Identification of a Putative Mexican Strain ofSerratia entomophilaPathogenic against Root-Damaging Larvae of Scarabaeidae (Coleoptera)

Abstract

The larvae of scarab beetles, known as "white grubs" and belonging to the genera Phyllophaga and Anomala (Coleoptera: Scarabaeidae), are regarded as soil-dwelling pests in Mexico. During a survey conducted to find pathogenic bacteria with the potential to control scarab larvae, a native Serratia sp. (strain Mor4.1) was isolated from a dead third-instar Phyllophaga blanchardi larva collected from a cornfield in Tres Marías, Morelos, Mexico. Oral bioassays using healthy P. blanchardi larvae fed with the Mor4.1 isolate showed that this strain was able to cause an antifeeding effect and a significant loss of weight. Mortality was observed for P. blanchardi, P. trichodes, and P. obsoleta in a multidose experiment. The Mor4.1 isolate also caused 100% mortality 24 h after intracoelomic inoculation of the larvae of P. blanchardi, P. ravida, Anomala donovani and the lepidopteran insect Manduca sexta. Oral and injection bioassays were performed with concentrated culture broths of the Mor4.1 isolate to search for disease symptoms and mortality caused by extracellular proteins. The results have shown that Mor4.1 broths produce significant antifeeding effects and mortality. Mor4.1 broths treated with proteinase K lost the ability to cause disease symptoms and mortality, in both the oral and the injection bioassays, suggesting the involvement of toxic proteins in the disease. The Mor4.1 isolate was identified as a putative Serratia entomophila Mor4.1 strain based on numerical taxonomy and phylogenetic analyses done with the 16S rRNA gene sequence. The potential of S. entomophila Mor4.1 and its toxins to be used in an integrated pest management program is discussed.

Rearing and Injection of <em>Manduca sexta</em> Larvae to Assess Bacterial Virulence

“…The susceptibility of M. sexta larvae to a variety of entomopathogenic bacterial species [1][2][3][4][5] , as well as the wealth of information available regarding the insect's immune system [6][7][8] , and the pending genome sequence 9 make it a good model organism for use in studying host-microbe interactions during pathogenesis. In addition, M. sexta larvae are relatively large and easy to manipulate and maintain in the laboratory relative to other susceptible insect species.…”

Detection of Insect Pathogen Serratia marcescens in Protaetia brevitarsis seulensis (Kolbe) from Korea

“…S. marcescens isolated from Drosophila flies is pathogenic to the insect when ingested with food or when injected into the hemocoel (Casper Flyg, 1980) and is represented as a bacterial pathogen of Rhagoletis pomonella flies (Carol R. Lauzon, 2003). Besides, S. entomophila is pathogenic against the root-damaging larvae of Scarabaeidae (scarab beetles), also called white grubs (Nunez-Valdez et al, 2008). S. entomophila causes Amber disease and is specific to Costelytra zealandica (Hurst et al, 2007a).…”

Insecticidal potency of bacterial species Bacillus thuringiensis SV2 and Serratia nematodiphila SV6 against larvae of mosquito species Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus

“…EML-SE1 was found against diamondback moth (Jeong et al 2010) Strains of S. marcescens have been reported to be recovered from other tephritids such as Ceratitis capitata Weidermann and Dacus (Bactrocera) dorsalis hendel flies (Grimont et al 1977), and these bacteria may possess some utility as insect control agents. Also, entomopathogenic strains of Serratia entomophila have been used to control various insect genera including Anomala, Costelytra, and Phyllophaga (Nunez-Valdez et al 2008). In addition, strains of S. entomophila and S. proteamaculans were shown to kill grass grub, Costelytra zealandica (Jackson et al 2001;Sikorowski et al 2001;Nunez-Valdez et al 2008).…”

“…Also, entomopathogenic strains of Serratia entomophila have been used to control various insect genera including Anomala, Costelytra, and Phyllophaga (Nunez-Valdez et al 2008). In addition, strains of S. entomophila and S. proteamaculans were shown to kill grass grub, Costelytra zealandica (Jackson et al 2001;Sikorowski et al 2001;Nunez-Valdez et al 2008). These combined results demonstrate that this species acts as a bioinsecticidal agent.…”