Bluebottle problems - dead pupae?

[PlayingMantis]

As my mantis collection grows, I figured I need flies in bulk amounts. Earlier this month, I decided to purchase 2,000 spikes from an online bait shop, and they arrived looking in great condition - large, juicy, actively wiggling maggots. I put half in the fridge and the other half at room temperature, and within a few days, they turned into pupae. Normal-looking pupae. A week passed and none of the pupae hatched, so I decided to cut one open. Inside was a glob of foul-smelling, rotten mess. I cut open a couple more, and all of them had rotten goop. It seems like the maggots died before even having the chance to begin turning into flies.

My room temperature is 82 degrees, humidity is 70%. In the past, I've only bought pupae, but because of practical reasons, I want to try spikes now.

So my question is, what did I do wrong? Or are bait-shop maggots inferior in quality, or are they treated with some chemical to prevent them from maturing properly?

 

[twolfe]

I've been ordering blue bottle larvae from an online store off and on for 5 years. This company started as a bait shop several years ago but now offers a wide variety of feeders. I've never had any issues with them. They may have raised them years ago, but I think they order from the same wholesale company where several buy their spikes in large quantities.

Two years ago I was thrilled to find a local bait shop that raises their own blue bottle larvae. I thought it was nice to have a local backup for emergencies or when I needed a smaller quantity. Their price was reasonable, and I didn't have to pay shipping charges. Unfortunately the hatch rate was so low that it didn't work out. I tried them a second time and talked to an employee. He said that people don't buy them to hatch them out. So, it didn't matter to them that their hatch rate was low. They said that they didn't treat them but agreed that it is lower but that they get enough that mature to adult flies to use for breeding purposes. With my second purchase, I had a higher hatch rate after misting the pupae but have not purchased from them again.

 

[SSimsswiSS]

Maybe the humidity @ 70% did them in. They need a dry place to pupae. Like dry wood shaving, or soil.

 

[Aryia]

I find that they will pupate anywhere if they have to, but as Steve said, high humidity (especially condensation) doesn't do them any good in my experience.

I used to place them on top of a light because I thought warmer would be better, but the direct contact to the heat source actually ended up overheating them I guess. Some still hatched but I had a lot of dead ones. Maybe try and change a location? I would keep them out of direct sunlight for the same reasons too.

Not sure if this is possible but you could also try feeding them a bit, maybe they aren't ready to pupate quite yet when the bait shop is selling them. After all most bait shops do not want their larvae to pupate immediately on their customers.. that would be bad business.

 

[hibiscusmile]

Most all bait shops buy from forked tree. They may tell you they raise their own, but sorry they lie. I know cause I asked and then purchase and I know what I got was from forked tree. Grubco swears they do their own, but when they send you a large box that they forgot to take the old label off of, well u figure it out. I also brought off of one in Michigan I think, same thing there.

I set mine either outside in my maggot box or inside if weather is bad, they always pupae and hatch. I dont bother with temps as they dont really matter as long as it is warm. Never mist pupae or maggots. Keep them dry with sawdust.

 

[twolfe]

There is a Minnesota bait shop that raises their own blue bottle flies. They have photos of their set up on their website, and I've talked to their employees. I hope PlayingMantis doesn't mind me sharing that the bait shop she ordered from is in Minnesota. It's not the same one where I got mine, but it's possible that they supply to other bait shops in the area. As I mentioned, I had a very low hatch rate...less than 20%.

Interesting that Grubco swears that they raise their own. I'm sure they did at one time. But they are listed as a bait shop dealer on Forked Tree's website.

Since Playingmantis has been hatching out pupae in the past, I'd guess it wasn't anything she did.

 

[Rick]

In my experience it takes longer than a week. Give them more time.

 

[PlayingMantis]

Sorry it has taken so long for me to get back. The vast majority of the pupae never developed and turned rotten or dried out. A few developed partially into flies but died somewhere along the way. In total, I ended up with less than 10 flies out of all the pupae!

I tried pupating them in wood chips and in different locations around the house, but to no avail. Also, as Aryia mentioned, there were a handful of maggots that were pretty small in size (mostly near the bottom of the container) and they weren't mature enough to pupate properly. I guess I could've fed them some fruit or something.

I wish there is some way for me to lower my indoor humidity, because it is always awfully high in summer.

More recently I bought some pupae from Rebecca and they hatched fine. Interesting. I still wonder if the bait shop maggots were treated with something to delay pupation, and in the process, renders them unable to pupate properly,