Nest guarding in male bees: supplement

I recently wrote a letter to the editor in PNAS in which I pointed out that nest guarding in males was not novel behavior: https://www.pnas.org/content/116/20/9711

In that letter, I was limited to 10 citations. I tried to put more in, but the journal would not let me. I then tried to complain about citation limits, but the journal wouldn’t let me do that either:

As a result, I am listing the additional citations here:

• Fragmentary observations of male nest guarding behavior include observations by Rayment (1935) on L. seductum (Cockerell).
• Kerr (1997) observed three instances of male Melipona scutellaris Latreille driving spiders away from nest entrances, and he also noted examples of males doing nest maintanence work such as making and building with wax.
• Timberlake (1980) reported an observation of a macrocephalic male of Macrotera portalis (Timberlake) guarding a nest entrance, though doubt has been cast on the role of macrocephalic males as guards in this species (Danforth 1991).
• Houston (1970) speculated that macrocephalic males of Lasioglossum (Chilalictus) sp. represented a soldier caste, but did not observe their behavior.
• Camargo and Velthuis (1979) observed male Xylocopa frontalis (Olivier) guarding nest entrances and expelling ants that tried to enter. Though it seems likely that these males are brothers or sons rather than mates.
• Scholz and Wittmann (1987) also observed Xylocopa males guarding nests, especially against ants, though they did not specify which of the 5 species they talk about performed this behavior. Again, these are likely sons or brothers performing the nest guarding.
• In an unpublished thesis, Kislow (1976) records male Ceratina strenua blocking the nest entrance with the abdomen, but does not offer an interpretation of this behavior.
• Hefetz, Batra, and Blum (1979) states that “In nature, both sexes [of Ceratina smaragdula] guard their nest entrances by blocking them with the abdominal terga and probably by utilizing their sting in defense.”

References:

• Camargo JMF, Velthuis HHW (1979) Sobre o comportamento de Xylocopa (Megaxylocopa) frontalis (Olivier) (Hymenoptera-Anthophoridae). Dusenia 11: 35–39.
• Danforth BN (1991) The morphology and behavior of dimorphic males in Perdita portalis (Hymenoptera: Andrenidae). Behavioral Ecology and Sociobiology 29: 235–247.
• Hefetz A, Batra SWT, Blum MS (1979) Chemistry of the mandibular gland secretion of the Indian bee Pithis smaragdula. Journal of Chemical Ecology 5: 753–758.
• Houston TF (1970) Discovery of an apparent male soldier caste in a nest of a halictine bee (Hymenoptera: Halictidae), with notes on the nest. Australian Journal of Zoology 18: 345–351.
• Kerr WE (1997) Sex determination in honey bees (Apinae and Meliponinae) and its consequences. Brazilian Journal of Genetics 20.
• Kislow CJ (1976) The comparative biology of two species of small carpenter bees, Ceratina strenua F. Smith and C. calcarata Robertson (Hymenoptera, Xylocopinae). University of Georgia
• Rayment T (1935) A Cluster of Bees. Endeavour Press, Sydney, 752 pp.
• Scholz E, Wittmann D (1987) Bionomy of five xylocopine bee species in Rio Grande do Sul, Southern Brazil. In: Eder J, Rembold H (Eds), Chemistry and Biology of Social insects. Verlag J. Peperny, Munchen, 726.
• Timberlake PH (1980) Supplementary studies on the systematics of the genus Perdita (Hymenoptera, Andrenidae). Part II. University of California Publications in Entomology 85: 1–65.