small beetles distinguished by their long snouts and their voracious appetite for grain and malt.

The grain weevil (Sitophylus granarius) infests stores of barley, wheat, oats, rye, rice, and corn. In 16th-century England they were known as “maltworms” and the playwright William Shakespeare made several references to them and the damage they could do to grain.

Wingless, the weevil is about 2–4 mm long (3/16 inch) and has been the bane of maltsters’ lives for generations. In the 19th century the “ravages” to barley that had been stored for only 6 to 8 months could be enormous. Females can lay several hundred eggs at a time, one inside each grain kernel. As the larva develops, it can eat the whole of the inside of a kernel, leaving the husk to appear intact. Researchers estimate that one pair of weevils may produce up to 6,000 offspring a year. The larvae live for 5 weeks during the summer months but they can live up to 5 months in cooler temperatures. The adults, which can live for up to 8 months, feed on the outside of grain kernels.

Once established in a grain store, weevils are notoriously difficult to eradicate. Henry Stopes, the author of Malt & Malting in 1895 and a designer of malting facilities, despaired at the limited effectiveness of eradication methods, advising, “short of demolition of the building, few (methods) are really successful.”

Today good hygiene and the judicious use of approved pesticides can prevent weevil infestation of grain stores.