Rearing Trichogramma ostriniae on the factitious host Antheraea pernyi via multiparasitism with Trichogramma chilonis facilitates enhanced biocontrol potential against Ostrinia furnacalis

Abstract

The Asian corn borer (ACB) Ostrinia furnacalis is a voracious pest of corn in Asia. The egg parasitoid Trichogramma ostriniae is an important biological control agent of ACB. The possibility of mass-producing T. ostriniae on the factitious host Chinese oak silkworm, Antheraea pernyi, via multiparasitism with T. chilonis has been previously reported. Here, we evaluated the fitness parameters of A. pernyi-reared T. ostriniae via multiparasitism and its potential to parasitize ACB eggs of different ages (12 h and 24 h) in comparison to T. ostriniae reared on eggs of rice moth, Corcyra cephalonica. The results showed that rearing host species affected body size, longevity and lifetime fecundity of T. ostriniae. The A. pernyi host produced T. ostriniae of larger body size (female: 641.8 µm, male: 556.1 µm) than C. cephalonica-reared T. ostriniae (female: 482.1 µm; male: 457.6 µm). Consequently, the A. pernyi-reared T.ostriniae females lived longer (14.1 d) and were more fecund (180.7) than were C. cephalonica-reared T. ostriniae females (longevity: 10.2 d; lifetime fecundity: 140.1). In addition, A. pernyi-reared T. ostriniae females parasitized greater numbers of target ACB eggs at different ages (12 h: 43.2; 24 h: 41.0) than did C. cephalonica-reared T. ostriniae (12 h: 35.2; 24 h: 31.4). These results demonstrated that the rearing host species impacted the performance of T. ostriniae in biological control of ACB and that the fitness of A. pernyi-reared T. ostriniae females was higher than that of C. cephalonica-reared T. ostriniae females, which should render them more effective biological control agents of ACB.