title: Laboratory and field evaluation of an entomopathogenic fungus, Isaria cateniannulata strain 08XS-1, against Tetranychus urticae (Koch).
abstract: BACKGROUND
  The two-spotted mite, Tetranychus urticae Koch, is one of the most serious mite pests of crops throughout the world. Biocontrol of the mite with fungal agents has long been paid much attention because of the development of insecticide resistance and the severe restriction of chemical pesticides. In this study, the efficacy of submerged conidia of the entomopathogenic fungus Isaria cateniannulata strain 08XS-1 against T. urticae eggs, larvae and female adults was evaluated at different temperatures and humidity in the laboratory and under field conditions.
  
  
  RESULTS
  The results showed that a suspension of 2 × 10(7) submerged conidia mL(-1) caused the highest mortalities of mite eggs, larvae and females (100, 100 and 70% respectively) at 100% relative humidity and 25 °C in the laboratory. In the field experiments against the mites, a suspension of 2 × 10(8) submerged conidia mL(-1) achieved significant efficiency - the relative control effects were 88.6, 83.8 and 83%, respectively, in cucumber, eggplant and bean fields after 10 days of treatment.
  
  
  CONCLUSIONS
  The results suggest that the I. cateniannulata strain 08XS-1 is a potential fungal agent, with acceptable production cost of conidia, against T. urticae in the field in an area such as southwestern China with higher air humidity.
authors.affiliation: Institute of Entomology, the Provincial Key Laboratory for Mountainous Region Agricultural Pest Management, Guizhou University, Guiyang, China.
authors.forename: Xiaona
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Institute of Entomology, the Provincial Key Laboratory for Mountainous Region Agricultural Pest Management, Guizhou University, Guiyang, China.
authors.forename: Daochao
authors.initials: D
authors.lastname: Jin
authors.affiliation: Institute of Fungal Resources, Guizhou University, Guiyang, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Zou
authors.affiliation: Institute of Entomology, the Provincial Key Laboratory for Mountainous Region Agricultural Pest Management, Guizhou University, Guiyang, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Guo
mesh_terms: D000818:Animals; D002681:China; D005260:Female; D006813:Humidity; D006999:Hypocreales / Q000502:physiology*; D007814:Larva / Q000254:growth & development / Q000382:microbiology; D010063:Ovum / Q000254:growth & development / Q000382:microbiology; D010572:Pest Control, Biological / Q000379:methods*; D013172:Spores, Fungal / Q000502:physiology; D013696:Temperature; D040102:Tetranychidae / Q000254:growth & development / Q000382:microbiology*
keywords: Isaria cateniannulata; Tetranychus urticae; entomopathogenic fungus; field control; infection