| The backwash from this sucker's prop almost knocked me down
yesterday when it did a fly by with a dismembered leaf beetle held tenderly in its front
paws, impaled on its proboscis. This is the largest (and most
stately, imho) of the Laphria complex flies, a truly stunning
insect.
There are over 7,000 species of
robber flies world wide; nearly 1,000 in North America. All robber
flies have stout, spiny legs, a dense moustache of bristles on the face
(mystax), and 3 simple eyes (ocelli) in a characteristic depression
between their two large compound eyes. The mystax helps protect the head
and face when the fly encounters prey bent on defense. The antennae are
short, 3-segmented, sometimes with a bristle-like structure called an
arista. The short, strong proboscis is used to stab and inject victims
with saliva containing neurotoxic and proteolytic enzymes which paralyze
and digest the insides; the fly then sucks the liquefied meal much like
we vacuum up an ice cream soda through a straw. Many species have long,
tapering abdomens, sometimes with a sword-like ovipositor. Others are
fat-bodied bumble bee mimics; the effect is quite convincing. Take a
close look at any insect that looks like a bumble bee if it's sitting on
a leaf - chances are, it's a robber fly. (Bumble bees as a rule do not
sit in one spot for more than a few seconds). |
