SPERCHOPSINI Hansen, 1991

Minoshima, Yûsuke & Hayashi, Masakazu, 2011, Larval morphology of the genus Hydrocassis Fairmaire (Coleoptera: Hydrophilidae), Journal of Natural History 45 (45 - 46), pp. 2757-2784 : 2759-2760

Tribe SPERCHOPSINI Hansen, 1991

Key to the genera of the larvae of the tribe Sperchopsini (excludes the genus Cylomissus ) for all known instars

1. Nasale with two teeth; mandibles with two inner teeth; inner surface of stipes with more than nine rather stout setae; dorsal sclerite of abdominal segment 8 subdivided into two halves; Neotropical region. (Only third instar larvae are known.)................................................. Anticura Spangler

Nasale with four or five teeth ( Figures 2C , 4C , 10C ); mandibles with three inner teeth ( Figure 7B,C ); inner surface of stipes with five to eight rather stout setae; dorsal sclerite of abdominal segment 8 not subdivided medially ( Figure 6D ); Palaearctic, Nearctic and Oriental regions............................ 2

2. Clypeolabrum distinctly asymmetrical; epistomal lobes with stout setae; frontal lines not fused at base. (Only third instar larvae are known.)....................................................... Ametor Semenov

Clypeolabrum almost symmetrical or slightly asymmetrical ( Figure 6C ); epistomal lobes with rather slender setae ( Figure 6C ); frontal lines fused at base ( Figure 6B ).............................................................. 3

3. Inner surface of stipes with seven to eight setae; Nearctic region............................................... Sperchopsis LeConte

Inner surface of stipes with five setae ( Figures 3C , 5D ); eastern Palaearctic and Oriental regions...................................... Hydrocassis Fairmaire

Figures

Figure 2. Primary chaetotaxy of head capsule of Hydrocassis lacustris Sharp, first instar. (A) Dorsal view; (B) ventral view; (C) detail of anterior margin of head capsule, dorsal view.

Figure 3. Primary chaetotaxy of head appendages of Hydrocassis lacustris Sharp, first instar. (A) Right antenna, dorsal view; (B) left mandible, dorsal view; (C) left maxilla, dorsal view; (D) left maxilla, ventral view; (E) labium, dorsal view; (F) labium, ventral view. Black square indicates additional sensilla.

Figure 4. Hydrocassis jengi Satô, second instar, dorsal view. (A) Whole larva; (B) head; (C) clypeolabrum; (D) spiracular atrium; (E) tubercular pattern of thoracic and abdominal segments. Abbreviations: T3, metathorax; A1, 2, 6, 7, abdominal segments 1, 2, 6 and 7.

Figure 5. Head appendages of Hydrocassis jengi Satô, second instar. (A) Right antenna, dorsal view; (B,C) mandibles, dorsal view; (D) right maxilla, dorsal view; (E) right maxilla, ventral view; (F) labium, dorsal view; (G) labium, ventral view. Black square indicates additional sensilla.

Figure 6. Hydrocassis lacustris Sharp, third instar, dorsal view. (A) Whole larva; (B) head; (C) clypeolabrum; (D) spiracular atrium; (E) tubercular pattern of thoracic and abdominal segments. Abbreviations see Figure 4.

Figure 7. Head appendages of Hydrocassis lacustris Sharp, third instar. (A) Right antenna, dorsal view; (B,C) mandibles, dorsal view; (D) left maxilla, dorsal view; (E) left maxilla, ventral view; (F) labium, dorsal view; (G) labium, ventral view. Black square indicates additional sensilla.

Figure 10. Hydrocassis uncinata Ji et Schödl, third instar, dorsal view. (A) Whole larva; (B) head; (C) clypeolabrum; (D) spiracular atrium; (E) tubercular pattern of thoracic and abdominal segments. Abbreviations see Figure 4.