Sl. Blodgett et al., BLISTER BEETLE (COLEOPTERA, MELOIDAE) MORTALITY EVALUATED DURING ALFALFA HARVEST, Journal of economic entomology, 88(2), 1995, pp. 398-406
A striped blister beetle, Epicauta occidentalis Werner, found aggregat
ing in Kansas alfalfa fields, can be incorporated into baled hay and h
as been documented to cause horse deaths. Different types of alfalfa h
arvest equipment and operation were evaluated to quantify blister beet
le mortality using simulated swarms of known numbers. Mowing was respo
nsible for most of the beetle mortality. A self-propelled mower-windro
wer with crimper rollers removed gave the lowest beetle mortality of a
ny equipment tested. A self-propelled mower-crimper-windrower gave the
second lowest mortality. Although the sicklebar mower is widely recom
mended to reduce cantharidin contamination, identification of previous
ly unrecognized factors related to equipment operation has clarified i
ts contribution to blister beetle mortality. Three sources of beetle m
ortality ranked from most to least important were wheel traffic over m
owed forage before beetles could disperse, crimping, and, finally, the
cutting step itself. Raking and baling steps dislodged beetles from f
orage.