Fall Webworms Are Here!

It is not even fall and they are back! I am getting calls from people asking, “What is that web stuff on my pecan trees!” That stuff is the webbing created by the fall webworm

The fall webworm appears on pecans in summer as well as in the fall. The fall webworms build larvae nests on the ends of branches. In our area they appear mostly on pecans and up to 90 other deciduous trees.

Damage is caused by caterpillars that eat leaves within the nest and enlarge the nest as they grow. Damage to the tree is seldom serious, but several severe infestations can defoliate and stress a tree, particularly small ones. The adult insect is a one inch, snowy white moth, with dark spots on its wings. The caterpillars are one inch long and covered with silky hair. Their color varies from pale yellow to green with a black stripe on the back and yellow stripe on each side. People usually do not notice the caterpillars until the large, white webs with skeletonized leaves appear.

Although the fall webworm is not considered a deadly pest it does gets lots complaints due to its ugly web that detracts from the aesthetic value of the tree.

You usually do not need to worry about losing your tree is because the webworms are eating leaves relatively late in the growing season. Therefore the defoliation is much less damaging to the tree than had it occurred earlier.

Control of this pest is rarely needed or even effective. You could use stick or high water pressure to break their silk web nest and expose them to their natural predators: birds, yellow jackets, and wasps. Also, you could prune infected branches and burn or otherwise destroy them. Some people attach some newspaper to the end of a long pole, set it on fire, and burn the webs in place.

If using pesticides for the webworm, there are a few that are effective. For severe infestations, spray nests and leaves with Sevin, permithrin, spinosad, or malathion, according to label directions. The best way to apply these chemicals is to spray them around the nest, on branches that the worms may spread to, and inside the nest after first breaking it with a stick. There is an organic product called “B.t.” (Bacillus thuringiensis), sold under the product name of Biotrol, Dipel, or Thurcide. To apply break up newly formed nests, then spray with B.T. in early evening during mid-summer when the caterpillar nests are small. B.t. is slow acting so be patient.

Natural control is preferred whenever possible so poke that hole in the web and let Mother Nature take charge.

Pest Alert: Leaf-footed Bugs on Blueberries

Adult leaf-footed bug

      I have found and had a call about leaf-footed bugs in blueberries.  The call came from Lauderdale Co. and the ones I saw are in Clarke and Perry counties.

Leaf-footed bug cause damage when feed on leaves and fruit by piercing the blueberries with their proboscis and sucking the juices. The saliva of leaf‐footed bugs contains a toxic secretion, which further injures plant tissue. They may cause wilting and death of leaves and deformation and loss of fruit. Leaf-footed bugs can damage larger green and ripe fruits.  Feeding on fruit with piercing‐sucking mouthparts causes pitting, distortion and discoloration. Puncturing of fruit also allows secondary pathogens to enter and cause rotting.  



Immature leaf-footed bugs

Leaf-footed bugs also raise their young within the fruiting cluster which is annoying when harvesting.



     Insecticides should target the nymph and adult stages. Carbaryl (Sevin) and malathion should provide adequate control but be aware of preharvest intervals.   Homeowners can usually catch and kill the bugs by hand since they are relatively slow moving.  You might want to wear gloves since these bugs are in the stinkbug family. 

Coleus for Your Garden

   Coleus is a beautiful landscape plant prized for its colorful foliage, which comes in shades of green, yellow, pink, red, and maroon.

Alabama Sunset

    Coleus varieties can range from one to several feet in height. They can be used in hanging baskets, in containers on patios, or in landscape beds.

    These heat-tolerant, durable annuals have very few disease or insect problems.  Some varieties, such as the Kong series or Black Magic, grow better in shady conditions. 

Stained Glass

    Many new varieties, such as Alabama, Stained Glass, Duckfoot, or Mississippi Summer, thrive in full, hot sun.

 Coleus plants do best in well-drained soils amended with lots of organic matter. Pinch the growing stems of young plants frequently to encourage dense foliage. Remove flowers as they appear to keep the plants from going to seed and declining.

Azalea Leaf Gall

Galls on azalealeaves

    The warm, wet spring has been ideal conditions for leaf gall in azaleas. Leaf gall is a common fungal disease found on azaleas.  The leaf gall of azaleas is caused by the fungus, Exobasidum yaccinii.  Another fungus, Exobasidium camelliae, causes a similar problem in camellias. It occurs more commonly on the fall blooming ‘sasanqua’ varieties.

    This disease appears early in the spring. The new leaves and buds that are infected develop distorted growth. The leaves become thickened, curled, and pale green to white and in some cases pink. Leaves can be ten times thicker than normal leaves. The infected leaves are covered with a white powdery substance in the latter stages of the disease. Galls eventually turn brown and harden as the season progresses.

   Fundal spores overwinter in the bark. When the buds open in the spring, the spores are blown by the wind to the plant. Rain can also wash spores from the bark to the plant tissue. Spores need moisture to germinate. Plants that are grown in areas of poor air movement, deep shade, and high humidity are more likely to be infected.   After the plant is infected, the fungus stimulates a growth promoting process which causes the thickening and distortion of the plant.

   There are some varietal differences among azaleas in susceptibility.  Reported resistant varieties include: Gloria, Sensation, Coral Bells, Mrs. G. G. Gerbing, Sunglow, and Formosa.

   The disease usually does not do enough damage to require chemical control. If only a few plants are affected, prune the galls of the plant and throw them in the trash.  If the same plants get infected year after year then might be chemical control necessary.   Begin treat with captan, mancozeb, or triadimefon fungicide sprays starting wien the young leaves begin to unfurl then every 10 14 days after that until the young leaves mature. 

    Another procedure for controlling azalea leaf gall on badly diseased plants is to cut plants back severely. This is a good sanitation procedure and is a good way to reduce disease occurrence the following season because galls will be removed along with the pruned branches. It is also advisable to replace mulch beneath such plants since this will insure that fallen galls beneath plants will be removed.

Pruning Azaleas

     Azaleas are widely planted in Mississippi because of the colorful flowers they produce from late March through May.

      Pruning your azaleas can improve their blooming and help them develop into full, well-branched shrubs.  In many cases it is necessary to cut azaleas back severely because the wrong size variety was plant for the available site.

     If you need to prune your azaleas, do this in late spring or early summer, shortly after flowering stops, because azaleas set their flower buds for next year during the late summer.

 

     Remove shaded-out branches first, since these often become dead wood. Older plants may have tall leggy branches that need to be removed. Doing so gradually over several years reduces shock to the plant.

     Azaleas should be pruned several times during the growing season to develop a well branched plant. This involves pruning of the tips of the new, individual branches after five or six inches of new growth has been produced. This pruning not only results in a compact, well branched plant, but also one that will produce many more blooms than will plants not pruned in this manner.

    Pruning your azaleas correctly can keep them looking healthy and blooming strong!