Control in lawns is usually accomplished with bentazon (Basagran)
or halosulfuron, and neither is something you usually find in
the local garden shops. Roundup can help suppress it, but isn’t
very effective on the mature plants – and it will also kill your
grass. Usually you need at least two applications 10 days or so
apart at the minimum.
The other main weedy grass called watergrass is crabgrass, and
at this point it will probably just need to run its course for
the season. This grass is an annual which germinates from seed
each year. Sometime next month, it will brown out and be done.
Of course, that doesn’t help with the lawn this growing season,
especially since it stays wet most of the day.Next year, a
preventative treatment could be applied early and repeated 6-8
weeks later.
Cicada Killer Wasps
The cicada killer wasps have returned! They are actually
considered beneficial insects because they control cicadas. This
wasp gets its common name due to the fact that it hunts and
supplies its nest chambers with a cicada, which becomes a food
source for the young cicada killer. Other food sources could
include katydids and grasshoppers. We are getting cicada killers
now because of the beginning emergence of the dogday cicada.
Cicada killers are a nuisance pest, especially when nesting in
large numbers in a play area or near the house. People get
concerned because the cicada killers resemble giant
yellowjackets.
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Cicada killers are about 2 inches long and black to red, with
yellow banded markings on the abdomen. The head and transparent
wings are reddish brown. They are not dangerous, but they are
intimidating. Cicada killers are solitary wasps, with the female
digging a 6- to 10-inch burrow (1/2 inch in diameter) in the
ground. A pile of soil typically surrounds the entrance. The
female locates and stings a large insect such as a cicada or
katydid and then brings it back to the burrow. She places the
insect into a chamber and lays an egg on it; sometimes she puts
two in a burrow but lays an egg on only one. She then covers the
burrow, digs another, and repeats the process. The egg hatches
into a grublike, legless larva that consumes the paralyzed
insect. Full-grown larvae overwinter in the burrow, pupate in
the spring, and emerge as an adult during the summer, usually in
July and August.
Male cicada killers establish aerial territories and patrol
for intruders. A male cicada killer drives off other males that
enter his territory and attempts to mate with females. Anyone
else walking into the territory is typically confronted by a
very large wasp, which hovers in front of the face and zips to
the side and back. However, after determining that the
"intruder" is not a rival, the wasp ignores the individual.
Cicada killers are unlikely to sting a person. Wasp and bee
stingers are modified egg-laying devices (ovipositors), so males
are not able to sting. Females may sting if crushed, either by
being stepped on with bare feet or grabbed with bare hands.
Cicada killers are more common in areas with bare soil, so
mulching, planting ground covers, or putting down sod can reduce
problems. Applying permethrin, bifenthrin, another synthetic
pyrethroid, or Sevin (some suggest the Sevin dust gives better
control) to the burrowed area should kill females in high
traffic areas. Once females are gone, males leave. In home
yards, sandboxes can be covered with a tarp when not in use, as
this deters the wasps (and also keep cats out). Sand below
swings, jungle gyms, or other playground equipment is a popular
site for the cicada killer. Raking the sand may discourage the
wasps, or you could use mulch instead of the sand.
[By JOHN FULTON, COUNTY EXTENSION
DIRECTOR SERVING LOGAN, MENARD, AND SANGAMON COUNTIES] |