maggots...

[Jayburd]

Hi All,
Read something interesting in a really old magazine the other day.
Apparently the pupae is far more nutritious than the actual maggot. Maggots, apparently, are little balls of fat with a good centre. True? Anyone?

[Diane]

Chocolate eclairs for finches.

[gomer]

The problem is they don't seem to eat many if any pupae.softbills apparently eat the pupae though.

[GregH]

It's an interesting question Jay. Off the top of my head I instictively thought how can changing the shape of the meal affect it's nutritional value but apparently it does. There is an article in the Encyclopedia of Entomolgy which compares the nurtitional value of many insects from various published sources at different points in the lifecycle, preparation methods and with or without gut loading and the results appear startlingly different. Of course if they had all been standardized to the same species on the same diet and growht conditions and prepared on a dry weight basis that might disappear. Since your question related to Dipterans I've reproduced the table (I still wish I could do a table in this forum) below:

Dipteran Species/stage Method of preparation Moisture (%) Crude protein1 (%) Crude fat (%) Fiber (%) Ash (%)
Copestylum ann & haggi (larva) Whole raw, not fasted 37.0 31.0 15.0b 8.0
Drosophila melanagaster (adult) Whole raw, not fasted 67.1 56.3 17.9 5.2
Hermetia illucens (larva) Dried, ground, not fasted 3.8 47.0 32.6 6.7b 8.6
Musca autumnalis (pupa) Dried, ground, not fasted 51.7 11.4 28.9
Musca domestica (pupa) Dried, ground, not fasted 61.4 9.3 11.9

This is incomplete information and you have to compare between species but it does look like crude protein does increase form the larval stage to the adult. This is not unexpected as the adult has a heavy chitinous exoskeleton which must have been built up from precursors formed in the larva whilst pupating. The nutritional downside is that while chiton is a protein it is indigestable. What we need to find is a paper that reports the quality of the protein/amino acid content of the insects. I think I'll have to reserve my judgement on this until the research is done.

[E Orix]

They may or maynot be higher in Protien but have you ever tried to seperate them. We tried it once by floating them to
the top of a bucket of water and then skimming them off. This seperated them,then we had to dry them as they were a soggy mess.
After all that the birds didn't rush into eating them.To top that off some were hatching in the feed trays in the afternoon.
The other point worth thinking on, in the very hot dry times you can keep the moisture up to the Maggots and they will swell back to their normal size
which intern assists the young birds from becomming dehydrated.
That is why we don't feed them at that late stage.

[Pete Sara]

Tried the floating method a few times, a bit messy. All I do know is use pollard only so it much easier it sieve the maggots and pupae out. Leaving them a lot drier...pete

[Jayburd]

thanks guys, lots to ponder....

[Danny]

Its hit and miss as to who eats pupae. For various reasons I have had to buy in fly pupae to supplement my live food. In 31 aviaries of finches and softbills, 4 won't eat them, 20 will eat some pupae/some mealworms and the rest have gone off mealorms altogether and insist on pupae only (the mealworms are just left behind in the bottom of the dish). The one thing I prefer about pupae over maggots (although I'll be back to maggots as soon as I am able) is you can freeze them and still feed them out later so its handy to have a kilo or two in the freezer for one of those "Bloody Fly Box" days.

[gomer]

Never tried freezing pupae.Can they be thawed out and reactivated? Could be handy when i go away and the fly box goes to custard.

[spanna]

freezing would still kill pupae. i've kept them in the fridge for a long time (around 3 weeks) with them still being alive and hatching once put into the flybox again.