Bacteria from Ips sexdentatus (Coleoptera: Curculionidae) and their biocontrol potential

Abstract

Ips sexdentatus (Coleoptera: Curculionidae) is one of the most destructive pests of the spruce trees in Europe. In this study, we have isolated and characterized culturable bacteria from I. sexdentatus and tested their insecticidal activity against the last instar larvae of the pest as a possible biocontrol agent. A total of eight bacterial isolates was determined and four of them were identified at species level, and the others were identified at genus level. Isolates were identified as Stenotrophomonas maltophilia (Is1), Rahnella sp. (Is2), Pseudomonas sp. (Is3), Bacillus sp. (Is4), Alcaligenes faecalis (Is5), Panteoea agglomerans (Is6), Pseudomonas fluorescens (Is7) and Serratia sp. (Is8) based on their morphological, biochemical and molecular characteristics. Insecticidal effects of bacterial isolates were performed on the last instar larvae of the pest. The highest insecticidal activity was obtained from P. fluorescens (Is7) with 73% mortality within 10 days after inoculation (p < 0.05). Mortality values of the other isolates ranged from 20 to 53%. This study suggests that Pseudomonas fluorescens (Is7) seems to be a good candidate as a possible biocontrol agent against I. sexdentatus, and provides suitable strains that can be modified to express insecticidal toxins and/or other detrimental substances to develop new control methods for I. sexdentatus.

Influence of Starvation on the Structure of Gut-Associated Bacterial Communities in the Chinese White Pine Beetle (Dendroctonus armandi)

“…Based on the recent studies, it has been hypothesized that these symbiotic gut bacteria could be genetically modified by genetic engineering techniques as a host organism to express insect killing toxins or proteins to kill specific pest [46]. Bacterial symbionts can also be used to transform genes changing the insect physiological characteristics.…”

Investigation of the internal bacterial flora of Eurygaster integriceps (Hemiptera: Scutelleridae) and pathogenicity of the flora members

“…2009;Grimont & Grimont 2005). This species is also isolated from many insect species belong to different orders such as Coleoptera, Lepidoptera and Orthoptera (Sevim et al 2012a;Demirci et al 2013;Sezen et al 2004;Dillon et al 2000;Demir et. al.…”

“…Based on the recent studies, it has been hypothesized that bacterial symbionts can be genetically modified by using genetic engineering techniques to synthesize pest killing proteins or substances to provide new approaches for biological control of insect pests (Sevim et al 2012a;Li et al 2005;Lacey et al 2007;Beard et al 1992). In addition to their potential use in biocontrol, the bacterial symbionts should be important to insect feeding because, in some cases, they help in nitrogen processing, sulphate assimilation, fatty acid metabolism, and help to contribute deficient sterols, vitamins, digestive enzymes and essential amino acids to their insect hosts (Lundgren & Lehman 2010).…”

“…In an interesting perspective, these symbiotic gut bacteria could be used as a host organism to express insect killing toxins or proteins to kill specific pest (Sevim et al 2012). Therefore, there are many studies intended for determination of the bacterial flora of various agricultural and forest pests (Sevim et al 2010a(Sevim et al , 2012aDemirci et al 2013;Secil et. al.…”

The internal bacterial diversity of stored product pests

“…Among the known bacterial pathogens, Bacillus thuringiensis (Bt) is the most successful and holds considerable potential for further development. Bt has been used to control many insect pests worldwide (Burges 1982;Sevim et al 2012a). Apart from bacterial pathogens, the bacterial symbionts of insects could be used in microbial control of insect pests and they are possible contenders for future pest control (Dillon and Dillon 2004;Demirci et al 2013).…”