 |
 |
 |
|
|
 |
 |
 |
 |
 Acrobat Ants
Common Name: Acrobat ants
Scientific Name: Crematogaster species
Introduction
Acrobat ants’ common name is descriptive of these ants’ habit of
raising the abdomen over the thorax and head, especially when
disturbed. Various species are found throughout the United States, a
few of which are common in Ohio.
 Recognition.
Acrobat ant workers are 1/8 inch long and the queens range up to
3/8 inch long. They are light brown to black and some species are
multicolored. The thorax has 1 pair of dorsal spines. The waist
(pedicel) has 2 segments (nodes) and is attached to the upper side
of the gaster (large, main portion of the abdomen). The gaster is
heart-shaped from above. A stinger is present but is rarely used.
Workers of many species emit a repulsive odor when alarmed.
Similar Ants
Other 2-node ants having the pedicel attached to the top of the
gaster do not have a heart-shaped gaster.
Damage and Signs of Infestation
Often the only exterior indication of damage is the accumulation
of debris expelled by these ants, especially if the debris is rigid
foamboard insulation. They prefer wood softened by decay fungi or
rigid foamboard insulation, but may enlarge cavities in wood made by
other insects. They will occasionally strip the insulation from
electrical or telephone wires which can cause short circuits.
 Biology
Most structure-infesting acrobat ants are described as nesting
in moderate to large colonies. Probably the most commonly
encountered species is Crematogaster lineolata having workers 1/8
inch long, males 1/8 inch long, and females 1/4 to 3/8 inch long.
This species varies greatly in color. Many of the species, including
C. lineolata, tend aphids. Swarmers have been observed in nests or
swarming from mid-June to late September. The odor emitted by C.
lineolata resembles mammalian feces.
Habits
Inside structures, acrobat ants typically nest in wood which has
been subjected to high moisture and fungal decay, the same wood
conditions favored by carpenter ants and termites. Similarly, they
will nest in rigid foamboard insulation panels and in wall voids.
Outside, most species nest under rocks, in logs, firewood, or trees
where decay enables them to tunnel under the bark and/or into the
wood. They occasionally will nest in abandoned termite and carpenter
ant galleries as well as old wood borer and powderpost beetles
tunnels in structural wood.
The workers readily enter structures by trailing along tree lines
and utility lines as well as along the rails of connected fences and
decks. They enter via cracks and utility penetrations, window
frames, soffits, etc. Workers also will trail across the ground and
enter via door thresholds, weep holes, and other openings or cracks.
They have been found to trail over 100 feet.
Acrobat ants feed on honeydew from aphids and mealybugs which they
usually tend or “herd”. They also feed on live and dead insects,
including termite swarmers. Indoors they show a slight preference
for sweets and high-protein foods such as meats.
When disturbed or alarmed, workers of all but the smallest colonies
tend to be quite aggressive. They are quick to bite, and give off a
repulsive odor.
 Cultural Control & Preventative Measures
Inspection is the key to successful control and the inspection
methods are similar to those used for carpenter ants. When worker
ants are found indoors, the first place to inspect is the
structure’s exterior; one should look for: (1) trailing ants on the
foundation, (2) bits of foamboard insulation which would indicate a
nest behind the exterior sheathing or siding, (3) trailing ants on
all wires, utility lines and pipes coming into the walls, (4)
trailing ants on tree and shrub branches in contact with the wall
and (5) signs of excessive moisture such as peeling paint on wood
thresholds, soffits, window frames, trim and molding. Acrobat ants
that are foraging from the outside can be kept out by filling
obvious cracks and crevices using silicone sealer, builder’s putty,
mortar patch, etc. Tree and shrub branches should be trimmed away
from the roof and walls to prevent bridging contact points.
In the yard, one should inspect logs, stumps, firewood, tree
cavities, dead tree limbs, and loose bark for ant nests. Also, one
should look under rocks and debris lying on the ground for ant
nests.
Indoors, it is important to investigate current and past areas of
excessive moisture and consider past water leaks, plumbing problems,
etc. A moisture meter is useful to detect areas of high moisture.
Areas of old termite and carpenter ant damaged wood, if
recognizable, should be checked for ant activity.
Professional Control
Outside, a full perimeter treatment will be applied by a Rottler
technician using a residual liquid insecticide. Acrobat ant nests
located in structural wood will be treated by injection with
residual insecticide, aerosol or dust formulations. Nests in wall
voids will be treated by gaining access via electrical outlet and
plumbing penetration holes and injecting a dust or aerosol
insecticide. Nests located in wallboard behind siding and in
structural voids will be treated using high pressure aerosol
injections with non-residual and residual insecticides.
If ornamental plants and shrubs are infested with aphids, scale
insects or mealybugs, the customer should have these treated by an
arborist or landscape care professional to discourage acrobat ants
from foraging thereon.
Locations
Serving the St. Louis Metropolitan area since 1956, including
Arnold, Ballwin, Chesterfield, Crestwood, Creve Coeur, Des Peres,
Fenton, Florissant, Kirkwood, Maryland Heights, Overland, St.
Charles, Webster Groves, Wentzville and surrounding areas.
In Illinois: Belleville, Collinsville, Edwardsville, Columbia,
Madison, Waterloo, O’Fallon, Granite City, Alton, St. Clair, Monroe
and surrounding areas.
Columbia & Jefferson City, MO and surrounding areas. |
 |
 |
 |
 |
|
|
 |
 |
 |
|
|
|
 |
|
|
|
