What’s Happening to the Trees? Lecture Recap

On Thursday, October 15th the Orleans Conservation Trust (OCT) held its second to last lecture for the year at the Orleans Yacht Club. Ken Gooch, For
est Health Program Director for the state of
Massachusetts, fielded many questions during his hour long lecture pertaining to the current problems forests are facing, especially pertaining to invasive species that have been found in the state.

The first species in the presentation was the Asian Longhorned Beetle, a problematic species because they are generalists and go after many species of trees. The presentation began with an identification lesson, pointing out the differences between the Asian Longhorned Beetle and the native Whitespotted Sawyer. While both have long, looping antennae, the Sawyer has a distinctive white spot on the middle back, the Longhorned Beetle having many spots. Furthermore, the species emerge at slightly different times during the summer.


Another species of concern is the Winter Moth, a non-native species that defoliates many different types of trees. A form of control currently being used in the United States, including the state of Massachusetts, is using a natural predator taken from its home environment. Cyzenis albicans, a fly species, has been released and will hopefully keep the population of winter moth in check. The fly, also nonnative, lays its eggs in the eggs of the winter moth and the young flies eat the winter moth larvae. Research had been conducted on the fly to ensure it would only go after the targeted Winter Moth species.

The Cynipid Gall Wasp, another non-native, is wreaking havoc on local Black Oak populations of both Cape Cod and Martha’s Vineyard. Infested trees exhibit die back and defoliation and show small entrance and exit holes where wasps have burrowed. While trees don’t often die from the wasp, they can become weakened and unsafe.

The Woolly Adelgid has been causing problems on hemlock species. The adelgid, while small itself, lays large, white eggs sacs that are obvious at the base of hemlock leaves. Once they young emerge they predate the hemlock they were born on and then move on to lay eggs on other trees. One form of control that was attempted was a non-native bug known to be a natural predator of the adelgid called Laricobius nigrinus, but it is possible the cold winter knocked the bugs out.

While there are many non-native species that are proving problematic in our forests due to the lack of predators, there are some native species that are causing problems as well. This may be due to the spraying of insecticides for other invasive species, thus removing natural predators and allowing a boom in populations. Furthermore, abiotic factors such as storms also cause tree mortality.

The overall outlook of forest health might be grim, but many people are working on the best way to protect trees not yet infested and best management practices for bugs already found in the area. Furthermore, introduced predator species are well thought out and researched before release in order to decrease potential negative outcomes. One way to help is keeping cut wood local in order to stop the movement of these pests from place to place.

Our final lecture of the year will be held on Thursday, November 19th at 6:30 and is entitled “Sea-Run Fish of Cape Cod”. The lecture will be given by Brad Chase, Senior Marine Fisheries Biologist, Mass. Dept. of Fish & Game, Division of Marine Fisheries, and will include information about the fish of Cape Cod that survive in both fresh and salt waters and how they came to be.