Does the onset of sexual maturation terminate the expression of migratory behaviour in moths? A study of the oriental armyworm, Mythimna separata.
It is generally accepted that in most insects adults are sexually immature when they initiate migration and that migratory behaviour terminates with the onset of sexual maturation. However, a few studies examining the mating status of field collected moths have suggested that sexually mature individuals may continue migrating, but in these cases it was impossible to completely eliminate the possibility that the mated females captured came from local, non-migrant populations. In this study we examined the ovarian development of Mythimna separata females captured using a vertical pointing searchlight trap on Beihuang Island in the Bohai Gulf, China, a site >40km from land. Moths were collected from May to October from 2003 to 2008 in order to test the hypothesis that the onset of sexual maturation resulted in the termination of migratory behaviour. While females at the end of the summer had little ovarian development and were unmated, a significant proportion of those migrating northward in the early summer had developed ovaries and often had at least one spermatophore. Given that theses insects were captured while flying up to 500m above sea level, at a site with no local populations, the findings would not support the hypothesis and suggest that both ovarian development and mating may occur during migration.
Zhao
Xin Cheng
XC
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, PR China.
Feng
Hong Qiang
HQ
Wu
Bo
B
Wu
Xian Fu
XF
Liu
Zhong Fang
ZF
Wu
Kong Ming
KM
McNeil
Jeremy N
JN
D025041:Animal Migration; D000818:Animals; D002681:China; D005260:Female; D008297:Male; D009036:Moths / Q000254:growth & development / Q000502:physiology*; D010053:Ovary / Q000254:growth & development; D012726:Sexual Behavior, Animal; D012741:Sexual Maturation