ARS | Publication request: PATHOGENICITY OF THREE ENTOMOPATHOGENIC NEMATODE SPECIES TO SOME MAJOR STORED PRODUCT INSECT PESTS

Submitted to: Journal of Stored Products Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 10, 2004
Publication Date: April 1, 2006
Citation: Ramos-Rodriguez, O., Campbell, J.F., Ramaswamy, S. 2006. Pathogenicity of three entomopathogenic nematode species to some major stored product insect pests. Journal of Stored Products Research 42: 241-252.

Interpretive Summary: Stored-product insects in hidden and difficult to access areas inside and outside food facilities can lead to infestation problems for both bulk grain and processed grain facilities. Chemical controls are still widely used to treat insects in these refugia, but biological control agents that can actively seek out pests in these habitats offer a potential alternative. Nematodes that attack insects are a widely used biological control agent that have been shown to be effective at finding and killing insect pests in cryptic locations, but their effectiveness against stored-product insects has not been previously investigated. The objective of this study was to determine the most pathogenic of three nematode species against the widest range stored-product pest species and life stages. Our results showed that for many pest species, high mortality could be achieved at relatively low nematode doses. The nematode, Steinernema riobrave, was either the most pathogenic or of similar pathogenicity compared to the other nematode species tested. Based on our results and its high temperature tolerance and active host search, S. riobrave was selected for further evaluation to determine its effectiveness under environmental conditions found in the field. Ultimately these biological control agents may be developed into a new management tool for use in targeted situations.

Technical Abstract: Stored product insect infestations can be caused by persistence in, and immigration from, refugia in and around storage facilities. Chemical controls are widely used to treat insects in refugia such as cracks and crevices and empty bins. Entomopathogenic nematodes (Nematoda, Heterorhabditidae and Steinernematidae) are widely used as biological control agents of insects in cryptic habitats, but their potential to suppress stored-product insects in refugia has not been previously explored. Here, we provide data from the first step in a program evaluating entomopathogenic nematodes as biological control agents of stored product pests: determining their pathogenicity against some of the major stored-product pest species. Three nematode species (Steinernema riobrave, S. carpocapsae and S. feltiae) were evaluated against larvae, pupae and adults of six pest species (Plodia interpunctella, Ephestia kuehniella, Oryzaephilus surinamensis, Tenebrio molitor, Tribolium castaneum, and Trogoderma variabile) and adults of two additional pest species (Sitophilus oryzae and Rhyzopertha dominica). S. riobrave was either the most pathogenic or of similar pathogenicity compared with the other nematode species tested and this species was selected for further evaluation under more field like conditions.