Submitted to: Entomological Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 11/9/2012
Publication Date: 11/11/2012
Citation: Morgan, J.K., Shatters, R.G., Walter, A.J., Lapointe, S.L., Hunter, W.B. 2012. Insect compassion, evidence of altruism, reciprocity, and midwifery behavior in aphids [abstract]. 2012 Entomological Society of America Annual Meeting, November 11-14, 2012, Knoxville, Tennessee. Interpretive Summary:
Technical Abstract: Altruism is characterized by an act provided by a donor to a recipient that is considered detrimental to the donor yet benefits the recipient. Evidence of altruism is abundant in nature. In insects, altruism is manifest by ant and bee colonies where sterile workers provide labor, care of young, colony protection, and other services that do not benefit the donor but provides a general benefit to recipient colony. Altruism in aphids is exemplified in certain gall forming aphid colonies with soldier aphids that defend the colony. Here we demonstrate video evidence of novel altruistic behavior within and amongst aphids. Using Aphis nerii (Hemiptera: Aphididae, oleander/milkweed aphid), Aphis gossypii (Hemiptera: Aphididae, cotton/melon aphid), and/or Toxoptera citricida (Hemiptera: Aphididae, brown citrus aphid) in open or closed chambered environments, we induced a subset of supine (prostrate legs up) aphids (SA). We then observed prone (normal legs down) aphids searching out and assist the SA returning them to a prone position. This was typically accomplished as helper aphid (HA) extended a foreleg tarsus to interact with the hind leg tarsus of a SA, then leveraging a down force on the SA hind leg, the SA was returned to an upright position. HA assistance was observed amongst mature, nymphal, and alate aphids, suggesting that life stage was not a determinant factor in HA assistance. HA assistance was repeatedly observed in oleander, cotton/melon, and brown citrus aphid colonies. To determine if this behavior was intra-species limited or an inter-species trait, we mixed oleander and cotton/melon aphids and induced a set of SA within the population and observed inter-species HA assistance. Additionally, we present video evidence of behavior characteristic of midwifery, as a sister aphid rendered live birth assistance by aiding the detachment of newly born aphid nymph from the gonopore of the mother. Combined, these evidence a novel form of altruistic/reciprocity behavior amongst aphids that to our knowledge is the first evidence of these types of behaviors amongst lower order animals.