Help! What’s killing my zucchini plant?
If you’ve ever dealt with squash bugs, then you can understand my hatred of them. They have to be one of the worst, if not THE worst gardening pest I have to deal with. It is almost a personal challenge to beat them, but when the temps start to get above 110, it is a little hard to keep up with them, so I usually throw in the towel.
Squash bugs, Anasa tristis, are true bugs in the Family Coreidae. They mainly feed on cucurbits, including zucchini, cucumbers, melons, pumpkins and other squash. I have found they like zucchini the best, but will take to other cucurbits if those aren’t available. They have sucking mouth parts and will suck the juice out of the stems and leaves, excreting toxic salvia that slowly and sometimes quickly kills your plants.
They will lay their eggs on the bottom and sometimes the top of leaves in a cluster of about 20 little copper colored, oval shaped eggs and they take about 10 days to hatch. You will usually see a little cluster of greyish green nypmhs with black legs all hanging out together. There are 5 stages of nymphs and they take about 30 days to reach adulthood.
Squash bugs usually show up around June in Phoenix and will stick around for at least a couple months. The adults will overwinter in the ground, under debris, and crawl back out early the next summer. This is why it’s advisable to completely trash the infested plants, clean up debris and not grow any cucubrits in the same spot the following year after you’ve had them.
I have found that trying to completly eliminate squash bugs is a losing battle. You, instead, should just look to control their population, but this will take a daily commitment to keep up with them. You can hand pick adults and place them in soapy water to drown or you can smash them, which is a little more satisfying. They do not like water so if you flood the ground and spray the plant they tend to start crawling up the plant, this makes it a little easier to find them. If you are trying to stay organic, I have had luck with neem oil on the nymphs but the adults don’t seem to be bothered by it. Buy Neem Oil Fungicide Miticide Insecticide Concentrate 16 fl. oz. here. It is also advantageous to look under leaves and eliminate any eggs that you find. It also helps to keep dead and wilted leaves and branches trimmed as this is a favorite hiding spot for nymphs.
On the Friend or Foe Meter they are definitely a Foe!!!