Improvement of ethological methods for integrated management of fruit flies, Anastrepha spp. (Diptera: Tephritidae) in fruit orchards in the Dominican Republic

Abstract

During the last decade in the Dominican Republic, research efforts have been carried out to contribute to the ethological and biological components of the integrated pest management of fruit flies (FF) in mango, guava and other fruit orchards. Besides listing published results, this paper focuses on studies concerning one component directed to test and improve cost-effective trapping methods, especially in the use of locally produced experimental yeast-based lures (LC) and as enzymatically accelerated hydrolizates of yeasts (HdL) as lures for traps and for bait sprays. In on-farm trials with randomized blocks design and using baited Multilure. traps, the daily captures of Anastrepha suspensa were compared for several commercial lures based on hydrolyzed proteins in a commercial guava orchard. In addition, HdL were tested and improved versions compared for A. obliqua in mango orchards. In all cases the LC as check served (Ogando and Serra, 2006), whose results were at least similar to the best of the tested commercial attractants and improved HdL. The latter, but also residues of their production process named extraction cake 'erelative check' for the 2nd part), and other sources for protein may only have a potential to develop an efficient FF lure if used with additives (e.g., borax 2%, among others). These products help to increase and stabilize the pH (e.g., ≥8.2) of the attractant solution for at least 2-3 (or desirable up to 6) weeks. The amount of by-catches, mainly of flies from other families, seemed to be favored through the low pH of some attractant solutions and were noticed much more important in lures that do not effectively trap FF. The results of bait sprays with the organophosphate malathion and the microbial spinosad, both combined with a commercial lure or HdL, showed some short-termed effects on each of the FF species. These trials should be repeated on a much larger scale to impede a quick reinfestation and assure a more accurate measurement of the impact on the FF populations.