Lace bugs

Every year lace bugs practically ruin my Piers..I spray with orthenex and still they seem to get to the leaves. It is in shade....any suggestions???????

What is a Piers?

What do you mean by lace bugs. Can you be a little bit more specific or can you post a photo please?

Well I meant to say Pieris! Pieris Japnica. It is tiny little blacks dots on the underside of the leaves and then they turn yellow. Usually they get to Pieris when it is in too much sun, but this is not in sun.

Poor you. I learned the hard way too that chemicals usually make the situation far worse for a multitude of reasons. Interestingly enough, one of the major reasons why chemicals generally are ineffective in this situation is because they are non discriminatory and kill off all the "good bugs" that are far more effective at keeping the lace bugs in check than you and me with our cans of orthene. The “good bugs” work 24/7. By the way, those back dots you will see every where are actually the excrement of the lace bugs and the cast skins from developing nymps- eew gross.

Couple of things you can try. The nymphs don't fly so go and take your garden hose and attach a nozzle to it that you can blast the plants with. That high pressure blast of water to the entire plant paying particular attention to the underside of the leaves can knock many right off the plant where most can't get back up on the plant so they will die or become prey to other bugs.

Some people use insecticidal soaps to control them but I'd go for a horticultural oil. This should take care of quite a few of the lace bugs leaving the "good bugs" that eat the "bad bugs". Anyway, make sure you apply the oil to the undersides of the leaves. Do this after the plant has been "hosed" and has dried off.

If you are going to try a chemical again (not recommended by me), find a product that has Pyrethrum in it as this is not as lethal to the "good bugs" that keep lace bugs in check. Pay particular attention to the underside of the leaves.

There is a lifecycle to lace bugs and timing is critical.
From this site-
http://ohioline.osu.edu/hyg-fact/2000/2150.html
"The azalea lace bug (an example of a lace bug that attacks evergreens) overwinters in the egg stage. The eggs are partially inserted into the leaf tissues along the midvein and are covered with the resin-like excrement of the female. The nymphs hatch in the spring, usually mid-May, after the danger of frost is over. They feed in small groups on the under surface of leaves and molt five times before becoming adults. The adults mate and lay eggs for a second generation by mid to late-July. Often there is a third generation in the late summer and early fall. The andromeda and rhododendron lace bugs have similar life cycles." It is the nymphs you want to get.

Also from this site-
http://ohioline.osu.edu/hyg-fact/2000/2150.html

Control Tactics
Plants that attract lace bugs should be monitored early in order to determine if an infestation is building. Elimination of the first generation of lace bugs is necessary if visual damage is to be avoided. Existing spotting and yellowing of leaves will not disappear once the lace bugs have been controlled.

Option 1: Cultural Control - Planting Site Selection Most lace bugs seem to prefer bright, sunny areas. Plant lace bug susceptible plants in shady areas of the landscape. The azalea and rhododendron lace bugs are rarely a problem when their host plants are in heavily shaded areas.

Option 2: Cultural Control - Syringing Use a hard jet of water from a hose to dislodge the young nymphs as they hatch in the spring. The tiny nymphs often die before they can find their way back to suitable leaves.

Option 3: Biological Control - Encourage Predators Naturally occurring green lacewings, mites and assassin bugs attack lace bugs. However, these predators often arrive after considerable damage has occurred. In order to conserve these beneficial natural predators, use syringing or one of the insecticidal soaps instead of standard insecticides.

Option 4: Chemical Control - "Soft Pesticides" The insecticidal soaps are useful if contact with the nymphs is made. Be sure to cover the underside of the leaves where the nymphs are feeding. Additional applications may be needed to control nymphs hatching out of eggs laid late or if re-infestations occur from surrounding landscapes.

Option 5: Chemical Control - Standard Insecticides Over-the-counter products include acephate (Orthene), carbaryl (Sevin), chlorpyrifos (Dursban), malathion, and Rotenone plus Pyrethrum. Professional applicators can also use azinphos-methyl (Guthion), bendiocarb (Dycarb, Ficam), bifenthrin (Talstar), cyfluthrin (Tempo), dimethoate (Cygon), disulfoton (Di-Syston), fenithrothion (Pestroy), or permethrin (Pounce). Be sure to check each product's label because not all lace bugs or host plants are listed on each label. Make applications as soon as the eggs hatch in the spring, usually mid to late-May. Monitor the plants and repeat applications if re-infestations occur.

I have both rhodos and azaleas here and I had this problem several years ago on my Rhodos. I purchased an infected plant and didn't know it. I most probably had a different lace bug than what you have attacking your Pieris but both of our plants are evergreens so control should be similar. It was enough to make me want to scream and I was itching to use chemicals because they seemed like the quick fix so I did and got hit ten fold. It's been too long but I am relatively sure I finally found info on line about knocking them off the plants with my garden hose and then I went with Neem Oil a few times and that took care of the situation. The following year I got out there right after the last frost and started applying horticultural oils right out the gate before I could even see any activity and I kept it up. I had to replace a few plants that were just unsightly but the others were fine. I think I went with the hose and the horticultural oils again the next spring just to be on the safe side and I routinely hose down the undersides of my rhodos and azaleas now out of habit.

MANY, MANY THANKS...YOU ARE A WEALTH OF INFORMATION!

Tee he... No that caron who posts here regularly is the wealth of information as she is actually educated in this arena. I am nothing more than the trial and lots of error byproduct of someone who has bought a lot of plants and been repeatedly and systematically attacked by everything under the sun and then some. Sometimes it's enough to make me want to go postal particularly when I lose plants as I start having nightmares of dollar bills with wings lifting plants out of my ground here and flying off to plant heaven with them.

It's not good for you, but I'm glad to know I'm not the only one battling these! I asked what they were on a thread recently, then discovered on my own later. I haven't been able to find something to really get rid of them tho. I must use something other than trying to spray them off with water. There are just too many to do that. I used the insecticidal soap, but not sure that worked. I got a couple of books from the library the other day and did read that a citrus spray will work on them. I had already been trying my GardenVille Anti-Fuego mixture on them so maybe that will work. They are usually just on my lantana but found more things this year. :(

Have you tried Neem horticultural oils yet?

I haven't. Can you suggest a product name? I try to stay as organic as possible, but almost have no choice when they are destroying an entire plant. I only use a spray on the plants that are not a butterfly host plant.

Try this-

http://www.biconet.com/botanicals/ashdso.html

Thanks! I'll see if they have something I need. I need to learn more about how and when to spray to kill those that overwinter.