Surveying bees in coffee plantations

It’s been exactly 1 month since I started my research in coffee plantations in Puerto Rico. This project is similar to the last one, but we’re looking at a few more variables, in addition to agricultural practices. Specifically, we’re surveying bee abundance and diversity in sun and shade coffee plantations as well as ‘natural’ forested sites. We’re also accounting for the sites’ elevations as well as temperature and relative humidity. This information could be used to predict impacts of climate change on bee populations throughout the island. This past month I’ve had the opportunity to meet countless coffee growers and enjoy the beautiful views that they see on a daily basis. Since most coffee plantations are located at high elevations, the views are fantastic. From one farm, we can actually see all the way to the ocean!


In addition to enjoying the views, I’ve been able to set up malaise traps and bee bowls at twelve survey sites. It’s so exciting to see my malaise trap once it’s set up! Malaise traps are a wonderful survey tool since they ‘catch’ flying insects, and guide the insects toward a jar filled with liquid in which they are eventually trapped and drown. Here you can see a malaise trap in a sun coffee plantation.


Here’s the view from inside the trap. Bees are phototactic, meaning they move towards light sources. Once they’re in the trap, they fly up towards the light, and get stuck in the jar.


I’ll be leaving the traps out for year, collecting the insects from the liquid once a month. Hopefully this data will allow me to see differences in bee diversity over the year (wet vs dry season) and from site to site.  In addition to the malaise traps, I’m setting up 12 oz bee cups, which are painted yellow, white and blue. They’re filled with the same liquid as the malaise trap jar: 50% propylene glycol, 40% water, 10% formalin (to make it taste bad and prevent animals from drinking my liquid). I’m setting some at ground level and hanging some up in trees to see if capture rates differ. After this year, I’ll fine tune my collecting methods and select the most efficient ones for next year’s survey.

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So far things have been going so-so. One of my traps was pretty much ripped off the ground by one of the farm workers. I don’t think they realize this tent-like trap is worth $250! Anyways, they must have been clearing the area, and had to remove it. They tried to put it back, but it was all crooked. So when I went back to check on my traps, I had to fix it. Fortunately, that’s only happened at one site. In addition to my traps being removed, I’ve got a small rodent problem, which is affecting my bee bowls. Either rats, mice or mongoose have decided that my plastic cups are tasty. They knocked over the cup, and ate the bottom of it. Evil little animals, ruining my survey


This week I’ve started sweep netting in the farms to see if my traps might be missing any bees. Yesterday, my friend and I stumbled upon a few carpenter bee nests. The carpenter bees bore holes into dry, dead wood and create little cells in which they lay their eggs. Along with each egg, they leave a sweet ball of pollen and nectar. I broke one nest open to show my friend what they look like inside. Fortunately I only disturbed one little larva.


On the top you can see the holes through which the bees fly in AND you can see an old nest that must have been split open, since you can see all the brood cells. The bottom image is of the larva and it’s pollen-nectar ball.

This month I have to set up another 12 traps in the center of the island and then collect my first batch of data. I’ll try and sweep net as much as I can, also. Once that’s done I’ll head back home and have a technician collect my insects, while I’m there. I’ll be back in PR in another 3-4 months to see what goodies I’ve collected.


About saraguitiprado

I'm a Tropical Ecologist, Researcher, and Mother
This entry was posted in Bee pictures, Bee sightings, Exploring new places, New Life Experiences. Bookmark the permalink.

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