Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Sign In with Facebook Sign In with Google Sign In with OpenID Sign In with Twitter

In this Discussion

What pest is this?

Hi, i just started farming mealworms a couple months ago, and i think i might have brought in some kind of pest with the last bunch of oats i used. I'm fairly sure it's not grain mites, because the humidity in my bins is way low. It averages around 40%. I'm actually trying to raise it right now.

The bugs are incredibly small, in fact i can't see them. The only reason why i know they're there is when i agitate the bin a bit the substrate moves like crazy, and i see tiny specks jumping around.

I did have some weevils earlier in a bag of semolina earlier but i'm pretty sure those things aren't invisible and don't jump around like lunatics.

If anyone has any idea what these things might be i'd love to hear it.


  • I just cleaned out my pantry and found some tiny bugs walking around that looked like book lice, but i'm not sure. These are not the same bugs as in my colony though.

  • SThe mite that feeds under the wing of "flour" beetles is only 0.0079 inches (0.19mm long); mother's die after birthing. Possibly your oat batch had these Acarophenax tribolii, but am speculating. Pregnant ones would have been 0.0118 inches (0.29 mm). As they left their mother's body they would have been fertilized by the male among them; figure up to 15 of these progeny in each female & only one of these being male makes them proliferate.

    It's evolutionary relative that feeds on grain pest instars called Pyemotes ventricosus has the male fertilize the females just after they left their mother's body, instead of just inside her.This is another mite that would be classified as parasitic on grain insect pests, like mealworms are considered to be. Some mealworm handlers have developed dermatitis & this mite can cause it.

  • @gringojay thanks for the response. Would these things be jumping around like they're in the NBA though? I'm having a hard time finding information on these things on the interweb but it's my understanding that generally mites are fairly slow.

    I'm in Europe btw if that makes any difference. I'm seeing lots of references to Australia in my google searches, not sure if this is a pest that's around worldwide.

    Interesting bugs though. Pests that feed off of pests. Next you're gonna tell me there's even smaller mites that feed off of these Acarophenax Tribolii.

    Also worth noting is my skin did get a little itchy but that might just be my imagination.

  • Jumpers suggests fleas, but you imply unwanted bug tinier than fleas (smallest flea from memory is 0.0394 inch = 1 mm). My suggestion is to promptly change out what your mealworms living amongst & swab clear any traces of particulates on the container surfaces. Give your herd fresh substrate obtained from a different supplier.

    You don't describe if have larvae & breeding adults in the same container moving through the same substrate. If (& am not able to say) mites are there then just changing out the grain can miss the adult mites on beetles (& larvae).

    U.California, Berkeley division Entomolgy & Acarology used an insectividal mite poison (acaracide) during a 1964 lab beetle culture infestation by Acarophenax tribolii since when mites drops off beetle they suck out the beetle eggs. This mite only needs 4 days outside it's mother before it is itself ready to mate.

    The team used a now recalled acaracide called by the product name Morestan & passed over the more insecticidal endosulfan as the acaracide; I don 't know off-hand what would be a 2016 alternative to Morestan. The procedure was to mix 200ppm Morestan into flour & keep their beetles + adult larvae in that media for 10 days at 20 Celsius. After this the beetles were moved into good fresh flour to mate & give clean eggs to build back the lab colony (beetles in this case were Tibolium, so extrapolating to mealworms may not be exactly the same).

  • My set up is a set of shelving units that house breeding bins that have a mesh floor, so the eggs and baby worms can drop through. I transfer these to fresh bins every week that are in a seperate shelving unit.

    I did notice that one breeding is producing noticably less baby worms than the other bin, although they both house the same number of beetles. However when i checked the bin that catches the baby worms that bin doesn't seem to have the little jumping things in there.

    Actually, i'm checking all my other bins for comparison, and i can't get any of the substrate in any of the bins to show the jumpy behaviour anymore.. I did raise the humidity by a little over 10% in my nursery bins, from 44% to 57%. Do you think that could have killed them? The unwashed bins that they were in before i moved them to the new bins still have a little bit of dust in them that does show the erratic jumping behaviour when agitated.

    So in conclusion the pests don't seem to be in my beetle bins, don't seem to be in my nursery bins any more since i raised the humidity, but still seem to be in the bins that the baby worms were in before i changed them to new bins. Either the humidity increase, the change of bins (maybe they stuck to the old bins), or just luck solved my problem.

    Btw, what would fleas be doing in substrate? I've seen fleas before and these things are definitely smaller than 1mm. I'm gonna try and find someone with a microscope to see what's going on.

  • Fleas would come in with grain rodents or cats they jumped off in a warehouse. Your infestation always sounded much littler.

    Reduced progeny from beetles is what led 1964 lab to notice a mite problem. That specific mites' life cycle is not on baby larvae & after sucking out eggs will leave that. So the mite not living in collection bin can be explained.

    Look under the bottom-most wings of beetles living among the pest. About 10-12 of the mite A. tribolli fed at a time on that laboratory's kind of beetle. Pick some of your beetles from the bin with jumping pest, euthanize them so can inspect that part of their anatomy with a magnifying glass. Also check the bin related to plagued beetles for eggs & see if under microscopic examination find relics that might be sucked dry eggs.

    Like you I do not associate mites with jumping behavior. Maybe your infestation is a unknown variety. Small bugs associated with stored grain have been studied because commerce wants to reduce insect damage; mites (& fleas) get found as part of those grain eaters world. There are other tiny bugs associated with seed crops which are more likely to jump - but their lifecycle does not involve post- harvest stored grain.

  • I checked out a couple of bugs after putting them in the freezer and they seem fine. Nothing under or on their wings as far as i can tell.

    I also put a sample of the jumping things in the freezer yesterday and they don't seem so jumpy anymore, so i guess a simple solution would be to freeze my substrate before use.

    Still wondering what's preventing my one bin from producing though.. Do you happen to know of anything else that could cause this? AFAIK I'm feeding and treating both bins the same. Same humidity, same temperature, same substrate, same type of bin. The beetles are about a month younger than the beetles in the other bin, but they come from the same 2000 or so mealworms i bought from a seller and they're well over a month old now so i feel like they should be pumping out more worms.

  • Actually, i checked out a couple more just to be sure, and most do seem to have some stuff beneath the exoskeleton protecting the wings. However i'm pretty sure it's just dust. It's tiny white specks, maybe 1/10th of a mm, impossible to tell with a magnifying glass if it's a bug or just dust, but it blows off easily, doesn't seem fixed at all.

  • Hi VeeHouse, - I really have no additional ideas to offer why 1 bin is breeding less. Maybe Andrew sees some issue.

    Falling breeding results was that 1964 lab's problem. Before assuming blown off particle is not mite pest best to take some for a microscope look. Your infestation does not have to be the same kind of mites I know about. I still have no idea any jumping mites even exist.

    Springtails "jump" (bounce up) yet are usually bigger (about 1-6 mm); but they can be 0.25 mm & thousands of species exist. They could have come in with stored grain because springtails can eat fungal spores & fungi, if any, on your new grain. Liking fungi means they're adapted to humidity; so your raising humidity wouldn't have killrf them (or anything else eating fungi).

    Since springtails are not parasites on live insects they don't account for breeding loss. Which raises the possibility that there are 2 pests introduced: one that is not seen jumping & is a parasitic mite afflicting breeding + another that is visibly jumping which is noticed but just multiplying off of fungi & not impacting breeding.

  • I may have figured it out. Because i can't see any bugs and i can't seem to see any impact from the bugs being there, i think there may not be any bugs. I think maybe it's static electricity from the sliding plastic bins that rather explosively pulls on dust particles when they're disturbed. I think this might be the case because the exoskeletons the worms shed seem to stick to the sides of the bins, and when i tap the bins they seem to move for a second, just like the "bugs", and then stop. I examined the husks and there seems to be nothing but husk. This would also explain why it's only affecting one of my shelfing units and not all of them.

    The substrate i was using only showed the same behaviour when i put it in a plastic bag to freeze, and still showed the behaviour when the substrate got a little warmer again. This was after a day in the freezer.

    So there we have it. Mystery maybe solved!

  • edited May 2016

    Hey There,

    I'm new and trying to breed my own crickets and I noticed that there are tiny grain mites in the egg trays. I checked the web and I am pretty sure they are grain mites. There are only a few, even after several days. I had two questions:

    1) Is this going to destroy my whole colony? I'm just wondering if I should trash everything, bleach the bins, order more crickets and start over. Or if I should just keep going and wait and see if they hatch. There are tons of eggs, so it seems a waste to throw them out. 2) I am going to start freezing my feed regardless before putting it in the bins. Will that kill the potential mites in it?

    Thanks in advance!! Repo

  • @Repo - you might need to destroy those egg trays if you have a massive infestation, the mites will do a number on the eggs anyways. Fortunately your crickets should be able to refill your egg trays quickly. however if you keep the moisture low (still slightly damp to keep the eggs happy), you may only end up with a few mites. Your substrate for the eggs may have been too wet to begin with and allowed them to hatch.

    As long as you can keep the humidity low, the grain mite eggs in your feed shouldn't hatch, but if you're dealing with a small volume of feed you can stick it in your freezer. (if you're dealing in large volumes (hundreds of pounds or tons of feed) you may have to rely on managing humidity to prevent hatching of the grain mite eggs. Unfortunately we can't use diatomaceous earth to control them as that would kill the crickets / mealworms as well as the mites.

  • Yeas correctly said. We may also hire pest experts like termite treatment rocklin, they would also help us out with these problems.

  • Moving air/good ventilation also helps against mites. Maybe inducing a 'fever' (bumping the temperature up to 38-39 *c) will help as well, depending on the tolerance range for the mites, I think this was discussed with Gringojay once before.

  • Yes I too agree with this..

  • May be it could be fleas.

Sign In or Register to comment.