Click on a species of ants below to learn further information.
General Introduction to Ants
The two most numerous terrestrial animals on the planet are ants in the order Hymenoptera (including bees and wasps) and aphids (plant lice). Ants are extremely successful animals and range from the tropics into the arctic regions and from the dry desert areas down to sea level and moist regions. Part of the success of the ant is its social and communal nature and the fact that ant nests are usually terrestrial and are adapted to a great variety of climatic and soil conditions. One of the most outstanding survival characteristics of the ant is its ability to adapt itself to a varying environment. Another important factor in the survival of ants is their division of labor among the division of labor among colony members. Ants (as well as all insects in the order Hymenoptera) have a complete life cycle (metamorphosis).
The Anatomy of Ants
Ants come in a variety of sizes and colors. Ants are typically either, blackish, brownish, yellowish, or reddish in coloration, or any combinational mixes of the aforementioned. The largest ant is the female 0f Dorylus wilverthi and attains a length of up to 4 cm. The smallest ant is 0.8 mm long.
One of the distinguishing elements of the ant from other insects is primarily by the narrow pedicel
consisting of one or two joints, situated between the thorax and the abdomen. Ants also manifest noticeable elbowed antennae. The discernible pest control operator will notice that the narrow pedicel of the ant is distinguishable from that of the broad connection of the thorax and abdomen in termites.
The antenna harbors the many sensory cells of the ant and enables the ant in the primary areas of touch and smell. It is made up of a scape and funiculus (whip), the latter being much more mobile than the former. The funiculus has a tendency to rapidly vibrate and this vibration is associated with the high development of the olfactory sense in ants. An ant losing its antennae would be the equivalent to a man losing his hearing, speech, and eye sight, due to the fact that it is primarily through the antennae that they are aware of their environment and adjust themselves accordingly.
The sense of smell in ants is radically different to that of humans. Ants can smell with their antennae and even recall smells that are elongated, hard, soft, round, square, and even in a certain direction. There eye sight on the other hand is much poorer than that of humans. They have lateral compound eyes; the queen, male and workers of some species have three simple eyes (oscelli). Oscelli are adapted only for seeing light or dark. Ants are not believed to be able to see things clearly and distinctly.
Ant heads come in a variety of forms: long, short, wide, thin, protruding, etc. One of the chief
components of the ant head consists of the mandibles. The mandibles are used for a variety of endeavors: biting, building, carrying, cutting, gnawing, leaping, and sawing, but strangely enough, never for eating.
Spurs are usually present on the legs of ants and those on the forelegs are especially large and comb-like. The ant removes dust from the antennae and legs by drawing these through the comb of the tarsus and the spur of the tibia. Moreover, the tarsal hairs are lubricated by the tarsal glands. In this regard, the comb and brush are never absent from the fore-legs. The secretion of the glands of the tarsus causes the grains of dust and other impurities to stick to each other, and this makes it easier for the ant to dispose of them with its comb and brush.
Ant Biology and Habits
The ant egg is virtually microscopic in size. It hatches, producing a soft legless larva. After several
molts, the larva pupates. In some ants, the pupa is inside a silk, smooth-surfaced, light colored cocoon, while in others the pupa is "naked" (not in a cocoon). The cocoon resembles a large capsule-shaped egg, about the size of the ant itself (a good example of this is the common Argentine ant). Sometimes these pupae are mistakenly thought to be ant eggs. Indeed, the pupae of some of the larger species of ants are sold in pet stores as "ant eggs". A good method in which to see this more clearly is by moving a board under where the ants are living and you will see the adults ants carrying off the pupae (or "ant eggs") and larvae. By looking more closely, you can see that they also are carrying away the actual very tiny eggs.
The adult ant may require a few days to become completely mature after emergence from the pupa.
During this period, the body hardens and darkens. From egg to adult takes 6 weeks to 2 months or more, depending on the season, temperature, and species.
As with bees and termites, the ant colony is composed of individuals called castes. The ants have three distinct castes: (1) the workers; (2) the males; and (3) the females. All three of these castes go through the same process of egg, larva, and pupa stages of development.
The Establishing of the Ant Colony
The vast majority of ant colonies are formed when the newly mated queen rids herself of her wings, digs a nest or seeks a cavity under a stone or piece of bark. She then closes the opening of the cell and remains a volunteer prisoner for weeks or even months while the eggs are growing in her ovaries. The loss of her wings has a strange effect on the voluminous wing muscles in her thorax, causing them to break down and dissolve in the blood plasma. Their substance is carried by the circulation to the ovaries and utilized in building up the yolk of the eggs. As soon as the eggs mature, they are laid and the queen nurses the hatching larvae and feeds them with her saliva till they pupate.
Since the queen never leaves the cell during all this time and has access to no food, except the fat stored in her abdomen during her larval life and her dissolved wing muscles, the workers that emerge from the pupae are all abnormally small. They are in fact, always minimal in species which have a polymorphic workers' caste. They dig their way out through the soil, thus establishing a communication between the cell and the outside world, collect food for themselves and their mother, and thus enable her to lay more eggs. They take charge of the second brood of eggs and larvae, which, being more abundantly fed, develop into larger workers. The population of the colony now increases rapidly, new chambers and galleries are added to the nest and the queen devotes herself to digesting the food received from the workers and to laying more eggs. In the course of a few years, numerous males and queens are reared and on some meteorologically favorable day, the fertile forms from all the nests of the same species over a wide expanse of country escape simultaneously into the air and
celebrate their marriage flight. This flight provides not only for the mating of the sexes but also for the
dissemination of the species, since the daughter queens, on descending to the ground usually establish their nests some distance from where the parental colony is located.
The higher the rate of egg disposition of ants the more proportion of eggs escaping fertilization and
therefore the higher proportion of males. It therefore follows that if differences in the rate of egg deposition by the queen ant determine the occurrences of the various castes, the males and queens will be produced when the rate is high, that is, when the ripe eggs are retained in the ovary for a relatively short time, while the sterile female castes and associated anomalies will be produced when the rate is low, that it, when the ripe eggs are retained in the ovary for a relatively long time.
The workers are sterile and wingless females and may vary in size and forms almost as large as the
queen to very small ants. The larger ants may defend the nest or use their large jaws to crush seeds. When there are not intermediate forms, but only two classes of workers, small and large, the large workers are called "soldiers." In many species of ants, there may be only one size for all the workers. For example. Argentine ants are known as monomorphic ants (same size), whereas Carpenter ants are polymorphic (many sized). The workers perform all the labor in the ant colony such as nest building, nursing of the young, procuring the food and duties of similar nature. At times the worker may take over the egg-laying duties of the queen. Workers may live up to seven years, but usually exist under natural conditions for a much shorter period of time.
The male is winged and keeps his wings until death. He is somewhat larger than the worker but smaller than the female. He dies one to two days after his mating flight with the female. Of the three ants in the caste system he has the largest eyes (perhaps with which to spot the queen) and a huge thorax which harbors powerful wing muscles.
The queen is usually the largest ant in the colony. The queen mates only once, but may produce
offspring until she dies. In species where the queen is winged, virgin queens found in the nest still retain their wings, unlike the mated queen, who removes hers. Once the queen has reared her first brood, she usually becomes an egg laying machine and is cleaned and fed by the workers. Many colonies have more than one queen in the nest. Should all the queens in a nest die or be killed, specially fed workers may undertake the egg-laying function. Some ant colonies have been known to exist for up to 40 years. Queens have been known to live as long as 15 years. The original colony queen is often replaced several times before a colony is disbanded or destroyed.
The Eating Habits of Ants
Ants are primarily omnivorous (meaning they eat practically everything). They mainly feed on those
foods which are greasy, starchy, and sweet. Sense of smell is the most developed of the ant's senses and thus helps them find food by searching randomly and following their odor receptors (located on the last few segments of their antennae). Upon finding food, the ants find their way back to the nest and help direct the others to the newly found source of food. Ants have good memories and can recognize surroundings and landmarks in order to remember where the food source is located. Oftentimes ants will even use sunlight as a means of orientation. Another method of helping the ants find food is known as pheromones. Pheromones are substances secreted by the ant that influence the behavior of other ants in the colony. When a food source is located, the worker lays down a scent trail (pheromones) for others to follow. The other workers pick up the scent and help in gathering food for the colony.
Ants are liquid-sugar imbibers and obtain much of their nourishment either from the sweet exudations of plants or insects. These sugar-eating ants attend the nectarines on leaves and in flowers, as well as collect the "honey dew" deposits of aphids, white-flies, scale insects, mealy-bugs and other insects. This honey dew is the excess juice left over after the insects have assimilated the nutrients which they can use. These honey dew producers have changed the cane sugar to invert sugars which are similar to honey.
Ants enjoy liquids and hefty solid particles do not enter the digestive tract. When found feeding on solid material, they are merely squeezing the liquid juices from this food. Although the larvae of most ants feed on liquids, the larvae of a few different species may swallow solid food.
There are approximately 217 species of ants in California. We will examine a few of the most common ants likely to be encountered by the pest control worker in California.
Click on a species of pest below to learn further information.