Pyrethroid and organophosphate pesticide resistance in field populations of horn fly in Brazil

Abstract

Pesticides are used worldwide to control arthropod parasites in cattle herds. The indiscriminate and/or inappropriate use of pesticides without veterinary guidance is a reality in several countries of South America. Improper pesticide use increases the chances of contamination of food and the environment with chemical pesticides and their metabolites. Reduction of these contamination events is an increasing challenge for those involved in livestock production. The horn fly, Haematobia irritans (Linnaeus) (Diptera: Muscidae), is one of the most economically important parasites affecting cattle herds around the world. As such, horn fly control efforts are often required to promote the best productive performance of herds. Pesticide susceptibility bioassays revealed that pyrethroid resistance was widespread and reached high levels in horn fly populations in the Brazilian state of Rondônia. The knockdown resistance (kdr) sodium channel gene mutation was detected in all horn fly populations studied (n = 48), and the super kdr sodium channel gene mutation was found in all homozygous resistant kdr individuals (n = 204). Organophosphate resistance was not identified in any of the fly populations evaluated.

Preparation of Matrinic/Oxymatrinic Amide Derivatives as Insecticidal/Acaricidal Agents and Study on the Mechanisms of Action against Tetranychus cinnabarinus

“…Although many chemical pesticides have been extensively used to reduce the threat of pests to crop production, insect pest resistance and negative impacts on human health and environment usually occur. − Recently, much attention has been paid to develop new potential alternatives for efficiently controlling pests directly or indirectly from plant secondary metabolites. − Matrine ( 1 , Figure ) and oxymatrine ( 1′ , Figure ) are two quinolizidine alkaloids isolated from the roots of Sophora flavescens (Kushen). , Matrine, oxymatrine, and their derivatives not only displayed a variety of biological properties (e.g., anti-inflammatory, − anticancer, − and antiviral activities − ) but also possessed potential agrochemical activities. − …”

Pyrethroid Susceptibility in Stomoxys calcitrans and Stomoxys indicus (Diptera: Muscidae) Collected from Cattle Farms in Southern Thailand

“…Inappropriate and excessive use of insecticides causes contamination in the environment and induces resistance in arthropods. Their metabolites result in a reduction in contamination events and increase the challenges for those involved in livestock production, along with insecticide resistance issues [ 21 ]. Adult stable flies may be exposed to insecticides that are used during outbreak situations, such as insecticidal fogging and residual spraying to reduce the impacts of stable flies on animals.…”

Use of pesticides in agriculture and emergence of resistant pests

“…This mode of resistance was termed knockdown resistance (kdr) (Ying et al, 2019). The kdr sodium channel gene mutation was detected in horn fly populations, and the super kdr sodium channel gene mutation was found in homozygous resistant kdr individuals (Brito et al, 2019).…”

“…Consequently, mosquito-borne diseases have become resurgent, largely because of the developed insecticide resistance in mosquito vectors and the drug resistance of pathogens (Nannan, 2015). The horn fly, Haematobia irritans L. (Diptera: Muscidae), an important parasites affecting cattle herds around the world exhibited widespread resistance against pyrethroid insecticides while resistance against organophosphate insecticides was not identified in any of the fly populations evaluated (Brito et al, 2019). Pest resistance to transgenic crops (which are genetically developed to defend themselves against some pests) have also been reported in Bt (Bacillus thuringiensis) maize (Gassmann et al, 2011).…”