The pecan weevil, Curculio caryae (Horn), is a key pest of pecans in the Southeast. Entomopathogenic nematodes have been shown to be pathogenic toward the larval stage of this pest. Before this research, only three species of nematodes had been tested against pecan weevil larvae. In this study, the virulence of the following nine species and 15 strains of nematodes toward fourth-instar pecan we...

The Diaprepes root weevil, Diaprepes abbreviatus (L.) is the most severe weevil pest in Florida citrus. Entomopathogenic nematodes have effectively suppressed larval populations of D. abbreviatus. Our objective was to conduct a broad laboratory comparison of entomopathogenic nematodes for virulence toward larvae of D. abbreviatus. The study was conducted at three temperatures (20, 24, and 29 de...

Widespread planting of crops genetically engineered to produce insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) imposes selection on many key agricultural pests to evolve resistance to Bt. Fitness costs can slow the evolution of Bt resistance. We examined effects of entomopathogenic nematodes on Þtness costs of Bt resistance in the pink bollworm, Pectinophora gossypiella (Saun...

soil-dwelling nematodes from steinernematidae family are obligate parasites of insects and usually referred to as entomopathogenic nematodes (epns). these nematodes are symbiotically associated with entomopathogenic bacteria xenorhabdus spp. the bacterial symbionts are carried monoxenically in a special vesicle in the infective juveniles (ijs). in the present study we report the isolation of tw...

Entomopathogenic nematodes in the genus Steinernema and Heterorhabditis have been successfully commercialized as biological control agents for a variety of curculionid species. Nematode-based products have been introduced for: 1) root weevils, Otiorhynchus spp. 2) billbugs, Sphenophorus spp. 3) the apopka weevil, Diaprepes abbreviatus, and 4) the citrus root weevil, Pachnaeus litus. Several oth...

Methods are described for standardized in vivo production, rapid harvest, and storage, in a concentrated form, of infective juveniles of the entomopathogenic nematode, Steinernema carpocapsae Mexican strain Kapow selection. Nematodes were stored in nematode wool configurations, consisting of mats of intertwined infective juveniles. Freshly harvested nematodes are readily available in adequate q...

Previous studies have indicated that between 60 and 80% of a population of entomopathogenic nematodes do not infect their insect hosts at any one period in time. Two hypotheses explain this behaviour: the first that there is a subpopulation of non-infectious nematodes and the second that the non-infectious group is created by inhibitory cues derived from infected insects. Through an experimenta...