The effects of temperature on the insecticidal activity of Beauveria amorpha to Heptophylla picea

Abstract

The insecticidal activity of the entomopathogenic fungus Beauveria amorpha (strain HpBa-1) to larvae of the yellowish elongate chafer, Heptophylla picea was estimated under various temperature conditions. High mortalities were obtained and the mortalities of H. picea rose rapidly at 25°C and 20°C. Insecticidal activity of HpBa-1 was observed at 15°C and 10°C and infection of the fungus resulted under these temperatures. HpBa-1 showed little infectivity at low temperatures under the field conditions. Hence, HpBa-1 recovered infectivity when the temperature increased. These results suggest HpBa-1 is useful as a microbial control agent against larvae of H. picea.

Virulence of the entomopathogenic fungus Beauveria brongniartii to several life stages of the yellowish elongate chafer Heptophylla picea Motschulsky (Coleoptera: Scarabaeidae)

“…At present, H. picea can be largely controlled by chemical insecticides; however, this method of control is not adequate (Osakabe and Kodomari, 1984;Hiromori et al, 2004;Yaginuma et al, 2004b). Many alternative agents such as entomopathogenic fungi and nematodes have been explored (Ishikawa, 2001;Hiromori et al, 2004;Yaginuma et al, 2004a, b).…”

“…Many alternative agents such as entomopathogenic fungi and nematodes have been explored (Ishikawa, 2001;Hiromori et al, 2004;Yaginuma et al, 2004a, b). In particular, the entomopathogenic fungus B. amorpha (Strain: HpBa-1) was reported as an effective agent against H. picea larvae, but this fungus is not in practical use (Yaginuma et al, 2004b).…”

“…Currently, chemical insecticides such as fenitrothion are being used to control H. picea larvae (Shizuoka Plant Protection Office, 2003). However, it is difficult to control H. picea larvae with fenitrothion (Osakabe and Kodomari, 1984;Hiromori et al, 2004;Yaginuma et al, 2004b). Young larvae (first to second stage), which are susceptible to fenitrothion, inhabit the deep soil.…”

“…To overcome these problems, large amounts of fenitrothion are used to control these larvae. However, there is much recent concern about the environmental problems that could be caused by using large amounts of chemical insecticides (Hiromori et al, 2004). To resolve these problems, alternative control agents have been explored.…”

“…For example, studies have been conducted on entomopathogenic fungi to develop control agents of scarab grubs (Hasegawa and Koyama, 1941;Poprawski and Yule, 1991;Villani et al, 1994;Hiromori and Nishigaki, 1998;Yokoyama et al, 1998). Beauveria amorpha (Strain: HpBa-1) has been reported as an alternative to chemical insecticides for H. picea larvae (Hiromori et al, 2004;Yaginuma et al, 2004a, b). H. picea larvae move to the soil surface in November (Osakabe, 1986).…”