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).

"Puparium" Assembly

Today we assembled a bucket to store our pupa to maintain a constant temperature of 24/25C and humidity of ~60%. We hope that this will reduce the amount it takes for the pupa to mature and for the adult to emerge.

Our contraption consists of a large cardboard box with our black bucket (that we place our pupa in), a heater, a thermometer and an air lift that we took from the chamber. We placed it inside of the classroom (in the Admin building) at UBC Farm.

We now keep a spray bottle with apple cider vinegar next to the pod. We think it's working because we've seen female adults check out the pod every day. By checking out the pod, I mean the female fly sits on the outside of the pod for an extended period of time, usually more than ten or fifteen minutes.

We also added more compost to the pod, hoping that it will attract more females and we will get some EGGS!

Today I checked the pod at 12 noon. The maximum temperature in the last 24 hours was 20.5C and the minimum was 15.1C; the current temperature is 18.4C.

The black pupa bucket has a current temperature of 21.6C and 80% humidity. We'd like to get it up to a constant temperature of 25C and lower the humidity to close to 60%. I'll have to think up a way to get our numbers up/down.

We had 87 crawl-off today, with about 80% crawling around, indicating they have not quite reached pupation and are still just mature larvae. I noticed that when we placed the mature larvae in the sunlight, they became significantly more active.

Right now we are looking for a place to overwinter our larvae (of course, IF we get eggs, and right now it seems that this is a big if). Likely, we'll settle on a large fridge or freezer.

Apple Cider Vinegar?!

Back at the farm for the 2nd time today after reading a thread on which people were discussing options on attracting BSF females back to the pod (to lay eggs). Fermented corn is a common tool used to attract them, but a much more user-friendly option is apple cider vinegar, likely due to its similar sour smell.
Although we've had 2 gravid females, we have yet to see any eggs in the pod, so we will give this apple cider vinegar idea a shot. I hope to have an exciting update soon!

Pupa and Adults Yes, But Still No Eggs

Today, I found 4 adults in the pod- one was female, the others were male. They seem to like to sit on the insulation.
Today was very cloudy and somewhat chilly- the current temp is 15.4C.
We had another huge crawl-off, this time it was 93. 12 were very large (and we are assuming female) while the other 81 were small or medium-sized. Of the 81, 8 were moving and likely very mature larvae on the verge of pupation.
We've had about 250 larvae crawl-off in the past few days likely because we have started to feed them more. We have started to feed them more, so that the maggots continue to create a synonome to attract the female BSFs back to the pod, and also, at this point, we wish to speed up the maturation process so that we can get as many adults as possible before the summer is out.
In the pupa bucket, there was also 1 female and 3 males.
I've noticed the adults are quite laid-back, they seem to enjoy crouching on top of the sawdust and don't move around too much. However, when I poked a female with my pen, she immediately flew away (unfortunately in the opposite direction of the pod however).
I have yet to find any dead BSF adults in the pod- I'm hoping to find one almost as much as I'm hoping to find eggs because adults are very neat looking and I wish to take samples of each gender so that I can preserve them to use in potential future presentations.

A Near Escape

Well, the maggots have once again demonstrated that they are adept at escaping. Rylo put together a large black bucket and drilled holes in the top of the sides for ventilation. Then he put 3 layers of thick tape around the bucket, to cover the holes. However, the maggots were not to be thwarted. If we had not gone to check on them a few hours later, we would definitely have had escapees- one was working its way through the tape and would have soon seen the outside world.
This was especially an issue, as this particular black bucket was in the kitchen of UBC Farm. The unfortunate soul who opened up the next morning could very well have been greeted by hundreds of maggots crawling all around the kitchen. If this were the case, I'm pretty sure we would not be invited back . .
In other news, the power was once again off in the growth chamber (for no apparent reason). This has now occurred 3 times (when we randomly check) in the past week and a half. There was a strange smell in our growth chamber #4 because the air pump in our aquarium was not functioning (as it needs electricity), so we ran an extension chord from the aquarium to a plug outside of the growth chamber room.

. . but no eggs

We checked the pod today, at 9:45am. The maximum temperature in the last 24 hours (within the pod) was 35.9C and the minimum was 15.2C. The max temp outside was 34.3C, and the min was 15.5C.

We found 1 adult male in the pod.

The maggots were quite active, especially with the current temperature of 15.4C. They ate all of the char that we put in the pod late last week, except for the stalk. Also, all of the chicken feed in the cat dish was eaten.

There was no smell in the pod, which was great.

Still no eggs though.

Today was quite rainy.

1 adult male in the crawl-off bucket.

2 adult males in the bucket with the pupa.

An astonishing 98 pupa were in the crawl off bucket. This is the most crawl-off that we have ever had; it may be b/c we fed them the most that we have ever fed them- an entire, full bowl of chicken feed (on Wednesday). Plus the seed was soaked for 2.5 days. It definitely didn't hurt that the max temp was 35.9C- definitely hot enough for them to have crawled off.
We need to figure out how to heat and control the temperature of the pupa bucket- perhaps using infrared light and a thermostat?
Also, to end with an interesting note, apparently the density of a population makes a difference in the size of the larvae. The greater the density of the population, the smaller the larvae will be, on average.

A Warmer Day, A Happy Update

Today started off well; we found 2 adult males in the pod. Also, we have seen 2 gravid females (with swollen abdomens). Very good news!

So, we have 5-6 adults total now.

There are about 5 rather large fungus maggots in the pod, but the BSF shouldn't be adversely affected by them.

There were 15 crawl-off today. We have noticed that BSF tend to crawl off in the evening, likely because they are very dark-coloured and to limit predation.

We are finding at least 1 adult male in the crawl-off bucket each day.

At 11am today, after placing the pod in the sun, the temperature quickly climbed from 28.9C to 33.9C. The maggots were very active and feeding.

Last night, the minimum temperature was 17.2C which is low, but we still had quite a bit of crawl-off.

Rylo and I spent about 3.5 hours maggot-sitting and were able to discuss quite a few things as well as design the signs. I hope to have them produced very very soon.

Maggot-Sitting

Spent a few hours today maggot-sitting. And for those of you who have never done this before, for BSF, this consists of placing the pod within a wheelbarrow and moving it in to direct sunlight and observing the BSF adults' interaction with the pod.

Doing this is especially important since temperatures lately have been especially low (below 22C), and the maggots have not been feeding. And when they're feeding, they are likely not making synonome. However, we have had 3 more adults in the pod emerge: 2 males and one pod (since yesterday). Hopefully they'll be able to find their way back to the pod w/o much synonome!

Rylo and I plan on putting together two signs to place by our pod on UBC Farm, as many visitors seem interested in our project and have been quite inquisitive. We also want people to know that they should not be scared of BSF, and preferably, to let us know if they have seen any adults (esp. females!) flying around.

The goal will be to have 2 signs. One will be large and rectangular with basic information about BSF. The other will be softball-sized and will solely contain a picture of an adult female and a maggot.

Some good news is that in Australia, BSF seem to have adapted to the higher temperatures; Aussie BSF's optimal temperatures are 45C, while our Vancouverite BSF are happy at a much lower 27C. This is great since it seems BSF are most content in tropical (v hot/humid) temperatures, but if they have this ability to adapt then it looks like Vancouver could be the home to many BSF and we can go on with our composting venture.

Pheremone vs. Synonome

So I've decided to put together a little science lesson. This is a differentiation that I have just recently learned about myself.

Pheremones are used in intraspecific communication, that is, when a member of a species wishes to communicate with another member. An example of this would be an alarm pheremone that an ant would release when his or her colony was being invaded, to warn the other members of his/her species within the colony.

On the other hand, a synonome is a chemical that allows interspecific communication, between two species. When actively feeding, BSF maggots produce a synonome that only attracts adult BSF females back to the pod, but tells pest flies to stay away.

Therefore, at this point in the project, where we have adults emerging every day, it is quite important that we don't forget about making the maggots happy and active, because without them, we would have a pod full of pest flies, and no adult females coming back to lay eggs.