These brownish eggs were found on the underside of our zuchinni plants. These belong to the insect, Anasa tristis, commonly known as Squash bugs. Within 10 days, these eggs would have matured into nymphs, feeding on the sap found in the leaves or stem, with their pierce-sucking mouthparts. If left undisturbed, these nymphs would have disrupted the nutrient and water flow of the host plant, evidenced by yellow and brown spots as well as possible wilting. These nymphs would have developed into adults within 4-6 weeks, overwintering under plant debris or rocks. (They did not!)
While these insects do not carry disease, they can be particularly harmful to young squash and cucumber plants, so limiting the damage is the best control. The use of floating row cover in the seedling stage is recommended, followed by regular inspection of the plants, crushing any eggs and dropping any nymphs and adults into a bucket of soapy water. Trapping adult squash bugs under a piece of wood, where they will group together at night, then into the soapy bucket, also helps. Lastly, it is important to clean up all plant debris at the end of each growing season to reduce overwintering sites. (University of Minnesota Extension)