A washable glue for trapping pests on sticky boards in honey bee colonies

Varroa mites are major pests of honey bee colonies and contribute to colony losses. Entomopathogenic fungi are a promising tool for Varroa control, but evaluating their efficacy requires follow-up infection assays. Conventional sticky board adhesives, such as petroleum jelly or vegetable oil, can trap fallen mites but are difficult to remove before testing. We developed a water-soluble glue made from cooked corn starch and glycerin that can be easily washed away with water or ethanol. The glue is prepared by cooking starch in water until thickened and then mixing it with glycerin to achieve the desired consistency. This adhesive simplifies mite recovery from sticky boards, reducing labor during mite collection and facilitating infection assays. It may also have applications in water-soluble insect traps and environmental DNA detection.