Cicada Killer |
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The cicada is one of our most common yet innocuous insects that abound in neighborhoods and country-side during the summer. They while away their days singing and breeding, yet from July to September they are savagely attacked by one of our largest native wasp, the Cicada Killer (Sphecius speciosus).
Female cicada killers fly about in yards and along forest edges searching for adult annual cicadas – the type we have that appear each summer. They frequently attack them on the wing and sting them until they become paralyzed. The cicada killers then take their prey to a 12 inch deep tunnel, often containing a right angle about mid-way, and deposit them in an expanded chamber at the end. After cicadas are placed in a chamber, the female places an egg on one and plugs the tunnel entrance. The egg hatches and the larva enjoys a living, though immobile, food source. The larva then pupates and emerges in the spring as an adult to repeat the cycle the following summer.
Of extreme interest is that the female cicada killer determines the sex of her offspring. After mating, sperm are stored in little pouches called spermathecae. The female produces a male egg by not fertilizing it, and a female results when she emits sperm from the spermathecae as the egg passes.
Research has shown that when she creates a male, she lays the egg on one immobilized cicada. If a female is produced, she lays the egg on two to three cicadas, thus allowing the females more food and more growth.
Cicada killers spend about 90% of their lives as larvae and pupae. Their adult lifespan is only two to six weeks. They are active only one summer season, then they die.
Obviously, the wasp gets its name from its choice of and method of acquiring larval food. The adults, however, feed on nectar as do most bees and wasps.
It is said that this species can be so abundant as to damage lawns with their tunnels, but the problem would be highly localized.
Cicada killers are very large, having a total length of about an inch and a half. Their dark brown or black abdomen is adorned with yellow rings, making it a striking beast. Possibly due to their size and the amount of venom they can inject, they are considered one of our worst stinging insects.
Delta Journal Article
Cicada wasp, Delta Journal, Times-Picayune, September 9, 2007, C-9
