Research

My research uses social insects as a model to understand the mechanisms that shape social traits.

Developmental plasticity and caste determination

Caste determination in Harpegnathos - Juvenile hormone induces queen determination, and workers bite larvae to inhibit queen development through mechanical stress.

Caste determination in Harpegnathos – Juvenile hormone induces queen determination, but workers bite larvae to inhibit queen development through mechanical stress.

William Morton Wheeler (the father of ant science) once confessed he thought ant larvae were “sluggish, legless maggots” that existed as “inert and passive objects” within an ant colony. But we know now that these legless grubs are capable of some of the most impressive transformations in the animal kingdom.

 

During larval life, an individual’s fate can shift between that of a worker or a queen. A queen can be nearly 20 times the size of her smallest workers and can live for over 30 years. And all of these changes can be produced by a single genome. My work has focused on social regulation of caste determination, especially concentrating on how interactions between adult workers and larvae lead to different castes.

 

 

 

Thermal adaptation of social traits

Duke forest warming chambers

Using these open-top chambers at Duke and Harvard forests, we literally heat the forest to see how species respond. (photo James Waters)

Ants have colonized every continent on the planet except Antarctica. Across this range, they have adapted to a wide array of habitats and climates spanning from deserts to boreal forests. Unlike solitary species, which face their environment alone, ants are social organisms and respond to environmental change as a collective.

 

In collaboration with groups at the University of Vermont, Harvard Forest, and the University of Tennessee, we are exploring how ants deal with climate change across the eastern United States. I am investigating how ant physiology and behavior shape a colony’s response to warming.

 

 

 

Nutritional ecology of urban insects

Broadway median - one of our field sites in NYC.

Broadway median – one of our field sites in NYC.

The people living in Manhattan consume 3.3 billion calories everyday and throw out nearly as much food in the garbage. For every person in New York, there are roughly 1000 ants, and all of those ants need to eat. As part of a collaboration with Rob Dunn and Amy Savage, I have been studying the nutritional dynamics of ants living in New York City. We want to know How human activities influence ant populations? Why some species do well in cities and others do not? And, What happens when ants sustain themselves on our junk food?

 

 

 

 

 

Aggression and social dominance

Social insects have been held as models of cooperation, but closer inspection of their societies has revealed complex dominance orders and high levels of aggression. My work has investigated the hormonal mechanisms, behaviors, and neurophysiological changes associated with reproduction and dominance in the ant Harpegnathos saltator. Workers of Harpegnathos compete to establish a reproductive hierarchy during tournaments that last nearly a month and involve highly ritualized dominance behaviors (see video “antennal dueling”). Studies on this charismatic species have led to insights into hormone dynamics, chemical communication, neural plasticity, and the emergence of complex animal hierarchies.

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