Insects, Mites and Disease Observed May 11 – 18, 2020

Over the last week I have come across the following problems on fruit trees at several locations in the Fraser Valley. Please reply to this list with anything you have seen on fruit trees in your area. In particular, if you are using Codling Moth traps please let me know when you make your first capture. It would also be help if you include your geographic location so I can develop a profile of the variation across the South Coastal area. If you see a problem that you cannot identify send me a picture and I will try to help you. 

Insects and Mites

Ambrosia Beetle – serious infestation in Italian Plum. These trees are growing well but a number of shoots did not leaf out. Inside the dead shoots were adult female beetles, lots of eggs and healthy fungi on the inside of tunnels. The likely reason for this infestation was flooding stress last year as this area is not well drained.

Apple Leaf Curling Midge – a heavy infestation on the new leaves of trees growing in 10 and 15 gallon containers. These trees had a high level of infestation in 2019.

Pear Blister Mite – infestations in several location showed up 2 – 3 weeks after leaves emerged. In one garden only the top branches infested because the sprayer used to apply dormant oil was malfunctioning and that part of the tree was not treated.

Budmoths and friends – Budmoths seem to have completed their life cycle have been replaces by a collection of Fruit Tree Leafrollers, Apples and Thorn Skeletonizes and others.

Currant Sawfly – Red Currant infested with tiny larva. These critters are very selective and will stay on the currant until they run out of leaves.

Diseases and Disorders

Apple Scab – early stage

Blossom Blast of Pear – Pear flower clusters turning black. This is appears to be bacterial blast (Pseudomonas syringae), have not done a lab test. It may also be boron deficiency. Only a few blossom clusters affected in both in ground and container grown pears. This is not Fire Blight.

Blossom Blight (Brown Rot) – Cherry and plum not grown under rain cover affected. We did have a rain fall during bloom. All this fungus requires is 6 – 7 hours wet at 7°C or 4 hours wet at 16°C.

Powdery mildew – primarily on apple but also on quince


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