Liquid preparation of diatomaceous earth against the lesser mealworm, Alphitobius diaperinus (Panzer, 1797) (Coleoptera: Tenebrionidae)

The lesser mealworm (LMW) is the most important pest in poultry production. Insects are associated to avian pathogens, mainly Salmonella. Its control is based on chemical insecticide, with limited efficacy in population reduction. Also, insect populations are resistant to the main active ingredients used. Diatomaceous earth (DE) is a mineral dust that has activity against the LMW when used in dust application. No information is available about DE liquid preparation against this insect. Thus, bioassays were conducted aiming to develop a strategy for DE liquid preparation to this insect control. In laboratory the ideal concentration for poultry house experiment was estimated and the effect of insect contact with poultry litter or chicken feed after application was checked. In the poultry house, DE liquid preparation (10% in water, 1 L·m­2) was applied on the dirt soil of a cleaned and empty poultry house. In the control poultry house, a chemical insecticide was used (cypermethrin 15 g + chlorpyriphos 25 g + piperonyl butoxide 15 g) (1 L·m­2). DE at all concentrations was efficient mainly when insects were dried for 24 h before contact with a substrate. In poultry house, both treatments obtained similar results at 15 days after treatment (94% of reduction of insect population). At 45 days after treatment, the insect population with DE treatment increased 39% while the insect population remained 17% smaller than the initial population with a chemical insecticide. DE liquid preparation has potential to be used as a safe treatment in LMW population management, as a shock treatment.

Sampling Methodology of Alphitobius diaperinus (Coleptera: Tenebrionidae) Population in Poultry Houses

Abstract This paper describes a methodology to evaluate Alphitobius diaperinus (Darkling beetle) population in order to estimate the effectiveness of control methods, consisting of direct sample collections from the poultry litter in 18 points, counting of adults and larvae, and subsequent comparison of the values obtained before and after of control strategies. It allows estimating the total population, population in a known area, as well to analyze the variations in different points all over the aviary. The method has shown to be very versatile, being indicated for population studies and efficacy evaluations, once it has already been validated in different experimental conditions.

Biological Parameters of Euschistus heros (F.) (Heteroptera: Pentatomidae) and its Susceptibility to Entomopathogenic Fungi When Fed on Different Diets

ABSTRACT: The effects of six diets on biological parameters of Euschistus heros (F.) (Heteroptera: Pentatomidae) and its susceptibility to entomopathogenic fungi Beauveria bassiana (Bb) and Metarhizium anisopliae (Ma) were studied. The diets included a standard diet (bean pods+soybeans, peanuts and sunflower) and diets in which the bean pods were combined with only one type of grain, either soybean, peanut, sunflower, pea or sesame seeds. The best performance was that of insects fed on standard diet, which had the shortest development period and 49.5% of egg-to-adult viability. The insects fed the pea diet exhibited less than 30% viability and 11% of adults had wing deformations. The finite rate of increase values for the treatment groups were: standard: 1.091; soybean: 1.077; peanut: 1.071; sunflower: 1.076; pea: 1.058; and sesame: 1.065. The susceptibility to Ma (55%) was greater than Bb (40%) only for insects fed on the sesame diet. Considering the effects of diet on susceptibility to both fungal species comparatively among the diet-treatment groups, the stink bugs fed the restrictive diets were more susceptible compared with those fed the standard diet. We concluded that diet composition affects the biological parameters of E. heros and differentially affects their susceptibility to Bb and Ma fungi.