Determination of fungal pathogens of Hypera postica (Gyllenhall) (Coleoptera: Curculionidae): isolation, characterization, and susceptibility

Abstract

Background: Fungal pathogens of Hypera postica (Gyllenhall) (Coleoptera: Curculionidae) were collected from the vicinities of Adana and Igdir in Turkey. The pathogenicity of the fungal isolates against the pest were investigated. According to morphologic (colony morphology, spore shape) and molecular (sequences of ITS1-5.8S ITS2 region and EF1-α, Bloc, and RPB1 genes) characterizations, the isolates were identified as Beauveria bassiana (HpI-2, HpI-6, HpI-7, HpI-10, HpA-3, HpA-4, HpA-5) and Beauveria pseudobassiana (HpI-4). All these strains were isolated from H. postica for the first time. In order to determine pathogenesis of all isolates on the target pest, bioassays were conducted against larvae and adults, as screening of (1 × 10 7 conidia/ml) and dose-response (1 × 10 5 , 1 × 10 6 , 1 × 10 7 , 1 × 10 8 , conidia/ml), under laboratory conditions. The fungal isolates, closely related to each other, yielded significantly varied mortalities on larvae and adults. H. postica larvae were found more susceptible than adults to the fungal isolates in all tests. The highest mortality rates (100 and 98%) for larvae and adults, respectively, were obtained by B. bassiana strain HpA-5 within 14 days at 1 × 10 8 conidia/ml concentration. The median lethal concentration (LD 50) of HpA-5 required to kill the larvae and adults of H. postica at concentrations of 2.37 × 10 4 and 1.4 × 10 5 conidia/ml, respectively. These results are promising; therefore, the B. bassiana strain HpA-5 can potentially be used against H. postica.

Biodiversity and pathogenicity of entomopathogenic fungi associated with the lesser spruce sawfly, Pristiphora abietina

“…A great number of EPF have been isolated from various insect species and tested against important agricultural pests (Ansari et al, 2008; Sevim et al, 2010; Kocacevik et al, 2015; Sonmez et al, 2016, 2017; Yucel et al, 2018). However, investigations related to fungal control agents of P. abietina have been quite limited, especially field experiments.…”

“…Indeed, the LC 50 value was estimated as 1.7 × 10 3 conidia ml −1 for isolate Pa4. In a previous study, the LC 50 of B. bassiana HpA‐5 isolated from Hypera postica (Gyllenhal) was determined as 2.37 × 10 4 conidia ml −1 against its host larvae (Yucel et al, 2018). In a study using B. pseudobassiana isolated from Dendroctonus micans Erichson against its host larvae, the LC 50 was 2.79 × 10 5 conidia ml −1 (Kocacevik et al, 2015).…”

Beauveria Pseudobassiana Rehner and Humber, 2011 a New Entomopathogenic Fungus From Gara Mountain, Iraq

“…Populations from hibernating pupae of Cameraria ohridella were found naturally infected with B. pseudobassiana in Slovakia (Schemmer et al, 2016). B. pseudobassiana was reported among the entomopathogens of Hypera postica (Gyllenhall) (Coleoptera: Curculionidae) in Turkey (Yucel et al, 2018).…”

Development of mycoinsecticide formulations with Beauveria bassiana and Metarhizium brunneum for the control of Orosanga japonica (Hemiptera: Ricaniidae)

“…The fungi (four × Metarhizum and four × Beauveria ) used in the current study were obtained from the entomopathogenic culture collection of Microbiology Laboratory, Department of Biology, Karadeniz Technical University. In earlier studies, they have been isolated from soil and insect samples in the Eastern Black Sea Region and they showed significant insecticidal effect on various pests (Table 1) (Sevim, Demir, & Demirbag, 2010; Sevim, Demir, Hofte, et al, 2010; Sevim, Demir, Tanyeli, & Demirbag, 2010; Yucel et al, 2018)…”