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Soldier fly maggots and anerobic smell

Posted by almadenmike San Jose, Calif. (My Page) on
Fri, Aug 28, 09 at 13:42

I've had to move my Can o' Worms bin outside during our home remodeling. Today I discovered an explosion of soldier fly maggots writhing in my top rack. My worms have retreated to the bottom rack.

I've read now on HappyDFarms's invertebrate page ( ) and Working Worms ( ) that these maggots are not really harmful to the worms, as long as the latter get food wherever they retreat to.

I was surprised however, that the bin suddenly has a putrid anerobic smell to it ... very different from the usual good-compost smell ... and the top layer is now stained black, not at all like the typical appearance. I hadn't overfed or given any different types of food. Is there something about the soldier fly maggots that give their surroundings this awful smell and appearance? I'm thinking that I should maybe toss that top layer out onto a remote part of my yard and let the birds have at the maggots and rebuild the compost (hopefully worm-only) in the upper rack.

Any insights or advice? (I've been worm composting with this unit for maybe 10 years, and this is the first soldier fly maggot infestation I've had.)

Also, if I do toss out my top bin, is the bottom likely to be free of maggots (as long as I can't see any active)? Or are there usually tiny eggs that will hatch over a long time and I'm looking at long-term bin-management headache?

Many thanks,

-- Mike in San Jose, Calif.

Follow-Up Postings:

RE: Soldier fly maggots and anerobic smell

Hi Mike
From what I've read, soldier flies are very good for the system. You might try the search at the bottom of this page and enter Kelly Slocum (soldier fly Slocum). She used to post here and is quite the expert.

RE: Soldier fly maggots and anerobic smell

Your only hope would be preventing the flies from getting in and laying eggs. From what I've read about BSF (don't get them here but I wish we did) they can be a bit of a bin management task to get rid of.

I'll second kathmcd7 in that they are good for a system in that they chew through organic material quite quickly but you should ensure that (1) there is adequate food for the worms below the BSF (they'll mostly be on top). (2)BSF will generate more heat while they do their thing so be sure that the worms can escape from excessive heat. Maybe if the BSF in your COW are in a top tray if you have one or more trays going they should be able to escape below. (3) Because the BSF consume organic material quickly the water locked in that material is "freed" into your bin faster than by just worm activity. You may want to watch the moisture level in the stacks below.

RE: Soldier fly maggots and anerobic smell

BSFL also don't seem to eat any bedding, which your worms can live off of. I don't produce a lot of waste, so I never get the BSFL in my worm bin. I was excited when I came across them in a compost bin that was just starting up.

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