This is the nymph of an assassin bug known as the Masked
Hunter, Reduvius personatus. It’s alive
and healthy and is looking just as it should.
The predatory bug excretes a sticky substance that traps dust and
debris. The result is a highly effective
camouflage and an odd looking bug.
I first found this non-native insect many years ago while I
was sweeping the concrete floor of my barn.
Before I could get the dust pan in position to collect the pile of dirt,
several lumps crawled free and took off across the floor. Until I learned the truth, I believed that
their dust covered condition was a result of being swept up, although it seemed
odd that they would end up so completely covered.
The Masked Hunter preys on a variety of small insects and
other similarly sized arthropods. The
fact that Bed Bugs are near the top of its list of favorite foods makes people
believe that the presence of the Masked Hunter indicates a Bed Bug infestation. This may be true if you keep finding them in
your bedroom, but they are most often encountered in barns and other
outbuildings. In those locations, the
Masked Hunters may be feeding on other Bed Bug species or one of the many other
prey items they are known to consume.
I’m normally unhappy at the presence of non-native species, but this one
seems to confine itself to man-made structures and that just doesn’t seem quite
as bad.
I don’t know if the dust covering just naturally accumulates
as the bug travels around its preferred habitat or if the bug actually applies
the bits to its body. Whichever the
case, the process must be repeated after each molt. The use of debris camouflage ends when the
bug reaches the adult stage. I’ve seen
the shiny black adults, but it took me a while before I realized that they came
from the dirty nymphs.
It seems that the dust covering would hinder the bug’s
sensory abilities. This is apparently
not the case since it will seek cover at my approach and its continued presence
is evidence that it is an effective hunter.
Like many other Assassin Bugs, this one is said to inflict a painful
bite if mishandled. I’ve chased a few
onto my hand without incident, but I’ve since stopped doing that. Most insects will walk on your hand without
biting or stinging if they are allowed to move freely. It’s when you close your hand or otherwise restrict
them that they are likely to defend themselves.
There have been enough times when innocent appearing insects have just
given me a bite that I no longer offer the really painful biters that opportunity. I don’t imagine that I’ll ever eliminate dust
and dirt from the barn, so these guys ought to be around for a long time.
