August Serenade
by
K. Marc Teffeau

 

One of the neat sounds of summer that I look forward to hearing is the song of the “locust.” It is relaxing to lie in the hammock slung under the shade trees, or sit on a chair on the patio or porch, nap and listen to the whirring song of the “locusts” in the trees. Although called a locust, the insects we hear are not the true locust but rather a cicada. The real locust of Biblical reference is a migratory species of grasshopper that travels in swarms of millions.
The cicadas in the trees are large, robust insects with broad heads and protruding eyes. Their wings are usually transparent and are held roof-like over the body. The song that you hear is produced by the male. He has special organs on his body that are concealed beneath two large plates on his underside. These musical instruments produce the drumming or singing sounds that we hear. Each species of cicada has a characteristic song.
The dog-day cicada, also called harvest flies, that you now hear in the trees are much larger than their notorious relatives the periodical cicadas. The dog-day cicada have a much shorter life span – from two to five years – while the periodical ones live from 13 to 17 years in the soil until they emerge. The dog-day cicadas normally do not damage trees and shrubs to the extent that the periodical cicadas can.
There is lots of color in the landscape in August as many of the perennials are in bloom and the annuals are peaking. Especially attractive are the crape myrtles. You can plant crape myrtles now if you give the plant some extra attention during the hot days by appropriate watering.
You normally see crape myrtles in two forms, shrubs and trees, but whichever you prefer, it all begins with the same plant. To grow a crape myrtle tree, select the straightest stem and cut out all the rest of the branches near the ground, or slightly below the ground, so that it will have the appearance of a tree. When your straight stem has achieved the desired height, prune the branches to develop and grow. From time to time you will have to do some pruning to eliminate undesirable branches and improve the appearance of the tree.
During hot, dry August days, avoid deep cultivation in your flower beds. Loosening the soil under these conditions reduces water uptake by increasing loss of soil water and damaging surface roots. Plants often look much worse after cultivation than before. When you do water, irrigate deeply and infrequently.
Now is the time to start planning you fall garden. Prepare beds for tulip and daffodil bulbs, hardy mums, winter-hardy pansies, ornamental kale, dusty miller and dianthus.
There has been a lot of news lately about a new insect pest – the brown marmorated stink bug (BMSB). Stink bugs, or shield bugs in general, get their name from being shield-shaped. Green and southern green stink bugs are bright green and are a common pest on a host of vegetable plants in particular. Other types of stink bugs can be very colorful.
The brown marmorated stink bug (Halyomorpha halys) is a new pest in North America and was apparently accidentally introduced to eastern Pennsylvania. They are native to China, Japan, Korea and Taiwan. It was first collected in September of 1988. They have become a serious pest of fruit and vegetable crops in the mid-Atlantic area. The problem is that they have no natural predators and are difficult to kill with insecticides.
Adult bugs are 5/8” and dark mottled brown. They emerge from overwintering sites from late March through June, depending on location. They immediately begin to feed.
Females lay clusters of light green, barrel-shaped eggs on the undersides of leaves from June to August. The young bugs (nymphs) are yellowish and mottled with black and red. Older nymphs more closely resemble the adults. In Maryland, due to our climate, there can be two or more generations in one year.
These critters have a long list of plants that they go after, including many ornamental plants, fruit trees, vegetables and legumes. The evidence of their feeding depends on the stage of the bug and the stage of the fruit or vegetable that they are feeding on.
The nymphs or young stink bugs tend to feed shallowly, while the adults feed deeply into plant tissue causing more damage. On leaves, stink bug damage can appear as small stippled areas and/or necrotic areas. On fruit, there may be water-soaked lesions, pitting, dimples, catfacing and/or depressed areas.
Adult stink bugs can cause deep feeding injury in fruit such as apples, making them unsalable. Damage on vegetables such as pepper and tomatoes appears as cloudy whitish areas on the fruit. On beans and okra there will be wart-like growths and deformation of shriveling of the pods.
It’s difficult to manage these insect pests in the garden and landscape. You might consider using a floating row cover to exclude the pests from vegetable crops that do not rely on bees for pollination. For small plantings, hand picking or knocking the bugs into a container of soapy water will help control them. In areas where populations are high, diligence is necessary because of constant migration into the garden from surrounding landscapes and wooded areas.
A common homeowner complaint about stink bugs is that they will invade your home. Like Asian lady bird beetles and box elder bugs, they also seek to overwinter inside our homes starting in the fall. Control for them is the same as with the ladybugs.
Exclusion is the first step to prevent them from coming in the home. Seal up cracks with caulk, use weather stripping around doors and windows, remove window air conditioners, and close all possible entry points. Inside, shop-vac up the bugs and place in an outdoor trash receptacle with a lid.
Stink bugs are appropriately named. They give off a strong odor as a defensive mechanism when threatened and really stink if you squash them!
Diseases show up in August as a result of the high temperatures and humidity. Mildew is a problem in the landscape in August on both ornamentals and vegetables.
Two different kinds of mildew – downy and powdery – are likely to affect vine-type vegetable crops. The first of these, downy mildew, is a problem on beans, cucumbers and cantaloupes. This fungus disease causes yellow to dark areas on the upper surface of older leaves. Turn the leaf over and you’ll see a whitish or gray-colored mold in patches on the under surface. The mold may also occur on bean pods. Affected vines may be scorched or killed.
Powdery mildew appears as a white or brownish talcum-like growth on leaves and young stems of squash, pumpkins, cantaloupes and cucumbers. Look for it especially on the upper surface of leaves. It will also sometimes affect fruit. Severely infected plants will turn yellow, wither and die.
To control either downy or powdery mildew, use resistant varieties, practice crop rotation within your garden and maintain good weed control. It also helps to space plants properly. Overcrowding keeps humidity high and favors development and spread of diseases.
Destroy residues of affected crops in the fall since they may serve as a source of new infections next year. There are really no effective fungicides for homeowners to use to control these diseases in vegetables, so use the cultural controls as best as possible.
Powdery mildew is also a problem on a number or ornamentals in the landscape. These infections occur most often in late summer when the days are hot and the nights cool. Powdery mildew is an unusual disease because, unlike most fungal leaf disorders, it often develops under dry conditions. Some mildew, particularly those on roses, apples and cherries, are also increased by high humidity.
Prevention by cultural practices is the first defense. Also grow resistant cultivars, space and prune plants to improve aeration and lessen shading. Water early in the day at the base of the plants and not the foliage.
For most shrubs, the disease appears so late in the growing season that control is usually not necessary. After the diseased leaves have fallen in the Fall, rake them up and destroy them. This will help to reduce the disease problem for next year.
Happy Gardening!