Faculty of Veterinary Medicine, Universiti Malaysia Kelantan, Locked bag 36, Pengkalan Chepa, 16100 Kota Bharu, Kelantan, Malaysia.
Mycology and Pathology Laboratory, Forest Health and Conservation Programme, Forest Research Institute Malaysia, 52109 Kepong, Selangor, Malaysia.
Trop Biomed. 2021 Mar 1;38(1):102-105. doi: 10.47665/tb.38.1.017.
Rhipicephalus sanguineus, commonly known as brown dog tick is a widespread species with considerable public health and economic importance. Tremendous efforts were performed to control the tick populations with the concern of resistance build-up and environmental issues. Alternative towards microbial control thus emerged as one option to reduce tick populations. In this study, the ovicidal efficacy of a native isolate entomopathogenic hyphomycetes fungi, Metarhizium anisopliae strain HSAH5 was evaluated against eggs of R. sanguineus. Spray applications with three different conidial concentrations of 10, 10 and 10 conidia mL; 40 ppm of Flumethrin and a negative control. The M. anisopliae strain was found highly virulent to R. sanguineus eggs by reducing the hatching percentages to ≈30% compared with 8.9% in Flumethrin eggs. The result showed a significantly higher mortality in M. anisopliae group than those of the control groups (F = 42.08, df = 32, P < 0.001) at 30 days post-infection. However, there are no significant differences within the M. anisopliae group, in which the mortality between different conidial concentrations is almost the same. The estimated LC of M. anisopliae against eggs of R. sanguineus is 1.36 × 10 conidia ml. Thus, these results suggest M. anisopliae strain HSAH5 could be a potential biocontrol agent of R. sanguineus in the integrated approach to managing ticks in the residential landscape by targeting on the eggs.
血红扇头蜱，俗称棕色犬蜱，是一种分布广泛的物种，具有相当大的公共卫生和经济重要性。人们付出了巨大的努力来控制蜱种群，因为担心会产生抗药性和出现环境问题。因此，人们转而寻求微生物控制方法，以减少蜱种群。在这项研究中，评估了一种本土分离的虫生真菌，玫烟色棒束孢 HSAH5 菌株对血红扇头蜱卵的杀卵效果。采用三种不同的分生孢子浓度（10、10 和 10 个分生孢子/mL）、40ppm 的氟氯氰菊酯和阴性对照进行喷雾应用。结果发现，玫烟色棒束孢菌株对血红扇头蜱卵具有高度的毒力，孵化率降低到约 30%，而氟氯氰菊酯处理的卵孵化率为 8.9%。感染后 30 天，与对照组相比，玫烟色棒束孢组的死亡率显著更高（F = 42.08，df = 32，P < 0.001）。然而，在玫烟色棒束孢组内，不同分生孢子浓度之间的死亡率几乎没有差异。玫烟色棒束孢对血红扇头蜱卵的 LC 估计值为 1.36×10 个分生孢子/ml。因此，这些结果表明，玫烟色棒束孢 HSAH5 菌株可能是一种潜在的血红扇头蜱生物防治剂，可用于住宅景观中 ticks 的综合治理，通过针对卵来进行控制。
