Seletividade de três espécies de Trichogramma a ovos estéreis de lepidópteros em condições de laboratório

Abstract

This work was carried out in the Entomlogy Laboratories of the Crop Protection Department, Escola Superior de Agricultura de Lavras. The climatic conditions used in this work were a photoperiod of 14 hours, relative humidity of 55 ± 5% and temperature in function-of the two tests (23QC and 27°C). Olphatometers. of the diffusion type were used for determination of the parameters employed in this study. The objective of this work was to study the selectivity of T. pn.ztioòum, Tn.ickogn.amma sp. and T. dzmon.azòi at the temperatures 23°C and 27°C in relation to the infertile eggs of the three host species, G. mzllonzlla, V. òacckan.alU and S. iungipzn.da, maintained under refrigeration for a period of 14 days, by means of the index of the search ability, and index of attraction, the number of males and females collected on the first, second and third days of counting as well as the total number of males and females on the three days of counting. The data for the above parameters were analysed using the Kruskall-Wal1is test and compared using multiple comparisons. It was verified that, in the selectivity process, alterations occurred in the search ability in attraction and in behaviour of host selection, both for males and females of the three species of Tn.ickogn.amma in relation to the infertile eggs of the three host species maintained under refrigeration for 14 days. It was also verified that the females of the Tn.ickogn.amma spp showed a greater preference for the host G. mzllonzlla, and the variation in temperature did not affect the selectivity process of the males and females of these parasites.