques for successfully applying this biological control-enhancing strategy. We also summarize some current challenges to the use of supplemental foods and discuss what future research is needed to adapt and optimize food supplementation for a diversity of natural enemy species.

Recent reports indicate that global insect populations are drastically declining, and amongst insects, bees have attracted significant attention. Decades of research on causal factors for bee population declines, indicate that extensive loss of natural habitats resulting from urbanization and agricultural intensification, has led to a dearth of critical nesting and forage resources essential for the sustenance of bees. To address these concerns and to meet the growing need for food production, simple but effective farm management practices such as restoring habitat diversity through planting pollinator habitats along field margins and underutilized areas, revegetating retired farmland with wildflowers and including pollinator-friendly forbs in cover crop mixes, have been recommended. Earlier studies have provided evidence that planting pollinator habitats along field margins and revegetating retired farmland are indeed viable ways to sustain bee pollinators. Here we report results of a case study exploring the benefits of cover cropping with a pollinator-friendly forb mix. Our results indicate that cover cropping to support pollinators can be effective, particularly when cover crops are retained until the flowering stage and that grazing of cover crops could extend support to those genera of bees that prefer grazed areas. Although the reports on global insect declines are dire, our studies show that pollinator-friendly farm management practices can offset the declines and play a significant role in supporting pollinator populations. Regular assessment of the efficacy of these practices will enable us to target efforts towards better implementation of habitat conservation programs.

In general, butterfly ventral hind wing eyespots are considered to play a role in predator–prey interactions. These eyespots are prominent wing pattern elements in Brassolini butterflies, and they vary in size, position, and number across taxa. Female Caligo Hübner, 1819 (Lepidoptera, Nymphalidae) appear to use the large eyespots of lekking males as a mate-locating cue, but female Opsiphanes Doubleday, 1849 (Lepidoptera, Nymphalidae) do not because males patrol to find mates. These behaviors led us to predict that male Caligo should have larger eyespots than females, but eyespot size would not differ between sexes in Opsiphanes. Our analyses supported these predictions. As displacement of the eyespots to the center of the wing might make them more conspicuous, we asked if eyespot position and size covaried across the Brassolini phylogeny. While we found a positive association between position and size, the relationship of these two variables contained significant phylogenetic signal. Two Brassolini species show strong sexual dimorphism where females converge on the color pattern of sympatric species of Caligo. Their ventral hind wing eyespots are much larger than those of close relatives, approximating those of Caligo, and further reinforcing the importance of ventral hind wing eyespots as a visual signal in this group of butterflies. Importantly, our results suggest that, in addition to antipredation defense, ventral hind wing eyespots can function in mating activities, and consequently they might be evolving under both natural and sexual selection in Caligo butterflies.

Deciduous Beech (Fagus spp.) forests have a highly disjunct distribution in the Northern Hemisphere, with greatest diversity in eastern Asia. Although Fagus supports a rich phytophagous insect fauna, the diversity, composition, and host specialization of insects associated with these trees in Asia are less well known compared with Europe and North America. For instance, two species of Catocala moths, both considered endemic to Japan, were previously known as the only beech-feeding specialists of this genus. However, two Catocala species were recently discovered from Taiwan during a survey of phytophagous insects on Taiwan Beech Fagus hayatae, a threatened plant. Identification of these two species of moths was determined by mtDNA (COI barcodes), adult morphology, including wing pattern and genitalia, and biology. Based on these multiple sources of evidence, we conclude that one species represents an undescribed species and the other a new subspecies of a species previously known only from mainland China. The taxonomic treatments in the present work include Catocala seiohbo sanctocula Hsu & Huang, subsp. nov., C. nimbosa Hsu & Wang, sp. nov. and C. nubila ohshimai, stat. nov. In Taiwan, Catocala spp. occur mainly in large, undisturbed patches of Taiwan Beech forest and are codependent on F. hayatae. Thus, they are not only considered to be at risk of co-extinction, but may serve as potential indicator species to monitor the extent and health of this threatened ecological community.

Climates around the world are rapidly turning warmer and often drier. Agricultural approaches must change accordingly. One important global practice is commercial use of cryptic species of the Chrysoperla carnea-group of green lacewings to control arthropod pests. Recently, one highly drought-tolerant species, originally present only in the Old World, is suspected of expanding its range to some of the driest habitats in the New World. Here we examine putative specimens of this species, Chrysoperla zastrowi (Esben-Petersen, 1928), collected in the desert southwest of the United States, the parched northwest of Mexico, and Guatemala. Using species-specific vibrational duetting-song phenotypes, subtle morphological character states, and mitochondrial DNA sequences, we confirm that C. zastrowi is now a naturalized part of the lacewing fauna of the Americas, making it the only species of the carnea-group to have a truly global range. As such, we encourage its broader commercial use for pest control on irrigated agricultural systems in the hotter, drier regions of the world to which it is best adapted and within which it now appears to be fully naturalized. We briefly consider future range expansion of both subspecies of C. zastrowi, C. z. zastrowi, and C. z. sillemi, in response to continued global warming.

Graphical Abstract

The invasive stink bug, Bagrada hilaris (Burmeister) (Hemiptera: Pentatomidae), is a serious pest of cole crops. Studies are underway to assess the potential of an exotic egg parasitoid from Pakistan, Ooencyrtus mirus Triapitsyn & Power (Hymenoptera: Encyrtidae), as a biological control agent for this pest. In the present study, the ovipositional preference of O. mirus reared for multiple generations on B. hilaris, Thyanta pallidovirens (Stal), or Nezara viridula (Linnaeus) (Hemiptera: Pentatomidae) for eggs of these three stink bug species was evaluated. The first host accepted for oviposition, the number of parasitoid eggs (as indicated by pedicels) laid on each host egg at different time intervals, and the number of wasps that emerged from parasitized eggs were recorded. Results show that O. mirus prefers eggs of its primary host, B. hilaris, for oviposition over the alternate hosts tested regardless of whether the parasitoids were reared on the primary or alternate hosts. The percent parasitism in the first 2 h of exposure also was higher on B. hilaris eggs although it was not significantly different from T. pallidovirens eggs for parasitoids reared on B. hilaris and N. viridula eggs. For all parasitoid populations, the mean number of emerged wasps per host egg ranged from 0.9 to 1.1 with no significant differences. Bagrada hilaris eggs were significantly smaller than T. pallidovirens and N. viridula eggs and female wasps that emerged from B. hilaris eggs had significantly shorter body length and head width than those that emerged from T. pallidovirens and N. viridula eggs.

Graphical Abstract