Integrative taxonomy of Trichogramma vitessoides sp. nov. (Hymenoptera, Trichogrammatidae), an egg parasitoid of Heortia vitessoides from southern China

Egg parasitoids of the genus Trichogramma Westwood, 1833 are widely used in integrated pest management, but their minute size and reduced morphology complicate identification. Using integrative taxonomy, we describe Trichogramma vitessoides Hu & Yang, sp. nov . from Guangdong, China, based on a laboratory colony established from parasitoids reared from naturally parasitised egg masses of Heortia vitessoides (Moore, 1885) (Lepidoptera, Crambidae), a defoliator of Aquilaria sinensis (Lour.) Spreng. Male genital morphology distinguishes the new species from morphologically similar congeners, particularly Trichogramma raoi Nagaraja, 1973, by differences in the shape of the dorsal extension, the aedeagus-to-apodeme ratio, and the length of the central ridges. The complete mitogenome is 16,221 bp in length, contains 37 genes, and has an A+T content of 84.4%. Bayesian and maximum-likelihood analyses based on the concatenated amino-acid sequences of the 13 mitochondrial protein-coding genes recovered the new species as sister to Trichogramma japonicum Ashmead, 1904. All 13 protein-coding genes had mean Ka / Ks ratios below 1, whereas atp8 showed the highest ratio, suggesting comparatively relaxed purifying selection. These results support recognition of the new species and expand genomic resources for Trichogramma systematics and biological control.