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 What creates the grubs to bloat up 
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Joined: Sat Nov 24, 2012 4:15 pm
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Post What creates the grubs to bloat up
I received some grubs from another grower and they looked good on arrival. After about a week I noticed that they were bloating up and getting very ridged. Does anyone have any thoughts?
I have noticed this before but have no idea if its food, or something else.
Thanks
Greg


Wed Aug 20, 2014 3:41 pm
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Post Re: What creates the grubs to bloat up
Greg are they light or dark? It could be that they're pupating if they've turned dark.

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Wed Aug 20, 2014 4:28 pm
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Post Re: What creates the grubs to bloat up
No they aren't pupating, it's something else. They are both light and dark in color. Here is an image.
Thanks
Greg


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Wed Aug 20, 2014 7:08 pm
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Post Re: What creates the grubs to bloat up
That doesn't look good. Are they moving at all?

There is this thread (link) about larvae mortality from a couple of years ago. IIRC eventually it was discovered that mortalities were a result of large numbers of larvae purging their gut contents prior to pupation which released in a 'bloom' of bacteria in a bin.

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Wed Aug 20, 2014 8:28 pm
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Post Re: What creates the grubs to bloat up
I don't know anything about your setup or where you're located, but is it possible they're getting too hot?


Sun Aug 24, 2014 6:06 pm
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Post Re: What creates the grubs to bloat up
"Preview" lost the detailed version of this comment - happened before. So briefly:

"Isolation and identification of bacteria producing enzymes from gut and skin of black soldier fly(Hermetia illulens)larvae" http://en.cnki.com.cn/Article_en/CJFDTO ... 005015.htm Explains BSF larvae gut bacteria are varieties of Bacillus subtilis.

B. Subitils produce their own niche anti-biotics. When pre-puapae gut purge the B. subtilis get a food rich environment & their anti-biotics challenge original microbes. At certain levels the challenge(s) induce their target bacteria to shift into stationary phase (search Forum for explanation).

Stationary phase bacteria produce distinct types of molecules & metabolites. These are, in my paradigm, what the bloated larvae are suffering from. It may be either osmosis changes at the larvae "skin" or/& ingested metabolites that impinge the larval malphigian tubes (insect version of kidneys). The side effect being swollen cells.

In terms of colony collapse I again think the active culprit is not the gut bacteria themselves "killing" larvae. Rather the side effect of original bin substrate microbes switching over to their stationary phase.

Here (colony collapse) there is logically a difference with progressive bloating showing up; but the same triggering is the gut B. subtilis causing original bin substrate bacteria into stationary phase. The colony collapse is, in my opinion, going to be the result of
phage(s) associated with bacteria activating in response to the bin substrate dynamic that has changed.

In laymans terms a phage (a kind of DNA entity which lives/multiplies inside a host microbe) can, after causing no problems eventually alter it's own phage behavior. When a phage breaks it's passive symbiosis it can "bust " (lyse) it's host leading to all kinds of molecules/metabolites being let loose & even a massive proliferation of it's own phage numbers. Of course I am not sure exactly what/which phage cascade of events in bacterial cells, which of any specific lysed cells are relevant & how the phage dynamic precisely kills off an entire larvae colony.


Mon Aug 25, 2014 5:59 pm
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Post Re: What creates the grubs to bloat up
Thanks gringojay

gringojay wrote:
"Preview" lost the detailed version of this comment - happened before.
Not sure why that happens but I've gotten in the habit of copying the text of long posts (Ctrl+A then Ctrl+C) before previewing or submitting. Then if your post is lost the text can be pasted into a new post.

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Mon Aug 25, 2014 6:09 pm
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Post Re: What creates the grubs to bloat up
I am not sure really if any of these situations is the cause:
Temperature in the containers is controlled and its about 85degree F, so I don't think its heat.
After i notice some die off, I rinsed out the container and took out all unhealthy grubs, at least those that were obviously not healthy and added the healthy grubs with fresh food. I am still noticing die off (bloating). All grubs are being fed grains only. This is happening only with the grubs that I purchased and not with my grubs. So I am still at a lost?
This has happened with my grubs as well, just not this time.
Thanks
greg


Mon Aug 25, 2014 10:50 pm
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Post Re: What creates the grubs to bloat up
You are suffering a colony collapse, most of the larvae will likely die even if you managed to transfer the "healthy" ones to another fresh container. Notice the odor, it is quite familiar and different from a healthy colony. There are many ways to prevent the collapse of the colony, but none for recovering the affected ones. It is not contagious directly or airborne, you can use the same container for a new culture.

I recommend to use sea water (if you live in the coasts) or salt water (30 parts of sodium chloride per thousand), you won't have this problem anymore. But you cannot use the larvae waste for composting, so your decision.

Best,

Alfredo.


Tue Aug 26, 2014 12:29 am
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Post Re: What creates the grubs to bloat up
Alfredo,
Are you saying 30 parts of salt per 1000 or parts of water (1 part salt to 33 parts water)?
Will it save the rest of the colony if there not contaminated?
What is the salt doing?
Thanks for your suggestions.
Greg


Tue Aug 26, 2014 12:45 am
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Post Re: What creates the grubs to bloat up
The same as the salt concentration in the sea water, 30-35 grams of salt per liter (1000 grams) of water. It changes the bacteria population in the media, killing some species of bacteria and other non-halotolerants organisms.

Salt won't save the larvae but prevents colony collapse, IMAO they got poisoned with some toxin, but it is my guess as most of them cannot be recovered.

Best,

Alfredo.


Tue Aug 26, 2014 9:39 am
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Post Re: What creates the grubs to bloat up
GrownLocally wrote:
No they aren't pupating, it's something else. They are both light and dark in color. Here is an image.
Thanks
Greg


Yeah, i'm now experiencing the same problems trying to setup my own starter colony and that's exactly how the dead looked like. My experience confirms the ongoing citizen science out there that no matter how big or small the bin, bsf larvae bloating, later turning into a writhing mush seems inevitable - It even occured in one of my ice cream container bins but i'm keen to share something I discovered from my backyard projects.

I remembered starting with a small ice cream container setup with BSF larvae when bloating corpses begin appearing. Alternatively, I drilled holes all along the bottom of the container and threw in some activated charcoal into the mix, and the problems disappeared - never got a single casualty after that. The only deaths that occured was when ants decimated my first colony.

Just wondering if the charcoal helped provide the calcium needed by the maggots for their exoskeleton. Afterall, swimming in all that rotting fruit and stuff can get pretty acidic if im not mistaken. Also, deliberately I experimented with two different bins, one with charcoal and other without. The second bin got off to a flying start untill bloating corpses started appearing with drier weather but the charcoal treated bin seems to be doing very well with no deaths yet, no matter how dry conditions are.

Hope this helps
Im gunna try sprinkling lime to see if it works..


Sun Aug 16, 2015 12:26 pm
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Post Re: What creates the grubs to bloat up
When you say you used charcoal, do you mean like wood charcoal, or leftover ash from a fireplace, or charcoal you bought or charcoal briquettes for cooking. I know this may seem simple to you, but trying to understand your process to get it wright isn't always.
thanks
Greg


Sun Aug 16, 2015 2:00 pm
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Post Re: What creates the grubs to bloat up
Sorry, Its just mangrove wood charcoal i got from the store. However, according to fellow forumners on the same issue, liming the substrate is recommended which seems to stop the problem but haven't tried this though.


Sun Aug 16, 2015 3:01 pm
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Post Re: What creates the grubs to bloat up
Might I ask - has anyone who has experienced CCD been using a 'dry' bin rather than a bin which is kept very moist and flushed? My composting experience only lasted a single summer but I never had any CCD with my drier method. I can't help but be prejudiced that the unnaturally wet conditions are what is causing the die-off. When I think about an animal carcass or pile of rotting fruit I know that while it's moist and juicy there is very rarely any pools of liquid, as these things drain into the soil quite readily. Alfredo have you ever had CCD in your no-bin piles?


Sun Aug 16, 2015 11:16 pm
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Post Re: What creates the grubs to bloat up
Alfredo Llecha wrote:

I recommend to use sea water (if you live in the coasts) or salt water (30 parts of sodium chloride per thousand), you won't have this problem anymore. But you cannot use the larvae waste for composting, so your decision.


I wonder if salt could be used, and then eventually flushed away with water. With my design you can hold a unit completely flooded for several minutes, and flush/drain thoroughly. I would imagine most of the salt would be removed after several weeks.

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Mon Aug 17, 2015 7:46 pm
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Post Re: What creates the grubs to bloat up
I was just fixing to post some observations I have been making on bloated grubs, but searched first and found this thread. During previous grows I have found some like this and thrown them out. This time I isolated and observed them.
With a hand lens I can see a milky fluid with many bubbles inside the skin, with a smaller darker grub looking body within the juice. After leaving the first batch in isolation overnight, they all had split that skin from head to tail and shed it. Every one of them. So I caught some in a lesser bloated stage, but they appeared to be headed in that direction. I watched with a hand lens again and could see them jerk their butt, which emitted a bubble and as they curled the bubble would travel to the head. This kept repeating until it was very bloated and tight. Next morning, the skin was split head to butt and a shiny new grub crawling.

I wonder if anybody else has saved their bloats to make sure they were indeed dead, or just pitched them out like I did in previous grows? I wonder id someone might watch now and confirm or deny my experience.

My tubs tend to be kept quite dry, have no tops, are inside 75f, usually have about 30-40% coffee.


Thu Mar 24, 2016 4:08 pm
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