Population growth of stored product insects on wheat containing wheat bugs

Abstract

AbstractIn the present study we examined the effect of the presence of wheat bugs (Eurygaster spp. and Aelia spp.) on wheat on the mortality, progeny production and infestation patterns of three stored product insects, Trogoderma granarium Everts, Sitophilus oryzae (L.) and Rhyzopertha dominica (F.). The bioassays were carried out under laboratory conditions (25 ± 1 °C, 60 ± 5% relative humidity (r.h.) and continuous darkness), and 20 adults of each stored product insect species were placed in plastic vials (3 cm in diameter, 8 cm in height) with wheat that contained different numbers of wheat bugs (1, 2, 3 or 5 adults). In general, stored product insect mortality was not affected by the presence of wheat bugs, in most of the combinations examined. In most of the cases, mortality of T. granarium was higher on wheat which contained Eurygaster that wheat containing Aelia, while progeny production of S. oryzae was also affected by the presence of wheat bugs. Frass production for all combinations was similar, but greater frass production occurred by all combinations of R. dominica with Aelia. Overall, the presence of wheat bugs could affect the survival and the progeny production of both S. oryzae and R. dominica. In general, our results showed that beetle longevity and fecundity can be affected by the presence of wheat bugs that are likely to be present in stored grains after harvest. Graphical abstract