Fungus Gnats Hovering Around Plants

Fungus gnats are typically weak fliers, so they usually remain near the potted plant or rest on foliage or growing media. Adult fungus gnats are 1/8 to 1/10 inches in length, grayish black in color, slender bodied with long legs and antennae. They are usually identified by the vein pattern on their wings, with the common species having a Y-shaped wing vein. Female fungus gnats lay tiny, oval eggs in moist, organic debris. The eggs hatch into larvae that are legless, elongate, white to clear in color, with black heads. The larvae eat organic mulch, compost, root hairs, and fungi and can damage roots of plants, causing wilting, poor growth and loss of foliage. Pupation occurs in the soil in silk-like cocoons. The complete lifecycle from egg to adult occurs in about 4 weeks, so continuous reproduction can occur in controlled environments such as homes or greenhouses.

Some Suggestions for Control Measures:

Prevention
Inspect plants before purchasing and use sterile potting soil.
Allow soil to dry for several days to kill some larvae, since over watering, poor drainage and water leaks can result in a large population of fungus gnats. If the top layer of the soil becomes dry, then the larvae will die and the female fungus gnats will not lay eggs in the soil.

Discard heavily infested plants as to avoid infesting other plants.

Biological Control

Some predators such as Steinernema spp. nematodes and Hypoaspis spp. mites that can be applied to soil to control fungus gnat larvae.

Bacillus thuringiensis israelensis (Bti) can be applied soil to control fungus gnat larvae.

Chemical Control

Larvae can be controlled by many chemicals, including azadirachtin, fenoxycarb and imidacloprid. Adult fungus gnats can be controlled by foliar treatments, including the chemicals horticulture oil, pyrethrins, and bifenthrin.

Picture of fungus gnat. Photo found at Texas A&M University: http://hortipm.tamu.edu/pestprofiles/other/fungnatd/fungnatd.html.

Aggregating Asian Lady Beetles

Eventhough this is a beneficial predator of aphids and scales, the multi-colored Asian ladybeetle tends to congregate in large numbers around buildings as they overwinter. This causes them to sometimes move indoors in the cooler months, where they can crawl on floors, walls and ceilings. They will exude a yellowish liquid when disturbed (reflux bleeding), which can stain fabric and can cause skin irritation. They can also bite since they have chewing mouthparts.
Exclusion practices should be used to prevent these ladybeetles from entering into buildings. All cracks and crevices, such as around windows, doors, air conditioners, and utility pipes should be sealed in late summer and fall. Also if beetles are spotted inside the home, then a vacuum should be used to remove them. Remember to dispose of the vacuum bag outside, so the beetles do not escape and re-invade the building.

Multi-colored Asian Ladybeetle. Photo by Mike Merchant, Professor and Extension Entomologist, Texas A&M University.

Increase of Squash Vine Borers

Squash vine borers are the most common and most damaging pests of squash. The larvae are borers so they will cause damage as they tunnel into the stems. They usually feed on squash and related wild plants but also can feed on melons and cucumbers.
The adult moths resemble a wasp, with a red abdomen surrounded with black bands at each segment; their front wings are covered with metallic brown scales and their back wings are clear with a brown band. Adult females lay eggs on the leaves and stems of primarily squash. The larvae hatch and begin burrowing into host plant stems. The larva is white in color with a brown head and grows to be an inch in length. The larvae will produce sawdust like frass near the base of the plant which may cause the stems to wilt and die. The larvae then climb from the stems to pupate in the soil.

Some Control Suggestions:

Some Non-Chemical Controls:
Keep natural enemies in the garden such as parasitic wasps that will attack squash vine borer eggs and larvae. Also adult ground beetles (Family Carabidae) will attack squash vine borer larvae. Split vines should be covered with soil immediately after the larvae have been removed. Also remove vines soon after harvest to destroy any larvae still inside stems.

Some Chemical Controls:

Some chemical suggestions include such active ingredients as pyrethrins, permethrin, or carbaryl. Apply the chemicals to the base of the plant, underneath the foliage and underneath the stems of the plant.

Southwestern squash vine borer, Melittia calabaza (Lepidoptera: Sessidae), adult. Photo by G. McIlveen, Jr, http://insects.tamu.edu/images/insects/common/images/cd-43-c-txt/cimg251.html.

Abundance of Hackberry Gall Nipple Makers

Many residents that live in neighborhoods with hackberry trees have been noticing many small cicada looking insects, about 3/16 inches in length with spotted wings on their window screens and doors. These insects are adult hackberry gall psyllids or also called hackberry nipple gall makers. In the fall, these insects invade indoors looking for an overwintering site. Normally, they will overwinter under the bark of trees, but will also come indoors through any cracks and crevices such as around windows and doors usually at night since they are attracted to indoor lights. However, those that come inside are going to die.
In the spring, the adult psyillds will emerge and lay eggs in the leaves of hackberry trees. When the egg hatches, the developing psyilld begins feeding and the leaf begins to form a small pocket around the psyilld as the insect develops, forming a gall. The galls that are produced vary in size from 1/8 to ¼ inch and are found on the leaves and petioles. The adult gall will then emerge in the fall. Even though the galls can be unsightly on the leaves and sometimes cause premature leaf drop, they do not appear to affect tree health. This means no chemical treatments are recommended.
Hackberry psyllids are not harmful to people or pets and will not attack indoor plants or furnishings. Since they are a seasonal annoyance, residents can vacuum them to remove them as needed. As the temperatures fall, so will the hackberry gall psyilld population!

Photo of hackberry gall psyllids, Pachypsylla sp. (Homoptera: Psyllidae), adults. Photo by C.L. Cole, Texas A&M University.

Argentine Ants Not Crazy Rasberry Ants

Argentine ants seem to be causing alarm to some homeowners. Many people are confusing them with the Rasberry crazy ant (recently in the news); since they form dense foraging trails and often invade homes and other structures. Argentine worker ants are all the same size, about 1/8-inches in length and are dull brown in color. These ants have multiple queen colonies allowing workers to move freely between colonies. Populations sometimes appear to be a giant super colony. Even though, argentine ants do not bite or sting, their colony size can be in the hundreds of thousands.
These ants usually nest in cavities in soil, under rocks, in flower beds and in branches or cavities of trees. They eat sweets, fresh fruit, and buds of some plants and tend honeydew-producing insects, such as scales and aphids. These ants travel in distinctive trails along sidewalks, up the sides of buildings, along branches of trees and shrubs, along baseboards, and under edges of carpets.

Some Control Options:
Some Non-Chemical Control Options:

Trim tree branches and other plants so they do not touch structures, since argentine ants can use these branches to get into structures.
Caulk and seal any cracks or little openings around the structure.
Do not stack firewood and building materials next to structures, since these ants can build nests in these materials.
Reduce moisture sources such as leaky plumbing and free-standing water in and around structures.
Clean window sills to remove dead insects, since these ants will feed on dead insects.
Check potted plants for ants before bringing the plants indoors by watering to check for ants moving within the soil.

Some Chemical Control Options:
Spot treatments at points of entry into structures such as around window sills and door thresholds may be effective. Insecticides used for these treatments should be a wettable powder or microencapsulated formulation labeled for this type of application. If colonies cannot be located, bait insecticides can be used. Argentine ants are mostly attracted to sweet baits. Such baits containing boric acid, hydramethylnon and sulfluramid are suggested for control.

Photo of argentine ant worker. Photo by Elizabeth “Wizzie” Brown, Program Specialist-IPM, Texas AgriLife Extension.

March of the Armyworms

The fall armyworm, Spodoptera frugiperda, eats foliage of many different kinds of plants, such as turfgrass, shrubs, and agricultural crops. Several reports of these armyworms have been seen in large populations as they march in and feed both day and night, causing circular or irregular deadened patches of turfgrass. Armyworms do not usually kill lawns, especially bermudagrass lawns, but will scalp them; however, St. Augustine lawns are more susceptible, and can be completely lost after armyworms feed.
Armyworms have four life stages: egg, larva, pupa and adult. The eggs are very small, and are laid on leaves at night. The larvae hatch from the eggs and feed mostly at night. They tend to hide in thatch and debris in the daytime. The young larvae are white with black heads but develop a prominent white line forming an inverted “Y,” with stripes along the body as it matures. The larvae will become 2 inches in length before entering the soil to pupate. Then the adult moths emerge, mate and lay eggs. The adult moth has a wingspan of 1 ½ inches, with silver-white hindwings and dark grey front wings with light and dark splotches.
The locations of large populations of armyworms vary each year throughout the state. However warm, humid climates, along with large amounts of thatch are favorable conditions for fall armyworms to multiply. Armyworms should be controlled when they occur in large numbers or plant damage becomes excessive.

Some Control Options:

Some Non-Chemical Control Options:
Eliminate thatch to reduce develop sites of the armyworms. Also monitor for sites of infestation in the turfgrass by flushing the area with soapy water if damage is seen but the armyworms are not seen. This will cause caterpillars to move around within minutes so they can be spotted.

Some Chemical Control Options: Armyworms can be controlled using such insecticides containing the active ingredients permethrin, cyfluthrin, bifenthrin or esfenvalerate. Spot treatments or whole lawn treatments can be effective, depending on the size of the population.

Photo of fall armyworm. Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.

Are Leafcutter Bees Making Holes in Your Leaves?

Most common leafcutter bees, Megachile sp., are the same size as honey bees. However, leafcutter bees are mostly black in color with light colored bands across their abdomens. Also, female leafcutter bees carry pollen on stiff hairs on the underside of the abdomens rather than on the sides of the hind legs like honey bees. Leafcutter bees tend to be non-aggressive and usually only sting when handled.
Leafcutter bees are solitary bees, so individual female bees dig out nesting areas, create nest cells and provide young with food. Adult females cut circular or elongate pieces of leaves from such plants as roses, azaleas, bougainvilleas, redbuds, and other cultivated and wild plants. They use the leaves to construct walls and partitions for nesting cells. These nests can be found in such places as hollow twigs, holes in buildings, and in the ground. The nesting cells are provided with nectar and pollen collected from flowers. One egg is laid in each nesting cell. When the egg hatches, a white, legless, grub-like larva emerges and develops within the cell. The larva then pupates before emerging as an adult out of the cell the next season.
Leafcutter bees are important pollinators of plants. However, they can cause damage to plants when large populations exist on smaller, developing plants.

Control Options:
There are many natural enemies of leafcutter bees such as parasitic bees and wasps, velvet ants and some blister beetles. The use of insecticides is usually ineffective for the prevention of leaf cutting. One control option is to cover susceptible plants with cheesecloth or other loose netting during periods when leafcutter bees are most active. Also, leafcutter bee populations can be reduced if breeding sites are eliminated so such items as rotting boards or thick stemmed plants with hollowed openings should be removed from the landscape.

A leafcutting bee, Megachile sp. (Hymenoptera: Megachilidae), adult. Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.