Little information is available regarding the lethal and sublethal effects of pesticides on Trichogramma achaeae (Nagaraja and Nagarkatti; Hymenoptera: Tricogrammatidae) during integrated management of Tuta absoluta (Meyrick; Lepidoptera: Gelechiidae), an important pest for tomato production. Twenty-two pesticides sprayed on Ephestia kuehniella (Zeller; Lepidoptera: Pyralidae) eggs were evaluated on the mortality of adult parasitoids upon contact with the hosts 24 h after the treatments and their sublethal effects on the parasitoids were assessed in laboratory conditions. Tests were carried out with fresh solutions at the recommended concentration. According to the International Organisation for Biological and Integrated Control (IOBC) standards, chlorpyrifos is harmful to the parasitoid; merthiocarb, methomyl, spinosad lambda-cyhalothrin, and acrinatrin are moderately harmful; and chlorantraniliprole, lufenuron, hexythiazox, cyromazine and Bacillus thuringiensis have no effect on the parasitoid. Sulfur is slightly harmful, and azoxystrobin is harmless. Chlorpyrifos was the most lethal among these pesticides and killed all females in less than 24 h. All other pesticides affected the biological parameters of T. achaeae to varying degrees. Regarding the lethal and sublethal effects, merthiocarb and spinosad killed all female offspring in less than 24 h; lambda-cyhalothrin and sulfur reduced the number of parasitized eggs; and acrinatrin, deltamethrin and azoxystrobin affected the emergence rate. After that, we can recommend the use of chlorantraniliprole and B. thuringiensis to control Lepidoptera, cyromazine to control Diptera, pirimicarb to control Homoptera, hexythiazox to control mites and azoxystrobin can be used as fungicide in an integrated pest management program with mass released of T. achaeae.

Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is an important pest of tomato crops. It is native to South America and has rapidly extended its range into Mediterranean countries. The parasitoid Trichogramma achaeae Nagaraja and Nagarkatti (Hymenoptera: Trichogrammatidae) has been recommended as a possible biological control agent of this invasive pest. The pest and parasitoid were accidentally introduced into the Azores Islands and became well-established owing to the climate conditions of the region. During an undertaken survey to determine the presence of natural parasitism, 2.5% of the T. absoluta eggs were found to be parasitized by Tr. achaeae, and no other egg parasitoid was observed. Other Trichogramma species, Trichogramma cordubensis Vargas & Cabello, was also selected to test, along with Tr. achaeae, against T. absoluta on caged tomato plants (microhabitats), and the effectiveness of these parasitoids in limiting the T. absoluta populations was assessed. The results revealed that Tr. achaeae had a high parasitism and emergence rate (29.6% and 65.9%, respectively), relative to those rates observed for T. cordubensis (6.1% and 39.3%, respectively). Greenhouse assays were also carried out between May and July in 2013 and 2014 on commercially produced tomatoes with the aim of evaluating the potential of Tr. achaeae mass releases for the control of T. absoluta under these conditions. In the second year, we observed a reduction in the mean number of leaf mines and of eggs, larvae, and pupae of T. absoluta per leaflet, and an increase in the Tr. achaeae parasitism rate.