The Mating Ritual

Today I wanted to talk about the mating ritual that male and female BSF adult flies participate in. The female will sit on the underside of a leaf, while the male will fly over and land on top of the same leaf. The males drum their antenna on the leaf, and eventually walk over to the side of the leaf, and peak over (presumably to see if there are any predators or dangers on the underside). Then the male and female fly up together, and (if they do mate), mate midair in bright sunshine.
One reason females have a green abdomen may be for camouflauge when they sit on the underside of the leaf. Also, yesterday, when I took the two adults (+ the one hitchhiker) for samples, I noticed that they became much more active when under a light. BSF need sunlight in order to mate.

Today, I opened the 'puparium' and was greeted by 14 beautiful, healthy adult flies! Four of them flew out immediately, and the rest were sitting on the side of the black 'puparium' (I have pictures!). It really seems like regulating the temperature (~25C) and humidity (~65%) has made a huge difference, as we have approximately 50 healthy adult flies alive at this time. Rylo and I hope to get to a point (soon, within the next couple of days even) when we open the 'puparium' and our count is 'lots' (as in, we have so many that we can't even count as they're-hopefully- flying out and mating).
We have so many adults now that I was able to take one male and one female as samples. I was also able to have a very close look at a live adult for the first time. Females are slightly larger, and have a noticeably green section to their abdomen. Their male counterparts have a grayish-green abdomen. I plan on making the samples (by freezing the male and female) and will take photos, hopefully next week.
Like I've said, I took one male and one female as samples (in a clear yogurt-sized container). But when I was busing back to campus from UBC Farm, I noticed a companion- a female fly was sitting on my backpack. She must have been there the entire time during my 20 min. walk to the bus stop! BSF flies are very docile and friendly- they are weak fliers and enjoy sitting as much as possible. They will sit on your hand for a very long time, making it much much easier to get a closer look at them. (I will post pictures when I get home!)

Today the minimum temperature of the 'puparium' was 26C, while the maximum was 31C. A bit warm, but still well within the happy zone.

We had 3 adults emerge- one was a beautiful, healthy female and the other two looked like males. The maybe-males had very very recently emerged- their wings had not even fully formed yet.

I counted an amazing, record-setting 278 crawl-off today. It seems like we really can hope for a saturation of BSF, and a much greater likelihood of a return!

The pupa bucket only had 1 adult fly, but it looks healthy, with fully-formed and functional wings.

15-crawl off in the last 24-hours.

We moved the pod to an open field, further away from distractions (esp. the large green dumpster and compost piles).

We again saw a female adult fly checking out the pod, so it looks like our idea to add more compost to the pod is in fact attracting females.

What is a Distraction?

A distraction is anything that would make a female (adult) decide to lay her eggs anywhere except for the pod.

Because maggots live on food scraps, females will choose a place with the largest amount of food to increase the chance that her offspring will survive.

Therefore, any area with a large amount of food scraps such as a compost pile of a large dumpster would distract the female from laying her eggs in the pod.

When eggs are laid outside fo the pod, they are not a part of our BSF colony, and the maggots are not in the pod to create the synonome. Nor can we increase the size of our colony or conduct experiments to determine the number of maggots needed to reduce a pound of food scraps in one hour (for example).

Because of this, when we first did a survey of UBC Farm, we looked for distractions. Although there was a large green dumpster as well as a compost bin nearby (about 50 meters away), we did not consider them to be worrisome since BSF are weak fliers and we thought they would prefer to stay close to the pod and would be attracted by the synonome.

However, because we have seen 2 gravid (pregnant) females but no eggs in the pod (yet!), we now consider the dumpster and compost pile to be worrisome distractions especially since we now only have about half of our maggots left, creating only half of the synonome.

Therefore we have decided to move the pod further from the dumpster and compost pile and hopefully will see the desired result- eggs.

23

When we took the lid off of the black pupa bucket ('puparium') and TWENTY-THREE adults flew out! Very exciting. This is by far the largest number of adults that we have had alive at one time; with this great, hot and sunny weather we are in a greatest position yet to see some eggs.

One female adult was checking out the pod for about a half hour. Very good sign.

On top of this, we have a record amount of crawl-off: 113! A very happy day in the land of BSF, overall.

Looks like our contraption is working- the black bucket, which Rylo and I refer to as the "puparium" had a minumum temperature of 24.4C. That's definitely in the 'happy' range.

We only had two adults emerge today, and both had issues with wing formation. For some reason, about 10% of our adults have wing issues, a fact which we attribute to a lower humidity. Hopefully the new environment we have created is more regulated and we will not see too many more of these gimpy adults.

We will expect a large emergence soon, as today is day 13 after 84 larvae pupated (on 2 August).