Parasitism rate and viability of Trichogramma maxacalii (Hym.: Trichogrammatidae) parasitoid of the Eucalptus defoliator Euselasia apison (Lep.: Riodinidae), on eggs of Anagasta kuehniella (Lep.: Pyralidae)

Parasitism rates and viability of individuals of two populations of Trichogramma maxacalii (Hymenoptera: Trichogrammatidae) were evaluated in two Eucalyptus plantations in the Counts of Ribeirao Preto, State of Sao Paulo and Nova Era, State of Minas Gerais, Brazil. These parasitoids were reared on eggs of the host Anagasta kuehniella (Lepidoptera: Pyralidae) with or without honey and were exposed to eggs of the host after 0, 6, 12, 24, 36, 48 and 60 h after emergence. Each recently emerged parasitoid female was placed in a 4.0 cm x 0.7 cm glass tube with a blue 3.5 cmx 0.5 cm cartoon with 40 glued non-viable eggs of A. kuehniella and parasitism was permitted during 24 h. Viability of I: maxacalii (above 96.0%) was not affected by the presence of food, by the origin of the parasitoid population, or by the period in which it was kept without eggs of the host. However, parasitism rate was higher than 75.0% and lower than 65.0%, for parasitoids with or without honey, respectively. Individuals of the population from Sao Paulo showed higher parasitism rates when they received eggs of the host at longer periods after its emergence. Parasitism was higher for the population from Minas Gerais when eggs of the host were provided soon after emergence. Parasitism behaviour in these two populations shows that they can be combined to obtain a better efficiency of I maxacalii in programs of mass release against Euselasia apisaon (Dalman) (Lepidoptera: Riodinidae) in Eucalyptus plantations. (C) 2000 Elsevier Science B.V All rights reserved.