Efeito de diferentes inseticidas sobre três linhagens de Trichogramma pretiosum Riley, 1879 (Hym.:Trichogrammatidae) em condições de laboratório

Abstract

This work was carried out with the objective of determining the effects of some insecticides on the parasitism and development of three strains of Trichogramma pretiosum Riley, 1879 (Hym.: Trichogrammatidae) in eggs of Anagasta kuehniella Zeller, 1879 (Lep.: Pyralidae) to obtain informations which can help in the utilization of these microhymenopterous in pest management programs. The experiments were conducted in the Biological Control Laboratory of the Plant Protection Department at the "Escola Superior de Agricultura de Lavras" (ESAL) in Lavras (MG), Brazil, from January to December of 1992, under controlled conditions (temperature of 25 ± 1°C, relative humidity of 70–10% and photophase of 14 hours). Eggs of A. kuehniella were sprayed in a Potter tower and later introduced to females of T. pretiosum. The insecticides tested and the dosages of the commercial products used were respectively diflubenzuron (Dimilin 250 PM – 0.6 g/l), triflumuron (Alsystin 250 PM – 2.0 g/l), flufenoxuron (Cascade 100 CE – 1.0 ml/l), deltametrina (Decis 25 CE – 0.3 ml/l), cartap (Cartap BR 500 PS – 1.5 g/l) e clorpiriphos (Lorsban 480 BR CE – 5.0 ml/l). Diflubenzuron was the best for pest management programs with all strains studied. On the other hand, triflumuron may be used in control programs with the Alegre strain only, not being recommended for the other ones. The results obtained showed that strains of T. pretiosum originated from different regions can react differently in their susceptibility to insecticides.