So many great questions were asked during the Question and Answer period, there wasn't time to address them all live. We have since compiled them into three groups by topic (plants, insects & birds, and management) and asked our in house experts to share their knowledge and suggestions. These are the bird and insect topic questions and answers.
Insect topics
On balance, are "local" [European] honeybees beneficial or harmful to the local ecosystem?
Local bee expert Dr. Robert Gegear notes that while European honeybees are very important for crop pollination, they compete for resources with our native bees in our local ecosystems, and he advises not introducing them in areas where biodiversity conservation is a goal, such as on conservation land. His website contains a lot of information about endangered native bees.
Are carpenter bees in decline? Why?
One reason so many of our native bees are in decline is the lack of shelter and food. Carpenter bees make their nest/homes in old rotting logs/wood, and if your yard has no brush piles or decaying logs, there is no place for them to live. Loss of vital resources such as shelter and food is a major factor in the worldwide insect decline we’ve seen documented over the past several years, not limited to carpenter bees.
What can we do about invasive black swallow-wort and its impact on monarchs?
Black swallow-wort (Cynanchum louiseae) is an invasive species in the milkweed family that is a problem for Monarch butterflies because females will lay eggs on them but the caterpillars cannot eat it. For more information read this USDA report. Once you can identify black swallow-wort, remove any that you see on your property.
Are you seeing Spotted lanternflies on your land?
Spotted lanternflies, native to Asia, are a quickly moving species, having established in Pennsylvania where they are devastating fruit crops and other agricultural crops, and are beginning to invade New England. If you see them on your property, immediately report to UMass extension here: Umass Fact Sheet Spotted Lantern Fly.
I know at least a half dozen people who search for monarch eggs outside and then raise them at home, then release them. Is this helpful?
Raising a few Monarch caterpillars from eggs you locate outside can be a great way to learn about them in depth and to contemplate how important it is to protect their habitat resources. If you do so, it’s important that they have enough space and air flow to prevent spread of disease. This means not too many in a container and stay away from using jars. Also important is to first make sure you have access to plenty of milkweed, and nectar flowers for the adults. Here’s a resource for how to do well by any eggs you collect. On the whole, raising Monarchs is more of an educational benefit to you than it is a population benefit to the Monarchs.
Do the same species pollinate native plants and exotic plants (including many vegetables)?
While some plants have highly specific relationships with their pollinators (meaning a plant species that is only pollinated by one pollinator species, e.g. a bee or moth species), many others have a more generalist relationship with their pollinators (plant species that can be pollinated by a variety of insect species) and most pollinators are generalists. We have native specialist- and generalist-pollinated plants, and their pollinators, here in New England. Insects that are specialist pollinators of particular native plants would be unlikely to pollinate the exotic plants, but generalists may (depending on how specialized the floral structures are).
Any tips for identifying all those moths, caterpillars, and other insects?
The online app iNaturalist is a very useful tool for quickly identifying plants and insects. Because you can use it on your phone, you can get an answer real-time while you are right there with the critter you’re looking at! Other helpful tools are Google image searches and online communities of insect enthusiasts. If you are a Facebook user, join the group Insects and Spiders of New England. Its membership includes experts in several groups of insects who are very willing to identify what you’ve captured in a photo. The Caterpillar Lab, in New Hampshire, is a great resource for caterpillar information, and their staff member Sloan Tomlinson specializes in the parasitic wasps that use caterpillars as hosts. A great paper-based resource is the book Caterpillars of Eastern North America by David Wagner.
Bird topics
Because of Equine encephalitis in this area, we spray for mosquitos. Are mosquitos part of a bird's diet?
Eastern Phoebes, in the flycatcher family of birds, eat a decent number of mosquitos. Did you know that mosquitos are a type of fly? They aren’t the only kind of insect eaten by Eastern Phoebes but are well suited to the bird’s habit of catching prey on the fly. Insect-eating bats are probably more dependent on mosquitos in their diet than birds are. In fact, research has shown bats shift foraging ranges based on mosquito abundance (or lack thereof). Use of insecticides that kill mosquitos can lead to a reduction in our overall local bat abundance--and, ironically, losing this predator pressure can lead to overall increases in mosquito populations. In their larval (immature) stage, mosquitos are aquatic insects in stagnant freshwater. You can remove standing water near your home to reduce their breeding opportunities, but in ponds, mosquito larvae are part of the aquatic food web as well. The relatively nontoxic spray used for mosquitos is Bt (using Bacillus thuringiensis bacteria protein), which is lethal to most caterpillars in addition to mosquito larvae. So be mindful that if you are trying to support caterpillars on your property, Bt sprays are not compatible with that goal.
What about tent caterpillars? Or gypsy moths? A real feast for birds?
Yes to both! Robins, blue jays, and other species eat them in the caterpillar stage. Ground-foraging species such as wild turkeys eat them in their pupal stage. In outbreak years, it may be hard for predators to keep up with the sheer numbers, but they do eat many.
If my yard is overrun with caterpillars and there are not enough birds to impact the population, am I going to lose my plants?
Unless you are in the middle of an outbreak year for a particular species, such as mentioned in the prior question, there are enough birds around to control caterpillar populations below the level that would kill off your plants. Such an outbreak would only affect the food plants for those caterpillars--so whether it affects only one plant or several would depend on the diversity of plants in your yard and how specialized the caterpillar is.