We’ve had more rain, which was great although one episode in particular moved a lot of mud and rocks down the streets and onto properties and I know that was a headache for a lot of people. Now here we are in August and have maybe two-and-half to three months of gardening season remaining. There haven’t been a lot of questions on any one specific topic lately so this column will just focus on some tidbits from questions asked in the last week or so.
For years, I would regularly receive calls concerning something feeding on the upper leaf surface of pears, cherries and plums, but nobody has inquired about this in quite a while — until recently. It was another case of the pear slug, which is the larvae of the sawfly, Caliroa cerasi. The adult sawfly is a black wasp that is about one-fifth of an inch long. The larva is called a pear slug because it looks slimy and is slug-shaped but it’s not officially a slug. The pear slug skeletonizes the leaf foliage by removing all of the leaf tissue, but leaves the veins. Many times nothing needs to be done, but if damage becomes extensive go the simple route by throwing some dust up into the trees. Yes, it does work. Or spray the leaves with a moderately strong stream of water and knock the pear slugs off.
Mushrooms in the yard
This next issue is about mushrooms growing in the yard. Yes, it does happen and no, it’s not necessarily yards where people are watering heavily. Admittedly, it’s not a common question but I do hear it from time to time and lately the subject has come up a bit more. Generally, just having the mushrooms growing isn’t a problem since they are beneficial by helping to break down organic matter and put nutrients back into the soil. However, many people don’t like their look, especially as they start to decay, and the mushrooms can be a problem if you have pets and/or children since you don’t want them eating them. They are most likely to be seen when there is a considerable amount of organic matter in or on the soil. It’s also not uncommon to see this after a tree is cut down, and over time, sometimes a couple of years, mushrooms start popping up along where the roots were.
The most basic of controls would start by knocking them over before they grow much and start releasing spores. Next would be to gather them up and dispose of them in the trash to be sure they don’t release any spores. Since they are growing due to the organic matter in the soil, you can fertilize the area with a quick-release nitrogen — 1 pound of actual nitrogen per 1,000 square feet — to speed up the decomposition process, thus stopping the mushrooms’ continued growth.
Green stink bug
An insect pest I have seen a lot recently and received calls about is the green or Say’s stink bug. They have a distinctive shield shape and stink bugs in general can come in a variety of colors. Due to their piercing, sucking mouthparts, they cause pinpricks in fruits and vegetables. These spots will become whitish or yellow and turn hard or corky. A bigger problem is that stink bugs can carry yeast and other pathogens so once they pierce the fruit or vegetable the yeast or pathogens can cause increased decay. As with many insect pests, weeds and piles of wood or trash can contribute to the number of stink bugs, so limiting those can help.
Since there usually aren’t significant numbers of stink bugs you can pick them off the plant, but from my experience they like to drop off the plant as you approach. You can also use yellow sticky cards to trap them. Another technique I have heard of, but am unsure whether it is effective, is to paint a bucket yellow and fill it with soapy water. Supposedly the stink bugs will fly into the bucket and get trapped in the water. If the problem is severe, an organic control is to spray the plants with kaolin clay, trade name Surround, which keeps the bugs from feeding on the fruit surface. This is essentially a protective coating rather than something that kills insects. If this is a yearly problem, start your control early and spray with an insecticidal soap, which does kill the young nymphs.
Thought for the day: “Maybe there are no excuses to be lazy, but I’m still going to keep looking.” —Anonymous.
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 [email protected]
ByBy Michael Johnson
Utah State University Extension Agent, Grand County