That extended period of nice weather allowed plants to really flourish and become more vibrant and leafy but led to an increase in insect pests. Now, a couple of problematic beetles have enjoyed the spring and become an issue for some.
Calls are coming in concerning flea beetles eating vegetable plants. We see this beetle from time to time, but most years it’s more of a limited issue. So why are we seeing more this year? Well, flea beetles love springs like we just had, which has led to population increases. Springs that are cold, then hot, then cold usually have fewer flea beetles.
There are many types of flea beetles eating many types of plants, but our current concerns are those that love the Brassicaceae (broccoli, cabbage and kale) and Solanaceae (eggplant, peppers, tomatoes) families. Due to their small size of 1/15 to 1/6 inches, which by the way likely inspired the flea beetle name, they aren’t readily noticed until they start feeding on leaves and defoliating plants. The damage starts with small irregular holes and usually progresses to the point where the leaves get a pretty ragged appearance.
Beyond feeding on leaves, the larvae feed on plant roots and also underground tubers. They can jump from plant to plant with their large hind legs as well as having the ability to fly. Like many other pests flea beetles start the season by feeding on weeds and then move to the quality plants you would like them not to eat.
For you gardening experts out there: What are the two main cultural practices that help to control these pests and, for that matter, others? Yes, that’s right, it’s proper irrigation and nutrition, which lessens stress and allows plants to grow quicker and be able to shrug off these pests. Another easy control is to use row covers over your plants, starting as soon as you transplant them to the garden or when seeds pop out of the ground, so the pests can’t get to them. Should you find a need to use an insecticide consider organic pesticides including neem oil, the fungus Beauvaria bassiana, pyrethrin and sabadilla.
Another beetle that came in today was the striped cucumber beetle. This one was found munching on squash and cucumber leaves. In the past we’ve seen this pest more often on watermelon and cantaloupe, but they will feed on most cucurbits as well as other vegetables, including beans, corn, tomatoes and fruits like apricot and peach.
Problems with this beetle start with feeding on leaves but the striped cucumber beetle is especially bothersome since it lays eggs on the plants, the larvae feed on plants roots which weakens the plant and both the larvae and beetle feed on the rinds or outside skins of produce. The beetles can grow as large as 1/3 of an inch but the ones I saw were smaller. They have a black head with a yellow segment behind the head called a prothorax, and the wings that cover the body have alternating black and yellow strips.
Controls again include row covers, and you should consider using some type of vacuum such as a good powerful hand vacuum to gather up the insects and drop them in a container of soapy water or water and vegetable oil. There are insecticides that can be used if necessary, including organic controls of azadirachtin, spinosad and pyrethrin.
Thought for the day: “You are what you eat. For example, if you eat garlic you’re apt to be a hermit.” —Franklin P. Jones
Previous articles are available at The Times-Independent website, www.moabtimes.com. Have an idea you’d like Mike to consider writing about? Want more information about these topics? Call the Utah State University Extension Grand County office at 435-259-7558 or email Mike Johnson at firstname.lastname@example.org.