Today was the last class of the winter quarter. When you look back on where were started in January – we’ve come a long way. Those were cold, dark days, with lots of mud. There were a lot of questions we hadn’t asked yet. Experiments we hadn’t yet designed. Papers we hadn’t yet read. We’ve come a long way.
Slowly, inevitably, the days have gotten longer, and our hemisphere is starting to warm up. We are five days away from the spring equinox, and then we’ll be officially into the spring. The days are getting longer fast at this point in the year, and spring is coming.
So it seems like a good day to end the winter quarter. We received our USDA permit today, and I placed our order for Spodoptera in class. The order won’t actually be placed until next week, but we might receive the eggs pretty quickly afterwards. Given this, we didn’t need to collect caterpillars and focused on tachinids instead. MC Kasey lead us in drafting a list of things to do, including:
- Get portion cups (Louie)
- Order spods (Louie)
- Make diet/add spods
- Print striped cards
- Transfer milkweed
- Find monarchs
- Check spods/feed flies
- Make schedule spreadsheet for trap checks (Kasey)
We spent most of the class in the field, with the class dividing up between the Arboretum, the Student Farm, the Village Homes community garden. The Student Farm crew also checked on the greenhouse (GH 302 still has a big hole in the wall, so we won’t be able to transfer the milkweeds in there until next week at the earliest), and set up the remaining Manitoba traps. The collecting was pretty good at the Student Farms. There were lots of insects flying in the notably warmer weather this week.
The lighter mesh aerial nets were easier to use than heavy canvas sweep nets. The alfalfa continued to be a good place to collect, and the rosemary and other flowering shrubs were also pretty active. We didn’t find any confirmed tachnids, but it seems worth spending some more time at the Bohart to figure out which other species of tachnids we are likely to encounter this time of year. We visited the demonstration garden side of the street for a few minutes afterwards, and there was a chicken.
We reconvened in the classroom around 3:30, with some folks identifying flies, printing striped and grey cards, fixing nets, etc for a while until everyone got back. We didn’t really get rolling as a class again until after 4. The other groups also reported mixed success, though we had a pretty good set of non-tachinid flies to work with afterwards.
We spent the last 45 minutes doing some really valuable pilot studies with caged and tethered flies. We learned that many of our test flies did not tolerate rapid cooling, and that most flies did not behave naturally with long (>50cm) tethers. They did seem to fly better with shorter tethers, but these short tethers presented some issues for mobility. With the longer tethers, some combination of the tether weight, cold treatment, tether obstruction or something else seemed to preclude natural behavior. They never seemed to behave naturally, but they did seem to behave better outside. If we were to try this again, tethers around 30 cm might be a good place to start, with gentler cooling or CO2 anesthesia, and the behavioral trials outside. But I think many of us were inclined to try mesh enclosures outside first, instead of tethering.
The cage group tested a few flies under a plastic enclosure in the lab, and tested out ways to time their behavior. They were able to collect data, and those tests seem like a useful way to get a sense for what might work with tachnids. We also tried setting up striped and grey cards in one of the BugDorm cages towards the end of the class; some version of this placed outside might be a good place to start again in a future class.
The plan for next week
For next week, we’ll be meeting on the actual spring equinox, March 20 during our scheduled finals time from 3:30-5:30. It sounds like we will probably divide the class to tackle two things: 1) making diet cups for spods, and 2) transferring the milkweed to GH202. We also need to leave some time to fill out course evals for the winter. Watch your Slack for changes.
Also, thanks to everyone for signing up to check the fly traps. Kasey will be creating those spreadsheets and sending them out. Please keep an eye out for strong wind in the forecast; if the forecast calls for sustained winds much above 20 mph, we should round up a crew to take the traps down until things, er, blow over.
Here are some other things which didn’t make it on to the chalkboard list, but would certainly be good to do over finals week and into spring break.
- Find other data/collections of tachinids, look for collection dates and locations, look for field identifiable characters
- Figure out if there is another species of local tachnid that is present earlier
- Think about how to set up a spod trapline to collect tachnids.
The Spring Potluck
After much scheduling and Doodling, it seems like the best day for our Spring Potluck will be Sunday, April 7 at 6. Looking forward to seeing you there!