Biology of the red flour beetle, Tribolium castaneum (Herbst), development on various rice fractions

The red flour beetle (RFB), Tribolium castaneum (Herbst), is a stored-product pest that commonly infests stored grains; however, there is little known knowledge on red flour beetle biology when present in rice.  To determine how RFB develop on rice, nine different fractions of rice were chosen based on the products and by-products found in a rice mill. The nine fractions of rice consisted of: brown rice, rice bran, broken milled rice, whole milled rice, rice bran, rice hulls, rough rice, rice paddy dust, and milled rice dust.  A size 9 dram vial with mesh lids were filled ¾ full with each of the rice fractions and placed randomly into a tray. Each tray was composed of nine rice fractions with six replications of each fraction, making a total of 54 vials per each tray. One RFB egg was then placed into each vial. The trays were stored in a rearing room that maintained a temperature of 27̊ C and 65% relative humidity. The study ran for a course of eight weeks, and each tray was monitored weekly, checking for  activity, tunneling, shed skin, and if the RFB was seen. If the beetle was seen it was noted what life stage (larvae, pupae, or adult)  it was at and where in the vial it was located (top, middle, bottom).  At the end of eight weeks, the experiment was stopped and the trays were placed into a freezer. To determine nutritional value of the fractions, any vial that had a larvae or adult in it, the dry weight of the individual was taken. Elytra length was also measured on any adult that developed. The results of this study will be presented.