Balance in the Garden: Ichneumon Parasitic Wasp

The tale of a parasitic wasp originally published by Loret T. Setters on November 21, 2014 at (beautifulwildlifegarden.com/).

ichneumonwaspRedbudOct2014ASometime ago I talked about how some wasps keep a garden in balance by using other arthropods as their larval hosts, laying eggs to hatch and feed off the caterpillars of moths or butterflies or beetle larvae.  It’s Nature’s way of ensuring you don’t get too many of one species.  The food chain in action.

Adult IO moths are quite pretty
Adult IO moths are quite pretty

My Eastern Redbud tree sapling (Cercis canadensis) draws in the Automeris io moth that is a member of the Giant Silkworm and Royal Moth family (Saturniidae). The caterpillars are a gregarious bunch that can strip the leaves of a host like the speed of light if there isn’t a predator that will hold it in check.

Eggs of IO Moth on Redbud Tree
Eggs of IO Moth on Redbud Tree

Redbud doesn’t really do all that well in this part of Central Florida; more a tree who likes a range of cooler weather or a heartier freeze found further north in our fair state.  So, while not the most lushly attractive of trees in my garden scheme, it still has a place in my garden because it is a host for the caterpillars of this pretty moth.  I purchased it before I understood that just because a plant is native to your state, it doesn’t mean it is native to your county or ecosystem.

Late instar IO Moth caterpillars which can be gregarious
Late instar IO Moth caterpillars which can be gregarious

Recently I met a new-to-me parasitic Ichneumon wasp (Ichneumonidae family). Based on a search of Bugguide I believe it is Anomalon spp.  This particular genus is not well documented down to species level in the guide.

My latest Icheumon Wasp find on Redbud
My latest Icheumon Wasp find on Redbud

With many arthropods, it is often minute details that separates one species from another…not always possible using a photograph.

Top or head/face
Top or head/face

The University of Florida’s Natural Area Teaching Laboratory’s listing of Ichneumon wasps found in the woods located on the campus in Gainesville (about 2 hours North of my location) has one species, A. ejuncidum, and it notes beetle, butterfly and moth larvae as hosts for the wasp.

A check of the Web Partners Database a.k.a. Taxapad doesn’t specifically list the IO moth as a documented host, it does indicate that armyworms, prominent moths and other members of the Macrolepidoptera (which includes Royal Moths) do host this particular genus of ichneumon wasps.

Could this parasitic eggmass be that of my newfound ichneumon species? (probably not)
Could this parasitic eggmass be that of my newfound ichneumon species? (probably not)

So, perhaps these stinging caterpillars do grow this variety of wasp.  Unfortunately, when I went back to continue my “cycle of life” observation, the cocoon mass was gone so I won’t know if it was from the Anomalon or from some other braconid or ichneumon wasp species.

I looked around for suspiciously chunky anoles nearby that could have had wasp eggs from the dinner menu. Again, food chain in action.

I’ll keep a close eye out next year to see if I’m lucky enough to catch it “in the act”
I’ll keep a close eye out next year to see if I’m lucky enough to catch it “in the act”

So, while not lucky enough to catch the emerging critters in action for proof positive, I will pay attention in the future to see if my observations are on target and I can solve the mystery of the fluffy cocoon mass.  Each month I check back to what was happening in the garden in prior years so I know what to expect or look for.

Once again this is a reminder that it is important not to use pesticides when dealing with what some consider “pest” insects.  Pesticides don’t distinguish the predator from the pest. A better alternative is to hand pick some of the chewers and move to the compost pile if you are so inclined, but leave some to grow the next generation of predators. Remember that each species has a role in the garden and we shouldn’t be too hasty to decide that one has more value than another does.

Enjoy all the critters in your beautiful wildlife garden.

Advertisements

3 thoughts on “Balance in the Garden: Ichneumon Parasitic Wasp”

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s