Photo of squash bugs showing long beak
Squash bugs have a long “beak” that they insert into the vine or foliage, and feed by sucking sap from the plant. Yellow specking that later turns brown may appear on leaves where they feed. Severe feeding on young vines, or older vines during the heat of summer, can lead to plant wilingt distal to the point of feeding.

Photo Source: Michael Bush, WSU Extension, Yakima, WA