The effect of egg extracts on the behavior of gravid female Bactrocera dorsalis and Bactrocera correcta and analysis of chemicals on the egg surfaces of these species
Author of the article:WEI Bo WEI Cheng-Mei LI Yun-Guo TANG Jia-Cai HU Xuan-Sheng LIU Hang DONG Wen-Xia
Author's Workplace:College of Plant Protection, Yunnan Agricultural University, National Key Laboratory for Conservation and Utilization of Biological Resources in Yunnan, Kunming 650201, China; Apple Industry Development Center of Zhaotong, Zhaotong 657900, China
Key Words:Bactrocera dorsalis; Bactrocera correcta; egg surface chemicals; behavioral response
Abstract:
[Objectives] To investigate the
effect of egg extracts on the behavior of gravid female Bactrocera dorsalis and B. correcta was measured, identify chemicals on the egg surfaces of
each species, in order to explain intra- and inter-species differences in the
role of semiochemicals in egg recognition, and provide a theoretical basis for
the chemical, ecological control of these pests. [Methods] The behavioral responses of mated female B. dorsalis and B. correcta to extracts from the eggs of these species were
investigated in a Y tube olfactometer, and their activity tracks analyzed with
the software EthoVision XT. Compounds on egg surfaces were identified by GC-MS and quantified by
calculating absolute calibration curves obtained from authentic standards. [Results] Egg extracts of B.
dorsalis attracted gravid females of this species (c2=9.383, P=0.002), but repelled female B. correcta (c2=6.737, P=0.009). However, egg
extracts of B. correcta were
attractive to both species (c2=4.235, P=0.040; c2=5.818, P=0.016). A total of 11
compounds were identified in egg extracts of B. dorsalis, including anethole, pentadecane, dodecanoic acid,
ethyl dodecanoate, (Z)-11-tetradecenoic
acid, tetradecanoic acid, ethyl tetradecanoate, ethyl (E)-9-hexadecenoate, hexadecanoic acid, octadecenoic acid and ethyl (Z)-9-octadecenoate.
Only 7 compounds were identified from extracts of B. correcta eggs, and these were also identified from extracts of B. dorsalis eggs. Anethole, dodecanoic acid, ethyl dodecanoate, (Z)-11-tetradecenoic
acid were only detected in extracts from B. dorsalis eggs. The amounts of tetradecanoic acid, ethyl (E)-9-hexadecenoate, and hexadecanoic acid were higher in extracts from B. dorsalis eggs than in those
from B. correcta eggs. [Conclusion] Species-specific egg surface semiochemicals
allow B. correcta to distinguish its
own eggs from those of B. dorsalis,
and there are significant differences in the chemical composition of the eggs
of these two fruit fly species.