It has long been assumed that members of the cynipid tribe Synergini (sensu stricto) are all inquilines, that is, gallers of galls: the larvae can modify the galls of other species but cannot initiate gall formation on their own. Surprisingly, Abe et al. recently showed that one member of the tribe, Synergus itoensis Abe, Ide et Wachi, is a true gall inducer: it produces small galls inside acorns without the help of other species. Here, we present a comprehensive phylogenetic analysis of the Synergini to determine whether S. itoensis acquired this ability recently or if it represents a survivor of ancient gall inducers from which inquiline Synergini evolved. We studied 71 species belonging to five genera, covering all the Palearctic inquiline genera associated with oaks and one outgroup, Rhoophilus loewi Mayr, which is an inquiline in Lepidoptera galls on Searsia (formerly Rhus) (Anacardiaceae). We obtained partial sequences of cytochrome c oxidase subunit I and 28S ribosomal RNA (1.1 kbp of data). The results show that S. itoensis is most closely related to two undescribed species, which have also been reared from acorns. Their life history is unknown but the molecular phylogenetic data and the similarity in gall and adult morphology suggest that they are also gall inducers.The three species are deeply nested within lineages known to be inquilines, strongly suggesting that they acquired the ability to induce galls recently. Based on the molecular phylogenetic data and morphological features, Synergus yukawai (Wachi, Ide et Abe) is transferred back to Saphonecrus (Saphonecrus yukawaicomb. rev.), where it was originally described.

Since the early 1900s, the Eurasian woodwasp (Sirex noctilio F.; Hymenoptera: Siricidae), a pest of pine (Pinus spp.; Pinales: Pinaceae) trees, has been introduced to various regions in Southern Hemisphere and North America. Among the most effective biocontrol agents of S. noctilio are hymenopteran parasitoids that parasitize various life-stages of woodwasps. Little is known about how these parasitoids locate their host in the wood, but presumably do so through chemolocation using antennae. We examined the external antennal morphology of Ibalia leucospoides ensiger (Norton) (Hymenoptera: Ibaliidae), a major parasitoid of native siricids in North America. Males were found to have two more antennal flagellomeres (13) than females (11), although the total antennal length was similar. The first flagellomere of the male has a distinctive excavated region. Using scanning electron microscopy, we identified seven types of antennal sensilla on male and female I. l. ensiger including campaniform, chaetica (types 1 and 3), coeloconic, fluted basiconica (FB), pits (PI), and placodea. There were no differences in the total number of antennal sensilla between male or female I. l. ensiger. However, females had greater numbers of chaetica type 1 and FB, whereas males had more sensilla placodea. Sensilla were unevenly distributed along the antennae of both males and females. Chaetica type 1 was the most numerous sensillum followed by FB, placodea, and PI. We present analyses of the morphology of the antennae of each sex of I. l. ensiger, and discuss possible function of each sensilla-type and how they may mediate mate location and oviposition activities.

A combination of arena,Y-tube olfactometer, and flight tunnel assays were used to determine responses of male and reproductive female Polistes exclamans Vierick (Hymenoptera: Vespidae) to odors and extracts of conspecific males and females, as potential pheromone-mediated sexual behaviors. Males rubbed the sternites of the gaster on filter paper in response to extracts of the female mesosoma and gaster, indicating possible scent-marking. In a Y-tube olfactometer, females oriented to extracts of the male head, gaster, legs, seventh sternite, and mandibular glands. In the olfactometer, males oriented to extracts of the female whole body, but were repelled by extracts of the female head. Both females and males oriented to solvent washes of glass jars that held wasps of the opposite sex, as well as volatile collections from the opposite sex. In a flight tunnel, males and females both exhibited chemoanemotaxis that consisted of upwind flight and close range casting in response to odor piped into the tunnel from live wasps of the opposite sex. Males mounted a female wasp model treated with an extract of the female mesosoma. Together, these experiments suggest pheromones stimulate male scent-marking, attraction of females to males and males to females, and mounting, in P. exclamans. Results indicate the mesosoma as a source of female pheromones, and the legs, gastral sternal glands, and mandibular glands, as male pheromone sources.

Here we describe an investigation of the life history characteristics, behavior, immature and adult morphologies of the Neotropical tortoise beetle Chelymorpha alternans (Boheman; Coleoptera: Chrysomelidae: Cassidinae) from the Republic of Panamá. Developmental times and behavioral characteristics for individuals maintained under laboratory and field conditions are evaluated. Survival rates of individuals maintained under field and laboratory conditions are compared. A list of convolvulaceous host plants utilized by C. alternans is provided. Empirical studies investigating the biology of C. alternans are reviewed. This study contributes to our knowledge of quantitative and qualitative aspects of this lspecies' biology. These findings demonstrate that C. alternans is an organism that develops, behaves, and interacts with host plants, much as other tortoise beetles do. Rigorous, multi-year investigation of this ecologically representative species has produced a comparative life history description that expands our knowledge of general Cassidinae and Coleoptera biology. The natural history background, life history descriptions, diet breadth information, and literature review provided in this contribution make a compelling case for continued utilization of C. alternans as a representative tortoise beetle species for a variety of field and laboratory based studies in plant–insect interactions, chemical ecology, natural enemy ecology, and phenotypic trait and diet breadth evolution.