Crepe Myrtle Aphid Diagnostic Guide
Crepe myrtle aphid is an important pest of crepe myrtles throughout their range. Aphids use their piercing sucking mouthparts to extract sap from the tender, new growth of plants. Aphid feeding creates distorted/chlorotic leaves, and copious amounts of honey dew in which sooty mold grows on. Honey dew and sooty mold can coat; leaves, stems, and anything else growing underneath affected plants.
Trees at Risk
Crepe Myrtle (Lagerstroemia spp).
Symptoms and Signs of Damage
- Aphid feeding causes curled discolored (chlorotic) leaves.
- Feeding aphids excrete honeydew making the plant sticky.
- A black fungus called sooty mold may be growing on the honeydew.
- Monophagous, only found on crepe myrtle.
- Aphids are slow moving, oval to pear-shaped insects ranging in size from 1/16 to 1/8 inch long.
- Pipe-like protrusions extending off the back of the insect are visible with a hand lens.
- Winged adults have dark tipped antennae and two double-pronged humps on the back.
- Crepe myrtle aphids nymphs resemble wingless adults, but are smaller and have black spikes on their abdomen.
- Overwinter as eggs on hosts bark.
- In spring the eggs hatch and aphids migrate into summer hosts.
- In late summer eggs are laid again.
- Several generations per year.
Early detection is the key in reducing infestations of aphid. Examine areas near the buds and on the undersides of the new leaves for aphids. When natural enemies, like the lady beetle, are not sufficient in keeping the population in check, insecticides are very effective for controlling aphids. Contact insecticides can be used on exposed aphids. Soil applied systemic insecticides are also very effective and can be applied once in the fall or spring to deliver control throughout the growing season.
Other Treatment Practices
Proper watering and the avoidance of heavy nitrogen fertilizer, which promotes succulent plant growth, can help reduce aphid damage.
Soil Application using Xytect 2F
Dosage: 0.1 - 0.2 oz/inch of DBH Timing: Early spring or fall Re-Treatment: AnnuallyXytect 2F$69.60
Foliar Spray using Xytect 2F
Dosage: 1.5 oz/100 gallons water Timing: As pest appear Re-Treatment: As neededXytect 2F$69.60
Soil Application using Xytect 75WSP 22 packets
Dosage: 1 packet treats 48 inches of DBH Timing: Early spring or fall Re-Treatment: AnnuallyXytect 75WSP 22 packets$148.00
Foliar Spray using Xytect 75WSP 22 packets
Dosage: 1 packer/300 gallons water Timing: As pest appear Re-Treatment: As neededXytect 75WSP 22 packets$148.00
Soil Application using Transtect
Dosage: 1 packet/5 – 17 inches DBH Timing: Early spring – summer (as pests appear) Re-Treatment: Annually
Systemic Bark Spray using Transtect
Dosage: 6 packets/1 gallon water (1.5 – 2 oz /inch DBH) trees < 24 inches DBH. 6-12 packets/1 gallon water (1.5 – 2 oz/inch DBH) trees > 24 inches DBH. Timing: Early spring – summer (as pests appear) Re-Treatment: Annually
Foliar Spray using Transtect
Dosage: 1 packet/25 – 50 gallons water Timing: As pest appear Re-Treatment: As needed
Soil Application using Lepitect
Dosage: 0.2 – 0.4 oz/inch DBH Timing: Begin applications early summer, just before eggs hatch. Re-Treatment: Follow up applications can be made at 30 day intervals as needed.Lepitect$59.20
Foliar Spray using Up-Star Gold
Dosage: 10.8 oz/100 gallons water Timing: As pest appear Re-Treatment: Applications can be made at 30 day intervals as needed.Up-Star Gold$33.33
Foliar Spray using Orthene TT&O WSP
Dosage: 10 2/3 oz/100 gallons water Timing: As pest appear Re-Treatment: Applications can be made at 30 day intervals as needed.Orthene TT&O WSP$15.20
Foliar Spray using Tengard
Dosage: 4 oz/100 gallons water Timing: As pest appear Re-Treatment: Applications can be made at 30 day intervals as needed.Tengard$59.77
Aphids are an easily controlled pest with Xytect™ and any of the products described above.
A Diagnostic Guide is designed to help you identify a pest issue and management solutions. Always refer to product label for all rates and approved uses. Some images courtesy forestryimages.org. Use of the images does not imply endorsement of treatments by forestryimages.org