Acaricidal activities of crude extract derived from Annona squamosa Linnaeus leaves against cattle tick, Rhipicephalus microplus Canestrini (Acari: Ixodidea)

บทคัดย่อ

Abstract

Rhipicephalus microplus Canestrini (Acari: Ixodidea) or cattle tick is considered as harmful and economically important external parasite, and its infestation has affected the cattle milk and meat productions worldwide. Therefore, this study aimed to evaluate the use of crude extract derived from Annona squamosa Linnaeus leaves for controlling engorged female R. microplus adults. The hexane extract of A. squamosa Linn. leaves at the concentrations of 4,000, 8,000,16,000 and 32,000 ppm was used to immerse female ticks, which then were constantly monitored for their mortality and egg-laying rates for 72 h. The crude leaf extract of A. squamosa Linn. was shown to induce tick mortality in adose-dependent manner with the LC99 value equivalent to 11,157 ppm. The concentration of the extract at 16,000ppm was found to be the most effective and could reduce the number of ticks for 95.00±5.00% within 48 h and 100%within 72 h. The concentration of 32,000 ppm was shown to completely suppress the oviposition of females (100%),followed by 16,000 ppm (99.71±0.28%), 8,000 ppm (95.93±2.48%), and 4,000 ppm (84.57±6.53%). The effect of storage duration on efficacy of the extracts was examined and the results showed that the extract stored for 1 day could cause significantly high rates of tick mortality (100%) than the extract stored for 90 days (80.00±8.16%). Hence, this revealed that the crude hexane extract of A. squamosa Linn. leaves at 16,000 ppm had the highest acaricidal activity against R. microplus females, and the long term storage caused the marked reduction on the efficacy of the extract.This data may be helpful for further development of A. squamosa Linn. leaf extracts as biological control products against R. microplus.

Keywords: Rhipicephalus microplus, Annona squamosa Linn., crude plant extract, acaricide, biocontrol