Host Suitability and Parasitic Activity of Local Groups of Habrobracon hebetor (Say, 1836) (Hymenoptera: Braconidae) as a Factor in the Management of Lepidopteran Pest Populations in Corn Agroecosystems

Abstract

Simple Summary Habrobracon hebetor is a key parasitoid of Lepidoptera, and its biocontrol potential requires understanding local population traits. We studied natural populations from maize fields in two districts of Krasnodar Krai, Russia. Under laboratory conditions, we assessed host range and parasitic activity against Noctuidae, Pyralidae, and Tortricidae larvae. Clear intraspecific differences in host suitability emerged: one population (pyralid-tortricid type) parasitized the European corn borer (Ostrinia nubilalis), pulse pod borer moth (Etiella zinckenella), and tortricids, but not the cotton bollworm (Helicoverpa armigera); the other (noctuid-pyralid type) attacked the cotton bollworm, corn borer, and pulse pod borer moth. Both showed high paralyzing (up to 100%) and parasitization (up to 91%) rates on medium and late instars. In comparative field observations under release conditions, corn borer damage was observed in 16% of plants in the treated plot versus 40% in the control plot, and cotton bollworm damage was observed in 13% of ears versus 65% in the control plot. Our results highlight the promise of native H. hebetor populations as potential bioagents against key lepidopteran pests in crop systems.