Tag Archives: spiders

June 19th: Rainforest Experiment Results!

Today we concluded both our pee pitfall experiment and the camera trap experiment! This morning we made a short hike through the Maya trail, and collected each of our pitfall traps filled with urine and unlucky arthropods. Along the way I spotted some cool looking harvestmen climbing along a sharp give-and-take palm! We also saw some really cool examples of moths that were killed by the “zombie” fungus Ophiocordyceps which takes control of the nervous system of its victims. These moths were in various stages of decay so it was like we were seeing the process itself, which was super cool!

 

Once back in the lab, we sorted our pee pitfalls and removed all of our captured arthropods to tally which traps had the most visitors. We found that in general, the arthropods were more often found in the nutrient rich pee, and there were many more arthropods found on the forest floor than the canopy. But the canopy arthropods actually had more guests in the water tubes, but the sample size for this area was very small. I actually did fish out a few harvestmen and a small spider during our data collection, so I did get some arachnids in there! Check out our title for the poster aka our most despicable pun yet (Urine for a Treet).

Some of the students went out to go collect all of the camera traps we had placed on our first day in the rainforest, and during this spotted a really cool spider, I wish I had been there! I have tried my hardest to identify this fuzzy guy just from the awesome picture Elena sent me, but still no luck. Its leg morphology points to it being some kind of ground-dwelling spider rather than orb-weaving. The coloration, leg shape, and fang placement resembles that of both huntsman and wolf spiders, but none of the spiders I’ve researched in this area have such distinctive fuzzy legs. What a cool little mystery! Fun fact, the “hair” on spiders legs are actually called setae and can be used for grip when moving around, sensing chemicals, and so many other cool things!

Mouse-sized cockroaches and bird-sized spiders ahead

We spent the whole day in the classroom today in order to finish up our project and some presentations and still be able to go on a night hike.

We wrapped up our nitrogen attraction experiment by counting all the arthropods and others in our urine and the water and finding the proportion. I had so many arthropods in my ground urine, but not in my tree urine. I found a very interesting spider related to a daddy long legs which had interesting markings on its back. It was about 1cm in body length. I nicknamed it the Leg Warmer Spider.

Leg Warmer Spider
Leg Warmer Spider

During the night hike it was a fabulous time for arachnids. We saw hundreds of wolf spiders and thousands of little spiders in the leaf litter which were too fast to get a look at. We saw one huge tarantula which was about 12 ft. up on a strangler fig. It was cinnamon-y in color, and probably a female of one of the species that have been described around here.

We also saw a huge black spider that was about 4-5cm in body length on the ground in some leaf litter off the trail. Its legs were bent so it was standing very tall off the ground. We looked for scorpions under almost every log along the train and did not find any. I wanted to see one under the black light cause they glow!

I think we also saw the leg warmer spider that I had named in class earlier. Its markings on its back were very similar and it was the same size. The markings themselves glowed in the black light.

Other than the arachnids, we saw some huge cockroaches and one of them excreted glue when we picked it up and it hissed. Sam didn’t even drop it. Also we found this huge cockroach that was as big as my hand and Adrienne overcame her fear and touched it.