Plum pest - Ask Extension
Hello!
I live in northeast denver, Park Hill, and I have planted a Stanley plum this year in the front yard facing west. It gets full sun with late a...
Knowledgebase
Plum pest #413320
Asked July 11, 2017, 12:39 AM EDT
Hello!
I live in northeast denver, Park Hill, and I have planted a Stanley plum this year in the front yard facing west. It gets full sun with late afternoon shade. I've noticed some shot gun type holes in a number of the leaves, seemingly new growth at the top, but elsewhere as well. The holes are various shapes, with browning on the edges. It receives adaquate water from irrigation below the tree. I can't tell if this is an insect or some bacterial disease. A diagnosis would be very helpful! Thank ou in advance.
Best,
Casey
Denver County Colorado
Expert Response
Casey,
Those holes are angular, not round, so it is beetle damage not a disease, and, unfortunately, probably Japanese Beetles. They have become a very damaging pest in the metro area in recent years and feed on many different species including plum.
Early in the morning and dusk are the easiest times of day to spot them. They are relatively large, shiny green and brown with white spots around the hind end (actually tufts of hair). Once you see one, you won't mistake it for anything else. If you can, knock them off into a container of soapy water to drown.
Here's a fact sheet with more details from CSU Extension: http://extension.colostate.edu/topic-areas/insects/japanese-beetle-5-601/
Those holes are angular, not round, so it is beetle damage not a disease, and, unfortunately, probably Japanese Beetles. They have become a very damaging pest in the metro area in recent years and feed on many different species including plum.
Early in the morning and dusk are the easiest times of day to spot them. They are relatively large, shiny green and brown with white spots around the hind end (actually tufts of hair). Once you see one, you won't mistake it for anything else. If you can, knock them off into a container of soapy water to drown.
Here's a fact sheet with more details from CSU Extension: http://extension.colostate.edu/topic-areas/insects/japanese-beetle-5-601/
