Short-tailed Ichneumon wasp.

 Ichneumon wasps are those strange-looking insects with thin waists, long "tails" (females only), and long antennae.  There are thousands of species and many different genera.  The one I photographed above belongs to the short-tailed ichneumons, genus Ophion.  It is estimated there are somewhere around 48 species in North America, many of them with a range covering that entire region.  Worldwide there are over 1000 species.

Ichneumons are insects whose larvae parasitize other insects.  As such, they are important organisms in the control of pest insect populations.  Ophiods almost always parasitize caterpillars.  The female lays a single egg into the body of its host.  It uses an egg-laying appendage, the ovipositor, to do the job.  The ovipositor in this genus is very small for ichneumons; other genera have ones that are longer than their bodies (most notably stump-stabbers).  Short-tailed ichneumons may actually "sting" humans, although no chemical irritant is delivered.  The sting is simply the ovipositor penetrating the skin; males cannot do this.

The life history is fascinating if not disturbing.  A single egg is laid in or on the prospective host.  After hatching, the larva begins to feed on the living tissues.  Typically the young leaves vital organs for the last and consumes only the parts that will ensure the host's survival.  Finally, before maturation, the developing young eat the internal remains leaving the outside integument intact.  It pupates with the now-dead caterpillar's body shell adding extra protection.  The pupa stays encapsulated until the following spring, when the newly emerged adult begins the cycle all over again.

Short-tails are typically brown in colour.   They can be difficult to identify down to the species level, close examination of wing venation if often required.  I can honestly say that it is enough for me to figure it out down to the genus level. One of the reasons I like to do these blogs is because it both allows me to publicly display my photos and encourages me to learn more about the natural world that I love.

Thanks for reading.   www.ericspix.com