And I see you've gotten your answer - Citrus Leafminer. You can Google CLM to see about treatments. The safest would be Spinosad, and you can add Volk Oil to it, if your temps are below 85 degrees (if above, do not use a hort oil, as it will fry your leaves).

Patty S.

like fruitnut suggested in that post, you can inspect each leave, usually on the underside, you can see a small worm-like larvae, scratch or squish it.

Yeah, I got my answer. Thanks. I looked at my leaves yesterday, but the culprits appear to have moved on in life. In the future I will know what to look for and I will probably remove them by mechanical means (finger- and thumbnails are mechanical right?) rather than chemical. I only have a few citrus trees and all are small enough, at the moment, to inspect by hand. So unless they become a huge problem, I will squish them and deal with some slightly deformed, but functional, leaves. Now... on to another question in a different post!

Trying to remove via mechanical means is not realistic. And, you don't want to remove the affected leaf, as your young trees need those leaves, deformed or not, to conduct photosynthesis. Much better to use a spray every 3 weeks of Spinosad, and if your temps permit (under 85 degress), add Volk oil to make it last and smother the little CLM moth. Yes, this is mainly a cosmetic issue for more mature trees, but for very young trees with small, tender canopies, you really should treat right before and during your CLM season. For us here in Calif, we have CLM once a year, starting in early to mid-July. We treat through about September/October. Some folks have used Imidicloprid, but there have been reports of some resistance to this product, and besides, Spinosad is much safer for both you and other bveneficials. Just be sure to spray in the evening, and avoid blossoms to protect your bees.

Patty S.

The most important thing for CLM control is to start early.

Begin your spray regimen at the first leaf flush in the Spring; the CLM is there at that time, but in very small populations. If you wait until you see the damage, usually the second flush, the population is larger and nearly impossible to stop before the damage is done.

Actually, you should check with your local extension office to find out when Citrus Leafminer is prevalent in your area, so you know exactly when to treat. For example, here in California, we do not see Citrus Leafminer until about mid-July. We only have one outbreak of CLM a year, and we usually start spraying with a combination of Spinosad and Volk or Neem Oil at early to mid-July. It is actually recommended to spray every 3 weeks, with a maximum of 6 applications. Do no use hort oils if your temperatures exceed 85 degrees, as you will severely burn your new growth. You want to avoid spraying Spinosad during bloom time, and spray in the evening, as Spinosad is moderately toxic to honeybees. So, for me, no sense in using Spinosad with my first spring flush, as I do not have issues with CLM at that time, and do have plenty of blooms, so I try to spare my honeybees. So, better to check with your extension office, first, to find out when you should treat properly, so as to lessen the impact on our honeybees and other beneficials. And, I only treat my young trees, and only spray new growth. I do not treat my larger, established trees. Just not necessary. Less pesticides and least impactful is always the better way to go. That is the concept behind Integrated Pesticide Management (IPM).

Patty S.

Here is a link that might be useful: UC IPM: Citrus Leafminer

Eahamel, I meant to address your post. Your cycling will work just fine. Very similar to our recommendations here in California. We combine the two products and spray a little less often. For me, that makes it a little easier since I have over 100 citrus trees, and it's just me doing the spraying :-) And, your timing may be different than mine in California, depending upon when you first see CLM. Some areas of the country see CLM in both spring and later summer/early fall. We are at least fortunate to only see it in mid-summer.

Patty S.

Patty,

According to the citrus entomology guru at Texas A&M Citrus Research Center, the CLM is definitely there at the first flush, only in small populations; and if you treat at that time, you will likely not have the main flush, being the first time you notice them.

I don't know for sure; because my experience in California pre-dates my expert advice; and I don't have to deal with that bugger here in Guatemala. We do, however have the Omnivorous Leaf Roller (OLR) and the cycle is the same; for that we treat at the first flush, not when we first see the damage.

Well, that's not what we have experienced with CLM here in California. I carefully check my first flush. Zero evidence of CLM. Nothing at all. Zero mining. According to what I have been told here in California, we really don't see it until July, different than the gulf states I will check again, but this is the current line of thinking and treating CLM here in Calif. Every grower I know, and that's a few for sure, do not treat until July. If I treat the beginning of July, I have no issues with CLM. I just missed that window, and this year I have a very small amount of affected leaves. Nothing like last season, when I tried to not treat. That was disastrous as I had all very new and young trees, and I have extremely heavy pressure, about 99% affected new leaves. Never again with young trees will I not treat. I'll re-check with the UC folks and see what they say (I know you don't care for them, but they are the resident experts here in California.)

Patty S.

Patty,

It's not so much that I don't like the resident experts; it is that they are out of touch with the growers. Unlike Texas A&M, whose experts are graded heavily on their grower connections, in California the growers tend not to trust the Univ. experts; and the Univ. experts tend not to know what the growers are doing. If I were looking for advice in California (and I did that for 2 weeks in April), I would drive around the groves and talk to the growers. Having said that, commercial growing is very unlike garden growing and the solutions to problems are so often not the same.

I don't know that to be true, John. What California citrus growers have told you they don't trust the folks at UCR? I certainly respect any commercial grower and their advice, and do talk with the folks at Clausen's quite a bit. They've been around here in the N. San Diego county area growing citrus, either a commercial crop or growing trees for wholesale/retail for over 3 generations. They work closely with UCR and don't have anything bad or disparaging to say (and they certainly do not hold back on their opinions.) And, you're right - our home hobbiest issues are somewhat different than how a commercial grower would manage their orchards for sure, but I feel very comfortable with the advice coming from UCR. Every commercial grower I've spoken with or have a relationship with work closely with UCR and have no issues with them that I am aware of. That would include Duarte, Citrus Treesource, Durlings, and Clausen to name a few.

Patty S.

Leek, this doesn't add much to the conversation (which I haven't read yet but am going to), but just wanted to jump about your comment regarding 'mechanical' controls. Horticultural oils ARE a form of mechanical control, as they work by either suffocating pests or by repelling them. Neem oil can qualify as a mechanical AND an IGR (insect growth regulator).

OK....carry on, everybody. :-)

Good point, Rhizo. John and I are off track on this thread. Rhizo is right - Neem Oil is an excellent choice, and I prefer to use this if I have it (currently using up the Volk Oil I have, which is why that's my choice at the moment.) Again, never apply any hort oil when temps exceed 85 degrees to avoid sunburn, which can end up damaging those new leaves worse than the CLM. John and I will carry on this conversation outside your thread if need be, sorry for commandeering it!

Patty S.

No worries, I got my answer(s) early on and was satisfied. The rest was just... umm... I wouldn't call it icing, but... at least very mildly entertaining to watch?

I fear that Neem Oil won't work for me if temps can not exceed 85F. This summer has been very mild for us. Ironically while the rest of the country, even the northern states, has been baking at 100F+ temps, the highest we had was about 98F and on average our summer has been about 92F this year. Last summer and the summer prior it was about 96-98F averaged I think.

Thanks again. Now that the intermission is done... FIGHT!

Oh, dear, we're not fighting, Leekle. John and I are friends. Just have a difference of opinion about the UC folks, who were admittedly not very helpful when John came knocking at their door for some help and education. He did find that assistance with the folks at Texas A&M, and glad he was able to get his questions answered, as he has quite the facility going on in Guatemala. I respect John's opinions and his large undertaking.

Patty S.

Hey, Patty....I wasn't hinting that your discussion should be taken to ' the back room '! Sometimes, differences of opinions can turn rancorous...usually because one person HAS to be right, above all reason. But when disagreements are polite, they can be really educational for us by-standers. This thread is interesting.

I could be accused of commandeering a thread or two myself and if I ever get bossy, I hope that someone will just clobber me!

Yes Patty, I kind of figured, but somehow "DIFFER OF OPINIONS!" just doesn't have the same ring to it.