A new species of Trichogramma (Hymenoptera: Trichogrammatidae) parasitic on eggs of the alderfly Sialis melania (Neuroptera: Sialidae) from Japan, with comments on its phylogeny and male wing polymorphism

Abstract

A new species of Trichogramma that parasitizes Sialis melania eggs is described as Trichogramma tajimaense Yashiro, Hirose and Honda, sp. nov. from Japan. Its phylogenetic position is based on a DNA‐based analysis, and data regarding its male wing polymorphism are also presented. The view that T. tajimaense is closely related to T. semblidis, another parasitoid of Sialis eggs, is supported by the results of a phylogenetic analysis, as well as by the biological and morphological similarities between both species. Trichogramma tajimaense is also similar in male wing polymorphism to T. kurosuae, a gregarious egg parasitoid of the lepidopteran Ivela auripes, as both Trichogramma species exhibit male wing trimorphism (fully alate, brachypterous and apterous forms) in contrast to the male wing dimorphism (fully alate and apterous forms) of T. semblidis. However, no phylogenetic analysis reveals a close relationship between T. tajimaense and T. kurosuae, and a difference exists between these two species in the mean percentage of flightless (brachypterous and apterous) males that emerge from a host egg mass; 96% of T. tajimaense males are incapable of flight, whereas about 50% of T. kurosuae males are flightless. Because all or almost all males of T. semblidis parasitizing Sialis eggs are apterous, T. tajimaense is more similar to T. semblidis than to T. kurosuae in the proportion of flightless males. In addition, male wing polymorphisms of Trichogramma in relation to mating systems could also show a similarity between T. tajimaense and T. semblidis when considering both species as quasi‐gregarious parasitoids of Sialis eggs.

Description of three new species of Ooencyrtus (Hymenoptera: Encyrtidae) from China

“…Several species of Trichogrammatidae are reported as egg parasitoids of Sialidae (Aurivillius 1897;Salt 1937Salt , 1939Thompson 1951;Peck 1963;Herting & Simmonds 1978;Pinto 1999;Yashiro et al 2012). Noyes & Hirose (1997) described O. yoshidai based on material reared from eggs of Protohermes grandis (Thunberg) (Megaloptera: Corydalidae) in Japan, marking the first record of parasitoids from Corydalidae.…”