27 May 1988
Vol 240, Issue 4856

About The Cover

Adult brown wheat mite, Petrobia latens Muller (body size about 0.5 millimeter). This spider mite species transmits the causal agent of a unique virus-like disease of barley. Although the disease is currently known to be confined to Montana and contiguous areas in Canada, the mite is distributed throughout the world and therefore presents a threat to other barley-producing regions. See page 1188. [Nancy L. Robertson, Montana State University, Bozeman, MT 59717]