INVESTIGADORES
BUTELER Micaela
congresos y reuniones científicas
Título:
Toxicity and cuticle softening effects of a petroleum oil and vegetable oils to the cotton boll weevil Anthonomus grandis Boheman (Coleoptera:Curculionidae).
Autor/es:
STADLER, T.; ZERBA, M.I.; BUTELER, M.
Lugar:
Sidney, Australia
Reunión:
Conferencia; Spray Oils Beyond 2000; 1999
Institución organizadora:
University of Western Sidney
Resumen:
To better understand the toxic effects of oils on insects, we
tested soybean (Glycine max (L.) Merr. [Fabales: Fabaceae]),
cottonseed (Gossypium hirsutum L. [Malvales: Malvaceae])
and an nC23 mineral oil on cotton boll weevil (Anthonomus
grandis Boheman [Coleoptera: Curculionidae]) to compare
their effect on insect cuticle hardness and to correlate this
with oil toxicity.
Adult weevils were obtained from USDA-ARS Mississippi,
USA. In 2 independent bioassays, groups of insects
were treated topically with oils (1 µL or 0.5 µL) to assess
changes in cuticle hardness and toxicity. Cuticle hardness
was evaluated by measuring the pressure required to crush
the cuticle of the weevils with a Gel-Tester. Toxicity was
evaluated from mortality.
The reduction in cuticle hardness was in the order cottonseed
oil (11.8%) < soybean oil (17%) < mineral oil (22.4%).
However, cuticles of insects treated with cottonseed oil were
not significantly softer than cuticles of untreated insects.
We found a relationship between cuticle softening and
toxicity: greater softening correlated positively with oil toxicity.
Variation in cuticle hardness could represent structural
changes at the cuticular level, with lethal consequences for
the insects. These results allow speculation on a new target
for insecticide oils. This could encourage further research
on the influences these products have on the structure and
properties of the body surface of insects.