Collecting Treasure: Valuable Insect Data from the Field

By Christine Helie

In 2012, as part of our work in preserving trees in the city of Boston, we began monitoring elm trees for Dutch elm disease and its primary vector, the elm bark beetle.

Using large sticky traps infused with a pheromone that attracts the beetle has helped us better understand and manage this particular insect. While this data alone is of remarkable importance, another exciting feature of these traps is their ability to help us realize the diversity of insects in the city.

Many insects are difficult to observe in nature because they are extremely tiny, well camouflaged, or fast moving. These sticky traps, simply by design, are capable of capturing other insects, called bycatch, in the area. Each time I monitor my traps I have a view into a world very few people get to see.

While most of the trap insect inventory is of interest, focusing on the pest species is necessary.  In April 2012, young larval stages of the winter moth caterpillar stuck in the glue became the first bycatch insect to demonstrate the supplemental use of these traps. When adult buprestids (jewel beetles) become active in June several different species show up on the traps. In combination with regular monitoring of our ash and oak trees, the elm bark beetle traps are another tool in the detection of invasive species, such as the Emerald Ash Borer and the European Oak Borer.  The traps also allow me to identify beneficial bugs, giving us insight to insects that are helping control pest species.

A biological inventory or a survey of plants and animals in a community is the first step to understanding an ecosystem. Serving as a baseline, these inventories help us to track changes over time and determine biodiversity.  Fenway Victory Gardens, with its varied plantings that include vegetables, herbs, and native flowering plants, along with a fresh water source nearby, has the potential of supporting an extensive population of insects. My hope is this valuable information will increase our knowledge of our urban ecosystem and encourage everyone to have a greater appreciation of insect life in our parks. Christine and her husband, Normand, are independent contractors working for the Friends of the Public Garden.