The Supermodel in the Sewer: /Dolichovespula maculata/, Bald-Faced Hornet

Setting aside for a moment the less-than-appealing staging, this is a beautiful creature.
/Dolichovespula maculata/, Bald-Faced Hornet
This is Dolichovespula maculata, the Bald-Faced Hornet. Despite its prevalence, this is my first direct encounter with one.


I’m more familiar with its signature creation: its nest. Here’s a huge one I found a few years ago high in one of the Lilacs at the Brooklyn Botanic Garden. It was March; this one was left over from the previous year.
Wasp nest, Lilac Collection, BBG, March 2009

They typically nest high in trees, or large shrubs like the Lilac above. Sheltered by summer foliage, and camouflaged the color the bark, they’re difficult to spot. We’re more likely to discover them when they fall. Here’s one that was downed when a tornado swept through Brooklyn in August 2007 …
Downed Hornet Nest

… and flagged – if mislabelled – by a helpful neighbor.
DSC_3675

Earlier in the year, the nests are much smaller. New queens emerge, and create new nests, each year. Here’s one Matthew Wills and I came across during our Magicicada hunt in Staten Island.
Fallen Bald Hornet Wasp Nest

The “setting” of the opening photo is canine dung, aka “dog poo.” I prefer to think of this as an image from a photo shoot of an aspiring hipster photographer (me) of a model wearing haute couture (hornet) in a sewer (dung).

Much more glamorous now, ain’t it! Except this hornet is too zäftig to be a modern model.
/Dolichovespula maculata/, Bald-Faced Hornet

I observed this individual scrambling over, flying off, then returning to such, uh, settings repeatedly. In between visits from the hornet, each was buzzing with flies. As the horned honed in, the flies flew off.

I think this explains this hornet’s interest. The adults are largely vegetarian, eating nectar and fruit. They capture and pre-chew flies and other insects to food to their larvae. This is the same child-rearing strategy used by a majority of bird species, most of which need insects to feed their young, but are largely vegetarian as adults.

Far from being a “pest” (in human terms) this is a beneficial (in human terms) insect. Carnivorous wasps such as this one help keep insect populations in check. A diversity of species – emerging and active at different times of the year, occupying different habitats, and specializing in different prey – ensure that no one species of insect will get out of control, at least not for long. The better able we are to at least tolerate, if not celebrate, less charismatic species such as wasps and hornets, the more we will be able to enjoy the spaces surrounding our homes, and the healthier will be our interactions with our co-habitants in nature.

Related Content

Flickr photo set
Other Hymenoptera posts

Links

Bald-Faced Hornet (Dolichovespula maculata), BugGuide
Bald-faced Hornet, Dolichovespula maculata, Study of Northern Virginia Ecology
Baldfaced Hornet, Virginia Cooperative Extension
Dolichovespula maculata (Linnaeus, 1763) – Baldfaced Hornet, Biological Survey of Canada

Cry Wolf: /Philanthus gibossus/, Beewolf

Philanthus gibossus, Beewolf, on Pycnanthemum muticum, Clustered Mountain-Mint, in my native plant gardens this past weekend.
/Philanthus gibbosus/, Beewolf, on /Pycnanthemum muticum/, Clustered Mountain-Mint

This thirsty little wasp face down in a cup of nectar is a Beewolf, so-named because they provision their larvae with bees. Despite the size of the image, these wasps are small; the individual flowers of this Pycnanthemum are about the size of a pencil point.

Pycnanthemum muticum, Clustered Mountain-Mint, Detail of Flowers with Pencil Eraser for Scale

Their prey is also small. They favor Halictids, Sweat Bees. I grow a wide variety of native plants, attracting any different species of bees and wasps. There are several species of Halictids that frequent my gardens, making good hunting grounds for the Wolves.
/Lasioglossum/ (Subgenus /Dialictus/) on /Clematis virginiana/, Virgin's Bower/Halictus ligatus/ on /Rudbeckia triloba/Halictus rubicundus (Halictus (Protohalictus) rubicundus) on Pycnanthemum, Mountain-MintAgapostemon, Jade Bee, on Rudbeckia triloba

I first noticed and identified this species in my garden last summer. I noticed them again this year, then realized I’d never uploaded last year’s photos. They are numerous this time of year, along with the little sweat bees.

/Philanthus gibbosus/, Beewolf, on /Solidago/, Goldenrod

Beewolves earn that name. The females target small bees, and even other wasps, as food for their larval offspring. Not all beewolves you see around flowers are there for nectar. The females will actively stalk bees that are busy gathering nectar and pollen themselves. …

A victim is stung immediately between its front legs, disabling a nerve center and rendering the bee paralyzed. The wasp then carries the bee beneath it, held in the wasp’s middle legs. It takes several bees to feed one larval beewolf wasp.

Wasp Wednesday: Beewolves, Bug Eric

Related Content

Philanthus gibossus, Beewolf (Flickr photo set)

Other Wasps from my garden:
Scolia dubia, Blue-Winged Digger Wasp, 2012-08-13
Gardening with the Hymenoptera (and yet not), 2011-07-31
Sphecius speciosus, Eastern Cicada Killer, 2009-08-18
Monobia quadridens, Mason Wasp, 2009-07-12

Links

BugGuide: Philanthus (Beewolves), Philanthus gibbosus
Wasp Wednesday: Beewolves, Bug Eric (Eric Eaton), 2011-08-17

Scolia dubia, Blue-Winged Digger Wasp

Scolia dubia, Blue-winged Digger Wasp, on Pycnanthemum, Mountain-Mint, in my garden.
Scolia dubia, Blue-winged Digger Wasp, on Pycnanthemum, Mountain-Mint

Another little jewel of a wasp that is new to me this year. I’ve been seeing it on the Pycnanthemum, but was unable to get decent photos of it until yesterday. I’ve also seen it on the Clethra alnifolia, Summersweet in my garden, which just started blooming in the past week.


With the wings held back, the blue iridescence of the wings might lead one to mistakenly identify this as a small Sphex pensylvanicus, Great Black Wasp.

Scolia dubia
Scolia dubia, Blue-winged Digger Wasp, on Pycnanthemum, Mountain-Mint

Sphex pensylvanicus
Sphex pensylvanicus, Great Black Wasp, on Pycnanthemum, Mountain-Mint

But once the wings spread to the sides, the exposed abdomen distinguishes it. The cinnamon- colored abdomen and two bright yellow spots make for a clear identification, once you know the species.
Scolia dubia, Blue-winged Digger Wasp, on Pycnanthemum, Mountain-Mint

Adults feed on nectar, which both the Mountain-Mint and Summersweet offer in abundance.
Scolia dubia, Blue-Winged Digger Wasp, on Clethra alnifolia, Summersweet

Females dig in search of grubs of June Bugs and Japanese Beetles to parasitize with their eggs. The wasp larva feeds on the beetle grub and overwinters as a cocoon, emerging the next year.

This species is another example of the importance of providing habitat for wasps in the garden; they are natural bio-controls of other insects that might otherwise overwhelm the gardener’s intentions.

Related Content

Flickr Set: Scolia dubia, Blue-Winged Wasp

Links

BugGuide: Blue-winged Wasp (Scolia dubia)

Sphecius speciosus, Eastern Cicada Killer

Although I’ve lived in Brooklyn since 1992, I didn’t encounter Sphecius speciosus, the Eastern Cicada Killer, until we moved to Flatbush in 2005. It was summer, and I was working outside in the garden. Suddenly, here was the biggest wasp I had ever seen, large and loud, buzzing around my driveway and digging into the lawn next to it. I freaked out. I hosed out the burrow and destroyed the nest.

I regret having done that. I attribute my over-reaction partially to the stresses of being a first-time homeowner. I now find them beautiful. I consider myself lucky that we live in an urban area where these specialists can thrive. Besides, they are much too busy during their short adult lives to bother with people.

Sphecius speciosus, Eastern Cicada Killer, with prey, just inside the Eastern Parkway entrance of the Osborne Garden at Brooklyn Botanic Garden, August 2009
Sphecius speciosus, Eastern Cicada Killer

They have a fascinating, if gruesome by human standards, life history. It could easily be the inspiration for the xenomorph of the Alien movie series.

After mating, the female digs out a deep tunnel leading to a multi-chambered nest. They’re impressive excavators. This debris pile appeared overnight alongside our driveway and sidewalk in August of 2012. The concrete curb is 3″ high.
Burrow of Sphecius speciosus, Eastern Cicada Killer

Here’s the entrance to a nest in Cattus Island Park in Toms River, in the coastal pine barrens of New Jersey, in August of 2011. Note there are 4 different colors of sand, showing the different layers, and depths, the female reached.
Nest, Sphecius speciosus, Eastern Cicada Killer

The female then hunts for and captures an adult cicada, paralyzing it with its sting without killing it. It returns with the cicada to its burrow, dragging it into one of the chambers of the nest. It lays a single egg on the cicada. It repeats this process several times. The female dies soon after egg-laying.

Sphecius speciosus, Eastern Cicada Killer, with prey, at the Flatbush CommUNITY Garden, July 2008
Spechius speciosus, Eastern Cicada Killer

When the egg hatches, the larva feeds on the still-living cicada. When the cicada hs been completely consumed, the larva spins a cocoon and overwinters as a pre-pupa. In Spring it emerges from the cocoon as a pupa, eventually metamorphosizing and emerging as adults, male and female, for mating and renewing the cycle.

Dog-day Cicada (annual Cicada) in Prospect Park, July 2008
Dog-day Cicada

Cicada killers are solitary wasps. Males emerge from pupal cases in mid-July to early August, a few weeks before the females. The males tunnel out of the ground, leaving telltale holes, and select a territory that they actively defend. Females mate soon after emerging, and then begin digging burrows in the ground using their mandibles and legs. The burrows can be several feet deep with numerous branches.

Once construction is complete, the female searches in trees and shrubs. Upon capturing a cicada, the female stings it injecting venom. Then, she carries the cicada back to the burrow, where she lays an egg on its living, but paralyzed body. Within two weeks, the egg hatches into a larva, eats the cicada, and develops into a pre-pupa, the stage at which it will spend the winter. Cicada killers are active in late summer, the same time that cicadas are present. By September, most adults have died.

Although visually alarming, these wasps pose little threat. Females are not aggressive and rarely sting, unless excessively provoked. Males often display territorial behavior and will dive-bomb people’s heads; however, they have no sting and pose no real threat.

Cicada Killer, Master Beekeeper Program, Cornell University

Felis catus ssp. cicadakilleratus ‘Ripley’ on my back porch, August 2009
Ripley with Cicada



I was prompted to write this in response to a message sent out on the Flatbush Family Network:

We seem to have an underground yellow jacket nest on our front walkway with a “Queen” that is about 2.5 inches long…..a little frightening to me but will absolutely scare the wits out of my kids- she looks like she can carry her own luggage! Anyone know an exterminator that can come and get rid of this Quick!?

Thanks, Lori

[bit.ly]

Related Content

Dog-Day Cicadas, 2008-07-11
Flickr photo set

Links

BugGuide

Wikipedia

University of Kentucky Entomology
Ohio State University Extension