Key to the genera and sex for last instar nymphs and cast nymphal skeletons of Eastern North American Cicadidae

So far as known, all cicada nymphs live in burrows they make underground, and feed on xylem sap from roots of grasses, forbs, or woody plants. Rather like xylem-feeding spittlebug nymphs, they flood their bodies with anal fluids, but are not known to trap bubbles in these non-frothy fluids. All cicadas take several years to mature, and molt four times underground in going through five nymphal instars. The fifth molt to an adult, with few exceptions, takes place above ground, usually on a plant. Walking in their burrows, cicada nymphs position their middle legs over their backs, but not so above ground. The nymphs have rather mole-like fore legs with elongate coxae and flattened femora and tibiae, with which they dig. Except for the two Australian species of Tettigarcta (see key to subfamilies for more details), cicada nymphs have most abdominal tergites produced laterally and ventrally as flaps overlapping their sternites, covering their spiracles at the junction of the sternites and tergites, and reminiscent of the structure of nymphs of most spittlebugs.

1 1 Some abdominal tergites with apexes pigmented (brown or black), the nymphal skeleton itself appearing banded; mesosternum and metasternum with or without a median low crest but without a prominent tubercle (Figs. ); genera Beameria, Neocicada, Melampsalta, Okanagana, Okanagodes, and Pacarina [western North American genera, not included in key below, but would segregate here: Clidophleps, Neoplatypedia, Platypedia, Tibicinoides?, Zammara] 4
1' Abdominal tergites not pigmented at their apexes, and if sub-apically pigmented, then not heavily so and nymphal skeleton not appearing strikingly banded; mesosternum and metasternum both with a prominent crest or tubercle (Figs. ); genera Diceroprocta, Magicicada, and Tibicen [western North American genera, not included in key below, but would segregate here: Cacama, Cornuplura?, Quesada, Zammara] 2
2(1') Three apical, metatibial, seta-bearing spines present (setae are born anteapically on the inner side of each tibial spine, associated with an articulating pit and slight swelling of the spine; when missing as a result of rough handling the pit and swelling can usually be located to confirm the original presence of a seta), the outer spine much larger than the inner two (Fig. ); first and third antennal segments about the same length, and both longer than the second (Fig. ) Magicicada
2' Four to eight apical, metatibial seta-bearing spines present, the outer spine not the largest (Figs. ); first antennal segment longer than either second or third (Fig. ) 3
3(2') Mesotibiae without lateral seta-bearing spines above apex; metatibiae with 3 - 5 (usually 5 ) large, ventral, apical, seta-bearing spines (Fig. ); second abdominal sternite with a median, setiferous, triangular process (Fig. ); metasternal process large and usually strongly mounded (Fig. ) Tibicen
3' Mesotibia with one or more lateral seta-bearing spines above apex; metatibiae with 4 - 8 (usually 6) large, ventral, apical, seta-bearing spines (Fig. ..); second abdominal sternite without a setiferous, triangular process (Fig..); metasternal process crest-like (Fig..) Diceroprocta
4(1) Two large, apical, metatibial seta-bearing, spines present (Fig. ) (setae are born anteapically on the inner side of each tibial spine, associated with an articulating pit and slight swelling of the spine; when missing as a result of rough handling the pit and swelling can usually be located to confirm the original presence of a seta); three large, apical, mesotibial seta-bearing, spines present, the inner one longest and the outer two subequal in length (the outermost shorter than middle in some western species) Okanagana
4' Three or more large, apical, metatibial and mesotibial seta-bearing spines present, the inner spine on both pairs of legs may be the longest 5
5(4') Three large, apical, metatibial seta-bearing spines present (sometimes two on one side), three or four large, apical mesotibial seta-bearing spines present, the inner spine longest on both pairs of legs (Figs. ); body length over 18 mm; antennal segment 1 slightly longer than or subequal to 2 Okanagodes
5' Three or more large, apical, metatibial and mesotibial seta-bearing spines present, the inner one on the mesotibiae not the longest (Figs. ) 6
6(5') Body length over 18 mm; five large, apical, metatibial and mesotibial seta-bearing , spines present, the second from the inner longest, the outer spine smallest (Fig. ); antennal segment 1 obviously longer than 2, and 2 longer than 3 Neocicada hieroglyphica
6' Body length under 18 mm; three or four large, apical, metatibial and mesotibial seta-bearing spines present (Figs. ); antennal segments 1 - 3 approximately the same length 7
7(6') Three large, apical, metatibial seta-bearing, spines present (Figs. ); fore tibiae with a single apical claw-like process (Figs. ); especially common in prairie areas 8
7' Four large, apical, metatibial seta-bearing spines present (Fig. ); apex of fore tibiae cleft, showing two prominent claw-like processes (Fig. ); especially common in mesquite areas Pacarina puella
8(7) Mesonotum with an anterior, broad, transverse, brown band (Fig. ); triangular area around median ocellus (front between epicranial arms and fronto-clypeal suture) brown in strong contrast to the cuticle of the compound eyes (Fig. ); apex of fore femoral thumb in front of projected midline of femur (Fig. ) Melampsalta calliope
8' Mesonotum without a basal, transverse, brown head; front between epicranial arms and fronto-clypeal suture not pigmented in strong contrast to the cuticle of the compound eyes (Fig. ); apex of fore femoral thumb behind projected midline of femur (Fig. ) Beameria venosa


Key to sex for fourth to last (fifth) instar cicada nymphs

A Terminal, ventral abdominal structures similar to those in Fig. , ninth sternite with a small central single bulbous lobe Male
A' Terminal, ventral abdominal structures similar to those in Fig. , eighth abdominal sternite with a pair of finger-like longitudinal processes at midline Female
Revised 1 Apr. 2001