|Guedes, Raul - UNIVER FED DE VICOSA|
|Zhu, Kun Yan - KANSAS STATE UNIVERSITY|
Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 22, 2008
Publication Date: August 7, 2008
Repository URL: http://hdl.handle.net/10113/23184
Citation: Guedes, R.N., Campbell, J.F., Arthur, F.H., Opit, G.P., Zhu, K., Throne, J.E. 2008. Acute lethal and behavioral sublethal responses of two stored-product psocids to surface insecticides. Pest Management Science. 64(12): 1314-1322. Doi: http://dx.doi.org/10.1002/ps.1634. Interpretive Summary: Psocids, or booklice, are emerging pests of stored products, such as in grain storages and flour mills. Previous studies have shown low to moderate efficacy of insecticides used for controlling psocids on concrete surfaces in flour mills. We tested susceptibility of two species of psocids, Liposcelis bostrychophila and L. entomophila, to three insecticides applied to experimental concrete surfaces, and also the sublethal effect of these insecticides on the mobility of these species. The insecticides beta-cyfluthrin and chlorfenapyr showed high short-term efficacy against both psocid species, unlike pyrethrins. Liposcelis bostrychophila was slightly more tolerant than L. entomophila to all three insecticides. Behavioral assays indicated that the insecticides reduced the mobility of both species and that pyrethrins elicited weak repellence in L. bostrychophila. Lower mobility observed in L. bostrychophila may be a contributing factor to its higher insecticide tolerance. Beta-cyfluthrin and chlorfenapyr, unlike pyrethrins, were effective against both psocid species and should be useful tools for management of these pests.
Technical Abstract: The psocid species Liposcelis bostrychophila and L. entomophila are recognized as major pests of stored products. Although their behavior, particularly their high mobility, may contribute to the reported relatively low efficacy of insecticides against them, studies to investigate this have not been conducted. The present study aimed to assess efficacy of the label rate of three commercial insecticides (beta-cyfluthrin, chlorfenapyr, and pyrethrins) applied on concrete surfaces against L. bostrychophila and L. entomophila, and also their sublethal effect on the mobility of these species. The insecticides beta-cyfluthrin and chlorfenapyr showed high short-term efficacy against both psocid species, unlike pyrethrins. Liposcelis bostrychophila was slightly more tolerant than L. entomophila to all three insecticides. Behavioral assays with fully-sprayed and half-sprayed concrete arenas indicate that the insecticides reduced the mobility of both species. Pyrethrins seem to elicit weak repellence in L. bostrychophila. Beta-cyfluthrin and chlorfenapyr were effective against both psocid species, but not pyrethrins. The mobility of both species does not seem to play a major role in the differential selectivity observed, but the lower mobility of L. bostrychophila may be a contributing factor to its higher insecticide tolerance.