Coconut Coir issues

[MikeMikeSierra]

So, I had begun to have concerns that there was a problem with my colony.  It had been doing pretty well, then I stopped seeing any crawl off, not a single mature BSFL in the collection bucket.  And I started noticing more fruit flies, and more filth flies.  And the food stopped disappearing, so I knew something was amiss.  After a few days some oatmeal I had added was covered in mold and fruit flies [major red flag because the BSFLs have devoured oatmeal in the past], so I decided to clean out the pod & basically start from scratch as I didn't think I had any BSFLs still living in the colony.  Well I started pulling out the old food, castings, etc., and I as dug down, I could hear the gurgling sound of BSFLs, but couldn't see any.  Weird.  I kept digging & had gotten everything out except the layer of coir that lined the bottom & the part of the sides.  Still couldn't see any BSFLs.  Pulled out the coir layer & holy smokes!!!  It seems my entire colony had migrated under the coir, with lots & lots of them intertwined in the coir fibers.  The coir was wet on the bottom, but the filter didn't seem clogged & there has never been any liquid to speak of in the collection jar. 

Well, it took about 2 hours to separate the BSFLs from the coir [seriously, they were really tangled up in there], but I think I have the colony put back together.  Has anyone else ever had this problem?  The consensus has always seemed to be that coir is important to keep the filter clear & the colony dry, but this really seemed to cause a problems?  Any ideas on how to avoid this in the future? 

[GW]

That's interesting MMS. I've seen and heard of others who had the coir expanded by the the BSF but not gone under it. Since the weather is cooling I wonder if it was to keep warm? I've been wondering if a coir welcome mat might be better than other forms because it would be less likely to expand but they could still get under it. I can't think of any way to stop that from happening. Maybe this wouldn't have happened if you had an insulating disc on top of the pile.

I'm glad you got your colony back in order, I just wish I could give you some advice!

[MikeMikeSierra]

Thanks GW.  As a post script, two observations:  First, I had an enormous amount of BSFLs in the collection bucket this morning.  Probably 3 inches deep.  That large & sudden crawl off seems to indicate that the larvae really were trapped in the coir & got out as soon as they could!  Second, my colony was actually larger than I realized.  I couldn't see a whole lot of activity because so many grubs were under the coir.  This was a pleasant surprise because I had never seen a single egg laid on the egg disk, or anywhere else that I could see.  Clearly though, there were eggs being laid, because I had lots of grubs.  I guess it's like you say, the females don't always follow the script when oviposting  . 

[GW]

Often the females will scatter eggs on the walls or the underside of the BioPod and ignore the disc.

I've always had fluctuations in mature grub harvest. It's hard for me to picture the grubs being trapped under or in the coir. As a general rule, if you could pick them out then I believe they could have moved out on their own. Any grubs that were hanging out under the coir layer could probably have crawled away until reaching the wall and then simply climbed up if they were ready to do so. It's not easy to trap a BSF larvae. I would guess that the behavior you observed had more to do with temperature than anything else. Just a guess.

[GW]

Mike, my BioPod™ is almost full so I think I'll be removing some material from it soon. That will give me that chance to see if I also have grubs under the coir layer. It has also been a while since I had any mature grubs in the collection bucket, but I did get a half bucket of juvenile grubs last week, whatever that means....  Were the grubs you recently collected juvenile or mature?

I wonder if we're not seeing as much crawl off of mature grubs because they're starting to slow their development down for the winter?

[MikeMikeSierra]

They were about 99% mature, dark black grubs.  There was the occasional, very occasional, immature grub, although those were very large & looked to be on the verge of turning from white to black. 

Along those lines, is there such a thing as enough grubs in the pupation stage?  I now have 3 pupation buckets, all with loose coco fiber in the bottom & I have added so many grubs to each bucket I have to think they are stacked in on top of each other  .  I would guess-timate there are 250 grubs in each pupation bucket.  Any harm in just releasing any future crawl off into the wild, at least until I get some pupation out of the current group?

[GW]

I'll bet you have more than 250 per bucket. If you cupped one hand you could easily hold 250 mature larvae, that is until they crawl away.

I just began releasing mature grubs because at this point in the season I think they'll overwinter as pupae and I think they can probably survive better on their own than in a bucket. Today it only got into the low 60's where I live and I was surprised to see about a dozen adults emerging in my pupation bucket today. Tomorrow is forecast to be sunny and in the mid 70's so I may have more mating and possibly egg laying. I found several egg clusters today that must have been laid over the past few days which were fairly warm. I'm glad to have any new grubs now because I've seem a lot of my colony maturing in past few weeks and I hope to have a decent colony for the winter.

[Andrew]

...at this point in the season I think they'll overwinter as pupae and I think they can probably survive better on their own than in a bucket.

What risks do they face in a pupation bucket? I had not planned on releasing any into the wild, but if there's a reason they will have a better survival rate out there....? Did I miss something? Can it be too crowded in a pupation bucket?

[MikeMikeSierra]

Can it be too crowded in a pupation bucket?

I was wondering the same thing.  Can a grub with no elbows need elbow room? 

[GW]

I'm mostly worried about the pupae dehydrating in the bucket. I suppose I could monitor that and add moisture when I think it might be needed but I'm not sure that I can replicate the exact conditions that allow pupae to last 4-5 months until spring. Obviously they do it on their own with some degree of success. The truth is that I live in an area rich in BSF and I never really need to protect pupae to keep a colony going. Because I sell starter kits I do try to maximize my local BSF population, but I'm sure that's optional.

I was wondering the same thing.  Can a grub with no elbows need elbow room?  Huh

I have pupae about 2-2.5 inches deep in one bucket with a little sawdust, but mostly pupae. They seem to manage.

[BelgianPup]

It would be interesting to know if they would overwinter well (temperatures being within their survival range) within a wood pile or rock pile 9aged shingles?).  Although rodents might eat them, and you'd have a population explosion of the wrong creatures...

Sue

[GW]

I wish I knew more about how BSF overwinter, especially in the northern part of their range. Aariq found wild BSF in central Illinois so they're avoiding freezing in a fairly cold area. Can we assume they burrow into the ground?