# Houseflies Pupae Not Hatching



## PowerHobo (Dec 4, 2018)

Definitely starting to think I'm doing something wrong here.

My first order of houseflies was delayed in shipping, and arrived almost entirely hatched out. I put them in a 32oz cup with a moist sugar cube in the bottom and stuck it in the fridge. They lived for a surprisingly long time, and I fed out from that container for probably a month.

My next order had zero hatch. Seller said he thinks an expired batch got sent out somehow and sent me a replacement.

This order arrived with 4 or 5 hatched, and I've had probably 15 more hatch since then (easily half of which have already been dead in the bottom of the cup when I find them). It's been about 3 weeks, so I'm not having a lot of confidence in getting more hatches.

I haven't kept this container in the fridge at all except for 3-4 five-minute periods to grab flies to feed out. It's in a room that's about 72-74f at all times. It's the exact same lid (regular clear deli, about 50 pin holes) as was on the first batch's cup; same style cup. I don't have any sugar cube in this one because I haven't really seen any population of flies to that I'm not immediately going to feed out. I have noticed there's a sort of oily residue on the sides of this cup that has accumulated since the pupae were put inside, not sure what it is, but it's not water condensation (the room is actually _very_ dry).

This is reminding me a lot of the one fruit fly culture I tried (using a guide from here). I only had about 15 _D hydei _to put in to start, and I forgot to color the media so I couldn't really see the larvae, but there is a ton of dark brown pupae all up the sides of the cup and on the excelsior... none of which ever hatched (it's been like 3 months, but I'm a disgusting human being and have never thrown it away). The media never dried out, so I don't think they desiccated, but I'm just not sure.

Any thoughts on what I'm doing wrong? My ghosties are too big for fruit flies, but not quite big enough to confidently take on small dubias.


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## ohaple (Dec 4, 2018)

I have had the same problems but haven't been able to diagnose. Our fly pupae only has like a 5% hatch rate, and many of those died in the process of emerging from the pupae. I don't know the solution, but am interested to see if others have advice.


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## Graceface (Dec 5, 2018)

Freshness may be an issue, if the pupae are older they may not be viable. if the pupae were stored in the fridge for too long they can die also. Ive heard you should take pupae out of the fridge periodically to keep them active. I've been trying this lately myself, but sometimes you do get bad batches


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## Synapze (Dec 6, 2018)

Graceface said:


> Ive﻿﻿ heard you should take﻿ pupae out of the fridge periodically﻿ to keep them active﻿.﻿


I take them out for about an hour every few days. I have a smaller cup inside a larger cup and place a damp (not dripping) paper towel or cotton ball with a small drop of honey on top. The flies seem to stay larger and last longer in the fridge. I usually get high hatch rates and the batch lasts about a month. When fly count starts diminishing I just leave them out of the fridge to hatch out any remaining pupae. 

It may sound a little gross, but when your flies are all hatched out you can dump your pupae onto a clear plate. Shine a light from underneath and you'll be able to see approximately how many pupae didn't hatch. I can recommend a dealer who's BBFs I have a lot of success with via DM.


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## Graceface (Dec 6, 2018)

Synapze said:


> It may sound a little gross, but when your flies are all hatched out you can dump your pupae onto a clear plate. Shine a light from underneath and you'll be able to see approximately how many pupae didn't hatch. I can recommend a dealer who's BBFs I have a lot of success with via DM.


Great idea! I will try that. I'd love to get your BBF supplier name


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## Mantis Lady (Dec 7, 2018)

I have some flies hatching in my fridge again, I feed them from there to my mantids (toss a fly in the cup and mantis can grab it when the fly warms up and get active again), at the moment I don't need to feed the dubia pieces. I think my ghosts wont eat FF anymore after their next molt because FF will be to small.


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## Graceface (Dec 8, 2018)

Little Mantis said:


> I think my ghosts wont eat FF anymore after their next molt because FF will be to small.


Yup, time to move on the house flies


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## hysteresis (Dec 8, 2018)

I'll be feeding black soldier flies and dubias soon enough.


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## MantisGirl13 (Dec 8, 2018)

hysteresis said:


> I'll be feeding black soldier flies and dubias soon enough.


Cool! I just started breeding dubias and have my first L1s as of a few days ago!

- MantisGirl13


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