Squash Bugs, Again

-

Southwest Yard & Garden
Squash bug eggs on leaves and stems. Photo credits Bdm23, Wikimedia Commons (left) and Pollinator, Wikimedia Commons (right)
Question: Back in April, I had questions about what turned out to be aphids on my peach trees. Now my melon plants are covered in squash bugs. Is there anything I can do to control them this late in the season?

-          Lorraine J., Los Lunas
 Answer: I wish I had better news for gardeners with the squash bug blues. Squash bugs are difficult to control, and even more so as the bugs mature because insecticides are a much less effective tool.
Some people delay planting squash until July to avoid the squash bug, but this tactic is not foolproof. As many gardeners have reported this year, delayed planting seems to work some years, but not reliably.
Dr. Carol Sutherland, NMSU Extension Entomology Specialist and NMDA Entomologist, has suggested that you take a hint from their name and “squash” the squash bugs. Look for clusters of shiny orange-brown eggs on the underside of the lower leaves and smash them too. Sutherland also suggests that you handpick or scrape the bugs and their eggs from the plant into a can of soapy water. (I might use a large can or even a five-gallon bucket to save on repeated trips to dump and refill.) Manual removal is the most effective way for homeowners to manage this common garden pest at this stage. Manual removal is also the preferred control method earlier in the season, in addition to scouting for eggs and destroying them.
I know some readers are getting stressed thinking about collecting—and squashing—all of the bugs that are smothering their poor pumpkins right now. Our new NMSU Extension Integrated Pest Management (IPM) Specialist, Dr. Amanda Skidmore, shared a trick: “One way to get them to congregate is to put some newspaper, cardboard, or old boards near the base of the plant overnight. Squash bugs like to be in protected areas, especially when it starts to get cold at night. Check underneath in the morning and remove any squash bugs.” If you try this, please keep a body count each time and share your numbers with us via social media 
Facebook: @NMDesertBlooms and @NMSUIPM
Instagram: @NMDesertBlooms and @NMPlants&Pollinators
Twitter: @NMDesertBlooms
As described in past columns on these pests written by Dr. Curtis Smith, “Dr. Sutherland explained that squash bugs are very strong flyers with a very good sense of smell. If they are in the area and they detect your squash, they will appear in your garden. This can happen any time during the summer… She explained that squash is not their only food supply. They feed on any cucurbit (squash, cucumber, ornamental gourds, and even native gourds). They do have favorite plants, and if they are feeding on native gourds and detect your squash, they will leave the gourds and infest your squash. If you choose to not plant squash for several years, this will not assure a year without squash bugs if these alternate hosts exist nearby, or if neighbors' gardens have been supporting squash bugs.”

This is my third fall as the state Extension Horticulture Specialist and my third fall fielding late-season pleas for squash bug help. I promise next year to post frequent reminders, starting early in the season, to check under leaves for clusters of the shiny eggs when your cucurbits are still small and a little more manageable. Dr. Skidmore offered this idea to try next season, “One organic solution is to use kaolin clay as a deterrent. It’s a fine, white powder that’s mixed with water and sprayed onto plants. The clay is abrasive to the insect's exoskeleton and can impact their ability to feed. It does not contain any chemical insecticides, but can be irritating to the skin, eyes, and nose, so wear a mask and hand protection when handling it. It does wash away when it rains hard or when plants are watered from above, so it may need to be re-applied.” I worked with kaolin clay years ago on young pecan trees. The white, chalky clay coating made them look like frosted mini-trees.
We’ll revisit the recommended practices for using kaolin clay as an insect deterrent in the spring. For now, round up as many squash bugs as possible, enjoy your harvest as much as possible, and, as Dr. Skidmore warns, burn or throw away any remaining material from infested plants at the end of the season because squash bugs will overwinter in it, allowing them to get a leg up next year.


For more gardening information, including decades of archived Southwest Yard & Garden columns, visit the NMSU Extension Horticulture page (http://desertblooms.nmsu.edu/), follow us on social media (@NMDesertBlooms), or contact your County Extension office (https://aces.nmsu.edu/county).
Marisa Thompson, PhD, is the Extension Horticulture Specialist for New Mexico State University and is based at the Agricultural Science Center at Los Lunas.

Comments

Post a Comment

Popular posts from this blog

Saving Zinnia Seeds

-
Image
Southwest Yard & Garden by Dr. Marisa Thompson Zinnia showing off both disk and ray flowers at the NMSU Agricultural Science Center in Los Lunas. Photo credit M. Thompson     Question: I have a large monarch butterfly garden, and I gathered zinnia seed heads to plant next spring. Zinnia seeds appear to have two distinct morphologies. The ray flower seed is shield-shaped and the disk flower seed is smaller and flatter. Which of the seeds is viable? I have researched and found some who say only the ray seed, some say only the disk seed, and some say both. Please let me know which zinnia seed is most viable and why. -           Tim P., New Mexico Answer: I know exactly what you mean. I’ve had this question before myself. Zinnias were one of my first garden successes when I moved to Las Cruces in 2009. I too gathered the seed heads and I too wondered which part was the true seed that sho...
Read more

Controlling Weedy/Invasive/Polleny Siberian Elm Trees

-
Image
LOOKING FOR IDEAS on   WHAT TO DO WITH  SIBERIAN ELMS AFTER REMOVAL?  I'll keep posting ideas HERE over time. đź‘Ť Southwest Yard & Garden  by guest author Dr. Leslie Beck   &  Dr. Marisa Thompson   Additional Info On This Noxious Weed Below Siberian elm seedlings can have a taproot that’s longer than the above-ground parts. Try to get all or most of the root when you pull them. Photo credit M. Thompson.   Question : What’s the best way to kill Siberian elm seedlings? - Mellene Pablo, Los Lunas Answer: I’m glad you’re asking this question when these weedy, invasive trees are small and relatively easy to control (emphasis on the “ relatively ”). We all know how precious shade is in New Mexico, and we love our trees for providing it, but weedy trees like Russian olive ( Elaeagnus angustifolia ) , tree of heaven ( Ailanthus altissima ) , salt cedar ( Tamarix spp. ) , and the Siberian elm are real problems across the state. Several tr...
Read more

What’s Wrong with MY Tree? PART 2: Oozing Stains on Tree Trunk

-
Image
Southwest Yard & Garden by Dr. Marisa Thompson   The stained, oozing spot is slimeflux (aka bacterial wetwood), and I bet it stinks like strong chemical paint thinner. The bad news is it’s not fixable, but it’s also not causing a problem. Slimeflux is an indicator of an underlying decay issue. Photo credit Joy E. Question: My husband and I just bought a house with a beautiful cottonwood tree in the back yard. We noticed a gooey, rotting section in the crook of the trunk. We certainly don't want to lose this gorgeous tree! Do you know what this is and how we can treat it? Answer: Yes, I know what it is and what caused it. But no, I don’t have easy answers for how to treat it. What you’re seeing is called slimeflux, aka bacterial wetwood. If you were to smell it, you’d never forget it. It smells to me like nail polish remover that’s gone rancid. My uncle, also an arborist, said it smells like gym socks. So basically it smells like what it looks like: gross. There...
Read more