Endocrinology Abstracts

Effects of pheromones in artificial diets for predatory bugs

J. C. Zanuncio 1 , J. B. Torres 2 , E. F. Vilela 1 & M. D. A. Coracini 1

1 Dep. de Biologia Animal, Univ. Federal de Viçosa. 36.571-000 Viçosa, Minas Gerais, Brasil; 2 . Univ. Federal Rural de Pernambuco. Recife, Pernambuco, Brasil

[0587] , . Predatory bugs can present satisfactory results with alternative prey but rearing them represents an additional cost. For this reason artificial diets are been used but development and reproduction of these bugs with them are inferior than with natural or alternative prey because these predators feed on diet for short periods of time than with prey. Two studies were developed aiming to increase attractiveness of an artificial diet to Podisus nigrispinus and Supputius cincticeps. The first evaluated possible attractant and feeding stimulant effects of extracts of dorsal abdominal glands of these predators in the diet of their nymphs compared to those fed factitious prey. The extract spread over the diet attracted 88% of the nymphs of P. nigrispinus. Nymphs feeding on diet with extract (spread over and added– 84%) or M. domestica larvae showed similar results. Nymphs of S. cincticeps feeding on the same diet showed maximum value of 60 and 56% but lower than that achieved on the factitious prey Tenebrio molitor (92%). Second instar nymphs of P. nigrispinus and S. cincticeps showed similar lower weights when reared on the artificial diet (2.7 mg and 1.2 mg), diet with extract (2.8 and 1.6 mg), extract spread over the diet (2.1. and 1.0 mg), or spread over and added to the diet (2.4 and 1.3 mg) than that on the factitious prey (3.1 and 3.0 mg). Effect of the synthetic sexual pheromone of P. nigrispinus on the localization and acceptance of an artificial diet and also on nymphal development and female fecundity of P. nigrispinus were evaluated. The complete synthetic sexual pheromone or its components were applied to the diet at 0.05 ?g/?g concentration. The artificial diet with pheromone promoted an weight gain similar to that with M. domestica larvae, but did not improve the development of this predator over several generations compared to those fed only pure diet. Nymphal development period was longer for nymphae with pure diet, diet with pheromone, with ?-terpinol or with (E)-2-hexenal; and it was shorter in the treatments: diet with linalool, M. domestica larvae, diet with the three major components, with trans-piperitol or with benzyl alcohol. During three generations nymph survival was generally lower when fed M. domestica larvae than with pure diet or diet containing complete pheromone. Females fed M. domestica larvae presented shorter longevity and greater egg production than those fed pure diet or diet containing complete pheromone. Extracts of dorsal abdominal glands or sexual pheromone of P. nigrispinus or S. cincticeps added to artificial diet can increase performance of these predators in such diets. Index terms: Podisus nigrispinus, Supputius cincticeps, olfactory responses

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