Pests of Alabama


The Argentine ant, Linepithema humile (Mayr) is one of the most troublesome ants in Alabama. Argentine ants are mainly a nuisance to people because they are found indoors, forming wide, noticeable lines or trails of ants into homes.

These ants do not sting or bite. They are 2-3 mm in length and black to brown in color. Argentine ant workers are all about the same size (monomorphic), in contrast to fire ants, where workers can be different sizes (polymorphic). Workers emit a faint musty odor when crushed.

Fire ants are several species of ants in the genus Solenopsis. Imported fire ants are aggressive, reddish brown to black ants that are 1/8 to 1/4 inch long. The construct nests which are often visible as dome-shaped mounds of soil, sometimes as large as 3 feet across and 1 1/2 feet in height. In sandy soil, mounds are flatter and less visible. Fire ants typically build mounds in sunny, open areas such as lawns, pastures, cultivated fields, and meadow, but are not restricted to these areas.

Mounds or nest may be located in rotting logs, around trees and stumps, under pavement and building, and occasionally indoors. When their nests are disturbed, numerous fire ants will quickly run our of the mound and attack any intruder. These ants are notorious for their painful, burning sting that results in a pustule and intense itching, which may persist for 10 days.

Crazy Ants, Paratrechina longicornis (Latreille), occur in large number in homes or outdoors. They often forage long distances away from their nests, so nests are often difficult to control. The name “Crazy Ant” arises from is characteristic erratic and rapid movement not following trails as often as other ants.

The crazy ant worker is relatively small (2.3-3 mm). They are dark brown to blackish (Creighton, 1950); the body often has faint bluish iridescence.

The Pharaoh Ant, Monomorium pharaonis (Linnaeus), may be the most difficult of all building-invading ants to exterminate. They have large colonies with multiple queens, nest almost anywhere within a structure, and will split large colonies into smaller ones at the slightest sign of stress.

Pharaoh Ants do not cause direct damage to the structures they inhabit, nor are they known to harm humans by biting or as disease carriers. They are a nuisance pest. Pharaoh Ants are very small. They do not exceed 1/12 inch in length. They are yellowish to reddish brown in color.

The Carpenter Ants, of the genus Camponotus, are known as carpenter ants because they house their colonies in galleries they excavate in wood. Carpenter ants do not eat the wood they remove during their nest building activities, but deposit it outside entrances to the colony in small piles. The wood is used solely as a nesting site. The galleries of carpenter ants are kept smooth and clean, and are not lined with moist soil as termite galleries are. Carpenter ants rarely cause structural damage to buildings, although they can cause significant damage over a period of years because nests are so long-lived.

Carpenters ants vary in size and color but are usually large (1/4-1/2 inch) and blackish. Occasionally, swarms of winged carpenter ant reproductive individuals will emerge inside a home. Carpenter ants swarms usually occur in the spring and are a sure sign that a colony is nesting somewhere inside the structure.

*Not to be confused with termite swarms.*


Subterranean termites are the most destructive insect pests of wood in the United States. They cause more than $2 billion in damage each year, more property damage than that caused by fire and windstorm combined. In nature, subterranean termites are beneficial by breaking down many dead trees and other wood materials that would otherwise accumulate. The biomass of this breakdown process is recycled to the soil as humus.

Termites become a pests when they attack the wooden elements of human structures– homes, businesses, and warehouses. Their presence is not readily noticed because they hide their activity behind wall boards, siding, or wood trim.

Termite workers make up the largest number of individuals within a colony. Workers are wingless, white to creamy white, and 1/4 to 3/8 inch long. They do all of the work of the colony, i.e. feeding the other castes, grooming the queen, excavating the nest, and making tunnels. Their “work” consists of chewing and eating wood, causing the destruction that makes termites economically important.

It is important to be able to distinguish between swarming termites and ants. They often swarm around the same time of year, but control measures for each differ greatly.


The German Cockroach, Blattella germanica (Linnaeus), is the cockroach of concern. This is the species that gives all other cockroaches a bad name. It occurs in structures throughout Alabama, and is the species that typically plagues multifamily dwellings. German cockroaches spoil food or food products with their feces and defensive secretions. They also transport, and often harbor, pathogenic organisms that may cause severe allergic responses.

The adult is 10 to 15 mm long, brown to dark brown in color, with two distinct parallel bands running the length of the pronotum. The sexes can be distinguished by the following characteristics: male- thin and slender body, tapered posterior abdomen with visible terminal segments, no leathery outer wings (tegmina); female- body stout with rounded posterior abdomen entirely covered by tegmina.

Smokybrown Cockroach, Periplaneta fuliginosa, is a relative of the American cockroach and resembles it in shape and size. These cockroaches are more common in the southern United States. They are a little over 1 inch long, and both sexes have wings that are longer than the abdomen. Their very dark mahogany color is striking. No light markings appear on the ronotum or wings.

Smokybrown cockroaches are susceptible to losing moisture through their cuticle, and so are usually found in damp, dark, and poorly ventilated environments. They rarely infest the welling part of buildings, and are instead found in sheds, wall, and roof spaces, sub-floors, mulched areas, and in and around grease traps and drains.

Adult American cockroaches are reddish-brown to dark brown (except for a tan or light yellow band around the shield behind the head), about 1 1/2 to 2 inches long, and have wings capable of flight. Males and females are about the same size.

American cockroaches can be detected by examining the premises after dark with a flashlight. They occur in dark, damp, warm places, often near steam pipes, in sewers, grease traps, amp basements, etc. During the day, probing hiding places with a wire will expose roaches. Household sprays of pyrethrins applied to hiding places will flush out roaches, sometimes killings them if they contact the spray.


The only dangerous spiders we have in Alabama are the Brown Recluse and the Black and Brown Widow spiders. For the most part, spiders are beneficial by eating insects and other spiders.

The Brown Recluse, Loxosceles reclusa, belongs to a group of spiders that is officially known as “recluse spiders”. These spiders are also commonly referred to as “fiddleback” spiders or “violin” spiders because of the violin-shaped marking on the top surface of the cephalothorax (fused head and thorax). These spiders are commonly found in undisturbed areas, typically in garages and storage rooms. These spiders are “reclusive” so finding them running across the floor is uncommon. Be aware of corners and under chairs when cleaning out those “undisturbed areas”.

A mature brown recluse spider will have a well defined, dark “violin” marking on the head with the neck of the violin pointed toward the bulbous abdomen. The abdomen is uniformly colored ranging from light tan to dark brown, and is covered with numerous fine hairs that provide a velvety appearance. The spider has long, thin, brown legs covered with fine hairs, not spines. Adult Brown Recluse spiders have a leg span of about the size of a quarter. The body is typically about 3/8 inch long and about 3/16 inch wide. Male bodies are slightly smaller than females, but males have proportionally longer legs. Both sexes are venomous.

Southern Black Widow, Latrodectus mactans, is a venoumous species of spider in the genus Latrodectus. These spiders are known for their distinctive black and red coloring in the females. The southern widow is indigenous to the southeastern United States. Their webs are made of irregular, tangled, sticky silken fibers. They prefer to nest near the ground in dark and undisturbed areas, like under chairs and in basements.

A mature female will have a body length (excluding legs) of about 8-13 mm, and males are about 3-6 mm. The legs are long in proportion to the body. Females are shiny and black in color with the red hourglass on the under side of her abdomen. Juveniles have a grayish to black color with white stripes. Males may be either purple or have coloring similar to juveniles.

The common house spider, Archaearanea tepidarorium (C.L. Koch), may be the most abundant of the several species of spiders that live in the company of man in the southeastern United States.

The common house spider is yellow to brown with darker rings on the legs. The abdomen is higher than it is long. The males are typically darker and smaller than the females. Females range from 5-8 mm in length, and males are about 4 mm.

Wolf spiders, family Lycosidae, are usually large, hairy spiders that are not associated with webs. They look much worse and scarier than they actually are. They live mostly in solitude and hunt alone, and do not build webs. Wolf spiders are unique in that they carry their eggs on their backs in an egg sac.

The size and look of wolf spiders varies greatly. They can be from only 1/4 inch to 1 1/2 inches in body length, with a leg span of up to 3 inches. The coloring can range from brown (earth tone) with black to white markings. Their long bodies are covered with hair.


Yellow Jackets are predatory social wasps of the genera Vespula and Dolichovespula. These wasps live in nests and problems usually occur when these nest are disturbed, like during spring cleaning and readying your yard for summer. They have the ability to sting as a means of the ensuring survival. A hollow stinger is located at the rear of the yellow jacket’s body. Upon penetrating the skin, a venom is injected through the stinger. These stings can be quite painful. They can also be very dangerous to people who have developed an allergy to the stings. Unlike the bee, a yellow jacket can sting more than once. Wasps can also damage fruit when they create holes by eating the flesh.

People often mistake bees for yellow jackets because of their coloring. However, they are very different. Bees sting once and then die, but wasps can sting repeatedly. Yellow Jackets have a shiny black and yellow body, and measure from 1/2 inch (workers) to 3/4 inch (queen). These social insects live in large colonies.

The Bald-faced Hornet, Dolichovespula maculata, is actually a large yellow jacket and not a true hornet. Bald-faced Hornets make large, pear-shaped nests that are often seen in trees after the leaves have fallen in the fall. The paper covering of the nest is made from chewed up wood or paper. They will attach their nests to trees, bushes, and sometimes even the side of a structure.

These wasps differ from yellow jackets in their white and black coloring. The head is white or “baldfaced”. They have three stripes at the end of their bodies. They are also notable larger than other species of Dolichovespula. The average adult is about 3/4 inch in length, with the queen being larger.

Common Pests

Centipedes are reddish-brown, flattened, elongated arthropods with one pair of legs attached to most of their body segments. The first pair of legs is modified into poisonous jaws located below the mouth to kill insects. Their antennae are longer than those of millipedes. Centipedes feed on live insects and other small animals. they do not damage plants.

They are a nuisance in households and basements. They feed on small insects such as cockroaches, clothes moths, house flies. They do not damage food supplies or household furnishings. If crushed, they may bite causing some pain and swelling.

Millipedes are slow-crawling, round bodied pests which have two sets of legs on each body segment. Millipedes develop best in damp and dark locations with abundant organic matter (food). They often curl up into a tight “C” shape, like a watch spring, and remain motionless when touched. The body is long and cylindrical.

Millipedes range from 1-4 inches long and are dark brown in color.

The Earwig name originates from the superstition that they crawl into the ears of sleeping persons and bore into the brain. Although earwigs appear somewhat dangerous due to their forceps, they are practically harmless to man.

Earwigs vary in size from 1/2 – 1 inch in length. They are brown to black in color. Species may be winged or wingless, and only a few species are good fliers. The body ends in a pair of forceps. These forceps are used in capturing prey and mating.

Ladybugs, Harmonia axyridis, are usually about 1/4 inch in length with round bodies. The wings are usually red or orange. Spots will vary. Ladybugs are predators of aphids and the plant pests, so they may be found on a wide variety of plants outside.

As the weather cools in late summer and early fall, the sun warms the southern and western walls of buildings. The warmth attracts these insects to buildings where they crawl inside cracks and stay there for the winter. This would be fine, but during warm winter days, some insects “wake up” and come inside the building.

The House Mouse, Mus musculus, is a small rodent that arrived in North America via baggage and stores of the early settlers. These mice are prolific breeders, reaching sexual maturity in just 35 days of life. They have several 21 day pregnancies per yer and product 4-7 offspring per litter. These pests are primarily nocturnal in activity. Their food sources consist of grains, fruit, vegetables, stored food, and refuse.

The House Mouse will grow to about 3-4 inches in body length with a tail up to 4 inches long. In the wild, they vary in color from grey and light brown to black. These mice have become domesticated as “pets” and laboratory test creatures. The colors of the domesticated mouse can vary widely.

The most common domestic flea is the cat flea, Ctenocephalides felis. The adult cat flea, unlike many other fleas, remains on the host. Adults require a fresh blood meal in order to reproduce. The dog flea, Ctenocephalides canis, appears similar to the cat flea, but is rarely found in the United States. CAt fleas are commonly found on both cats and dogs in North America, while dog fleas are found in Europe.

In order to effectively control an infestation, fleas must be removed from the pet, the home, and the yard. Removal of fleas from the animal alone is futile. Immature fleas, which have developed into adults off the animal, simply jump on causing subsequent re-infestation. Flea combs may be sued to treat the pet, yet they only remove 10-60% of the fleas. By shampooing the animal, the dried blood and skin flakes, which provide food for the larvae, are removed.