COMPARATIVE KAIROMONAL CHEMICAL ECOLOGY OF DIABROTICITE BEETLES (COLEOPTERA, CHRYSOMELIDAE, GALERUCINAE, LUPERINI, DIABROTICINA) IN A RECONSTITUTED TALLGRASS PRAIRIE ECOSYSTEM
Rl. Metcalf et al., COMPARATIVE KAIROMONAL CHEMICAL ECOLOGY OF DIABROTICITE BEETLES (COLEOPTERA, CHRYSOMELIDAE, GALERUCINAE, LUPERINI, DIABROTICINA) IN A RECONSTITUTED TALLGRASS PRAIRIE ECOSYSTEM, Journal of economic entomology, 91(4), 1998, pp. 881-890
The olfactory response to volatile semiochemicals was determined for D
iabrotica undecimpunctata howardi Barber, the spotted cucumber beetle,
Diabrotica virgifera virgifera LeConte, the western corn rootworm, Di
abrotica barberi Smith & Lawrence, the northern corn rootworm, and Dia
brotica cristata (Harris), a nonpest species in a tallgrass prairie ec
osystem and adjacent corn and cucurbit agroecosystems in Illinois. The
results indicate that the divergence in response to plant volatiles b
y these Diabrotica species can be correlated with currently accepted p
hylogenetic groupings between the virgifera and fucata groups, as well
as within the virgifera group. For example, cinnamaldehyde is most at
tractive to D. u. howardi (fucata group), whereas 4-methoxycinnamaldeh
yde is a specific attractant for D. u. virgifera (virgifera group). Th
e 2 closely related species D. barberi and D. cristata (virgifera grou
p) were both attracted to eugenol, cinnamyl alcohol, and 4-methoxyphen
ethanol on one or more test dates. Although D. cristata is not normall
y found in cucurbit blossoms, adults were attracted to traps containin
g shredded blossoms of Cucurbita maxima Duchesne ex Poir. Furthermore,
all 4 Diabrotica species responded to a multicomponent synthetic lure
(a cucurbit blossom mimic), suggesting a commonality of response to c
ucurbit blossom aroma. A review of the literature on Diabroticite chem
ical ecology suggests cucurbit volatiles acted evolutionarily as synom
ones, providing a primitive means of pollination for cucurbits. For se
veral Diabrotica species, the olfactory response to these volatiles al
so may have facilitated the finding of noncucurbitaceous pollen source
s.