Volume 45, Number 4,
July 1999: Carpenter Ants

Text-only version

ISSUE HOME PAGE

ABOUT THIS ISSUE
- about KSN
- about the authors

IN THIS ISSUE

Section 1:
- introduction
- what is a carpenter ant?

Section 2:
- life cycle
- colony size

Section 3:
- how carpenter ants find their way around

Section 4:
- feeding habits
- optimizing feeding
- territorial ants go to war
- avoiding war

Section 5:
- why active at night?
- ecological value of carpenter ants

Section 6:
- surviving winter
- destroying wood
- contrast between termites and carpenter ants

- References

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Carpenter Ants
by John H. Klotz, Laurel D. Hansen, Byron L. Reid and Stephen A. Klotz

LIFE CYCLE

A winged ant begins the life cycle. Carpenter ant colonies are formed after reproductive adults (winged virgin queens and winged males) emerge from their nest of origin for mating flights, usually during the first warm days of spring.  After mating, the male dies. Each inseminated queen selects a nesting site, often in a small cavity in a stump or long, or perhaps under bark in a standing tree.  She then breaks off her wings and within a few days lays her first eggs. In two to three weeks, the eggs hatch into larvae that are fed by the queen, who mobilizes food stored in the flight muscles of her thorax and in the fat bodies of her abdomen.  The queen does not leave the nest to hunt for food during this time.  Instead, she remains to protect, feed, and raise the brood (Figure 3). At the end of the larval developmental period, the larvae pupate and emerge as minor workers, numbering some 10 to 25 individuals.  Workers, which are all female, assume the functions of foraging, nest excavating, and brood rearing.  In two years, a population of workers ranging in size from small minors (6 mm) to large majors (13 mm) will be present.  The size of a worker is not genetically determined; rather it is dependent on environmental factors such as larval nutrition. Winged adults (reproductives) are produced in six to 10 year-old colonies when populations exceed 2000 workers. Mature, or parent colonies, establish satellite colonies nearby whenever there is a need for more territory, resources, or a drier, warmer nesting site for development of their larvae and pupae.  The queen, workers, and small larvae are always present in the parent colony whereas the satellite colonies contain workers, larger larvae, and pupae.  Except during winter diapause, workers travel between various satellites of the colony that are connected by well-defined trails (discussed later).

COLONY SIZE

Populations of ant colonies can reach tremendous numbers.  For example, over 50,000 workers have been found in colonies of Camponotus modoc (cover), a western carpenter ant.  This is a relatively small social group in comparison with another carpenter ant found in the West, Camponotus vicinus, whose colonies may number over 100,000 workers.  Part of the explanation for the vast difference in populations of colonies is the presence of multiple queens, a condition called polygyny, that is common in C. vicinus colonies.  As many as 41 functional queens have been collected in a single C. vicinus colony.  Most species of carpenter ants are monogynous (possessing only one queen) and as a consequence, the colonies are smaller and require years to reach maturity.