Project Results

31 Jul Project Results

Posted at 18:16h in MIS 2019, Montana, Mosaics 2019, Wyoming by Alyssa Canova 0 Comments

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What is an Orthoptera? Orthoptera is an order of insects that include grasshoppers, crickets, and katydids. For our Orthoptera survey, we were looking for the presence and abundance of Mormon crickets (which are actually katydids) and grasshoppers. Additionally, we wanted to determine the dominant life stage at different points of the season and at different elevations. After hatched eggs emerged from the ground as nymphs, we were able to see them and catch them.

For each of our sites, we drew a “t” chart in blue ink and wrote our initials, the time, and the date. After surveying, we calculated the density and the dominant instar and included that information as well. If we were able to catch a GH, we drew a blue circle around the “t” chart. Writing in red ink indicates the presence of Mormon crickets.

Essentially, our fieldwork consisted of 1) Orthoptera density surveys and 2) sweep net capture for each of the seven sites. In the lab, we determined the species of the adults we captured along with the developmental stage for each juvenile grasshopper. The University of Nebraska-Lincoln app contained wing pad photos and descriptions that made determining the instar much easier.

For our results, we have seven maps, one for each site. Each map has the name of the site, the elevation in feet, and the coordinates of the transects. The survey information is in blue at the top right portion of the map. The orange arc represents our survey route when throwing the metal hoop. Having this arc overlaid on the satellite image of the site allows you to get a better sense of what kind of vegetation was present during the survey. When conducting the surveys, we tried our best to avoid the pitfall traps, transects, and climate stations. There is a scale on the bottom left corner and a key of what each symbol means on the bottom right corner.

As you may have noticed, we did not find or catch any grasshoppers at Washburn South, Washburn North 2, and Washburn Top. These being our three highest sites, the cooler climate at higher elevations may contribute to later grasshopper emergence. Also, we did not find any Mormon crickets at any of our sites.

Next steps include surveying for the rest of the year and throughout many years so that we can look at trends and differences between sites. Additionally, it would be interesting to know which species overwinter, their temperature tolerance, and what sites they can be found at.

When comparing the old photographs (from the Third Edition of Field guide to common western grasshoppers by Robert E. Pfadt) and new photographs of the bigheaded grasshopper, we notice the differences in clarity, detail, and color. These differences highlight the important role macrophotography plays in enhancing both the accuracy and ease of insect identification. The structures on the last abdominal segment are critical in identifying this particular species, and this aerial view of the reproductive structures show a great amount of detail. The full body side photos of the bigheaded grasshoppers aren’t as different, however, it is important to note that it is much easier to see the abdomen from the side on the newer photograph. Also, the color is much more vibrant and the image isn’t as blurry. The same goes for the spotted-winged grasshopper and the four-spotted grasshopper: the color and clarity have improved, and the abdomens are easily seen from these full body side photographs.

As for the temperature loggers, some did not acquire data for the entire year. This was most likely due to damage to the logger done by an animal or weather exposure. Also, at times the data was recorded but could not be transferred from the logger to the shuttle to the computer. For example, we could not retrieve any data for Washburn North 2 site 1 and only some data for Washburn Top sites 2 and 3, Washburn North 1 site 1, Tower site 3, Mammoth site 1, and Gardiner site 1.

Below are the graphs for the temperature logger data. For the three transects at each site, we plotted the daily maximum and minimum temperature across the date range. Each graph represents all the data from one site, although some transect data may be missing. We can see that there are slight variations within each site. Whether or not the differences are significant enough to be considered microclimates has yet to be determined and will be a question for future studies.