I hate Leafhoppers, there I said it. They can devastate a specimen Japanese Maple in a matter of days. They make all other native garden pests look like a gardeners best friend. Here is my experience with the miniature sized terror that packs a big punch... Leafhoppers are 1/8 to ½ inch long with an elongated wedge shaped body when viewed from above and a triangular cross-section. They vary in color, but the variety that invaded my garden were green with orange eyes. The mature bugs have wings and can fly. The hatchlings resemble the adults, but are much smaller with no wings or small developing wings. Unlike the slow moving awkward aphid, the leafhopper moves very fast and will try to hide from you by moving sideways around the other side of a twig, drop suddenly, or even fly. It takes determination to find one and they are not always on the tip of new growth like an aphid. They attack the leaf stalk, new stems, and even last year’s growth in some cases. Like aphids, they suck sap, but if they only stopped there… In addition to sucking sap, they release a toxin that causes the leaf or whole stem to fail. Instead of laying eggs on the surface, leafhoppers inject them into the stem. The beginning signs of damage are discolored leaves. Depending on the variety, the leaf may start to turn yellow, red, or orange starting at the tips. Then the discoloration turns brown and within a few days several leaf pairs from the branch tip will turn dry and straw colored. The damage will make you think your maple was hit by a heavy frost or may make you believe the tree was stressed by heat or drought. For example, a grower in my area with decades of experience growing rare and unusual trees and shrubs thought his field of Japanese Maples was devastated by a late season frost. I asked him if he saw any tiny green fast moving lite green bugs on any of his trees. When he said yes, it took a lot of convincing for him to believe it was not frost damage. I invited him to check out the damage the leaf hopper did to my 'Goshiki Shidare' (I am by Lake Erie so the warm light lake breeze protects my area from late season frost). After seeing my tree he left my house to go spray his entire field. (this is the first year our area ever experienced leafhoppers) It’s my understanding that the leafhopper that attacked our area is native to the Gulf States. After doing research, I learned that they have been found as far north as Chicago in the Midwest US. They tend to ride the strong winds out of the Gulf up to the Southern part of the Great Lakes region. Which explains the adults, but I think our wet mild winter allowed any eggs they laid last year to overwinter and hatch (usually our harsh winter would cause any eggs laid to fail). I sprayed lime sulfur spray in late winter that usually solves all bug problems with my maple collection. But since leaf hoppers lay eggs under the bark, the lime sulfur spray did not treat the leafhopper eggs. It seems systemic and even pesticides are highly effective against the leafhoppers. The problem is spotting them before the tree shows sign of damage and killing the leafhopper before they kill the leaves and this years or last year’s growth. I am not one who had or wanted to spray regularly, but now I have to if I want a healthy looking tree. To some, this maybe old news (like someone declaring man figured out how to fly as if it were news to this modern world of jet travel). But to me and many growers in my area this is a new pest that no one knew about. Once we figured out it was a threat, most of the damage was already done. I guess the lesson learned is to expect the unexpected in this time of changing climates and strong weather patterns. Now we not only need to be familiar with the native pests, but we need to become familiar with the non-native pests brought in by strong winds or even plant material brought in from other regions. I guess that is where sharing information is more important than ever if we want to be successful in growing plants in today’s world. My lesson learned, if you see something out of the ordinary, investigate it and don’t turn a blind eye. If your plants are showing signs of stress, take a closer look at what’s causing it. Don’t make assumptions based on your past experience when assessing the symptoms, then miss-diagnosing the problem, and prescribing the incorrect treatment. Learn from my mistake.
Great post JT, thank you for the very detailed information. I think I have seen some hoppers around here and there, but will definitely go over my maples - and other plants - very carefully this summer. You mention that the sprays - obviously - don't work. Is there anything that you have found to be at least somewhat effective with this bug? For situations where the damage is already done, do you simply cut back to healthy wood and hope for the best? Any other insight or thoughts you care to share would be greatly appreciated!
Thank you for taking the time to read it, I can be a little too wordy at times :-) We are still learning what is the best approach to treating the problem. With an infestation, you need the quickest possible solution to limit further damage. We found using a pesticide containing the chemical Merit (Imidacloprid) is highly effective at killing the leafhopper. A possible long term solution is a systemic that contains Merit like Bayer 12 month Tree & Shrub. If you live in an area with Japanese beetle outbreaks, then you may already be using this product or something similar. The failed leaves that were bitten at the stalk, I pruned the leaf off at the stalk and waited for secondary buds to form. This proved to be effective on mature wood. Young stems from this year’s growth that was bitten failed. The failed stems from this year’s growth failed completely and needed to be pruned off. Last year’s growth came back after leaf pruning the dead leaves. A few weeks later new healthy growth pushed from newly formed buds. Only about 20% of last year’s growth needed to be pruned because it failed completely after being bitten. Linearilobum and Matsumurae varieties seemed to be unaffected by this pest. Shirasawanum seemed to stand up well with the exception of newly formed leaves at the tips failed. Many palmatums stood up well with the exception of ‘Coral Pink’, ‘Kawahara Rose' and ‘Geisha’. Dissectum varieties seemed to be hit the hardest in my friends growing field and in my garden. The hardest hit were 'Goshiki Shidare' and 'Hana matoi’. But close by ‘Baldsmith’ and 'Tamukeyama' were not affected at all.
What species of leafhopper do you think this is, and did you get any other pics of your pest? Every summer we see potato leafhopper here in Ohio, and it regularly attacks maples and many other species of ornamentals and vegetable crops, but I have never seen damage like that from potato leafhopper. The nymph in your pic looks like it could be close to PH, but the adult pictured doesn't even look like a leafhopper at all, so you have my curiosity piqued.
I had leafhoppers on my vegetables.They were moderately represented and did major damage.They were a light brown or beige color and smaller than an eighth inch.I did manage to catch the odd one but they hop just like grass hoppers with surprising velocity for such a little insect.In desperation I didn't want to use toxic chemicals for obvious reasons and the fact that I am certified organic.so I resorted to neem oil.It works like a charm but requires continued vigilance like anything else.After three applications at regular 5 day intervals I seem to be ahead of the game.IMO the use of noxious chemicals that are not omri listed should be banned everywhere.It is interesting to me that those with education and knowledge in this forum promote the use of deadly substances.
Trento, welcome to the forum and thank you for sharing your experience. From my experience, I find Neem oil is effective, but its not an option when treating my Japanese maples. It causes severe leaf damage and can kill new tender growth. It is also interesting how quick you conclude that members promote the use of deadly substances, since this is your first post after all.
I have had a huge probelm with Leaf Hoppers on my lawn. Terrible. Lawn looked like is had never been watered. But, I found what seems to be a solution. I put on Bayer "Season Long Grub Control plus Turf Revitalizer" using a spreader and hoppers almost all gone. After a second application 2 weeks later - no hoppers. I like it 'cause it seems less likely to harm bees and other nice insects that fly around the yard and it has some fertilizer in it. Much better than spray insecticides - that didn't work well anyway. Jim
