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Spider mite questions

Stank TaNk

New member
Hi yall. So I am ashamed to say that my last two grows I got spidermites. The former time I wasn't certain to how I got them, figured I tracked them in from walking around outside or something.
This go around, i was very careful, switched clothes and shoes whenever entering the grow room. Now I am fairly certain I got them from going to my local Steins Garden and home. I buy fox farm happy frog from there and Im not positive if they were in the soil or somehow I brought them home on me from walking around the store. I transplanted and switched to flowering cycle and what do ya know, 2 weeks into flowering and I spotted what I believe to be maybe 6 or so spider mites on the top of the plants towards the light. I inspected every inch of every plant and squashed what I could see with my thumbs. Then I sprayed with spinosad and pyrethins, turned off all fans and circulation and put two brandnew No Pest Strips along with the two I used previously and two older ones from a couple years back. Thats 6 NPS in a room thats about 12'x10'. Came back two days later and I inspected all plants again and see no sign of the borg, no webs, no damage. Sprayed again and put the NPS out. Had a busy week ahead and couldnt be back in the grow room for about 6 days. Come back 6 days later and there is spider mite damage on most of the ladies. The weird thing is, I then inspect the plants and find no sign of them, I see no mites, no webs, nothing but the damage left. Sprayed with spinosad again, and left NPS out again. So its been about 9 days since I had put the No Pest Strips out.



My questions are, can spider mites survive 9 days of being gassed out by 6 No Pest Strips? Was the increased damage from a boom of them populating knowing they were in danger? If I don't see them or the webs, could they very well have died and the damage is just the scarred remains of them feeding? Also if spinosad and pyrethrins aren't effective in killing them, what is?
 

Mr. Greengenes

Re-incarnated Senior Member
ICMag Donor
Veteran
It's been about 20 years since I tried a NPS, but my memory is that it killed only the adult mites, not the eggs. But, if you left them in for 9 days, that's more than a mites life cycle, so I would think it would get the next 'wave' as well. Either way, I stopped the nasty chemicals years ago. Now, I just use full plant water dips. Sometimes I do a soap/neem dip first, then rinse with water. That wipes mites and eggs too. Just get a 5g bucket and turn those babies upside down and swoosh swoosh.
 

aridbud

automeister
ICMag Donor
Veteran
Used Grower's Trust Spider Mite Killer (kills eggs and pesky little buggers). Too,you need to bleach your area well, wiping down everything. Spray walls with alcohol/water solution.

Good luck!
 

Douglas.Curtis

Autistic Diplomat in Training
Welcome to ICMag!! :D

My questions are, can spider mites survive 9 days of being gassed out by 6 No Pest Strips? Was the increased damage from a boom of them populating knowing they were in danger? If I don't see them or the webs, could they very well have died and the damage is just the scarred remains of them feeding? Also if spinosad and pyrethrins aren't effective in killing them, what is?

To me it looks like thrips maybe?

Spider mites, even russet mites, are stupid simple in veg. Zero need for any products which will stay in or on the plants. Potassium fat based insecticidal soaps like Safer's Insecticidal Soap work just fine. No need for neem, no pest strips or anything like this. Seriously, save your money and keep your cannabis cleaner. ;)

The key is to break the breeding cycle. To keep their breeding slower, lower your temps below 82F for best results. 70F is much better.

Russet mites take approximately 5-7 days to mature after hatching. Regular mites take about 4-5 days. Killing mites every 3 days for 15 days will kill all mites and leave no new eggs.

Sulfur and insecticidal soaps work awesome in veg. If you've sprayed neem or any other oil in the last 30 days, using sulfur will burn your plants quite well. Another reason not to use oil based products. Make sure you cover your soil/reservoirs well when spraying soaps/sulfur.

Completely drench the plant. No sissy spraying, no spritzing with the dollar store bottle, get a real sprayer. Mondi makes a great half gallon one, and there are backpack and ATV models by different companies for spraying trees. You want a lot of solution drenching your plant. You want a lot of solution rinsing your plant later. ;)

Keep Your Cannabis Clean! :tiphat:
 

Stank TaNk

New member
Thx for the suggestion guys. [FONT=Arial, Helvetica, sans-serif]Douglas.Curtis, in my 10 years of growing experience I would still say its spider mites. The damage is too familiar. I try not to use neem oil anymore cuz it always seems to burn my plants. Im guessing the pyrethrins kinda burned them too as they seemed pretty sad looking after I used it. It just sucks to have everything going right to all the sudden have mites and now my whole grow is just pretty sad looking. Spider mites are the n\bane of my existence. I'm just really worried at 2 weeks in flowering , even if I do get rid of the mites, my grow will be severely stunted.[/FONT]
 
M

Mr D

The plants that are 2 weeks in to flower can be washed as per Mr. Greengenes suggestion.

Rather than dipping I'd use the shower to blast those suckers off. Outdoor plants endure heavy rainfall when in flower. So a plain water blast will not hurt anything. Let them drip dry for a bit before putting them back under the lights.
 

Douglas.Curtis

Autistic Diplomat in Training
Thx for the suggestion guys. [FONT=Arial, Helvetica, sans-serif]Douglas.Curtis, in my 10 years of growing experience I would still say its spider mites. The damage is too familiar.[/FONT]
[FONT=Arial, Helvetica, sans-serif] 15+ years indoor and the first time I had thrips I thought it was mites as well. lol I just couldn't find any mites!

[/FONT]
[FONT=Arial, Helvetica, sans-serif]
I try not to use neem oil anymore cuz it always seems to burn my plants. Im guessing the pyrethrins kinda burned them too as they seemed pretty sad looking after I used it. It just sucks to have everything going right to all the sudden have mites and now my whole grow is just pretty sad looking. Spider mites are the n\bane of my existence. I'm just really worried at 2 weeks in flowering , even if I do get rid of the mites, my grow will be severely stunted.
[/FONT]

Mites are so stupid easy, it's a crime how much poor information is out there on them. So sorry to hear of your worries.

You're only 2 weeks into flower, you can beat them with some care and time.

Make sure you have excellent ventilation
Mix 1 ounce of 91% isopropyl alcohol to 1 gallon of water
Use a REAL sprayer, not some hand spritzer bottle thingy, something with pressure and a lot of flow
Completely cover your root zones so nothing drips into soil or reservoirs
Drench the plants completely, top to bottom, stems, inside new growth, EVERYTHING.
Do this every 3 days for the next 15 days

Most likely, if you're as thorough as you should be and you've eliminated the mites from all house plants and outside, and you've identified the source and removed it as well, the mites will be gone in 5 days. Keep up the extra days to be sure. You're still new at this. ;)

Yes, the iso will remove some of the terpenes. Yes, it may remove a little of the cannabinoids which have built up at 3 weeks. No, it won't completely ruin your harvest and your plants will be fine. :)

Mix fresh solution each time, and be sure to report back on your success. :tiphat:
 

Douglas.Curtis

Autistic Diplomat in Training
The last time I used isopropyl and water, it completely fried my plants and dried them out and made them crisp up.
MUST KEEP FROM ROOTS!
Water absorbs iso really well and does not let it evaporate easily. So when you spill this in your soil or your reservoir, it's going to be there for a while. It will kill roots. This is what happened to your plants. Sorry this little info wasn't included when you read up on it. :(

Cannabis sprayed with alcohol and water will show zero negative reaction. They look great. :D
Also would this sprayer be sufficient?
I have no idea, I only have experience with the Mondi half gallon types. Solid construction and I've used mine for years now.
 

Mr. Greengenes

Re-incarnated Senior Member
ICMag Donor
Veteran
The plants that are 2 weeks in to flower can be washed as per Mr. Greengenes suggestion.

Thanks Mr D, I forgot to mention that you can water dip right up to the day of harvest no problem. As to whether it washes trichomes off, I don't really think it does. I use fairly warm water, but if you used cold it might, but I can't say from experience. I do think it's a mechanical thing, so I really swish them around and plunge them in and out of the container a lot.

I've done The Wolf (Harvey Keitel in pulp fiction) thing quite a few times by saving peoples crops that were covered with webbing when they thought it was a total loss. Washes those terrorists right off and plants are pretty and ready for harvest.

I dip by myself, but my plants are fairly small. In commercial grows, I've dipped 5'+ plants with a helper and a trough of water instead of a bucket. One person holds the container and lowers the plant to about horizontal while the other pushes the branches into the trough and washes. That way you're not even inverting the plants completely, so it's easier to keep soil mix in. People make rigs to hold the plants now, I've seen a few on youtube. Seems like the method is gaining popularity.
 

gladysvjubb

Active member
Veteran
If you have a closed room I would just use NO PEST STRIPS. I've been doing this a long, long time. They are not too expensive, they are not messy, they do not take up any room and they are deadly to the bugs. Read and follow the directions. Bugs are not a worry for me and my grow.
 
M

Mr D

The only problem I had dipping them was keeping the medium in the container. Those cheap plastic saucers and tape solved that problem.

I prefer the shower head method because I have a hand held with multiple spray settings. I can use a more forceful setting for the underside of the leaves without damaging the plant.

I like to do this as a preventative before moving a new plant in to the flower room. Years ago I had spider mites and I've been paranoid ever since. Been 20 years since I've seen one indoors but the russets got one of my outdoor plants last season.
 

mr.brunch

Well-known member
Veteran
Whatever you end up doing, I’d say definitely bleach the room and all equipment after this run (as per earlier suggestion) they’re hardy little fuckers who can sit dormant when they need to.
Best of luck.....
I hate spider mites
 

f-e

Well-known member
Mentor
Veteran
That's not spider mite. It's something a bit more juicy. Like Thrips. But you have already been told this.

Get some yellow sticky cards, and catch some. Then you won't be using specific pest solutions, aimed at pests you don't have. Which is terrible.



Edit: Do you notice how the tips of the leaf serrations show damage. Something must of been sucking on them really hard to impede water flow like that. Or it's something crawling within the leaf tissue. Damaging the waters pathways. Causing the damage that's a bit like a K deficiency. There is certainly damage everywhere, but the edges and tips show the most. I would lay a leaf over a torch to see through it's tissue. You could have leaf minors. Maggot like things. Extra veins in the tissue that head off seemingly nowhere, are the bodies of mining bugs. Though anything unexpected needs looking at.


Mining bugs will need a systemic treatment. A drench aimed at fruit tree's perhaps. You may need to trawl through some long lists of allowed pesticides for tobacco and cannabis use.
 
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Stank TaNk

New member
@f-e, I've inspected each plant inch by inch. Used a x100 scope on leaves. I have seen no thrips. I have seen no flying insects in the room. I've used spinosad which in the thrips thread in the infirmary says is particularly lethal to thrips. I have 6 no pest strips. How are these not aimed at thrips if it is indeed what you think I have?



Does these thrip damage here





look anything like the damage on my leaves here?



I mean, doesn't look similar to me. I'm not saying it can't be thrips but it diffidently doesn't look plausible to me. Also the burning on the tips is probably from over fertilization as I had used too much flora nova. I will shine a light through some leaves and take a look though.
 
M

Mr D

No pest strips use Dichlorvos or 2, 2-dichlorovinyl dimethyl phosphate (DDVP) a highly volatile organophosphate.

EPA has classified dichlorvos as a Group B2, probable human carcinogen.A study by the National Toxicology Program (NTP) reported an increased incidence of tumors of the pancreas, mammary glands, and forestomach in animals.

Yeah.... I want to use this stuff around my family and weed.
 
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