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Abstract
Seasonal history of the chinch bug, Blissus leucopterus leucopterus (Say) (Hemiptera: Lygaeidae) was studied in the field at Panama, Nebraska. Use of day degrees for predicting the peak of each ontogenetic stage of first generation chinch bugs was little better than calendar dates, indicating air temperatures are only one factor determining development rate.
In laboratory studies, biology of the chinch bug was influenced by variety or species of host plant upon which raised. Chinch bugs fed corn laid more eggs and lived longer than those fed sorghum, barley, oats, or wheat. Host plant did not affect egg viability or size of resultant adults. Nymphs reared on oats, Early Sumac and DeKalb DK-61 sorghum had higher mortality and slower development than those on wheat, corn SX-19, ACCO GR-1089 sorghum, or barley. When provided a choice between sorghum varieties, chinch bugs more severely damaged GR-1089.
The effect of three populations of chinch bugs at two stages (nymphs vs. adults) on seedlings of two sorghum varieties at three heights resulted in greater damage and lower yields for Early Sumac than DeKalb DK-61. Chinch bug mortality did not differ with variety. Both varieties were initially stunted but attained normal height by maturity. Plants infested with 10 bugs/plant had greater damage than those with 5 bugs which was greater than uninfested. Average yield of uninfested plants was significantly greater than for infested plants but 5 and 10 bugs/plant caused similar reductions. Grain yield was not influenced by plant size at time of infestation or stage of bug used.
Stenotaphrum secundatum exhibited antibiosis to chinch bug nymphs. Other grasses had varying degrees of resistance to chinch bug injury.
