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Two new species of Ormyrus Westwood, 1832 (Hymenoptera: Chalcidoidea: Ormyridae) are described: Ormyrus myrae Nastasi, Alcorn, & Davis sp. nov. and Ormyrus bellbowl Nastasi, Alcorn, & Davis sp. nov. Species of Ormyrus are parasitoids in insect galls, especially those induced by Cynipidae (Hymenoptera: Cynipoidea), and the new species are parasitoids in galls induced by Antistrophus Walsh, 1869 (Cynipidae: Aulacideini) on rosinweeds of the genus Silphium L. (Asteraceae: Heliantheae). Ormyrus bellbowl is a parasitoid of Antistrophus meganae Tooker & Hanks, 2004 in stems of S. terebinthinaceum Jacq., as well as other species of Antistrophus inducing inconspicuous galls in stems of S. laciniatum L. Ormyrus myrae is a parasitoid of Antistrophus laciniatus Gillette, 1891 on S. laciniatum and S. terebinthinaceum; the latter represents a new association of A. laciniatus with S. terebinthinaceum. Previous records of O. labotus Walker, 1843 in association with Antistrophus species are suggested as the results of misidentifications.  

Endophytic insects, including gall insects and leaf miners, are prominent in both natural and agricultural plant communities. We catalog the endophytic insect fauna in North America that are known to associate with rosinweeds (SilphiumL., Heliantheae, Asteraceae). We provide details on host plant species, brief descriptions of insect associations, and known distributions of their association withSilphiumspecies. We report associations with rosinweeds for 41 insect species from 18 families across four insect orders and detail the host plant tissue where these insects occur. The complex community we describe suggests that a further study of rosinweed endophytic insects could be useful to understanding evolution of host‐plant preferences andSilphiumspecies boundaries. 

Cryptic species present challenges across many subdisciplines of biology. Not all “cryptic” species, however, are truly cryptic; many are simply underexplored morphologically. We examined this idea for theAntistrophus rufusspecies complex, which previously contained three species thought to be morphologically cryptic. To determine whether theA. rufuscomplex are truly cryptic species, we assessed species boundaries of members of theA. rufusspecies complex using morphological, ecological, and DNA barcode data, and tested whether a set of 50 morphological characters could adequately diagnose these species. We revealed that this complex includes five species, and that there are useful phenotypic diagnostic characters for all members of this species complex. This enabled redescription of four species and the description ofAntistrophus laurenaeNastasi,sp. nov., which induces externally inconspicuous galls in stems ofSilphium integrifoliumMichx., a host not associated with other members of the complex. We use these new diagnostic characters to construct a key to the five species of therufuscomplex. We conclude that theA. rufuscomplex was not a true case of cryptic species. Our Bayesian analysis of DNA barcode data suggests possible cospeciation of members of therufuscomplex and theirSilphiumhost plants, but further study is necessary to better understand the evolution of host use in the lineage. 

Abstract Many herbivorous insect species are capable of hijacking plant development to induce novel plant organs called galls. In most groups of galling insects, the insect organs and molecular signals involved in gall induction are poorly understood. We focused on gall wasps (Hymenoptera:Cynipidae), the second largest clade of gall inducers (~1,400 spp.), for which the developmental stages and organs responsible for gall development are unclear. We investigated the female metasomal anatomy of 69 gall-inducing and 29 non-gall-inducing species across each of the major lineages of Cynipoidea, to test relationships between this lifestyle and the relative size of secretory organs. We confirmed that the venom apparatus in gall-inducing species is greatly expanded, although gall-inducing lineages vary in the relative size of these glands. Among these gallers, we measured the largest venom gland apparatus relative to body size ever recorded in insects. Non-galling inquiline species are accompanied by a reduction of this apparatus. Comparative microscopic analysis of venom glands suggests varying venom gland content across the lineages. Some oak gallers also had enlarged accessory glands, a lipid-rich organ whose function remains unclear, and which has not been previously studied in relation to gall formation. Together, the massive expansion of secretory organs specifically in gall-inducing species suggests a role of these secretions in the process of gall formation, and the variance in size of venom glands, accessory glands, and the contents of these glands among gallers, suggests that gall formation across this clade is likely to employ a diversity of molecular strategies. 

The morphology of insect-induced galls contributes to defences of the gall-inducing insect species against its natural enemies. In terms of gall chemistry, the only defensive compounds thus far identified in galls are tannins that accumulate in many galls, preventing damage by herbivores. Intrigued by the fruit-like appearance of the translucent oak gall (TOG; Amphibolips nubilipennis , Cynipidae, Hymenoptera) induced on red oak ( Quercus rubra ), we hypothesized that its chemical composition may deviate from other galls. We found that the pH of the gall is between 2 and 3, making it among the lowest pH levels found in plant tissues. We examined the organic acid content of TOG and compared it to fruits and other galls using high-performance liquid chromatography and gas chromatography–mass spectrometry. Malic acid, an acid with particularly high abundance in apples, represents 66% of the organic acid detected in TOGs. The concentration of malic acid was two times higher than in other galls and in apples. Gall histology showed that the acid-containing cells were enlarged and vacuolized just like fruits mesocarp cells. Accumulation of organic acid in gall tissues is convergent with fruit morphology and may constitute a new defensive strategy against predators and parasitoids. 

Ants disperse oak galls of some cynipid wasp species similarly to how they disperse seeds with elaiosomes. We conducted choice assays in field and laboratory settings with ant-dispersed seeds and wasp-induced galls found in ant nests and found that seed-dispersing ants retrieve these galls as they do myrmecochorous seeds. We also conducted manipulative experiments in which we removed the putative ant-attracting appendages (“kapéllos”) from galls and found that ants are specifically attracted to kapéllos. Finally, we compared the chemical composition and histology of ant-attracting appendages on seeds and galls and found that they both have similar fatty acid compositions as well as morphology. We also observed seed-dispersing ants retrieving oak galls to their nests and rodents and birds consuming oak galls that were not retrieved by ants. These results suggest convergence in ant-mediated dispersal between myrmecochorous seeds and oak galls. Based on our observations, a protective advantage for galls retrieved to ant nests seems a more likely benefit than dispersal distance, as has also been suggested for myrmecochorous seeds. These results require reconsideration of established ant-plant research assumptions, as ant-mediated seed and gall dispersal appear strongly convergent and galls may be far more abundant in eastern North American deciduous forests than myrmecochorous seeds. 

Pollinator nutritional ecology provides insights into plant–pollinator interactions, coevolution, and the restoration of declining pollinator populations. Bees obtain their protein and lipid nutrient intake from pollen, which is essential for larval growth and development as well as adult health and reproduction. Our previous research revealed that pollen protein to lipid ratios (P:L) shape bumble bee foraging preferences among pollen host-plant species, and these preferred ratios link to bumble bee colony health and fitness. Yet, we are still in the early stages of integrating data on P:L ratios across plant and bee species. Here, using a standard laboratory protocol, we present over 80 plant species’ protein and lipid concentrations and P:L values, and we evaluate the P:L ratios of pollen collected by three bee species. We discuss the general phylogenetic, phenotypic, behavioral, and ecological trends observed in these P:L ratios that may drive plant–pollinator interactions; we also present future research questions to further strengthen the field of pollination nutritional ecology. This dataset provides a foundation for researchers studying the nutritional drivers of plant–pollinator interactions as well as for stakeholders developing planting schemes to best support pollinators.