Aging and development in social insects with emphasis on the honey bee, Apis mellifera L.
Introduction
Advanced insect societies are characterized by overlapping generations, where offspring, members of the ‘worker’ caste, remain in the nest and contribute to the reproductive success of their parents, the reproductive caste, at a cost to their own reproduction (Wilson, 1971). Therefore, longevity of the reproductives was a key enabler of the evolution of social insects. The maternal parent, the ‘queen’, is usually anatomically adapted to high output egg production, is larger in size, and has a longer length of life than her non-reproductive worker offspring. Workers are often anatomically distinct from the reproductives, and sometimes anatomically differentiated into subclasses of workers (subcastes). These differences between queens and their worker offspring, and among worker anatomical subcastes, are usually trophogenic in origin, a result of differential feeding during larval development.
Section snippets
How long do social insects live?
To address this question, we must distinguish between how long they ‘do’ live and how long they ‘can’ live. Wilson (1971) and Hölldobler and Wilson (1990) list numerous published accounts of observations of length of life for different species of social insects: ants (29 species), wasps (4), bees (8), and termites (9). For queen ants, maximum recorded life spans vary from 9–10 weeks for Monomorium pharoanis to 30 years for Pogonomyrmex owyheei. Queens of 15 ant species were reported to live more
Honey bees
Honey bees typically live in colonies consisting of a single queen, approximately 10–30 thousand “sterile” female workers, and from zero to a few thousand males, depending on the time of year (Fig. 1). Workers perform all of the tasks associated with colonial living while drones fly daily from the nest-seeking mates. Queens mate with many males while in flight, soon after they develop into adults. They store the sperm from these many mates in a specialized structure, the spermatheca, for the
Honey bee queens
Queens require just 16 days to develop from egg into an adult, 3 days as an egg, 6 days as a feeding larva (has 5 instars during the larval stage), 7 days as a pre-pupa and pupa. At emergence, they weigh about 178–292 mg (see Winston (1987) for review).
Honey bee drones
Drones are derived from unfertilized eggs laid by the queen. They are haploid, inheriting just one set of chromosomes from their mother. Drones require 24 days to develop from egg to adult. Eggs hatch after 3 days, larvae feed for about 6 days, and the pre-pupal and pupal stages last about 15 days. Drones weigh about 196–225 mg when they emerge as adults, making them about the same size as queens and about twice as large as workers (see Winston, 1987).
Honey bee workers
We know far more about the life history of worker honey bees than any other group of social insects. Worker honey bees require 21 days to develop from egg to adult: 3 days as an egg, 6 days as a larva, and 12 days as a pre-pupa and pupa. They weigh about 81–151 mg when they emerge as adults (Winston, 1987). After they emerge as adults they go through an age-correlated progression of behavioral changes that has been called behavioral development. The youngest bees typically clean the nest and feed
Conclusion
What do we know about aging in social insects? (1) Queens of some species of ants and termites live a very long time. (2) It appears that workers usually do not live as long as their queens. (3) Individual sperm cells live much longer than the males that produce them. (4) Differences between honey bee queens and workers result from differential feeding that results in differential gene expression that results in differential humeral control of development. (5) Processes of maturation continue
References (110)
- et al.
Variations of brain biogenic amines in mature honeybees and induction of recruitment behavior
Comp. Biochem. Physiol. A
(1998) - et al.
Rapid dendritic spine stem shortening during one-trail learning: The honeybee's first orientation flight
Brain. Res.
(1982) - et al.
Temporal polyethism and behavioural canalization in the honey bee, Apis mellifera
Anim. Behav.
(1996) - et al.
Juvenile hormone effect DNA synthesis and apoptosis in caste-specific differentiation of the larval honey bee (Apis mellifera L.) ovary
J. Insect. Physiol.
(1998) - et al.
Development and experience lead to increased volume of subcompartments of the honeybee mushroom body
Behav. Neural. Biol.
(1994) - et al.
Neurogenesis is absent in the brains of adult honey bees and does not explain behavioral neuroplasticity
Neurosci. Lett.
(1995) - et al.
Changes in weight of the pharyngeal gland and haemolymph titres of juvenile hormone, protein and vitellogenin in worker honey bees
J. Insect. Physiol.
(1982) - et al.
Neuroactive compounds in the brain of the honeybee during imaginal life
Comp. Biochem. Physiol.
(1989) - et al.
Elevated brain dopamine levels associated with ovary development in queenless worker honey bees (Apis mellifera L.)
Comp. Biochem. Physiol.
(1995) - et al.
Social insect polymorphism: Hormonal regulation of plasticity in development and reproduction in the honey bee
Curr. Top. Devel. Biol.
(1998)