Brood XIV (14) of the 17-year Periodical Cicadas (Magicicada spp.) have come and gone in Ohio, leaving behind oviposition damage (flagging) as a reminder of their spring fling. Annual Cicadas and their nemesis, Cicada Killer Wasps (Sphecius speciosus, family Bembicidae) are now arriving on the scene. Later, another trophic level may be added with the arrival of Red Velvet Ants (Dasymutilla occidentalis, family Mutillidae)
Participants in this week’s OSU/OGIA Diagnostic Walk-About held in Smale Park on the shores of the Ohio River in Cincinnati heard an annual cicada buzzing in search of love. During this week’s Tuesday morning BYGL Zoom Inservice, Curtis Young (OSU Extension, Van Wirt County) reported that he has been hearing annual cicadas in his neck of the woods since June 28.
Annual cicadas share several behavioral traits with their periodical cicada cousins. The nymphs of both types of cicadas develop underground sustained by juices sucked from tree roots and it takes multiple years for them to complete their development from eggs to new adults.
Once the periodical and annual cicada nymphs complete their development, they leave the soil and climb stems to molt. The cicadas leave behind their shed “skins” (plural exuviae, singular exuvium) stuck to the stems of trees and other vegetation.
As with periodical cicadas, annual cicada females use their long, spade-like ovipositors to insert eggs through the bark of twigs and into the white wood. They can produce twig dieback (“flagging”); however, owing to the smaller numbers, their egg-laying damage usually goes unnoticed.
Periodical and annual cicadas differ in several ways, from their mating behavior to the length of time required for their development, to the time of the year when they arrive, to their size and markings. Adult periodical cicadas have black bodies and orange to yellow wing veins. One of their most notable features is their wide-set red to orangish-red eyes.
Adult annual cicadas are usually larger than periodical cicadas, measuring as much as 2 inches from the front of their head to the tip of their wings. The top of their bodies is black with patterned markings of green, tan, or brown, depending on the species. The underside of their bodies of some species is covered in a whitish bloom. The veins of their wings may range in color from green to brown.
Of course, the names periodical and annual speak to a big difference between the two types of cicadas found in Ohio. Periodical cicadas take 13 or 17 years to complete their development from eggs to adults, and they emerge in the spring.
Annual cicadas develop more quickly compared to periodical cicadas, taking 2-3 years for the nymphs to complete their development. We see and hear adults every year because of overlapping generations. They emerge in the summer and are sometimes collectively called “dog-day cicadas” for arriving during the hot and humid dog days of summer.
Like periodical cicadas, annual cicada males "sing" to attract females, and each species has its own tune. This prevents females from experiencing awkward moments as well as wasting time and energy by responding to males of another species.
Unlike periodical cicadas, annual cicada males don’t "chorus" with large numbers synchronizing their songs. The songs of annual cicada males singing solo to entice females don’t compare to the sheer volume of sound created by a multitude of periodical cicadas singing in unison. It’s like the differences between Bruno Mars and Metallica concerts.
Ohio is home to 12 species of annual cicadas belonging to 4 genera: Cicadettana, Megatibicen, Neocicada, and Okanagana. Based on observations in iNaturalist, the 4 most common species found in our state are: Common Swamp Cicada (N. tibicen tibicen), Scissor(s) Grinder (N. pruinosus pruinosus), Northern Dusk Singing Cicada (Megatibicen grossus (formerly M. auletes), and the true Dog-Day Cicada (N. canicularis). The specific epithet, canicularis, is derived from the Latin word canicula, which references the Dog Star, Sirius.
Although annual cicadas have different markings, they have excellent eyesight, making it difficult to observe them up close for identification. The best way to identify the cicadas is by listening to their songs. You can listen to the different songs by visiting the webpage titled, Common Cicadas of North America, on the website Cicada Mania:
https://www.cicadamania.com/cicadas/common-cicadas-of-north-america/
Cicada Killer Wasps: The Nemesis of Annual Cicadas
Cicada Killer Wasps feed exclusively on annual cicadas; they do not prey upon periodical cicadas or any other insects. Their synchrony with annual cicadas makes sense if you consider that the wasps would starve to death waiting 13 or 17 years for a periodical meal.
Cicada killers are the largest native wasp found in Ohio, measuring 1 1/8 to 1 5/8” in length. As with all Hymenoptera (wasps, bees, etc.), only the females possess stingers (ovipositors); however, they are not aggressive. The males are aggressive, but they lack stingers.
The females spend their time digging and provisioning burrows with paralyzed cicada-prey. They prefer to dig their brood burrows in bare, well-drained soil that is exposed to full sunlight. Although the wasps are considered solitary, it is not unusual for there to be numerous burrows in a relatively small area.
The driving force(s) behind this collective nesting behavior is not known. It’s been speculated that the high concentration of females increases their chances of being mated. Another hypothesis is that females gather together because they share the same environmental nesting requirements.
The males spend their time establishing and defending territories that encompass multiple females. They are notoriously confrontational and will aggressively buzz any transgressor who dares to enter their territory, including other males as well as picnickers, golfers, gardeners, and entomologists. Indeed, participants in this week’s OSU/OGIA Diagnostic Walk-About in Cincinnati observed a pugnacious cicada killer male staking out its territory.
Although the males can't sting, their large size, coupled with low-level flights over sand volleyball courts, sparse lawns, and bare areas in landscapes, can be disconcerting, generating demands for control options. However, insecticide applications to kill the killers are not recommended.
Cicada killers are considered beneficial insects, and the females are not aggressive; stinging encounters are extremely rare. If the killers take up residence in a public location, one option is to educate the public. This approach was very successful several years ago in a park in Hamilton County. Complaints dropped to zero after the sign was posted.
The best way to manage cicada killers, if they appear where they're not wanted, is to modify their habitat. Renovating lawns late this summer to thicken the turfgrass will keep the killers out of lawns. Applying mulch to cover bare soil or raking mulch to disturb and redistribute possible burrowing sites will convince females to nest elsewhere. The same is true for golf course sand traps and sand volleyball courts. Periodical raking will prevent the wasps from becoming established.
Cow Killers (??)
Velvet Ants (family Mutillidae) are sometimes called Cow Killer Ants, presumably because of their painful sting. However, they are not ants (family Formicidae) and are more closely related to wasps.
Their common name comes from the velvety appearance created by the short, densely spaced hairs that cover the entire bodies of both males and females. There are a number of species of velvet ants in the U.S., with most species living in the desert southwest. All species are brightly colored, presumably to advertise their stinging personality.
The species most commonly encountered in Ohio is the Red Velvet Ant. Measuring around 3/4" in length, this is one of the largest velvet ants found in the worl,d and it packs a serious stinging punch. Indeed, the intimidating alternate common name, Cow Killer, is less associated with the potential for these wasps to slay bovine, and more likely associated with the painful surprise when someone gets stung by one of these "ants.”
As with all velvet ants, red velvet ant males have wings and are good flyers, while the females lack wings. Female velvet ants are solitary and may be found crawling across the ground.
Female red velvet ants lay their eggs on the larvae of ground-nesting parasitoid wasps, and cicada killer wasp larvae are one of their favorite menu items. A velvet ant female will dig into the larval chamber of a ground-nesting wasp and lay a single egg next to the wasp larva. Once the egg hatches, the velvet ant larva consumes its wasp larval cell mate. Since the cicada killers are parasitoids, the velvet ants are considered hyperparasitoids.
