Doug Tallamy, Entomologist

Large group attends Tallamy tour of Parade Ground.

Large group attends Tallamy tour of Parade Grounds.

Doug Tallamy is a University of Delaware entomologist who burst onto the scene after the 2007 publication of his book, Bringing Nature Home. Tallamy, who is happy to eschew “Prof.” and “Dr.”, became nationally recognized after he connected some ecological dots: Without native plants to feed native insects, there will not be enough food for birds and other animals.

Native vs. non-native plant species

Pristine leaves vs. eaten leaves are at heart of problem: Native insects will not eat non-native species.

Tallamy’s epiphany came in 2000 after he and his wife began clearing their new 10-acre property in southeastern Pennsylvania. At least 35 percent of the vegetation on their land was aggressive non-native plant species that were crowding out their native plants. While attacking the invaders, he noticed a striking pattern: The “introduced” or non-native plants had very little or no leaf damage, while the native species were well-eaten.

After checking scientific literature, he discovered something that no one had considered: If native insects cannot eat, then insect populations are reduced, hence less food for birds and other animals. Native insects can eat only the local native plants with which they have evolved. Introduced plants can come from another continent or another region in the United States.

“The big thing that I connected is the insect component,” Tallamy said. “Without enough food for insects, the bottom falls out of the entire food web, which is nature’s system of interlocking and interdependent food chains.

“The majority of entomologists focus on how to eliminate insects from agriculture and from gardens. Most people don’t want insects, so homeowners try to eliminate them and then put out bird feeders to feed the birds. But birds rear their young primarily on insects, not seeds.

“With massive amounts of land converted for agriculture and suburbia, there is precious little habitat left for animals. All that remains are small islands of habitat throughout the United States. National parks and open spaces are not enough. People must start thinking about landscaping, not only in terms of decoration, but also in terms of contributing to the larger ecosystem.”

Large group attends second Tallamy tour of Parade Grounds.

Tallamy’s hope is that the success of the Parade Grounds, and the accompanying Demonstration Garden, will encourage Island homeowners to remove invasive plants from their properties and increase the percentage of native plants. This, in turn, will attract insects and the birds that eat them and help safeguard the ecosystems on which we all depend.

Tallamy has about 100 speaking engagements and conferences every year. At the same time, he is writing another book, teaching graduate and under graduate students at University of Delaware, and conducting studies, including one to determine which native plants provide the most food for insects.