Apple trees in residential backyard
Hi. We bought a rental home and the previous owners have grown and taken care of three really beautiful and very fruit bearing trees. I think they have been groomed well prior to my ownership and they are shaped in a very umbrella like shape and very tall. This last year the apples all had small worms or maggots in them and we tossed 95%. Like to know what poison or services I should employ to get harvestable fruit from them this year. Currently there are new buds beginning to just now open on the branches . Thanks for any help
Without seeing the insect, larvae, or damage to the apple it is not possible to identify the specific insect damaging your apples. Below is the link to the Pacific Northwest(PNW) Insect Management Handbook, “Managing Insects in Tree Fruit”. In the section for Apples there are listed 28 insects that harm apple trees. Not all would attack the fruit or have the appearance that you described, but several would at various stages in the insect’s life cycle.
In addition to those listed, there is a new invasive insect from Asia (China, Korea, Japan), the Brown Marmaladed Stink Bug (BMSB). The BMSB female lays her eggs in variety of fruits and vegetables, to include apples. Here is a link to a USDA paper on the BMSB with photos of the damage they produce in apples.
Here is an additional link to an Oregon State University Extension Circular (EC631) that will provide information on “Managing Disease and Insects” in your trees. This Circular lists Chemical that can be used to control the insects and diseases. It also provides a annual spraying schedule for applying the chemicals
Some of the sprays listed on the recommended annual schedule are for various damaging insects. Only those sprays that have the square with the ‘H’ inside are available to the home gardener. If you decide to do the spraying, be sure you follow all directions and warnings on the package label.
There are several of the larger nurseries, as well as commercial spraying companies, in the Albany / Corvallis / Philomath area that provide spraying services. As commercial sprayers they have many more products to use in controlling diseases and insects in your trees.
You will see in EC631 that it is the law in Linn County to spray your apple trees. Most of Oregon’s largest fruit producing counties have this same law, as a protection for the commercial growers in Oregon’s multi-million dollar orchard industry.
Thank you for sending in this very timely question to “Ask an Expert”. Good luck with your apples in 2018! If you have a problem this year please bring samples of the larvae and damaged apples to your county extension office so we can identify the insect and narrow the spray to use on it.