Abnormal Antennal Olfactory Sensilla Phenotypes Involved in Olfactory Deficit in Bactrocera correcta (Diptera: Tephritidae)

SIMPLE SUMMARY: Tephritidae fruit flies sense odorants mainly through antennal olfactory sensilla with nanopores. Therefore, theoretically, the development of nanopore-targeted pest control technologies is an important direction in the future. Here, we report naturally occurring abnormal antennal trichoid and basiconic olfactory sensilla phenotypes consisting of abnormal bulges and reduced nanopore numbers in a long-term laboratory rearing colony of the guava fruit fly Bactrocera correcta, and further find that the reduction of nanopore numbers in these sensilla led to an olfactory deficit. Our findings provide a basis for developing nanopore-targeted pest control technologies in the future. ABSTRACT: The guava fruit fly, Bactrocera correcta, is one of the most destructive pests in the genus Bactrocera and detects environmental odorants mainly through antennal olfactory sensilla phenotypes with nanopores. However, it is unclear whether there are naturally occurring abnormal antennal olfactory sensilla phenotypes that affect olfaction. Here, we found that there were abnormal bulges besides nanopores on the surface of trichoid and basiconic olfactory sensilla in the antennal flagellum of long-term laboratory rearing colony (LTC), and that nanopore number in these olfactory sensilla was also remarkably reduced. Notably, the electroantennogram (EAG) responses of LTC insects to methyl eugenol or β-caryophyllene were inhibited, and their behavioral responses elicited by the same odorants were also impaired. These results revealed naturally occurring abnormal antennal olfactory sensilla phenotypes which were involved in olfactory deficit in B. correcta, providing a platform to further study nanopore-targeted pest control technologies in the future.