Acaricidal Activity of Peel Oil of Citrus spp. On Boophilus microplus

Abstract

Peel oil from three varieties of Citrus maxima Merr. (pomelo): Khaao-phuaing (immature fruit), Thong-dee (immature and mature fruits) and Khaao-nam-phueng (mature fruits); Citrus reticulata Blanco., Citrus suncris Linn., Citrus sinensis Linn. And Citrus hystrix DC. were collected by mechanical pressing. These peel oil and the d-limonene substance were diluted with 95% ethanol into 1:5, 1:10 and 1:5 (V/V) and tested the acaricidal activity on the engorged female cattle tick (Boophilus microplus) by dipping method. The acaricidal activity on the tick larvae was tested with these oil and d-limonene dilution of 1:10 and 1:15 (V/V). The peel oil of C.reticulata and C.maxima variety thong-dee (immature and mature fruits) showed high acaricidal activity at the concentration of 1:10 (V/V) on engorged female ticks. These peel oil activity were 2 times thigher than that of d-limonene. The peel oil concentration 1:10 of C.sinensis and C.maxima (mature) exhibited high larvicidal activity, while the oil of C.hystrix, C.reticulata, C.suncris and C.maxima (immature fruits) showed relatively high larvicidal activity. Their larvicidal activity were 1.5 times stronger than d-limonene. The peel oil of the other citrus spp. Exhibited weaker acaricidal activity. This indicated that the peel oil from the citrus fruits could be directly applied to control the cattle tick. The waste of the over fruiting immature pomelo, would be of potential usage as a biocontrol substance.