Rpj. Potting et al., GEOGRAPHIC-VARIATION IN HOST SELECTION BEHAVIOR AND REPRODUCTIVE SUCCESS IN THE STEMBORER PARASITOID COTESIA-FLAVIPES (HYMENOPTERA, BRACONIDAE), Bulletin of entomological research, 87(5), 1997, pp. 515-524
Local parasitoid populations may be adapted to their sympatric major p
lant host complex. Parasitoid strains may thus differ in their propens
ity to search for a particular micro-habitat or host or they may diffe
r in their physiological compatibility with particular plant or host s
pecies. Cotesia flavipes Cameron, a larval parasitoid used worldwide i
n biological control against tropical stemborers, has a wide host rang
e in diverse habitats. The existence of plant and/or host specific str
ains in C. flavipes has been postulated. To provide insight into the e
xistence of strains in C. flavipes, we compared the plant/host complex
selection behaviour, and physiological compatibility with different s
temborers, of six different geographic strains of C. flavipes that dif
fered in the plant/host complex they were obtained from. The results o
f the host selection experiments indicate that there is no intraspecif
ic variation in host selection behaviour among C. flavipes strains. Ho
wever, our comparative experiments show variation in reproductive succ
ess among strains. The most significant result was that the strain wit
h the longest period of co-existence with the new host Diatraea saccha
ralis Fabricius had the highest reproductive success on this host spec
ies. We argue that the reported existence of C. flavipes strains is ba
sed not on differences in host selection behaviour, but on differences
in physiological compatibility between local parasitoid and host popu
lation.