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ARS Home » Northeast Area » Newark, Delaware » Beneficial Insects Introduction Research Unit » Research » Publications at this Location » Publication #355035
Research Project: Host Specificity and Systematics of Insect Biological Control Agents

Location: Beneficial Insects Introduction Research Unit

Title: Evolution of glandular structures on the scapes of males in the genus Aphelinus Dalman, 1820 (Hymenoptera: Aphelinidae)

Author
item SHIRLEY, XANTHE - Texas A&M University
item WOOLLEY, JAMES - Texas A&M University
item Hopper, Keith
item ISIDORO, NUNZIO - University Of Perugia
item ROMANI, ROBERTO - University Of Perugia

Submitted to: Journal of Hymenoptera Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/6/2019
Publication Date: 10/31/2019
Citation: Shirley, X., Woolley, J.B., Hopper, K.R., Isidoro, N., Romani, R. 2019. Evolution of glandular structures on the scapes of males in the genus Aphelinus Dalman, 1820 (Hymenoptera: Aphelinidae). Journal of Hymenoptera Research. 72:27-43. https://doi.org/10.3897/jhr.72.36356.
DOI: https://doi.org/10.3897/jhr.72.36356

Interpretive Summary: Introductions of parasitic wasps from other regions of the world has proved a successful strategy for controlling invasive insect pests. In particular, species of wasps in the genus Aphelinus are being considered for introduction against pests like soybean aphid and Russian wheat aphid. Reliable identification of wasp species is critical for the safety and effectiveness of such biological control introductions. Aphelinus species are difficult to tell apart using the traits often used by taxonomists. Here we report research on glandular structures on the antennae of males of Aphelinus that provide a new set of traits that can be used to identify species groups and even species within the genus. These structures are also interesting because of their potential importance in mate recognition during courtship. Mate recognition is important not only for the evolution of new species, but also for predicting the likelihood of hybridization between parasitic wasps introduced for biological control and native species of wasps.

Technical Abstract: The secretory structures on male antennomeres of parasitic Hymenoptera are diverse and widespread and function during antennation in courtship. However, nothing has been published these structures in species of Aphelinus (Chalcidoidea: Aphelinidae), a genus of parasitoid wasps that has a long history of use in biological control. Preliminary scanning electron microscopy (SEM) and transmission electron microscopy (TEM) with Aphelinus varipes showed external structures on the ventral side of the scapes of males that were connected internally to gland cells. Using SEM, we surveyed these structures in ten species in six complexes of Aphelinus, as well as in two species, Aphytis melinus and Centrodora sp., that served as outgroups. The external structures differed in the number and position of the pores, the conformation of cuticle surrounding pores, and the shape of the carina delimiting the area around the pores. The morphology of these pores is diagnostic for the species groups of Aphelinus and maps well onto a molecular phylogeny of these species Aphelinus.