Efficacy of native entomopathogenic fungus, Isaria fumosorosea, against bark and ambrosia beetles, Anisandrus dispar Fabricius and Xylosandrus germanus Blandford (Coleoptera: Curculionidae: Scolytinae)

Abstract

The efficacy of the native entomopathogenic fungus, Isaria fumosorosea TR-78-3, was evaluated against females of the bark and ambrosia beetles, Anisandrus dispar Fabricius and Xylosandrus germanus Blandford (Coleoptera: Curculionidae: Scolytinae), under laboratory conditions by two different methods as direct and indirect treatments. In the first method, conidial suspensions (1 × 10 6 and 1 × 10 8 conidia ml −1) of the fungus were directly applied to the beetles in Petri dishes (2 ml per dish), using a Potter spray tower. In the second method, the same conidial suspensions were applied on a sterile hazelnut branch placed in the Petri dishes. The LT 50 and LT 90 values of 1 × 10 8 conidia ml −1 were 4.78 and 5.94/days, for A. dispar in the direct application method, while they were 4.76 and 6.49/days in the branch application method. Similarly, LT 50 and LT 90 values of 1 × 10 8 conidia ml −1 for X. germanus were 4.18 and 5.62/days, and 5.11 and 7.89/days, for the direct and branch application methods, respectively. The efficiency of 1 × 10 6 conidia ml −1 was lower than that of 1 × 10 8 against the beetles in both application methods. This study indicates that I. fumosorosea TR-78-3 had a significant potential as a biological control agent against A. dispar and X. germanus. Further studies are necessary to evaluate the efficacy of the isolate on the pests under field conditions.

Efficacy of native isolates of Metarhizium anisopliae and Beauveria bassiana against the invasive ambrosia beetle, Xylosandrus germanus Blandford (Coleoptera: Curculionidae: Scolytinae)

“…The results of this study are in line with those of previous studies as many researchers have reported that efficacy of EPF increases according to concentration increase. Therefore, the LT 50 and LT 90 values of the fungi decreased (Kocaçevik et al 2016and Kushiyev et al 2017, 2018. Kushiyev et al (2017) found that LT 50 and LT 90 values of Fig.…”

“…Mycelia were removed by filtering conidia suspensions through four layers of sterile cheesecloth. The concentrations of conidia were adjusted to both 1 × 10 6 and 1 × 10 8 conidia ml −1 , using a Neubauer hemocytometer under Olympus CX31 compound microscope (Olympus America Inc., Lake Success, NY, USA) for each isolate (Kushiyev et al 2018).…”

“…After 24 h of incubation, germination was determined by counting 200 conidia/dishes with an Olympus CX-31 compound microscope at × 400 magnification. Conidia were regarded as germinated when they produced a germ tube at least half of the conidial length (Kushiyev et al 2018).…”

“…Vuill., Isaria fumosorosea Wize, Lecanicillium spp., and Metarhizium anisopliae (Metch) Sorokin play an important role in the regulation of insect populations (Zimmermann 2007a(Zimmermann , 2007b(Zimmermann and 2008. Previous studies have showed that they were effective on ambrosia beetles including, X. germanus, A. dispar, Xylosandrus crassiusculus Motschulsky, and Xyloborus glabratus Eichhoff (Castrillo et al 2013;Carrillo et al 2015;Kushiyev et al 2018). Kushiyev et al (2018) determined that I. fumosorosea at 1 × 10 8 conidia ml −1 against female adults of X. germanus applied on adults and on branches caused 100 and 90% mortality rates, respectively.…”

“…Previous studies have showed that they were effective on ambrosia beetles including, X. germanus, A. dispar, Xylosandrus crassiusculus Motschulsky, and Xyloborus glabratus Eichhoff (Castrillo et al 2013;Carrillo et al 2015;Kushiyev et al 2018). Kushiyev et al (2018) determined that I. fumosorosea at 1 × 10 8 conidia ml −1 against female adults of X. germanus applied on adults and on branches caused 100 and 90% mortality rates, respectively. EFP may affect not only adults outside the host trees but also larvae inside the beetle galleries (Castrillo et al 2013).…”