Grad student Nate Green travels to Joshua Tree National Park for grant-funded collecting

Nate Green applied for and received a fellowship to work at JTNP for a week in April. He had a great time looking for pollen wasps and has written a blog post to share. Read on!

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Guest post  -->

Pseudomasaris coquilletti

Last November, I found an unexpected email in my inbox; an announcement for a grant program through the Joshua Tree Association with the aim of funding graduate research at the National Park. The Association was interested in biological studies, particularly with regard to ecology. Guess whose study group is found in Southern California!
​       I’m studying the evolutionary relationships between North American pollen wasps in the genus Pseudomasaris (Hymenoptera: Vespidae) using genetic methods. One of the interesting things about these little-known wasps is that they provision pollen and nectar for their young, like bees do.

            In North America, pollen wasps are only found on the western half of the continent, with most of the diversity being found in the southwestern United States and northern Mexico. After doing some preliminary research, I found that there were zero public records of Pseudomasaris inside the boundaries of Joshua Tree (map below), despite many records of the group around (and on the very border) of the park. I knew this would be a great opportunity for me to make new records in the park, collect specimens for future DNA work, observe new species in the wild, and to have fun exploring an absolutely breathtaking part of the world!
            I submitted my application in January and was thrilled to find out in February that I was awarded the grant! I spent the next few months preparing. I did lots of research on the park’s fauna and it’sits distribution. Pseudomasaris are always associated with their host plant, which varies from species to species, but Pseudomasaris are generally found on: Phacelia, Penstemon, or Eriodictyon. I used the Consortium of California Herbaria data portal (cch2.org) to find records of the plants in the park and worked with the park botanist to find potential sites for Pseudomasaris.

​Finally, on April 13th (My birthday!) I arrived in Palm Springs, where I stayed the night before traveling to Twentynine Palms. While working in the park, I stayed at the Luckie Center, housing owned by the NPS which is free for researchers at the park to use. It’s located on the north edge of the park and is a beautiful spot to watch the sunset. While there I met Bill, an NPS employee working on bighorn sheep in the park.
            I spent nine days exploring the park and the surrounding area. I saw a lot of the Joshua Tree highlights: Skull Rock, Cracked Rock, Jumbo Rocks, Arch Rock (there are a lot of named rocks…), the Cactus Gardens, Ryan’s Mountain, Barker Dam, Cow Camp, Cottonwood Springs, Pinto Dunes, Lost Horse Mountain, Covington Flats, and, my favorite, Eureka Peak. Most of my time was spent in the northwest corner of the park, which has gotten the most rain. Other sections of the park saw less rain this winter and not nearly as much was blooming.
            On my second day in the park, the first successful Pseudomasaris day, I got back to the Luckie Center and started chatting with Bill. We talked about my wasps and how I had been working with the wonderful Tasha LaDoux to pick collecting sites. He suggested that I check out Cow Camp, an old cattle watering hole with a dam and standing water. ‘Everyone loves finding water in the desert’, Bill told me. It’s a place most people that go to Joshua Tree never get to see, but since I had a research permit, I was allowed to go anywhere I needed. Since plants need water, and wasps need plants, why not find water?
            The next morning I continued to my planned site near Black Rocks Campground and had a successful morning where I found two species of Pseudomasaris. In the afternoon, I decided to try out Cow Camp. It was a quick third of a mile hike from the parking lot over to the base of the dam (I suspect I saw a Pseudomasaris at some Phacelia on the way, but I scared it off and didn’t get a good look). I quickly realized that if I wanted to actually find water in the desert, I was going to have to scramble up giant boulders. So I did, and it was worth being sore for the next few days. I wasn’t able to get down to the water (there didn’t seem to be much flowering near it anyways) but the views were incredible. To the west I could see for miles across the valley, to the mountains where I had spent the morning. To the north, and below me, was the small reservoir created by the dam. I sat on that rock formation for a while just taking in the world.
            While in the park, I collected approximately 100 specimens. Less than I hoped for, but with many years in a row of major droughts, it’s to be expected. Of those, nine were Pseudomasaris! I had the opportunity to collect a lot more than nine, but with the dry spring I didn’t want to risk hurting the population. I found three species in the park, P. edwardsii, P. coquilletti, and the less common P. macswaini. I suspect that at least two more species can be found in the park. P. wheeleri is likely present in the far western portion of the park, but emerges in mid-March, earlier than the other species. P. bifarius is likely in some of the southern canyons, but those areas were hit heavily by the drought this year and did not see many flowers blooming.
            I’m considering going back next year to continue looking for Pseudomasaris and to document other Hymenoptera in the park. A few years ago, Dr. Michael Orr visited the park to document bees, but bees and other Hymenopterans are understudied within the bounds of the park. If you study Hymenoptera, consider doing work in Joshua Tree!