Life tables for worker honeybees

Abstract

SummaryLife tables for worker honeybees covering all life span, and those for adults, were prepared for three seasonal cohorts, June bees, July bees and wintering bees. Survivorship curves for June and July bees show a convex type being exceptional for insects, with relatively high mortality at egg and feeding larval stages and at later adult stage after most bees became potential foragers. Adult longevity greatly lengthens in Winteriing bees and survivorship curve drops approximately with the same rate. A remarkable similarity of survivorship curves for men and honeybees was demonstrated, apparently due to highly developed social care in both. Some comments were given on mortality factors. The importance of life tables for population researches was shown by applying our result to the population growth curve made byBodenheimer, based upon the data byNolan. At the asymptote of the uncorrected curve, the ratio of total population estimated by uncorrected curve to that by corrected curve reaches about 3∶2.

Labor division in Melipona compressipes fasciculata Smith (Hymenoptera: Apidae: Meliponinae)

“…1). According to Sakagami & Fukuda (1968), the type of survival curve is directly correlated with the division of labor.…”

“…1). According to Sakagami & Fukuda (1968), the type of survival curve is directly correlated with the division of labor.Convex curves are found in species with low mortality during the initial phases of life. The high mortality was observed to be true of age brackets in which workers became foragers.…”

Mortality rates of honey bees in the wild

“…Forager bumblebees (Bombus terrestris) also exhibit reduced immunocompetence compared to hive workers of similar ages (Konig and Schmid-Hempel, 1995) suggesting differential effects of senescence on foragers and hive bees. Nevertheless, the few published life tables for honey bees and bumblebees in the field have used chronological age rather than the biologically relevant forager age (Goldblatt and Fell, 1987;Rodd et al, 1980;Sakagami and Fukuda, 1968). Still, chronological age does have some effects on worker honey bees as indicated by the positive correlation between worker age and mortality rate in fed (Rueppell et al, 2007b) and starved bees in the laboratory (Remolina et al, 2007) and by the negative correlation between the age of foraging onset and worker lifespan (Guzman-novoa et al, 1994;Rueppell et al, 2007a).…”

“…In the same study, however, Rueppell et al (2007b) failed to document the predicted decline in cognitive and behavioural parameters with bee age. In the field, studies by Sakagami and Fukuda (1968) indicated increased mortality rate with honey bee age. Neukirch (1982) also examined honey bee life span in large cohorts of foragers, but did not explicitly examine patterns of senescence.…”

Scientific Opinion on the science behind the development of a risk assessment of Plant Protection Products on bees (Apis mellifera,Bombusspp. and solitary bees)

“…The calculations made on the basis of the bees collected in cages will be an underestimate because the efficacy of this gathering method varies according to the environment the hives are situated in and the season (Porrini et al, 2002). The daily mortality rate for all bees in a colony was estimated as about 1% based on the following publications; i) Sakagami and Fukuda (1968), used by DeGrandi-Hoffman et al, (1989), Schmickl and Crailsheim (2007), and ii) Gary (1960) cited by Moritz and Southwick (1992). A mortality rate of 1% corresponds to about 400 -500 honey bees for summer colonies containing 40 000 to 50 000 bees.…”