Survival and Fecundity of Anopheles stephensi and Anopheles albimanus Mosquitoes (Diptera: Culicidae) After Ingesting Bovine Blood Containing Various Veterinary Systemic Parasiticides

Abstract

Systemic parasiticides in livestock can control zoophilic malaria vectors that contribute to residual malaria transmission. Membrane feeding techniques were used to screen seven systemic parasiticidic drugs currently in veterinary use for livestock and dogs. Drugs were tested in two laboratory strains of zoophilic Anopheles – A. stephensi (South Asian vector) and A. albimanus (Central American vector). To assess the relative potentials of these drugs, the resultant LC-50 for each drug was compared with what is known about the pharmacokinetic of the drug. Drugs with LC-50 values below the reported maximum plasma concentration of treated animals were considered as showing the most promise for use in the field. Ivermectin and fipronil showed the greatest promise for use in cattle against A. stephensi. Fipronil showed the greatest promise for use in cattle against A. albimanus. Both fluralaner and afoxolaner were highly effective against both mosquito species but pharmacokinetic data for these drugs in cattle are lacking. Eprinomectin, moxidectin and abamectin showed marginal to no promise for either mosquito species. At sublethal doses, ivermectin, fipronil, and afoxolaner (but not fluralaner) significantly reduced the larval production of surviving A. stephensi and A. albimanus. Further testing of candidate systemic parasiticides, including their product formulations, in livestock against field-collected populations of Anopheles is the next logical step toward full implementation of this strategy to manage zoophilic vectors.

Effect of Fluralaner on the biology, survival, and reproductive fitness of the Neotropical malaria vector Anopheles aquasalis

“…aquasalis. The low values determined here are more than suitable to cause a lethal effect on this malaria Neotropical vector even though it is known that much higher maximum concentrations of the drug are presented in the bloodstreams of dogs (45), cats (46), and cattle (47).…”

“…The administration of insecticidal drugs to cattle to reduce malaria has been used and indicated for disease control in eld regions (50). Recently, Fluralaner has been explored for this purpose (47). The authors showed that while Fluralaner signi cantly affected mortality in An.…”

Topical, contact, and oral susceptibility of adult Culicoides biting midges (Diptera: Ceratopogonidae) to fluralaner

“…stephensi LC 50 : 123 ng/ml; An. albimanus LC 50 : 23 ng/ml) [ 36 ]. Conversely, fipronil outperformed fluralaner 100-fold when Ae.…”

“…To assess oral toxicity, females were offered a blood meal spiked with fluralaner in an artificial membrane feeding system; 100 mg of technical grade fluralaner was dissolved in DMSO to the concentration of 2 mg/ml. This solution was further diluted in PBS (Sigma-Aldrich, St. Louis, MO) to 2000 ng/ml [ 36 ] to create a stock solution. This fluralaner spiked PBS stock solution was then diluted in defibrinated sheep blood (Carolina Biological Supply Co., Burlington, NC) to concentrations of 10, 30, 50, 70, 300, 400 or 1000 ng/ml.…”

Potent mosquitocidal effect of ivermectin-treated nettings and sprayed walls on Anopheles gambiae

“…Mosquito mortality at 7, 14 and 21 days post-treatment was signi cantly higher for those fed on blood samples from individuals treated with IVM compared to the control group, with the highest mosquito mortality observed at day 7. Likewise, the lethal effect of IVM on mosquitoes fed on cattle treated with IVM has been shown in several studies [8, [12][13][14][15]. IVM, when ingested with blood meal, targets the mosquitoes' glutamate-gated chloride ion channel (GluCl) in the muscle and nerve cells to exert neuronal signals that manifest in mosquitoes' paralysis and death [16].…”