QuestionI have a little leaf linden tree next to my driveway.It seems to be producing a lot more sap this year than others, and all of it is laying on the car parked below. I know I can move the car, thats the smart thing, but how long should this continue.The tree is approximately 10/12 years old and seems to be very healthy.
Date today July 24, 2009
I live outside of Philadelphia
Thank you, Ray
AnswerSound like aphids or scale insects. Both will suck the plant juices from the leaves and twigs and secrete a substance called honeydews. Honeydew is high in sugar content and is sticky to the touch. Usually a black sooty mild will grow on the honeydew making everything black and sticky.
You can either spray the tree's foliage or use a systemic insecticide on the soil beneath and the tree will absorb the insecticide through the roots and take the insecticide to the leaves and twigs. Spraying a large tree can be difficult.
Chemical Control - Contact Insecticides Numerous contact insecticides are registered for aphid control. Since aphids are often placed under considerable pesticide pressure in field crops and greenhouses, they may be resistant to certain categories of insecticides. Therefore, if you do not obtain reasonable control, consider rotation to another insecticide. Contact insecticides currently registered for aphid control include: acephate (Orthene), bifenthrin (Talstar), chlorpyrifos (Dursban), diazinon, malathion, nicotine sulfate, pyrethrum, rotenone, resmethrin, and tetramethrin + sumithrin.
Chemical Control - Systemic Insecticides Several systemic insecticides are useful in aphid control. Aphids have sucking mouthparts and are thus very susceptible to pesticides located in the plant vascular system. Some of the systemic insecticides also have contact activity. Systemics injected or applied to the ground are less harmful to beneficial insects. Systemic insecticides include: acephate (Orthene)
Certain persistent insecticides that move systemically in the plant may provide control through the fall. Imidacloprid (Bayer Advanced Garden Tree and Shrub Insect Control) is a newly available systemic insecticide that can provide aphid control on trees for several months following application to the soil.
Since you have tried the spray I would use the bayer product. it will take a week or so to take effect but it has a linger last effect. Here is a web link to this product. http://www.bayeradvanced.com/product/Tree-Shrub-Insect-Control/concentrate.html
Check with your local nursery for the product.
Control the sucking insects and the honeydew will stop.
