Side Effects of Organic Products on Telenomus podisi (Hymenoptera: Platygastridae).

Telenomus podisi Ashmead, 1893 is an important biocontrol agent, both in conventional and organic production systems. It can be used in association with other control strategies, such as natural botanical products and biological insecticides. Studies of selectivity and side effects are fundamental for proper management of insect control strategies because the interaction between different control strategies may negatively affect T. podisi. In this context, the present study evaluated the side effects of commercial natural products on T. podisi under laboratory conditions. Five natural products (insecticide, fungicide, and leaf fertilizer) allowed in organic farming were evaluated at concentrations recommended by the manufacturer in three bioassays. First bioassay (free-choice test), the preference of T. podisi parasitism between treated and non-treated E. heros eggs was assessed. In the second and third bioassay (no-choice tests) the treatments were applied to E. heros eggs, repectively before and after T. podisi parasitism (pre- and post-parasitism) and parasitism, emergence, offspring sex ratio, developmental time, and adult longevity were assessed. The products formulated with Metarhizium anisopliae (Metsch.) Sorok. (Hypocreales), Beauveria bassiana (Bals.) Vuill. (Hypocreales), orange oil fertilizer, and the fungicide copper oxychloride did not have side effects on T. podisi because they did not affect most of the evaluated characteristics. In contrast, azadirachtin A/B had a sublethal effect due to the reduced parasitism in all tests performed and, although it did not affect other aspects, this could compromise the performance of the parasitoid.

Selectivity of neem to Trichogramma pretiosum Riley and Trichogrammatoidea annulata De Santis (Hymenoptera: Trichogrammatidae)

Trichogramma pretiosum Riley and Trichogrammatoidea annulata De Santis are commonly found in avocado and persimmon orchards in northern Parana state. However, their abundance depends on whether insecticides are used or not to control the key lepidopteran pests Stenoma catenifer (Wals.) (Lepidoptera: Elachistidae) and Hypocala andremona (Stoll) (Lepidoptera: Noctuidae), respectively. The aim of this work was to evaluate the effects of an aqueous neem seed extract (ANSE) at 15, 3 and 1.5 percent, and of an emulsifiable concentrate neem oil (ECNO) at 2.5, 0.5 and 0.25 percent on lifetime parameters of these trichogrammatids as a way of testing the feasibility of integrating the biological and chemical control methods. Chemicals were applied on Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae) eggs before or after parasitization (one, three or five days). ANSE was more deleterious to both parasitoid species than ECNO, regardless of the concentration and the time of application. The chemicals acted on a concentration and time dependent manner. Treating the host with neem before parasitism was less deleterious to wasp emergence, especially for T. annulata. Pre-treatments (24h) of the host eggs with ECNO at concentrations varying from 0.5 percent to 0.25 percent did not affect T. pretiosum longevity, but 2.5 percent reduced T. annulata survival. Feeding wasps with honey mixed with 0.25 percent ECNO negatively affected T. annulata survival.