The bane of every gardener growing zucchini, squash, pumpkins and winter squash. Egg masses are found on the underneath side of the plant leaf. They can be squished with your finger to control the number that hatch. Scouting the plants is the best way to keep the pest under control. Good garden sanitation is highly important to reduce the places and food sources for overwintering nymphs and adults. Here are a couple of links from K-State Research and Extension & University of Minnesota with more information about squash bugs and control measures.
https://hnr.k-state.edu/extension/info-center/common-pest-problems/common-pest-problem-new/Squash%20Bug.pdf
https://www.vegedge.umn.edu/pest-profiles/pests/squash-bug
https://hnr.k-state.edu/extension/info-center/common-pest-problems/common-pest-problem-new/Squash%20Bug.pdf
https://www.vegedge.umn.edu/pest-profiles/pests/squash-bug