The Kwapich lab opened in January 2020, at the University of Massachusetts Lowell. This page describes my previous work, while we build a new laboratory website. Our research asks how variation is maintained across levels of social organization, and in turn, how sociality shapes ecosystems.
Research interests include ant colony economics, nest architecture and the ecology of myrmecophiles (Myrmecophilidae, and spiders). By combining large-scale field experiments with behavioral, molecular, and physiological approaches, we address questions inspired by organisms. Our field sites are located in the Sonoran Desert, the Apalachicola National Forest on Florida's panhandle, and in throughout New England.
Recently, we asked how heterogeneous groups succeed in harsh environments (Kwapich et al., Philosophical Transactions of the Royal Society B, 2018). We found that patriline number corresponds to worker polymorphism in colonies of a desert seed harvesting ant. In turn, polymorphic colonies were able to excavate deeper and more complex nests than monomorphic colonies. These traits correspond to both survival and fecundity. This work integrated molecular ecology, network analysis, and subterranean nest casting to connect individual and collective traits. It also revealed that seed harvesting ant colonies provide important ecosystem services by converting approximately 3.4 Kg/ha of Sonoran Desert seeds into ant biomass annually; equivalent to 28 kangaroo rats/ha (Kwapich et al., Behavioral Ecology and Sociobiology, 2017).
My graduate research focused on adaptive labor allocation in a Florida seed harvesting ant (Pognomyrmex badius). I showed that predictable environments select for behaviorally inflexible individuals, with fixed development rates and no functional senescence. In essence, colonies are unable to re-allocate labor despite experimental increases in demand for labor, instead producing workers on an adaptive demographic schedule (Kwapich et al., Behavioral Ecology and Sociobiology 2013, 2015).
A related study showed that ants move sand upward in caching steps, and significantly disturb the natural soil strata without bringing sand grains to the surface. In collaboration with archaeologists and geochronologists, we demonstrated that ant-mediated bioturbation was an important obstacle to quartz-clock aging of Weedan Island cultural artifacts from Florida’ Big Bend region (Journal of Archeological Science 2013, and PLoS ONE 2015).
My publications and projects address the following questions:
- How much biomass do desert ants generate per hectare, annually?
- How do different harvester ant lineages store and process seeds?
- How do colonies tune worker birth rate to worker death rate to maintain their size across years?
-How does polyandry correspond to investment in worker size vs. worker number?
- Do neighboring conspecifics influence forager longevity, and colony growth?
- How does metabolic rate relate to colony size, worker size and worker tempo across ant species?
- Are ant communities shaped by depth to the water table, vegetation and shade structure?
- How do colonies initiated by single or multiple unrelated queens differ in size and survival over time?
- How much insect biomass do bears consume in desert habitats?
Nest Architecture and soil
- Does subterranean soil deposition by ants influence the dating of human cultural artifacts?
- Do harvester ants rely on the germination to open seeds stored in subterranean chambers ?
- How does colony-level variation in worker body size influence nest architecture?
- How does colony genetic structure influence nest architecture?
-How do polymorphic workers divide labor between soil particle sizes during nest construction?
-How do ants efficiently move sand and seeds across 2m of vertical nest space?
- How do ants perceive their colony size during nest construction?
- How can we use new tools, like network theory and wax nest casting in buckets to study animal architecture?
Life history, demography and behavioral flexibility
How do individual worker traits correspond to multiple colony-level traits?
Do ant colonies have an adaptive demography? adaptive labor ratios?
Is worker development rate fixed? Is worker death 'programmed'?
Does labor allocation respond to changes in demand for labor? On what scale (hourly, weekly, monthly, seasonally)?
How do seasonal differences in diet influence worker development rate, and age-correlated division of labor?
Is there a difference between expected and realized longevity in worker ants?
How do colonies detect and anticipate worker mortality rate?
Does excess forager survival suppress the behavioral maturation of young workers? How?
Ant associates, parasites and predators
Why don't generalist myrmecophiles speciate, despite experiencing significant life history trade-offs across multiple hosts ant species?
How do ant colonies act as ecological islands for other organisms?
Do worker size and colony size influence myrmecophile size, abundance, sex ratio and facultative parthenogenesis?
How do spiders, ant crickets and beetles co-opt hydrocarbon recognition signals to infiltrate ant nests?
Do harvester ants rescue nestmates from spider webs (Steatoda spp.)? How do they detect and remove theridiid webs? Why do they invest in rescue behavior?
How do host-associated differences in body size influence jumping height in ant crickets (Myrmecophilus manni)?
How do beetles use appeasement, adoption and defensive gland secretions to exploit ant colonies (Hymenorus, Amphotis, Lomechusoides)?
Are some generalist myrmecophiles actually cryptic species?
History and philosophy of biology
- How does selection act on multiple levels of biological organization?
-What is a biological individual (gene? genotype? organism? colony?)?
- How did the concept of biological individuality change across the 20th century?
- How are ant colonies analogous to organisms?
Listen to my recent seminar at The Ohio State University, Department of Entomology: Presentation