Performance of Chouioia cunea reared from a coleopteran alternative host as a biocontrol agent against the invasive lepidopteran pest, Hyphantria cunea.

BACKGROUND

Chouioia cunea is a generalist pupal endoparasitoid. Native to Eurasia, the parasitoid has been mass-reared on an alternative lepidopteran host (Antheraea pernyi) to successfully control the exotic invasive lepidopteran pest Hyphantria cunea in China. To solicit more accessible hosts, this study evaluated the potential of an easily cultured coleopteran beetle (Tenebrio molitor) as a substitute for rearing C. cunea through comparing the relative performance of the parasitoids reared from both alternative hosts on H. cunea.

RESULTS

Compared with those reared from A. pernyi, the parasitoids reared from T. molitor (i.e., T. molitor vs. A. pernyi groups) performed equally well in terms of parasitism rate (94.4 vs. 88.9%), number of offspring produced per parasitized host (278 vs. 286), and female body length (1.334 vs. 1.351 mm), hind-tibia length (0.322 vs. 0.324 mm) and number of mature oocytes in the ovarioles (171 vs. 187), or even better based on offspring pre-emergence time (16.0 vs 16.9 days) and percentages of emerged offspring (99.8 vs. 99.1%) and female offspring (97.1 vs. 91.3%). Flight performance testing indicated that young C. cunea adults emerged from T. molitor had a similar percentage of actively flying wasps (76.9 vs. 72.9%) and a lower percentage of inactive wasps (2.3 vs. 10.6%) when compared to those reared from A. pernyi.

CONCLUSION

Given the remarkable adaptability of C. cunea and the vast availability of T. molitor as a common resource insect worldwide, this indigenous parasitoid could be mass-reared on T. molitor to improve the prospect of biological control of H. cunea in its invaded regions. © 2022 Society of Chemical Industry.