Maria
De Jesus P. de Castro, Paulo Henrique S. da Silva, Jonas
R. Santos e José Algaci L. da Silva
Callosobruchus
maculatus (Fabr.) is one of
the main pests of stored cowpea (Vigna unguiculata
(L.) Walp.). This
study investigated alternatives for the chemical control of these
insects by
determining, in lab conditions, the bioactivity of plant powders of Piper
tuberculatum Jacq., Lippia
sidoides Cham.,
Sapindus
saponaria L. AND Melia
azedarach L. on C.
maculatus oviposition preference. A completely randomized
design was
performed with eight treatments and four repetitions (four treatments
with 10%
of one type of vegetal powder mixed to the grains and four control
treatments
with pure grains). Eighty adult insects were released and kept for 48 h
in a
eight-port olfactometre to choose among the treatments. The adults were
then
removed and the number of eggs laid on the grains recorded. The most
efficient
treatments were the powder of L. sidoides leaves,
with 100% control,
followed by P. tuberculatum fruits and S.
saponaria leaves and
seeds. The other treatments did not affect C. maculates
oviposition
significantly.