Solitary Wasps: Cicada Killers, Mud Daubers
There are many species of wasps (yellow jackets,
paper wasps, hornets, mud daubers, spider wasps and
cicada killers) and all are beneficial by virtue of their
predatory habits. However, since these insects are
capable of stinging they can cause a considerable
nuisance.
Wasps can be divided into two groups based on their
habits. Social wasps construct small to large-sized nests
of grey paper which may contain 50 to 5,000 individuals.
On the other hand, solitary wasps are not colonial and
they nest in the ground or in tubular mud nests.
Solitary wasps differ from the social wasps in nesting
habits and life cycle. Solitary wasps have no worker
caste; the queens "care" for their own young. Therefore,
solitary wasps usually have a single nest, or a small
group of nest. Solitary wasp queens use their sting to
paralyze their prey (flies, caterpillars, spiders, etc.),
rather than to defend their nest(s). As a result,
solitary wasps are non-aggressive and rarely sting
(unless touched or caught in the clothing).
Two species of solitary wasps are most frequently
encountered--mud daubers and cicada killers. The mud
dauber wasps are medium to large-sized, shiny black or
metallic blue-black wasps with slender abdomens. They
build finger-like nests of mud. The nests are usually
attached to flat, vertical surfaces. The queens provision
their nests with paralyzed prey and then leave the young
to develop on their own.
Control can be achieved by killing the offending
adult wasps with a fly swatter or "wasp or hornet"
aerosol spray (most contain resmethrin and/or
pyrethrins). Remove and destroy the mud nests to prevent
emergence of the developing young.
Cicada killers are large (1 1/2 inch or longer) wasps
with dark brown bodies and black abdomens with yellow
markings. They are ground nesters which prefer sandy or
other well-drained soils, and the queens dig tunnel-like
chambers. The adults are active in the summer, usually
after early July. They are frequently seen flying about
in the nesting areas. The queens search for cicadas to
provision their nests (hence the name). Each chamber in
the nest (often as many of 16) is supplied with a
paralyzed cicada and a wasp egg. When the larva hatches
it feeds on the cicada. Later the larva pupates and the
wasp hibernates in the nest as an immature adult.
Locate the nests during the daylight hours (they are
easily spotted because of the large amounts of soil
excavated from the nests) and mark them if necessary so
you can find them at night. These wasps are large, but
non-aggressive, although they do have a potent sting. All
insecticidal treatments MUST be done late at night or in
the pre-dawn hours when the wasps are in the nests and
when it is cool (preferably less then 60 degrees F. Use a
flashlight covered with red cellophane for lighting.
Apply an insecticide (carbaryl 5% dust works best) into
each nest entrance and then fill the hole with a handful
of moist soil.
For a complete listing of suggested control options
for all home, yard and garden insect pests contact your
local Extension Service, found under local government in
the phone book.
Read and follow instructions on the pesticide label.
Heed all warnings. Check with your physician if you have
any concerns regarding your personal health risk.