Resistance of the stable fly, Stomoxys calcitrans (Diptera: Muscidae), to cypermethrin in outbreak areas in Midwestern Brazil

Abstract

Population explosions of the stable fly (Stomoxys calcitrans) have become a serious concern for livestock producers near sugarcane mills in some regions of Brazil due to the insect’s massive reproduction on sugarcane byproducts and waste. Despite the limited efficiency of insecticides for controlling stable fly outbreaks, producers still rely on chemical control to mitigate the alarming infestations in affected areas. This study evaluated the susceptibility of S. calcitrans populations to cypermethrin in the state of Mato Grosso do Sul, Brazil. Stable flies were tested from three field populations and two colonies, established from flies previously collected at sugarcane mills. Wild flies were collected with Nzi traps in areas of sugarcane plantations. Both wild and colonized flies were exposed to eleven concentrations of cypermethrin in impregnated filter paper bioassays. All the populations proved to be resistant to cypermethrin, with resistance factors among field populations ranging from 6.8 to 38.6. The intensive use of insecticides has led to the development of pyrethroid resistance in stable fly populations in the proximities of sugarcane mills in the state of Mato Grosso do Sul.

Insecticidal Activity of Plectranthus amboinicus Essential Oil against the Stable Fly Stomoxys calcitrans (Diptera: Muscidae) and the Horse Fly Tabanus megalops (Diptera: Tabanidae)

“…In the present study, we selected and used only unfed flies to reduce the factor of physiological status in accordance with WHO recommendations [ 32 ]. Indeed, several studies on insecticide susceptibility used wild caught flies, such as sand flies [ 35 , 36 ] and stable flies [ 12 , 37 ].…”

“…However, the repeated use of chemicals causes insects to develop resistance to insecticides, leading to adverse effects on human and environmental health. Stomoxys calcitrans is reportedly resistant to organophosphates and pyrethroids [ 11 , 12 , 13 ]. The use of natural products, especially plant essential oils, as an alternative to chemical agents has attracted increasing interest because they are safe and exhibit biological activity against insects [ 14 , 15 ].…”

A Historical Review of Management Options Used against the Stable Fly (Diptera: Muscidae)

“…Five years later, signs of permethrin resistance were evident in Florida stable fly populations [61] and first noted in European populations soon after [62,63]. Most recently, the widespread use of insecticides against stable fly outbreaks in Brazil have resulted in the populations around sugar cane mills in the state of Mato Grosso do Sul becoming resistant to cypermethrin, with resistance factors up to 39 [64]. Similarly, Reissert-Opperman et al [65] found that stable flies across dairy farms in Germany were 100% resistant to deltamethrin.…”

Infection and reinfection of Stomoxys calcitrans larvae (Diptera: Muscidae) by entomopathogenic nematodes in different times of exposure

“…Arthropod pests have become resistant to most chemical pesticides (Barros et al, 2019). In addition, society is becoming increasingly aware about the effects of these substances on nature and human health, so new means are needed to control these organisms.…”