Date of this Version
J. stored Prod. Res. Vol. 33, No.3, pp. 187-198, 1997
Protecting stored grain from insect damage, with minimum pesticide risk, will require pest management based on comprehensive understanding of storage environments and their interactions with pest populations. Computer modeling offers the means to this understanding. To obtain data sets for modeling selected pests of stored maize, we studied maize storages on six farms in a four-county area of southwestern South Carolina. Grain moisture content was measured monthly, and grain temperatures were recorded hourly for one storage season. Insect populations were monitored by taking grain and pitfall trap samples at weekly or monthly intervals. Hourly mean grain temperatures remained below optimal levels for growth and development of insects during most of the storage period. Grain moisture content varied from 11.2 to 16.4%. Forty three species of insects and one species complex, representing 26 families in four orders, were detected. The estimated importance of each species in the farm storage habitat, as measured by relative abundance and frequency of occurrence, depended on whether grain sampling or trapping was used. With trapping, Cryptolestes species (mostly C. pusillus (Schonherr)), the Carpophilus dimidiatus complex (C. dimidiatus (F.), C.freemani Dobson and C. mutilatus Erichson), Sitophilus species (mostly S. zeamais Motschulsky), Xylocoris flavipes (Reuter) and Oryzaephilus surinamensis (L.) appeared most important. With grain sampling, S. zeamais, Sitotroga cerealella (Olivier) and C. pusillus appeared most important. Insects were most abundant (or active) in the fall and again in the spring, if storage extended that long. Grain samples indicated more insects near the grain surface, but traps sometimes detected more near the bottom of the bulk.