Morphological Senescence and Longevity: An Experiment Relating Wing Wear and Life Span in Foraging Wild Bumble Bees

Abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. British Ecological Society is collaborating with JSTOR to digitize, preserve and extend access to Journal of Animal Ecology. Summary 1. The insect wing appears to degenerate with use, so that wing wear increases with increased flight activity. Wing degeneration may affect an insect's mortality. 2. The rate of mortality is known to increase with age in worker bumble bees. This study examines whether wing wear can account for mortality in foraging bumble bees. 3. Workers in eight wild-foraging colonies of bumble bee (Bombus melanopygus Nylander) were divided into two treatment groups: clipped (the outer margin of each forewing trimmed, reducing wing surface area by an average of 18%) and unclipped controls. The mortality and behaviour of foraging individuals was assessed with colony watches and night censuses. 4. Treatment did not detectably affect the proportion of foraging bees, the lengths of foraging or within-nest bouts of foragers, or pollen load sizes, but wing-clipping did cause bees with the greatest amounts of initial wing wear to stop foraging. 5. Mortality was positively related to natural wing wear among unclipped bees. In addition, relative to control foragers, foragers with clipped wing margins experienced significantly reduced life expectancies. 6. These results support the hypothesis that wing wear is a proximate factor responsible for an increase in mortality in older workers. The wing-wear hypothesis therefore provides one functional reason for foragers to adopt a currency that maximizes the ratio of net benefit to cost (i.e. 'efficiency').

Cellular senescence in honey bee brain is largely independent of chronological age

“…Foraging is a risky task that is associated with a high rate of mechanical senescence (Cartar, 1992), and frequent exposure to pathogens and ultraviolet (UV) light (Kefuss and Nye, 1970). Mechanical senescence, such as wing wear, has been found to reduce life expectancy in the honey bee (Neukirch, 1982), possibly because it induces an increased work load and, thereby, a higher metabolic rate (Neukirch, 1982;Cartar, 1992).…”

“…Foraging is a risky task that is associated with a high rate of mechanical senescence (Cartar, 1992), and frequent exposure to pathogens and ultraviolet (UV) light (Kefuss and Nye, 1970). Mechanical senescence, such as wing wear, has been found to reduce life expectancy in the honey bee (Neukirch, 1982), possibly because it induces an increased work load and, thereby, a higher metabolic rate (Neukirch, 1982;Cartar, 1992). UV light, moreover, constitutes a major environmental insult to all exposed tissues, including the visual system, and exposure can potentially damage a wide variety of macromolecular components, ranging from DNA to proteins and lipids, through the generation of ROS (Podhaisky et al, 2002;Parker et al, 2004;Linsenmayer et al, 2005).…”

Mortality rates of honey bees in the wild

“…Limited data indeed suggest that forager honey bees slow down with advanced age (Dukas and Visscher, 1994) and that there is a positive correlation between forager honey bee age and the degree of wing damage (Higginson and Barnard, 2004). Furthermore, experimental evidence in bumblebees (B. melanopygus) indicates that wing damage increases mortality rate (Cartar, 1992). Future research should critically examine the effects of senescence on the highly demanding tasks involved in long flights and predator avoidance.…”

Effect of the own colony odor on olfactory and thermal preferences of the honeybee (Apis mellifera) workers

“…According to Neukirch (1982), progression of aging in worker bees is driven by intense flights. Foraging is considered to be associated with a high rate of mechanical senescence (Cartar 1992), frequent exposure to pathogens, and ultraviolet light (Kefuss and Nye 1970). Life expectancy is reduced by wing wear (Neukirch 1982), which leads to increased work load and, as a consequence, to a higher metabolic rate.…”