EFFECT OF VEGETABLE POWDERS AND DIATOMACEOUS EARTH ON BIOLOGICAL ASPECTS OF ZABROTES SUBFASCIATUS (BOH., 1833) IN STORED BEANS

ABSTRACT

The objective of this work was to evaluate the effect of powders from 4 plant species anddiatomaceous earth,in different concentrations and mixed with stored beans, on the oviposition and some biological parameters of Zabrotes subfasciatus (Boheman, 1833) (Coleoptera: Chrysomelidae: Bruchinae) raised on beans, Phaseolus vulgaris, variety IAC-Carioca, under laboratory conditions (T = 25ºC ± 2, RH = 70 ± 10%; and photoperiod = 12h). An experiment in factorial design was conducted, the treatments being powders (4 vegetable, diatomaceous earth an control) and concentrations (0.1%, 0.5%, 1.0%, 2.0% and 3.0%) in a completely randomized design, with 10 replicates. Five pairs of the bruchin were placed within plastic containers, containing 10g of IAC-Carioca beans impregnated with the different concentrations of the powders. The following biological parameters were evaluated: oviposition, larval viability, and number and weight of emerged adults. The interaction of different powders with the concentrations was significant for all parameters evaluated, indicating that increased concentration increases the efficiency of the materials against the insect. The treatments with powders of leaves from Mentha pulegium L. and diatomaceous earth presented the highest efficiencies, followed by leaves + branches + in florescence from Chenopodium ambrosioides L. and leaves from Ruta graveolens L.; the powder of seeds of Azadirachta indica A. Juss. revealed the lowest efficiency in the control of Z. subfasciatus.

KEY WORDS  Phaseolus vulgaris ; mexican bean weevil; botanical insecticides; powders