Past, Present and Future: Walking along the Blue Marsh Lake

Yesterday while walking along the Blue Marsh Lake in Berks County, I was much encouraged by the non-native invasive plants I saw with disease and insect herbivores. Two species I expect to be extinct on this trail in the next several years. The third species will take a few years longer. The best part is that we did nothing to cause the changes including introducing no non-native biocontrols.

The good:

Ailanthus altissima Atteva aurea was in 2 distinct populations separated by @ mile and at least 3 age classes were present. This means that they have a healthy active breeding population. I saw the claw shaped leaves signaling the beginnings of Aculops ailanthii infestations. There were several trees showing wilt and chlorosis. I am not yet sure the significance of this. Trees heavily infested last year with A. aurea and A. ailanthii appeared to be showing the effects of last years infestation by showing mild chlorosis. There was also herbivory from unknown insects ranging from mild to severe. Many plants had malformed leaves that looked crumpled. I am not sure the cause of this. There are also many dead trees which were probably the result of phytopathogenic fungi. I will start investigating this in about 2 weeks when the symptoms are more pronounced.

Drill and fill using glyphosate on Ailanthus appears to have second year effects. Trees which were injected to trace fluid flow within the tree are showing added damage this year. Im not sure why but will repeat part of this experiment next week.

Lonicera morrowii Chlorosis and browning of leaves is epidemic the entire length of the trail. I hope the next couple years will see the end of this plant in this area as there is dieback to go along with the disease.


Lonicera maackii There are some signs that the disease attacking L. morrowii is beginning to attack this plant.

Lonicera japonica Some plants with chlorosis.

Broussonetia papyrifera Showed continuing signs of disease on the leaves.

Elaeagnus angustifolia At least one plant showed heavy chlorosis.

Rosa multiflora Two different diseases were apparent acting on separate and the same plants: a yellowing/chlorosis and rose rosette disease along the whole trail. Dieback is extensive. I expect this plant to be eradicated in next several years from this stretch of trail.

The bad:

Dipsacus sp. and Centaurea biebersteinii were healthy and much larger than this time last year.


Poison ivy, Toxicodendron radicans, a native plant, is flourishing this year with leaf clusters larger than dinner plates on some trails. I have had mild to moderate dermatitis from this plant most of the last couple months and I am careful. So be careful and read the accompanying article on poison ivy tips.

Atteva aurea adults appear to be generalist nectar feeders preferring compound flowers as this is a very efficient feeding strategy. Their bright colors (aposematic coloration) and lack of evasive flying suggest that they are noxious or toxic to most predators. My guess is that the A. altissima leaves they consumed as larvae leave chemical defenses in their tissues in a way similar to monarch butterflies.

Richard Gardner lives in Upper Bern Township. His passions are ecology and history because with these we are able to understand our world, our place in it and our future.