TY - JOUR
T1 - Reproductive hierarchies in the African allodapine bee Allodapula dichroa (Apidae: Xylocopinae) and ancestral forms of sociality
AU - Tierney, Simon M.
AU - Schwarz, Michael P.
PY - 2009
Y1 - 2009
N2 - The social organization of allodapine bees has been described in detail for most genera, although there remains a notable gap for one major lineage, the genus Allodapula. Here, we provide the first detailed study of social organization in Allodapula dichroa. Colony sizes are small and the frequency of cooperative nesting is low compared with other allodapine taxa, but there is very clear evidence for reproductive differentiation among adult nestmates. Reproductively dominant females tend to be larger than their nestmates and have much higher levels of wing wear, suggesting that they perform most foraging activities. Multi-female colonies have: (1) lower rates of complete brood absence, suggesting a substantial benefit to cooperative nesting; and (2) larger numbers of brood, suggesting that the presence of a second adult female leads to a greater reproductive output. These data suggest a major phylogenetic split in the form of social organization within the allodapines. In the genus Macrogalea (sister clade to all other allodapines), body size does not preclude young females from laying eggs, and there appears to be, at most, weak reproductive queues. However, in most other allodapines, reproductive hierarchies are prominent and younger and/or smaller females queue for reproductive opportunities, adopt permanently subordinate roles, or disperse. Interestingly, the most common forms of reproductive hierarchies in allodapines do not involve subordinates undertaking foraging roles before reproduction, but instead involve the delaying of both reproduction and foraging. This has implications for the understanding of suggested developmental ground plans in the early stages of social evolution.
AB - The social organization of allodapine bees has been described in detail for most genera, although there remains a notable gap for one major lineage, the genus Allodapula. Here, we provide the first detailed study of social organization in Allodapula dichroa. Colony sizes are small and the frequency of cooperative nesting is low compared with other allodapine taxa, but there is very clear evidence for reproductive differentiation among adult nestmates. Reproductively dominant females tend to be larger than their nestmates and have much higher levels of wing wear, suggesting that they perform most foraging activities. Multi-female colonies have: (1) lower rates of complete brood absence, suggesting a substantial benefit to cooperative nesting; and (2) larger numbers of brood, suggesting that the presence of a second adult female leads to a greater reproductive output. These data suggest a major phylogenetic split in the form of social organization within the allodapines. In the genus Macrogalea (sister clade to all other allodapines), body size does not preclude young females from laying eggs, and there appears to be, at most, weak reproductive queues. However, in most other allodapines, reproductive hierarchies are prominent and younger and/or smaller females queue for reproductive opportunities, adopt permanently subordinate roles, or disperse. Interestingly, the most common forms of reproductive hierarchies in allodapines do not involve subordinates undertaking foraging roles before reproduction, but instead involve the delaying of both reproduction and foraging. This has implications for the understanding of suggested developmental ground plans in the early stages of social evolution.
KW - Apidae
KW - bees
KW - reproduction
KW - sex allocation
KW - social evolution in animals
UR - http://handle.westernsydney.edu.au:8081/1959.7/uws:42974
U2 - 10.1111/j.1095-8312.2009.01236.x
DO - 10.1111/j.1095-8312.2009.01236.x
M3 - Article
SN - 0024-4066
VL - 97
SP - 520
EP - 530
JO - Biological Journal of the Linnean Society
JF - Biological Journal of the Linnean Society
IS - 3
ER -