It’s insect season! Just as gardeners anticipate the first bite of a ripe juicy tomato or the crunch of fresh-picked lettuce, the insects are dashing in to enjoy the results of our labor. Be on high alert for problematic pests. Your garden plants can go from glorious to gutted in a matter of a few hours or days so be vigilant.
The common asparagus beetle arrives when the first stalks of asparagus begin popping from the soil so check your asparagus patch regularly. The beetles lay their eggs perpendicularly on the spears or ferns and they are easy to see. The eggs hatch within a week and can be easily wiped off by hand. If the eggs hatch, they feed for a couple of weeks and then pupate in the soil, emerging in seven to 10 days to start the cycle anew. Scout your garden now to prevent a larger infestation later.
Flea beetles are back. Once they find your tender young greens, these tiny hopping insects are difficult to control and can wipe out seedlings quickly. Sticky traps may catch part of the invaders, but prevention is the best solution. Cover your seedlings with floating row cover fabric or very fine nylon netting. Keep the plants covered until they are mature enough to withstand a bit of damage. If the beetles have already moved in, you can try using an insecticide, but these sprays must contact the beetle to kill it. Since the flea beetle hops about, contact can be tricky. You can plant a trap crop of mustard seed or radishes, both favored foods of the beetles, to detract them from your main crop. Or spray them all away with the hose and then quickly cover the plants.
The imported cabbageworm can be a major pest to broccoli, cauliflower, kale and other plants of this family. Most gardeners are familiar with the devastation the cabbageworm larvae can cause. Look for white butterflies with one or more black spots on the edge of their wings. See photo and life cycle here: https://tinyurl.com/lslrxnw. If you see them, take action. Inspect your brassicas regularly and hand pick any worms you may see. A brisk spray of water can dislodge the eggs. Natural insecticides effective against the larvae are Spinosad or Bacillus thuringiensis (Bt). Brassicas do not require outside pollination and thrive under a floating row cover. Our spring brassicas seem to be protected by house wrens who like to perch on the tomato cages and then swoop down to eat the larvae.
The Colorado potato beetle will be here soon, as will the lined or spotted cucumber beetle. Both can cause severe damage to your crop. The best protection for the potato beetle is hand picking the orange-red larvae every day or two. Make this a game and the job will get done quickly. The spotted or striped cucumber beetle is more difficult to control. Prior to blossoming, dust a bit of insecticide at the base of the plants and lightly on the leaves. Your other option is to erect some sort of cover for these climbing plants until they are well established.
Whatever you do, act quickly. Perhaps you can’t eliminate killer insects, but their damage can be controlled. For help in diagnosing your problem, turn to your local garden center. Take a photo of the insect or the damaged plant for ease in diagnosis. Check with your local Extension office or visit https://tinyurl.com/y34bhd9g. This website provides links to publications on individual insects. These fact sheets can be read in PDF format for free or purchased as a hard copy.
Beverly Carney can be reached at firstname.lastname@example.org.