Physocephala tibialis, Thick-Headed Fly

2013-12-29: Identified as Physocephala tibialis by Aaron Schusteff, Contributing Editor of BugGuide.

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A few weeks ago, I tweeted:

2013-06-11 19:57: Found - or rather one of our cats did - an incredible wasp-mimic fly. Chilling in refrigerator for later identification.

2013-06-11 20:01: The fly looks very similar to /Physocephala/
http://bugguide.net/node/view/7190/bgimage except all-black at first glance. Will examine more closely later.

This is what she found:


Yes, that is a fly, not a wasp. You can tell it's a fly from the antennae in the center of the face, instead of the top of the head, the large, rounded eyes that cover both sides of the face, instead of being restricted to the upper part of the head, and the "forked" feet.

Trichopoda pennipes, Feather-legged Fly

Trichopoda pennipes, Feather-legged Fly, on Pycnanthemum, Mountain-Mint, in my garden yesterday. Although it's widespread and common, occurring throughout North America, this was the first time I've noticed this species in my garden.

This photo shows several of the keys to identifying this species:

• "Feathered" fringes on the hindlegs, true of Trichopoda.
  
• Orange abdomen. Females have a black-tipped abdomen. Males, such as this one, have a completely orange abdomen. 
• Wings are completely black. This species has a transparent margin to the wing.

Trichopoda is a parasitoid of Hempitera, true bugs, including many agricultural and garden pests, such as squash bugs and stinkbugs. For this reason, it's considered a "beneficial" insect:

Each female fly lays on average 100 eggs, which are placed singly on the body of a large nymph or adult bug. Most of the small, white or gray, oval eggs are placed on the underside of the thorax or abdomen, but they can occur on almost any part of the bug. Many eggs may be laid on the same host, but only one larva will survive in each bug. The young larva that hatches from the egg bores directly into the host body. The maggot feeds on the body fluids of the host for about two weeks, during which time it increases to a size almost equal to that of the body cavity of its host. When it has completed its development, the cream-colored third instar maggot emerges from the bug between the posterior abdominal segments. The bug dies after emergence of the fly, not from the parasitoid feeding, but from the mechanical injury to its body. The maggot pupates about an inch down in the soil in a dark reddish-brown puparium formed from the last larval skin, and an adult fly emerges about two weeks later. There can be three generations per year depending on location.

The fly overwinters as a second instar larva within the body of the overwintering host bug. Adult flies emerge in late spring or early summer. The only bugs large enough to parasitize at this time are overwintered adults. Subsequent generations develop on both nymphs and adults of the next generation.
- Trichopodes pennipes, Parasitoid of True Bugs

Related Content

Flickr photo set: Trichopoda pennipes, Feather-Legged Fly

Links

BugGuide: Trichopoda pennipes
University of Wisconsin-Madison, Department of Entomology, Midwest Biological Control News, Trichopodes pennipes, Parasitoid of True Bugs
North Carolina State University, Raleigh, Dept. of Entomology, Biological Control Information Center, Trichopoda pennipes

Gardening with the Hymenoptera (and yet not)

Contents

• Bees
• Wasps
• Mimics
• Photographing Insect Activity
• Related Content
• Recommended Reading
• Links

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One of the great pleasures of gardening is observing the activity the garden invites. I can lay out the welcome mat, and set the table, but the guests decide whether or not the invitation is enticing enough to stop by for a drink, a meal, or to raise a family. While charismatic megafauna such as birds and mammals are entertaining, the most common and endlessly diverse visitors are insects.

The Hymenoptera includes bees, wasps, and ants. Although my garden also provides amply for ants, we'll stick with the bees and wasps today. Following are some of the few portaits I've been able to capture of the many visitors to my gardens. The pollinator magnet, Pycnanthemum, Mountain-mint, in the Lamiaceae, provides the stage for many of these photos. I'm always amazed at the variety and abundance of insect activity it attracts when blooming.

Multiple pollinators on Pycnanthemum

Bees

There are over 250 species of bees native to New York City alone. I'm still learning to identify just a handful of the dozens of species that frequent my garden.

My current favorite is the bejeweled Agapostemon, Jade Bee

Eristalis transversa, Transverse Flower Fly

This beautiful creature is not a bee. It's a fly of the Syrphidae, a family of flies renowned for bee mimics. This is Eristalis transversa, Transverse Flower Fly. I had noticed it in my garden for the first time this summer. yesterday was the first chance I had to capture some photos of it. Consider this a belated Garden Blogging Bloom Day post, but with a native pollinator as the focal point.





The flower it's visiting is Aster novae-angliae 'Chilly Winds', a selection of the native New England Aster from Seneca Hills Perennials in upstate New York. This plant has been a pollinator magnet in my backyard native plant garden for weeks. It's massive and overgrown and poorly placed, crowding out everything else around it. I'll have to find it another place for next year.



[bit.ly]

Related Content

Flickr photo set
My BugGuide images

Links

BugGuide page
Seneca Hills Perennials