Hy. Ho et Jg. Millar, Identification and synthesis of a male-produced sex pheromone from the stink bug Chlorochroa sayi, J CHEM ECOL, 27(6), 2001, pp. 1177-1201
The reproductive behavior of the stink bug Chlorochroa sayi was studied in
the laboratory. There was a sexual maturation period of about 10 days befor
e bugs began mating. Sexually mature adult bugs engaged in courtship consis
ting of antennation and head-butting of the female by the male, before the
female adopted a receptive posture and copulation occurred. Both sexes mate
d multiple times during their life-spans, with the mean duration of copulat
ions of virgin bugs (42.3 +/- 19.6 min) and experienced bugs (37.3 +/- 28.4
min) being similar. Most matings were initiated in the late afternoon or e
vening, when pheromone production by males was greatest. Males transferred
sperm and nutrients constituting about 17% of their body weight to females
during mating. Three male-specific components, methyl geranate, methyl citr
onellate, and methyl (E)-6-2,3-dihydrofarnesoate in a ratio of 100 : 0.45 :
1.6, were first detected in volatiles collected from male bugs on green be
ans about 9-12 days after the final molt to the adult stage. In vertical Y-
tube bioassays, females were attracted to odors from mature male bugs, and
to a blend of the three male-produced components. Low numbers of females al
so were attracted in field trials with the three-component blend. The relat
ively weak attraction may be a result of other, as yet unknown cues being r
equired in addition to the pheromone, such as visual or substrate-borne vib
rational cues.