Gessius Distant

Viraktamath, C. A., 2006, Revision of the leafhopper tribe Krisnini (Hemiptera: Cicadellidae: Iassinae) of the Indian subcontinent, Zootaxa 1338, pp. 1-32 : 4-5

Gessius Distant

Gessius Distant 1908: 301 . Type species: Gessius verticalis Distant , by original designation.

Large green or reddish brown leafhoppers.

Head narrower than pronotum, crown short, of uniform length, anteriorly rounded to face, transversely striate. Eyes large, protruding. Ocelli on upper margin of face, sometimes visible dorsally, placed at a distance at least twice own diameter away from adjacent eye. Antennal ledges prominent, extending almost 0.25 distance on frons. Frontoclypeus transversely striate, slightly tumid. Gena wrinkled, lora shagreened. Labrum widened and shallowly emarginated apically. Labium extending to hind margin of prosternite. Pronotum gibbous, transversely striate, lateral margins less strongly widened posteriorly than in Krisna . Scutellum longer than pronotum. Forewings with large appendix, without accessory veins in apical region, claval veins apically forked, three closed subapical cells and four apical cells, inner apical cell narrow and elongate. Hind femoral spinulation 2+2+1; hind tibial spinulation R1 24±2, R2 11±1, R3 14±1; four platellae on apical transverse row of hind basitarsus. Basal tergal abdominal apodemes well developed, sternal apodemes not well developed. Male eighth sternite large, devoid of setae.

Male pygophore elongate, rounded at caudal end, junction between lobe and main body unpigmented, with a ventral process. Style typical of Iassinae , apophysis of style elongate, narrowed distally, apically curved, bluntly pointed. Connective T-shaped, with median lobelike prolongation on anterior margin. Aedeagus with well developed preatrium and short dorsal apodeme; shaft ventrally concave, gonopore subapical,.

Female with large seventh sternite, hind margin concave in the middle. First pair of gonapophysis arched, with scalelike sculpturing. Second pair of gonapophysis with three prominent teeth in distal 0.33.

Remarks: Gessius and Krisna resemble each other especially in the male genital structure and general form. There are, however, subtle differences in the two genera. The most important among them is the shape of the anterior margin of head which is rimmed or angled in Krisna , whereas it is rounded to face in Gessius ; in Krisna the ocelli are placed either close to the eyes or at a distance equal to their own diameter away from the adjacent eye; lora are wrinkled in Krisna but they are shagreened in Gessius ; the male eighth sternite is covered with setae in Krisna but lacks setae in Gessius ; the forewing of Krisna has a number of accessory veins in the apical cells but these veins are absent in Gessius ; the claval veins are not forked in Krisna whereas they are in Gessius .

The species of Gessius described by Baker (1919), G. malayensis Baker and G. pallidus Baker , do not belong to Gessius because of the shape of the head and position of the ocelli ( Baker 1919: Plate V, Figs 6, 7, 9 ). They probably belong to the genus Krisna .

Figures

FIGURES 1 – 11. Female Gessius verticalis Distant, topotype: 1. Head & thorax; 2 Face; 3. Head & thorax profile; 4. Forewing; 5. Hind wing; 6. Ovipositor; 7. Female seventh sternite; 8. First pair of gonapophysis; 9. Second pair of gonapophysis; 10 – 11. Sculpturing at apex and at base of second pair of gonapophysis.