Our white pine tree (approximately 7' tall) was planted in a mostly shady...

Asked October 6, 2014, 10:40 AM EDT

Our white pine tree (approximately 7' tall) was planted in a mostly shady area on a slope by a landscape profession in Spring 2014. Starting about a month ago, its needles began to yellow and then turn brown and drop off. We took several yellowed needles to a diagnostician at Homestead Gardens, and he said the needle drop is caused by "late blight" and recommended Daconil (which we have applied twice). A closer examination a couple days ago of a small branch of the tree revealed small black bugs, and we do not know whether they are the source of the problem or a secondary issue. The soil is heavy clay, but the landscaper added soil amendments prior to planting. The tree was watered consistently over the summer. The attached picture shows a soft pod attached to one of the branches, as well as one of the suspect bugs and a sample of the yellowing needles. Is there hope for this tree?

Anne Arundel County Maryland trees and shrubs white pine

3 Responses

Our entomologist has not had a chance to see this photo yet, but our pathologist sees no signs of disease in your photo. We're leaning toward environmental problems that have affected the roots. Please take this opportunity to attach some additional photos, one from a distance and any other symptoms that you consider to be significant.
By the way, the soft pod is actually a praying mantis egg case. You should place that twig outside, perhaps wedged into some of the branches of the tree it was found on. We brought one into the office last year where the inside warmth prompted the eggs to hatch and we had several dozen tiny praying mantids crawling around the office.

These are the additional three pictures you requested of our white pine trees. Thanks for the information about the praying mantis pod. We have returned the branch containing the pod to the pine tree. Don't want all those baby mantids running around the house!

We'll look forward to your advise as to whether we should take any further action to save our tree.

Thank you for the follow-up photos. White pines naturally lose old pine needles (the interior needles) every fall--being "evergreen" not withstanding. This is why they have a thick layer of mulch under themselves--they self-mulch with their own needles. You'll notice this needle yellowing this time of year as you observe other white pines in your area. Some years there is more needle-shed than other years. Because the needle yellowing is so evenly spread out in your tree, it is likely this phenomenon is what you are seeing on your white pine.

(The small black bug cannot be identified from the photo and there is no pine problem that would be related to any similar bugs. We are familiar with "Late Blight" on tomatoes, but do not know of any disease with that name on pines.) e