Q. Something is eating some of my vegetable plants. Whole leaves are just gone and are higher up on plants like peppers and tomatoes. Is this a bug or something else? I've been seeing some yellow bugs lately.
A. If complete leaves are missing, it is likely an animal. Insects rarely eat the midrib of the plant consistently, and beetles eat patches of the foliage. If the missing leaves are higher up on the plant, then deer is the most likely problem. To recognize deer browsing, look for torn leaves or stalks with ragged ends. Deer have no upper incisors and must jerk or tear plants when feeding. Woodchucks, rabbits and other small rodents usually leave cleanly cut plant stalks.
MU Extension has a 20-page publication regarding deer prevention and control, which we are happy to mail to residents at no cost. Two low-cost and interesting ways to repel deer are stringing up nylon mesh bags (with about two clumps of human hair) or similar with bar soap. What a perfect use for those little soaps you get when staying at a hotel. Also discussed in the publication are fencing and lists of plants that are less attractive to deer.
Q. Something is oozing out of a hole in my pin oak. The hole is about the size of a pencil. Is this a problem or not?
A. This is probably not a problem. The most typical borer to damage pin oaks is the red oak borer, which appears to be (at worst) a fleeting nuisance pest to pin oak. Most people only notice the holes from the resulting sap weeping. This pest causes damage to the lumber of oaks grown for timber, with the most afflicted oaks being red, black and scarlet. The hole is the "exit hole" of the adult, which emerges after almost three years tunneling around inside the tree. It is brown and about to 1 inch long.
While the holes can serve as entry points for more serious disease or insect issues, no remedy is suggested. The trees will generally heal on their own, and the amount of sap weeping out is inconsequential when considering how much is flowing. Woodpeckers are considered the best natural control to this insect.
Q. I'm concerned about bugs damaging my blackberries, especially stinkbugs and this little black beetle that I think is also feeding on them. What can I spray to make sure I don't lose too much fruit?
There are four different insects to be concerned about. The little black beetle is one of a group collectively called "sap beetles," which normally feed on overripe fruit or other decomposing matter. Try to keep up with picking the fruit, and they should lessen. Two "true bugs" can damage blackberries, stinkbugs and tarnished plantbugs. They can feed on the fruit, and stinkbugs are difficult to kill. Unfortunately we have few choices of effective insecticides for control, with Sevin being more effective than "natural" pyrethrins (an extract from chrysanthemums). Sevin will also control Japanese beetles, but remember to apply in the evening to reduce damage to bees. Japanese beetles mostly feed on the leaves, but may also a bit on the fruit. If Sevin is applied, one cannot harvest for seven days; thus it really should last be used prior to the "picking season" to knock down these pests.
Our new concern is an invasive fruit fly from Asia that has rapidly spread across the United States, first getting to Missouri in 2013. It is called Spotted Wing Drosophila and can lay its eggs about a week before the fruit ripens; then you have tiny maggots in the fruit. Telltale signs of the pest are fruit getting mushy too quickly and/or some juice weeping into the white receptacle (bottom of fruit that detaches). To control the pest, pick fruit promptly and destroy any spoiling fruit (flush it or run down garbage disposal). One insecticide is considered effective and is based on a natural ingredient. It is Fertilome Borer, Bagworm, Tent Caterpillar and Leafminer Spray and should be applied weekly if the pest is detected. Email or call us for more help with this pest and a fact sheet by Lincoln University.
The local Master Gardener hotline is staffed from 12:30-4:30 p.m. Tuesday and Friday afternoons; call 634-2824 then or anytime to leave a message. The Central Missouri Master Gardeners are a volunteer group of 191 members, 122 of whom are Cole County residents, who maintain 11 beautification sites in Cole County. Master Gardeners must complete a basic training program of at least 30 hours of horticultural training including landscaping, lawns, vegetables, flowers and fruits, as well as 30 hours of volunteer service.
Have a gardening question of your own? Submit it via email to [email protected] for possible inclusion in a future "Ask a Master Gardener" column.