Search Ability of Anisopteromalus calandrae (Hymenoptera: Pteromalidae) for Larvae of Lasioderma serricorne at Different Depths and over Time in Stored Tobacco.

ABSTRACT

During storage time of agricultural products, the attack of insect pests may cause great losses. In tobacco, it occurs in the producer's warehouses, and in processing companies, one of the species that cause damage is Lasioderma serricorne (Fabricius). Thus, the aim of this study is to evaluate the search ability of the parasitoid, Anisopteromalus calandrae (Howard), for larvae of L. serricorne in tobacco. For this, couples of A. calandrae were released into PVC tubes (50 × 10 cm) filled with crushed dried tobacco on plates containing 20 larvae of L. serricorne at four depths (10, 20, 30, and 40 cm). In addition, and as a comparison, bales of tobacco were placed in tissue bags. Six plates contained 30 larvae of L. serricorne each and 50 couples of A. calandrae were released in each bag. After 1, 3, or 7 days, the plates were removed and kept in climate room (28 ± 2 °C, 60 ± 10% RH, and photophase of 12 h) until the emergency of the offspring. In all bioassays, A. calandrae was able to find and parasitize the offered larvae. For the experiment set in the tubes, the parasitism level was up to 84% in the larvae placed closest to the surface, gradually decreasing as the depth increased. In bales, the longer the larvae were exposed to the parasitoid, the higher the rate of infestation control. These results show that A.calandrae is able to find and parasitize larvae of L. serricorne in tobacco storage environments.