Alien vs. Native Ootheca
As gardeners, we are very familiar with the debate of native versus invasive when it comes to plants but what about insects. There are many introduced insects some intentional and some by way of imported goods or accidental escapes. Kudzu bugs, Japanese beetles, Asian lady beetles, hemlock wooly adelgid, Africanized honeybees are a few that come to mind. We battle these constantly. But how do these introduced species impact the native populations of insects?
Recently I found some egg cases in our garden that were identified as the native Carolina Praying Mantis (Stagmomantis carolina) thanks to Janet at The Queen of Seaford and Clare at Curbstone Valley.
Female mantids lay their eggs in a case formed from a liquid foam secreted from the abdominal glands. The foam quickly hardens creating a protective shell. To see a YouTube video of a Carolina Mantid laying her ootheca click here.
In North America all adult mantids die in the winter. The eggs that overwinter in these cases are the next generation that will hatch in spring. I didn't recognize these initially as an ootheca because they are different from those that I normally see in our garden.
These are the egg cases from the Chinese Mantid (Tenodera aridifolia). They are significantly larger than the native cases.
There are twenty native mantis in the United States. Most of them are small and brown. The big, green mantis that I often see are from China, imported in the 1890's to work as biological control agents and eat pest insects. Unfortunately, they often eat the smaller native species of mantis contributing to their population decline.
I am thrilled to have the native species in my garden. Hopefully they will manage to co-exist with their Chinese relative or better yet thrive because I don't seen any way of getting rid of the alien insects. Have I become an insect snob? I would love to hear your thoughts and experiences on dealing with aliens.
Recently I found some egg cases in our garden that were identified as the native Carolina Praying Mantis (Stagmomantis carolina) thanks to Janet at The Queen of Seaford and Clare at Curbstone Valley.
 |
| egg sack from Carolina Mantid |
Female mantids lay their eggs in a case formed from a liquid foam secreted from the abdominal glands. The foam quickly hardens creating a protective shell. To see a YouTube video of a Carolina Mantid laying her ootheca click here.
In North America all adult mantids die in the winter. The eggs that overwinter in these cases are the next generation that will hatch in spring. I didn't recognize these initially as an ootheca because they are different from those that I normally see in our garden.
 |
| egg sack from Chinese Mantid |
There are twenty native mantis in the United States. Most of them are small and brown. The big, green mantis that I often see are from China, imported in the 1890's to work as biological control agents and eat pest insects. Unfortunately, they often eat the smaller native species of mantis contributing to their population decline.
I am thrilled to have the native species in my garden. Hopefully they will manage to co-exist with their Chinese relative or better yet thrive because I don't seen any way of getting rid of the alien insects. Have I become an insect snob? I would love to hear your thoughts and experiences on dealing with aliens.
