Neotibicen auletes

Neotibicen auletes commonly, but informally called the Northern dusk-singing cicada, Giant oak cicada, or Southern oak cicada, is a large bodied annual cicada which occurs in the eastern, central, and Southern United States as well as southern Canada. This cicada is the largest cicada in the genus Neotibicen and the largest cicada in North America, north of Mexico. Despite its frequently used common name, this cicada is most abundantly found in the south. N. auletes is almost exclusively associated with oak trees, Quercus, rather than other eastern hardwoods.

Description

Average body length for this cicada (not including wings) is between 39–46 mm for males, and 34–38 mm for females. Body coloration is mostly olive green of varying shades/tints. The pronotum is typically a rich olive green with well-defined black markings. The Mesothorax is black with olive green or brown pattering. The patterning on the body of this species is characteristic of all Neotibicen cicadas. The abdomen is black. The venter is heavily pruinose, and a black medial stripe is present. The eyes of this cicada when alive are usually light tan or green, although they may also be brown or slate. It should also be noted, that this particular species is heavily pruinose on the body, and may appear to be dusted with flour, or moldy. Some individuals may be entirely covered with pruinosity, and the body coloration and markings may be obscured or masked.

Neotibicen auletes has two color forms. A common color form described above ("Green form"), and a less commonly encountered "Red" color form. The red form is similar to the normal form, but instead of being mostly green and olive in coloration, the body is mostly reddish brown. Typical patterning and heavy pruinosity are retained, however, "greens" are replaced with "reds/rusts" as the dominant body color. The red form is isolated in distribution to the mid-Atlantic states particularly North and South Carolina and Virginia. Because of the coloration of the red form, it can be readily confused with Neotibicen resonans, a similarly-colored and sized cicada species found primarily in coastal areas of Florida and the Deep South.

The call of Neotibicen auletes is a loud, grating, pulsating drone lasting up to 50 seconds. Vocalization of the call can be best described as rapid Dirr-Dirr-Dirr-Dirr, etc. lasting 40–50 seconds before winding down. Before calling, there is also a slow "winding up" phase; rrrrrrrrrrrr...Dirrrrrrrr...Dirrrrrrr, before the "true" call begins.

Distribution

Neotibicen auletes is found across the Eastern 1/3 of the United States, as well as extreme Southern Canada (Ontario). It is abundant across the southern United States and moderately-abundant across the Great Lakes states, Mid-west, Mississippi River Basin and Upper-Atlantic states. This species is rare in New England and Southern Canada. Although abundant in the Southern states, Neotibicen auletes is absent from coastal areas of the South and the lower half of the Florida peninsula. In these areas, N. auletes is replaced by the similar Neotibicen resonans. N. auletes is most abundant east of Mississippi River, but is also common west of the river. As with all cicadas, N. auletes can be abundant in preferred areas.

Habitat

This cicada is most frequently encountered in oak woodlands and deciduous forests of the eastern United States. Preferred trees are oaks Quercus. N. auletes is rarely associated with other trees and relies heavily on oaks for food, reproduction, and shelter. This cicada can also be found in urban areas were trees are abundant. Neotibicen auletes seems to prefer upland areas of higher elevation.

Season

For most of the range, this species is active between July and September. Although in some warmer areas, activity can decline as late as November. Emergence and decline dates can vary from year to year based on location and weather. Neotibicen auletes prefers to call at dusk between 6 p.m.-8 p.m., hence its common name "Dusk-singing".

Diet

As with other cicadas and Hemiptera, Neotibicen auletes have piercing, sucking mouthparts used to tap into the xylem of plants and drink fluids, in the case of N. auletes, the preferred host plant is oak. As nymphs, this species feeds on the roots of oak trees.

Life cycle

Males call to females from the tops of tall oak trees. Males form large competitive singing aggregations to woo females. Females respond to males by wing clicks. After mating females slit deep holes into tree branches using an ovipositor and lay eggs. The eggs of this species hatch within 2 weeks and nymphs fall to the ground and quickly burrow and feed and oak tree roots. The nymphs will grow larger with each molt and change instars. After a period of 3–5 years of feeding, the nymphs reach their final instar and come to the surface of the soil. Once the soil has warmed sufficiently, the nymphs emerge and crawl up tree trunks or other vertical structures and shed their final skin (emergence for this species usually occurs at night). Newly emerged cicadas are said to be teneral. Once their wings and bodies dry. The cicadas fly to the tops of trees and begin the cycle over again. Neotibicen auletes, as with other Neotibicen cicadas, are annual cicadas, they emerge every year. Unlike periodical cicadas, their emergence is annual due to overlapping generations.

Natural predators

Due to the relatively few defenses of N. auletes, these cicadas have many predators. Common predators include birds, other arthropods squirrels, raccoons, opossums, skunks, turtles, fish, snakes, mice, and domestic cats and dogs. The cicada killer wasp is a notable insect predator. Female wasps locate cicadas by sight, and upon finding cicadas, the wasp stings and paralyzes the cicada. Then the large wasp drags the cicada up a tree or post and flies away with it to its underground nest. The nest is 76–152 mm (3–6 in) deep and can be connected to multiple tunnels. The cicada is placed at the bottom of the hole and the wasp lays up to 5 eggs on the paralyzed cicada, the hole is then covered with dirt and leaves and the wasp larvae feed on the cicada, pupate, and emerge the following summer.

Female N. auletes have virtually no defenses but flight. Males are also strong fliers and can escape danger, but in addition, males can sound a loud alarm call to startle a predator or warn other cicadas in the area of danger. Both sexes can spray water at predators.

External links

• http://bugguide.net/node/view/6968