EARLY DETECTION OF INSECTS IN STORED WHEAT USING STICKY TRAPS IN BIN HEADSPACE AND PREDICTION OF INFESTATION LEVEL

Insect populations in 14 bins of newly harvested wheat on eight farms in Kansas were monitored with sticky traps in the bin headspace and wi th grain samples. Sticky trap catches during the first 3 wk of storage were used to provide an estimate of the species and densities of inse cts that were present in the headspace. Grain samples were taken every 2 wk during the first 3 mo of storage to provide an estimate of popul ation growth under the grain temperature and moisture conditions in th e bins. The sticky traps correctly predicted whether lesser grain bore r, Rhyzopertha dominica (F.), and rusty grain beetle, Cryptolestes fer rugineus (Stephens), would be found in the grain samples in 85.8 and 7 8.6% of the bins, respectively. Traps were less reliable for foreign g rain beetle, Ahasverus advena (Waltl), and hairy fungus beetle, Typhae a stercorea (L.), with correct predictions in 57.1 and 42.9% of bins, respectively. Indianmeal moth, Plodia interpunctella (Hubner), was fou nd in both traps and grain samples in only one bin and red flour beetl e, Tribolium castaneum (Herbst), and sawtoothed grain beetle, Oryzaeph ilus surinamensis (L.), were not found in both traps and grain samples in any of the bins. The traps in the center of the bin caught 4.7-14. 2 times more beetles than those on the bin walls, but only 1.3 times m ore P. interpunctella adults. The total numbers of C. ferrugineus adul ts in the grain samples could be predicted better from the product of mean grain temperature times maximum grain moisture than from sticky t rap catch.