Identifying Common Insect Problems
Although they may be climbing on your plants, some insects can be beneficials hunting for their prey. Eliminate the beneficials and you’ll inherit their jobs. If you can’t identify the bug – bring it in to a local nursery for identification.
Here are some typical insects found in and around the yard and garden and how to attempt to eliminate them:
Aphids: Tiny, white, green or brown soft-bodied insects grouped in masses along stems and leaves, primarily on new plant growth. Leaves become stunted, discolored and curled. Aphids suck plant juices and excrete a honeydew that attracts ants and forms the medium for black sooty mold. Organic controls include Ladybugs; spraying all parts of the affected plant(s) every morning for a week with a strong spray of water; or spraying visible insects with Safer Insecticidal Soap.
Chinch Bugs: Tiny, black insects that attack St. Augustine grass in hot, dry weather, causing irregular brown patches in the lawn. Infestation most often starts near sidewalks and driveways, or in areas where the soil is compacted and does not readily absorb water. Natural predator is the Big Eye Bug.
To prevent infestations in future years, increase lawn health by core aerating compacted areas in spring, increasing soil organic matter, and using good watering and mowing practices.
Earwigs: Small brown/black insects that are distinguished by “pincers” on their rear. The pincers are used for mating and not defense. They are actually beneficial insects that ingest decaying organic matter. However if there are many of them, they will consume plant tissues. If you have a population explosion of Earwigs, half-bury empty cardboard tubes behind plants – this provides a dark hiding place for them – throw the whole tube out the following morning. Spray visible insects with Safer Insecticidal Soap.
Lacebugs: Tiny bugs that suck sap from the undersides of leaves, leaving a brown excrement. Leaves have a mottled appearance from the top. Control organically with Neem Oil (Rose Defense). Control chemically with Eight or Malathion.
Pecan Phylloxera: Usually seen as swollen bumps on the leaves and twigs in late spring. Spray with dormant oil. Do not spray when daytime temperatures are predicted to rise above 85 F.
Scale: Adults are non-moving, small to medium bumps found on leaves and stems. There are many varieties that call Houston home. They can be white, reddish-brown, hard or soft. If a few are found, they can be manually removed. If there are many, use a systemic insecticide containing Disyston.
Spider mites: Yellowing, bronzed or “speckled” leaves. Organic controls include spraying tops and bottoms of leaves every morning for a week with a strong spray of water, or using Safer Insecticidal Soap. Chemical control includes Kelthane.
Stinkbugs: There are two types of Stinkbugs: Coreidae and Pentatomidae. The first are the Leaf-foots, the second are Shield-Shape. Both cause yellow specks on tomatoes which keep them from ripening well. The adult Leaf-foot is brown and about 3/8 in. long. It lays a cluster of red eggs. The resulting juveniles are ant-like, bright red and typically found in groups, often with their mother on tomatoes. Both the adult and young have a flat “leaf-shaped” upper rear legs. If squashed they stink, hence its name. Leaf-foot Stinkbug juveniles are easily confused with the beneficial Assassin Bug. An Assassin Bug is reddish and ant-like, but it is solitary and has no flattened upper rear leg. The Assassin Bug preys on juvenile Leaf-foot Stinkbugs.
The Shield-Shape Stinkbug comes in brown, gray and green. The beneficial Spined-Soldier Beetle looks just like a brown or gray Shield-Shape Stinkbug, but it has two sharp spines projecting from the shoulder area of its shield. Of the two stink bugs, the Leaf-foot is major cause of the damage on tomato fruit.
There are two ways to control stinkbugs. Whichever method you choose, consider picking the fruit when they are starting to turn from green to red (yellow or orange), and let them ripen indoors. When they reach that stage, there is enough sugar contained in the fruit that it will finish ripening in 2 – 3 days, without affecting the flavor. In this way you prevent the Stinkbugs from attacking the ripening fruit.
The mechanical way is to pick them off and squash them underfoot. The chemical way is to spray Sevin.
To prevent damage in the future, rotate your tomato crop to another location. This has the added benefit of avoiding any soil borne diseases that affect tomatoes. You can also plant small flowered herbs (e.g. chives), and nectar rich flowers (e.g. marigold) around the tomatoes to attract the beneficial Tachinid Fly. As noted earlier, the Assassin Bug preys on the Leaf-Foot Stink Bug. To attract them, plant sunflowers.
Tent Caterpillars: Also called Bag Worms. These are caterpillars that spin bag-like nests in tree branches. Organic controls include spraying leaves with Bacillus thuringiensis (Bt), and/or cutting the branch with the bag and burning it. Chemical controls include piercing bag and spraying the contents with Orthene, Malathion or Sevin.
Thrips: Microscopic bugs that suck on buds, resulting in malformed blooms. They can attack many kinds of flowering plants. Control thrips with Orthene.
Whiteflies: Tiny flies with white wings. They billow like powder when an infected plant is shaken. Spray with Safer Insecticidal Soap, Pyrethrum, Rotenone, Neem Oil, or liquid Malathion. DO NOT USE Malathion on Hibiscus.