It may be Friday the 13th, but this article is talking about some lucky ants. Canopy ants, in particular. Ants that forage in trees exhibit a high level of ecological dominance, and ants are usually the most conspicuous organisms running around on tree trunks and branches, especially in tropical forests. This begs the question: Why? Dr. Terry McGlynn and Erica Parra, in a paper published last year, set out to address this question.

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Nest of Polyrhachis ants, a dominant arboreal genus. Photo: Alex Wild

Trap-jaw ants are awesome – few dispute this fact. Yet despite the remarkable nature of the trap-jaw mandibular structure, quantitative assessments of predator-prey interactions and ecology in this group are fairly rare. This is particularly surprising given that trap-jaw ants are an ideal system for understanding how morphological structures vary within species across a wide geographic range. Recognizing this utility, Dr. Kyohsuke Ohkawara and colleagues recently conducted an interesting study in this group, which was published last month. They investigated the impact of variations in prey size on the shape of mandibles in Japanese trap-jaw ants.

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Head view of the trap-jaw ant Strumigenys lewisi. Photo: AntWeb

Pheidole is one of the most diverse ant genera in the world, with 1,004 currently described species. This genus is known for having two worker castes – a “minor” and a “major”. The major caste typically sports a head that is comically larger than minor heads. You can see why Pheidole species are called the “big-headed ants”:

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Two majors and a minor of Pheidole xerophila. Photo: Alex Wild

This ant group provides an excellent study system for investigating a fundamental question in ant research: How, and why, do major and minor worker castes evolve? Dr. Jo-anne Holley and colleagues addressed just this question in a study published earlier this year.

Regular readers of The Daily Ant likely already know that ants are very good at most things. From farming to construction to warfare, ants are rivaled perhaps only by humans. So, it is not surprising that along with a diverse array of interesting and intriguing behaviors, ants are also excellent at something we humans find a little less exciting: biological invasions.