There is a species of aphid that can infest crapemyrtles, but the white insects pictured are not aphids, they're scale (Crapemyrtle Bark Scale). The population pictured has probably been established for a couple years now. If any white scale look-a-like insects are moving up and down the trunk, they are not scale: they are beneficial ladybug larvae that are eating the scale. They look nearly identical, but are larger than the scale adults, and will walk whereas the scale do not move once they settle-down to feed after hatching.

If you decide to treat the tree with insecticide, use something that spares these predators so they can continue to reduce the population. We've seen examples where scale-infested crapemyrtle trees are being effectively managed by the ladybugs alone. You can learn about this scale insect's life cycle on the page above, which links to our Introduction to Scale Insects page that includes management options. Some insecticide options will require the hiring of a certified pesticide applicator based on pesticide restrictions in Maryland law.

The tree is in no immediate danger of dying; trees can live with a scale population for years and suffer no apparent ill effects, though if they are weakened by heavy feeding and then exposed to another overlapping stressor, like prolonged drought (as with last year) or winter cold snaps (also last year), then canopy dieback might be more likely.

Miri

So is the insect in the attached video the larvae of ladybugs?  

Unfortunately this platform does not accept video files, so we can't view your attachment unless you share a link to it hosted on another site. The species of ladybug that is feeding on the scale is not available for purchase, but they can be encouraged by avoiding pesticide use (including any aerial mosquito spraying of the yard) and cultivating a mix of flowering plants so that beneficial insects like these have alternate food sources and habitat to support them staying in the area.

Miri

Good morning Miri,

The photo wasn't received; can you please try attaching it again? (You can try pasting it into the body of your reply if attaching the file doesn't work.)

Yes, there are many kinds of ladybug larvae, and they don't all look alike (one of the most familiar to people is the black and orange "alligator"-looking type), and the species in this case looks like the scale it is feeding on (likely a camouflage tactic). There are two photo examples of one of these larvae, and a link to a blog post about them, in the Crapemyrtle Bark Scale web page we linked to earlier.

Miri

Sent from my iPhone



Yes, the photo came through that time, and yes, that looks like the type of ladybug larva that we were talking about (the one that eats Crapemyrtle Bark Scale).

Miri

Miri, 

PS - I was using an insecticidal soap to kill the “bugs” crawling up and down the tree, so hopefully wasn’t doing too much lingering harm. 

Insecticidal soap can kill insects on contact, but the residues (once dry) have little to no impact on them. (A bonus for avoiding damage to desirable insects like these, and a downside for the spray having any efficacy for very long after you apply it.) Since scale insects are largely protected by their waxy "shell" that covers their bodies for most of their lives, a topical spray like insecticidal oil often doesn't have much impact on them. (A topical spray that could is horticultural oil, applied at the dormant rate in winter when the beneficial insects are not active.) This information can be found on that web page. You can also learn about Crapemyrtle Aphid (which is yellow-green in color, not white, and much smaller than the adult scales and these ladybug larvae) on the linked page. These aphids live on the undersides of the leaves (not on the bark) and tend to blend-in more easily compared to the scale.

Miri