Variation of Chemical Concentration in Surface-Coated and Tableted Grain Baits

Abstract

Liquid scintillation spectrometry was used to determine the quantity of recovered carbon14labelled Mesurol (4-[methylthio]-3,S-xylyl N-methylcarbamate) from individual baits. The six grain baits tested were cracked corn, wheat kernels, and oat groats, each formulated as surface-coated baits and as tablets (ground grain mixed with the chemical and tableted). The concentration of Mesurol on the surface-coated baits was highly variable, with coefficients of variation (CV) ranging from 21.0 percent (wheat) to 48.] percent (cracked corn); Mesurol in individual cracked corn baits ranged from 99-532 ,ug. Such variation could easily explain erratic results in field baiting programs or laboratory tests. The tableted baits were more uniform (CV, 4.6-8.0 percent; greatest range, 274-360 yg) and are recommended for baiting situations where chemical concentration is critical. VARIATION IN SURFACE_COATED AND TABLETED BAITS * Bullard 925 , AND L. L. DICKSON. 1967. Thern10regulation in the desert iguana, Dipsosaurus dorsalis. Science 156 ( 3783 ) :1757-59. , AND T. P. SOUTHWORTH. 1967. Body temperature fluctuations in the Northern elephant seal. J. Mammal. 48 ( 3 ): 484-485 . Received for publication March 23, 1970. of untethered dolphin recorded by ingested radio transmitter. Science 144(3621):864-866. 1967. Bio-medical telemetry. New York, John Wiley, Inc. 388pp. McGINNIs, S. M. 1968. Biotelemetry in pinipeds; in the behavior and physiology of pinipeds. Appleton-Century-Croft, New York. 411pp. tions. The present experiment was conducted to determine the extent of such variation in grain baits for animal damage control by comparing the chemical concentration in three kinds of surface-coated baits, all prepared in the same manner, with that in bait tablets made from the same materials. I thank Ann H. Jones for editorial assistance, J. L. Oldemeyer for statistical assistance, and R. R. Bott for technical assistance irs the analyses. My thanks also to the co-workers who helped in the bait formula-