Susceptibility of Alphitobius diaperinus in Texas to permethrin- and β-cyfluthrin-treated surfaces

Five Surfaces Treated with d-Tetramethrin plus Acetamiprid for the Management of Tenebrio molitor and Alphitobius diaperinus: Which Is the Best?

Tenebrio molitor L. (Coleoptera: Tenebrionidae) and Alphitobius diaperinus Panzer (Coleoptera: Tenebrionidae) are two common tenebrionids occurring in grain storages. In this study, we assessed the immediate and delayed mortalities caused by d-tetramethrin plus acetamiprid on five different surfaces, i.e., plastic, glass, metal, wood, and ceramic, against adults of the two species. The tests included two label doses of the insecticide (minimum and maximum) and two food scenarios (food and no food). Generally, the maximum dose was more efficient than the minimum dose, and the presence of food resulted in lower observed mortalities than when food was absent. Tenebrio molitor was more susceptible than A. diaperinus, at all dose, food, and surface scenarios. At delayed bioassays, both doses killed all T. molitor on plastic, while on wood, mortality ranged between 80.6 and 100.0%, regardless of the food scenario. Concerning A. diaperinus, delayed mortalities ranged among treated surfaces, food scenarios, and dose from 58.3 to 100.0%. The insecticide killed the most individuals when it was treated on glass, while when it was applied on wood caused the death of the least individuals. Concerning plastic, metal, and ceramic surfaces, no general trend was observed. The maximum dose of the tested insecticide provides elevated mortalities for both species when food is absent.

Differences in the Susceptibility to Commercial Insecticides among Populations of the Lesser Mealworm Alphitobius diaperinus Collected from Poultry Houses in France

Simple Summary

The lesser mealworm Alphitobius diaperinus is a major pest from poultry houses worldwide. There was suspicion that populations of A. diaperinus had developed resistance to insecticides in poultry farms in France. Here, we evaluate the insecticide susceptibility of adult A. diaperinus from ten populations sampled from different poultry farms. The insects were exposed to four commercial insecticides: two pyrethroids, one pyrethroid/neonicotinoid and one organophosphate. Our results strongly suggest the occurrence of resistance to pyrethroid-based formulations in some farm populations from Brittany (France).

Abstract

The control of insect pests often relies on the recurrent application of insecticides. This is the case for the lesser mealworm, Alphitobius diaperinus, an invasive beetle infesting poultry farms. There is evidence that A. diaperinus can develop resistance to several insecticides. Evaluation of such resistance has never been conducted in France, despite the beetle’s presence since the 1970s. We assess insecticide susceptibility in 10 populations from French poultry farms and compare patterns with two susceptible populations. Adults are subjected to short-term exposures (4 h) to four commercial insecticides and their recovery is assessed. Temporal survival also is scored during constant exposures for seven days. Clear-cut differences among the farm populations are found. Except for three populations that have patterns similar to those of the two susceptible populations, all the other farm populations have a much greater capacity to recover and survive insecticide exposures, especially to pyrethroid-based formulations. Three populations in particular even exhibit clear signs of resistance to pyrethroids, with median lethal times more than 10-fold superior to values of the susceptible population. No insect in any population recovers from the pirimiphos-methyl exposure, and all beetles are apparently dead after 15 h. Our results demonstrate the existence of resistant populations to pyrethroids in Brittany France.

Effectiveness of Biocidal Paint Containing Permethrin, Ultramarine and Violet 23 Against Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) in Laboratories and Poultry Houses

Reducing Alphitobius diaperinus in poultry production is a difficult task. However, attempts should be made to control the insect pest, as it poses a serious threat to the life and health of the chickens, as well as the workers on a farm. Our research was conducted in two stages to assess the effectiveness of the biocidal paint against A. diaperinus, containing active substances such as permethrin and a mixture of ultramarine and violet 23. In the first stage, under laboratory conditions, after 22 days, 100% mortality of A. diaperinus larvae and adults was achieved. This allowed us to assume that the biocidal paint may also be effective in poultry houses. In the poultry house where biocidal paint was applied, the number of insects decreased continuously alongside the sampling dates. In both research stages, the biocidal paint proved more effective against A. diaperinus than traditional limewash, and also the time to effective interaction of the paint was noted. Additionally, it was observed that the larvae were more susceptible to the active substances than adults. The research was practical, however, further analyses are necessary to fully control A. diaperinus, especially in poultry houses.

Susceptibility of the Lesser Mealworm, Alphitobius diaperinus (Coleoptera: Tenebrionidae), From Broiler Farms of Southern Brazil to Insecticides

The lesser mealworm, Alphitobius diaperinus (Panzer, 1797) (Coleoptera: Tenebrionidae), is considered the primary insect pest in broiler farms in Brazil. In this study, we characterized the susceptibility of A. diaperinus populations from broiler farms of southern Brazil to cypermethrin and chlorpyrifos. Larvae and adults of A. diaperinus were exposed to these technical insecticides diluted in acetone in residual bioassays. A geographic variation in the susceptibility of larvae and adults of A. diaperinus to both insecticides was detected. The larval LC50 for cypermethrin ranged from 0.43 to 7.33 µg a.i./cm2. Two populations from Santa Catarina state presented higher resistance ratios of 13.6- and 17-fold. When adults were exposed to cypermethrin, the LC50 ranged from 0.46 to 4.93 µg a.i./cm2, with population SC-3 from Santa Catarina having lower susceptibility (resistance ratio of 10.7-fold). When exposed to chlorpyrifos, A. diaperinus larvae present LC50 values ranging from 0.21 to 4.30 µg a.i./cm2. Larvae from Paraná and Santa Catarina (SC-1 population) presented the highest resistance ratios, ranging from 10- to 20-fold. In adults, the LC50 of chlorpyrifos ranged from 0.17 to 5.30 µg a.i./cm2, showing a maximum resistance ratio of 31-fold in a population from Paraná state. Based on LC99 values, candidate diagnostic concentrations of 15 and 12 µg a.i./cm2 of cypermethrin and chlorpyrifos, respectively, were also estimated for the resistance monitoring of A. diaperinus in Brazil. The implications of these results in Insect Resistance Management are discussed.