Urban Ants in Peru (2020 to present):

Dr. Elsa Youngsteadt and I are setting up a research project in the Peruvian Amazon, in the city of Puerto Maldonado, where we will study the effects of urban warming on ants. We plan to assess whether ants’ physiological traits predict species’ persistence in warmed habitats, whether species adapt or acclimate to rapid warming, and to what extent these species compensate behaviorally for rapid warming. Cities provide an excellent study system to assess the effects of warming on organisms because of the ‘urban heat island effect’. We’ve all experienced this, when we’ve walked outside on the hot pavement and felt the heat radiating not only from above, but also from the asphalt. Buildings, streets and other urban structures can retain heat resulting in cities being warmer than the natural areas around them. In Puerto Maldonado, Peru, on one given day, temperatures in the city were 5-9°C warmer than natural forests around it. We all know that temperatures are predicted to rise over the coming years as the global climate changes. Here we use cities as a window into the future to see what might happen to ants if temperatures were to increase. Overall, we’re hoping this study will improve our understanding of tropical insect vulnerability to global warming.

Reforestation and pollinators in Puerto Rico (2020 to present):

This project is in collaboration with Dr. Kevin Grady from Northern Arizona University. We’re planning on studying visitation to and floral traits (appearance and floral reward quality) of several trees that are currently being used for habitat restoration in the Guanica State Forest. Currently, very little is known about their relationship with native pollinators.

Coffee pollination in Puerto Rico (2015 to 2018):

This was the topic of my dissertation conducted under the supervision of Drs. Jaime Collazo and Rebecca Irwin. I studied three main aspects related to coffee pollination:

  1. How do coffee floral traits vary between shade and sun agroecosystems?

    S.G. Prado, J.A. Collazo, P. Stevenson & R.E. Irwin (2019) A comparison of coffee floral traits under two different agricultural practices. Scientific Reports. 9: 7331.
  2. How does fruit set and pollen limitation vary between shade and sun agroecosystems?

    Prado, S.G., R.E. Irwin & J.A. Collazo (2018) Resurgence of specialized shade coffee cultivation: Effects on pollination services and quality of coffee production. Agriculture, Ecosystems and Environment. 265: 567-575.
  3. How does visitation to coffee flowers vary in response to floral availability, coffee floral traits and the microclimatic environment?

    Prado, S.G., R.E. Irwin, M.H. Marand & J.A. Collazo (In review) The influence of floral quality and availability and microclimate on pollinator visitation in an agro-ecosystem. Agriculture, Ecosystems and Environment. 

Measuring microclimatic variables using small, inexpensive data loggers with homemade radiation shields (2015 to 2017):

Have you ever wondered how people collected data on microclimatic variables? There are huge, expensive weather stations that people can use to tell temperature, wind speed, air relative humidity, etc, but those aren’t convenient if you want to measure how these variables vary on a smaller, more local scale. I originally wanted to collect data on how these microclimatic variables differed from farm to farm in Puerto Rico, where one can physically feel the difference in temperature and humidity in a shade coffee agroecosytem vs a sun one.

I reached out to a few colleagues who had been using iButtons under a small Solo brand cup to shield them from rain and direct sunlight, and asked why they had chosen this method. Turns out they had based it off of someone else who used that method but nobody had ever validated it! So, together with them, we set-up a small experiment to compare temperature readings from three brands of data loggers (Hobo onset, Hobo pendant and iButtons) that were shielded by some inexpensive homemade radiation shields, to a weather station.

  1. Terando, A.J., S.G. Prado, E. Youngsteadt (2018) Construction of a compact low-cost radiation shield for air-temperature sensors in ecological field studies. J. Vis. Exp. (141), e58273. doi:10.3791/58273
  2. Terando, A.J., Youngsteadt, E., Meineke, E.K. & S.G. Prado. 2017.  Accurate near surface air temperature measurements are necessary to gauge large‐scale ecological responses to global climate change. Ecology and Evolution. 8: 5233.
  3. Terando, A.J., Youngsteadt, E., Meineke, E.K. & S.G. Prado (2017) Ad hoc instrumentation methods in ecological studies produce highly biased temperature measurements. Ecology and Evolution. 7(23): 9890-9904.

Sampling bees in tropical environments (2013-2015):

While a research assistant in the Collazo lab, I surveyed bees in Puerto Rico and St-Croix, USVI. Throughout that time, I was able to find a few new bee species for the island as well as a few that were new to science.

  1. Engel, M.S. and S.G. Prado (2014) First record of the cleptoparasitic bee genus Sphecodes from Puerto Rico (Hymenoptera: Halictidae). Journal of Melittology. 39: 1-6. (

However, what was clear to me was that sampling bees in tropical forested environments was much more difficult than sampling bees in large agricultural fields, for example. The trees, the darkness and the lack of flowering vegetation at ground level were some of the differences between these two environments that made capturing bees in the sunny open fields, much easier than in the forested sites.

So, together with a few colleagues who also had experience sampling bees in tropical agroecosystems, we wrote a review on just that.

2. Prado, S.G., H.T. Ngo, J.A. Florez, & J.A. Collazo. (2017) Sampling bees in tropical forests and agroecosystems: A review. Journal of Insect Conservation. August: 1-18. (

Using the parasitic wasp Aphidius colemani as a biocontrol agent in greenhouses (2010-2012)

This was the topic of my MS thesis conducted under the supervision of Dr. Steve Frank. I studied four main topics:

1. How do plant growth regulators affect tritrophic interactions between Aphidius colemani and Myzus persicae

2. Do barley banker plants help in controlling pest outbreaks of Myzus persicae

3. What factors may affect the efficacy of Aphidius colemani at controlling pest aphids in greenhouses?

  • Prado, S.G., S.E. Jandricic & S.D. Frank. (2015) Ecological Interactions Affecting the Efficacy of Aphidius colemani in Greenhouse Crops. Insects. 6(2): 538-575.  (