Toxicity and ovicidal activity of different entomopathogenic fungi, Hirsutella extracts on Tetranychus urticae(Acari:Tetranychidae)

Crude ethyl acetate extracts of six entomopathogenic fungi, Hirsutellaspecies were screened against Tetranychus urticaeKoch (Acari: Tetranychidae). In this study, all extracts presented potential to control eggs and adult female activities. Laboratory evaluation of the crude extracts of Hirsutella citriformis,H. guignardii,H. petchabunensis,H. satumaensis, H. saussureiand H. thompsoniishowed slightly toxicityand median lethal concentration (LC50) values of 7,579.94, 8,910.38, 8,579.45, 5,055.96, 1,555.46 and 44,197.85mg/L at 72 h after treatment against adult females of T. urticae, respectively. Related LC50values that exhibited on eggs were 12,701.86, 30,922.72, 10,870.96, 12,635.56, 9,244.59 and 22,676.66 mg/Lat 5 days after exposure. The most effective on T. urticaeeggs and adult females is H. saussurei. Moreover, all extracts deceased the fecundity of T. urticaeafter being fed with mulberry leaf discs treated the crude extract of sixspeciesofHirsutella under residual effect bioassay. The results suggest that the ethyl acetate extracts of Hirsutella citriformis,H. guignardii,H. petchabunensis,H. thompsonii, H. satumaensi andH. saussureihave the potential to be used for the control of T. urticaein the future.