Ducetia Stål, 1874 .

Diagnosis: Radius of fore wings with pectinately arranged posterior branches, usually three or more in number and often closely parallel to each other. Pronotum without lateral carinae; lateral pronotal lobes with distinct angle in antero-ventral region of margin. Fastigium of vertex compressed, sulcate above. Fore tibiae with oval tympanic opening on both sides. Fore coxal spine very small or absent. Male cerci thick, moderately curved, apex with interno-ventral ridge, female cerci gradually tapering apically. Ovipositor relatively narrow, upturned almost semicircularly upward; apical part of lower margin and almost of upper margin finely serrate.

Key to Indian species of Ducetia, Stål 1874

1. 1. Venation: tegmina radius (Rs 4–6) branching pectinately (Fig. 1 (b)–(i))........................................ 293

- Venation: tegmina radius (Rs 2) not branching pectinately (Fig. 1 (b)–(ii))...................................... 294

2. 2. Fore coxa armed.................................................................................... 295

- Fore coxae unarmed.............................................................................. inerma

2. 3. Subgenital plate with deep medial furrow, space between hind lobes wider at top (Fig. 1 (c)–(i))................. japonica

- Subgenital plate with deep medial furrow, space between hind lobes narrow towards top........................... 296

2. 4. Subgenital plate triangular, with a deep medial furrow................................................ dichotoma

- Subgenital plate triangular, without medial furrow...................................................... serrata

2. 5. Hind lobes of subgenital plate with a pronounced medial ridge (Fig. 1 (c)–(ii)).......................... assamica sp. n.

- Hind lobes of subgenital plate without medial ridge (Fig. 1 (c)–(iii))................................... rohinii sp. n.