EFECTO DE POLVOS DE ASTERÁCEAS SOBRE EL GORGOJO DEL MAÍZ (SITOPHILUS ZEAMAIS MOTSCH)

Abstract

Eighty one species of Asteraceae collected
in the Mexican highlands were evaluated
for their usefulness against the maize weevil (Sitophilus zeamais Motsch). Flowers
and leaves of each species were separated,
dehydrated, and ground. One hundred
grams of disinfected grains of maize cv.
Cacahuazintle were placed in 250 ml glass
jar and mixed with 100 g of plant powder.
Ten pairs of 3 to 5 day old weevils were
then introduced into each jar. Only grains
and insects were placed in control jars.
All the experimental jars were kept under
constant relative humidity and temperature.
After 15 days, all the insects were removed and mortality was recorded. Fifty five
days after the experiment was initiated, F1
progeny emergence was assessed. Based
on mortalities ranging from 80 to 98%, the
best treatments were the leaf powders of
Aster subulatus, Chrysactinia mexicana,
Heliopsis annua, Heterotheca subaxillaris,
Parthenium incanum, Stevia serrata, and
Zinnia peruviana, as well as floral powders
of Thymophylla pentachaeta, Erigeron
longipes, Heterotheca inuloides var. rosei,
Senecio flaccidus, and Stevia serrata. With
regard to F1 emergence, the best treatment
was the leaf powder of C. mexicana,
which totally prevented F1 progeny from
emerging.