Effects of different flours on the biology of the prey Tyrophagus putrescentiae (Schrank) (Acarina: Acaridae) and the predator Neoseiulus pseudolongispinosus (Xin, Liang and Ke) (Acari: Phytoseiidae)

Abstract

ABSTRACT Laboratory investigations on the biology of Tyrophagus putrescentiae (Schrank), a stored-food mite and the predator Neoseiulus pseudolongispinosus (Xin, Liang and Ke) were conducted using the flour of soybean (Glysin max L.), wheat (Triticum aestivum L.), and maize (Zea mays L.) as hosts. Efficiency of food was estimated according to time required for immature development, female fecundity, and survival of both sexes. Results indicated that the breeding activity of predatory mites fed on T. putrescentiae that had been cultured on wheat flour was more viable than that when T. putrescentiae were fed on maize and soybean hosts. Egg, larval, protonymphal, and deutonymphal stages of T. putrescentiae that fed on T. aestivum had faster development compared to those fed on Z. mays and G. max. Fecundity of T. putrescentiae was higher (23.8) on T. aestivum, than on the other diets tested (17.1 eggs on Z. mays and 11.4 eggs on G. max); female longevity averaged 34.1, 27.0, and 40.8 days and male longevity was 23.5, 18.7, and 28.7 days when raised on Z. mays, G. max, and T. aestivum, respectively. On a diet of T. aestivum the mean generation time from egg to adult of T. putrescentiae lasted for 11.7 days compared to 15.2 and 18.8 days when fed on Z. mays and G. max, and net population growth was 119.0, 61.0, and 32.0 mites per g substrate, accordingly. The predatory mite N. pseudolongispinosus when fed on T. putrescentiae cultured on different diets could reproduce normally and completed its development as successfully as T. putrescentiae. Average duration of egg and nymph development of N. pseudolongisponosus was statistically fastest with T. aestivum-fed T. putrescentiae compared with Z. mays and G. max. Mean total longevities of the female (29.4, 25.8, and 17.7 days) and male (20.8, 16.8, and 13.1 days) were significantly longer on T. aestivum than on Z. mays and G. max, respectively. Mean daily fecundity of female adults also increased on T. aestivum (3.5 per day) but decreased (2.8 and 1.2 per day) with Z. mays and G. max, while, total developmental time was 10.1, 11.8, and 12.9 days, respectively. The assessment of macronutrients in soybean, maize, and wheat flours showed that wheat had more carbohydrate and ash but reduced protein and fat contents and merits as leading compound in supporting higher mite populations. Consequently, the mass production N. pseudolongispinosus as a potential biocontrol agent under field as well as storage conditions using T. putrescentiae reared on a wheat diet would be an appropriate strategy.