|Perez Mendoza, Joel|
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2004
Publication Date: 7/15/2004
Citation: Hou, X., Fields, P., Flinn, P.W., Perez Mendoza, J., Baker, J.E. 2004. Control of stored-product beetles with combinations of protein-rich pea flour and parasitoids. Environmental Entomology. 33(3):671-680. Interpretive Summary: Insects reduce the quality of stored grain and other stored products in the U.S. and in the world. It is estimated that losses due to insects are 5 to 10%, or about 1.25 to 2.5 billion dollars. We tested the use of parasitoid insects in combination with protein-rich pea flour to suppress stored-grain beetles in wheat. We found that the combinations of protein-rich pea flour and parasitoids reduced populations of rice weevil. Releasing parasitoids alone reduced the populations of weevils by 46% and rusty grain beetle by 49%. Combining parasitoids with 0.04% or 0.1% protein-rich pea flour reduced weevils by 76 and 98%, and rusty grain beetles by 42% and 75%, respectively. The technique of combining parasitoid insects with pea flour to suppress beetles in stored wheat should make the use of beneficial insects more effective and economical for grain managers.
Technical Abstract: Protein-rich pea flour is toxic and repellent to three major stored-grain pests, the rice weevil, Sitophilus oryzae (L.); the red flour beetle, Tribolium castaneum (Herbst); and the rusty grain beetle, Cryptolestes ferrugineus (Stephens). This study found that protein-rich pea flour was not toxic to, and did not reduce the offspring of Anisopteromalus calandrae (Howard), a parasitoid of S. oryzae, nor did it reduce offspring of Cephalonomia waterstoni (Gahan), a parasitoid of C. ferrugineus. Protein-rich pea flour was also not repellent to A. calandrae. Small-scale and large-scale tests of a combination of protein-rich pea flour and parasitoids were conducted in 2-liter jars and in barrels containing 330 kg wheat. A larger population of A. calandrae was found at a high host infestation rate (24 adults/kg for 25 d), but the parasitoid did not become established at middle and low host infestation rates (2.4, or 0.24 adults/kg for 25 d). The combinations of protein-rich pea flour and parasitoids reduced populations of S. oryzae in both tests. Additional effects of protein-rich pea flour and parasitoids were found in the large-scale test. Releasing parasitoids alone reduced the populations of S. oryzae by 46% and C. ferrugineus by 49%. Treating wheat at 0.04% or 0.1% protein-rich pea flour reduced the population of S. oryzae by 26 and 79%, and C. ferrugineus by 27 and 43%, respectively. Combining parasitoids with 0.04% or 0.1% protein-rich pea flour reduced S. oryzae populations by 76 and 98%, and C. ferrugineus populations by 42 and 75%, respectively. At the end of the large scale experiment, grain treated with protein-rich pea flour alone or in combination with parasitoids had better grain quality than the untreated controls.