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The fall garden and Cicada Killer Wasps
By John Fulton

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[September 03, 2015]  The Fall Garden - It doesn’t seem possible to think about fall, let alone a fall garden, after this period of heat and humidity, with very little moisture. However, if you are interested in planting a fall garden, the time is upon us.

Many of the commonly grown fall crops require about 50 days before harvest, and this group includes beets, kohlrabi, green beans, Swiss chard, turnips, and transplants of broccoli, cabbage, and cauliflower. A few shorter time required crops are leaf lettuce and spinach at 40 days, and radishes at 25 days. An average date for our first killing frost in the fall is October 10. Back off of this date by the days required for maturity of your crop, add a week to get them germinated, and we are at the latest date for many of the crops to get a crop this season. As you can probably figure, average weather means only the shortest maturity crops.

You should remove all the residues from former crops and weeds before planting. It is also a good idea to add some fertilizer, such as 12-12-12, at the rate of one to two pounds per 100 square feet. Then till to incorporate the fertilizer and remaining debris, as well as loosen up the soil. Late summer plantings often require some additional water, and sometimes a little shade to offset some of the hot soil temperatures we can encounter.
 


If you aren’t into fall gardening, you might consider options to extend what you have growing now. Covering plants for the first expected frosts can add weeks to the season. The use of row covers, hotbeds, and coldframes is even more of a sure thing.


Cicada Killer Wasps

With lower numbers than some years, and a later appearance than normal, 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 or other large insect such as a katydid, which becomes a food source for the young cicada killer. 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 (or the often reported but not confirmed Asian Killer Hornet).

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.

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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 attempt 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 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]

 

 

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