Characterization of Acaricide Resistance inRhipicephalus sanguineus(Latreille) (Acari: Ixodidae) Collected from the Corozal Army Veterinary Quarantine Center, Panama

Abstract

Rhipicephalus sanguineus (Latreille) were collected from the Corozal Army Veterinary Quarantine Center in Panama and characterized for resistance to five classes of acaricides. These ticks were highly resistant to permethrin, DDT, and coumaphos; moderately resistant to amitraz; and not resistant to fipronil when compared with susceptible strains. Resistance to both permethrin and DDT may result from a mutation of the sodium channel. However, synergist studies indicate that enzyme activity is involved. The LC50 estimate for permethrin was lowered further in the Panamanian strain then in susceptible strains with the addition of triphenylphosphate (TPP), but not with the addition ofpiperonyl butoxide (PBO). This suggests that esterases and not oxidases are responsible for at least some pyrethroid resistance. Elevated esterase activity and its inhibition by TPP were confirmed by native gel electrophoresis. The LC50 estimate obtained for coumaphos in the Panamanian strain was not lowered further than what was observed for susceptible strains by the addition of TPP or PBO. This indicates that enzyme activity might not be involved in coumaphos resistance. Resistance to amitraz was measured through a modification of the Food and Agriculture Organization Larval Packet Test. All tick strains were found to be susceptible to fipronil.

Mechanism of infection and colonization of Rhipicephalus sanguineus eggs by Mertarhizium anisopliae as revealed by scanning eletron microscopy and histopathology

“…Recently, the resistance development of R. sanguineus to some active principles used in these formulations was verified (12). One of the alternatives to the use of acaricides is the biological control, especially with fungi, that showed to be an effective and promising technique, as previously verified (6,13,15,16).…”

Toxicity of extract of Magonia pubescens (Sapindales: Sapindaceae) St. Hil. to Control the Brown Dog tick, Rhipicephalus sanguineus (Latreille) (Acari: Ixodidae)

“…Based on the results of the current study, M. pubescens should be recognized as an future alternative acaricide for the control of Brown Dog tick. These results reinforce the importance of the preservation of this soapberry in its natural biome.KEY WORDS: Botanical acaricide, soapberry, tingui, tick controlThe resistance related in Rhipicephalus sanguineus (Latreille) to some synthetic acaricides in some parts of the world (Fernandes 2000, Fernandes & Freitas, 2001, Miller et al 2001, together with the well-documented damage that these compounds can cause to the environment have resulted in a worldwide trend towards reducing their use as much as possible. In Brazil, acaricide resistance in R. sanguineus to some pirethroids was fi rst recorded by Fernandes (2000), in Goiânia, State of Goiás.…”

“…The resistance related in Rhipicephalus sanguineus (Latreille) to some synthetic acaricides in some parts of the world (Fernandes 2000, Fernandes & Freitas, 2001, Miller et al 2001, together with the well-documented damage that these compounds can cause to the environment have resulted in a worldwide trend towards reducing their use as much as possible. In Brazil, acaricide resistance in R. sanguineus to some pirethroids was fi rst recorded by Fernandes (2000), in Goiânia, State of Goiás.…”

Effect of Metarhizium anisopliae (Ascomycete), Cypermethrin, and D-Limonene, Alone and Combined, on Larval Mortality of Rhipicephalus sanguineus (Acari: Ixodidae)

“…Cypermethrin, a systemic pyrethroid insecticide with low toxicity for mammals, is commonly used with domestic animals (Kumar et al 2008). However, chemical control has potentially high ecological costs, including damage to nontarget organisms, and ticks are also likely to develop pesticide resistance (Miller et al 2001). Alternative methods or strategies of control of brown dog tick are required (Taylor 2001).…”