Original paper
Activation of host immunity benefits ectoparasitoid wasp offspring
Zhang, Yue; Liu, Die; Dai, Renhuai; Yang, Jiapeng; Liu, Li; Zhu, Yuyun; Yan, Yi; Smagghe, Guy; Yang, Hong
published online: Aug 12, 2026
manuscript accepted: May 10, 2026
final revised version received: Mar 20, 2026
manuscript revision requested: Dec 12, 2025
manuscript received: Oct 26, 2025
Open Access (paper may be downloaded free of charge)
Abstract
Parasitic wasps are typically viewed as immune suppressors, yet we uncover an opposite strategy in the idiobiont ectoparasitoid Anisopteromalus calandrae (Howard). In its beetle host Lasioderma serricorne (Fabricius), parasitoid envenomation activates rather than inhibits a specific signal of host immunity by stimulating the Toll signaling pathway, leading to robust induction of antimicrobial peptide (AMP) genes. This immune activation is associated with enhanced parasitoid offspring survival. Functional knockdown of AMPs or the Toll pathway transcription factor LsDorsal significantly reduced parasitoid fitness, demonstrating a causal role for host immune activation in parasite success. We identify two previously uncharacterized venom proteins, AcKazal and AcSalivary, that are sufficient to trigger Toll signaling. These findings reveal a previously unrecognized parasitic strategy in which a parasite co-opts and modulates host immunity to potentially benefit its own development. This work expands current understanding of host-parasite coevolution and suggests unexpected mechanisms relevant to immune manipulation, and biological control.
Keywords
Lasioderma serricorne • Anisopteromalus calandrae • venom proteins • antimicrobial peptides • host-parasite interaction • pest management • host immunity • coevolution