Ommatides, Uhler, 1894

Hoey-Chamberlain, Rochelle & Weirauch, Christiane, 2019, Taxonomic revision of the New World big-eyed minute litter bug genus Ommatides Uhler (Hemiptera: Schizopteridae), Zootaxa 4585 (1), pp. 73-99 : 79-80

Key to species of Ommatides (males only)

Because diagnostic features at the species level are heavily tied to the labial armature in males, the provided key to species can only be applied to male specimens.

1 Total body length less than 1.25 mm ( Fig. 1 , O. insignis and O. zanderij sp. nov.)................................... 2

- Total body length greater than or equal to 1.25 mm ( Fig. 1 , remaining species)..................................... 3

2 Proximal half of forewing pale ( Fig. 1 , O. insignis ), 1st labial segment extending from head at right angle in lateral view ( Fig. 2 ); short, thickened forewing, almost elytrous ( Fig. 1 ; O. insignis ), total body length 1.05 mm ............ O. insignis Uhler

- Proximal half of forewing mostly dark with pale border along claval suture ( Fig. 1 , O. zanderij sp. nov.), 1st labial segment extending from head as rounded lobe in lateral view ( Fig. 2 , O. zanderij sp. nov.); macropterous with short wing ( Fig. 1 , O. zanderij sp. nov.), total length 1.24 mm ..................................................... O. zanderij sp. nov.

3 1st labial segment armed with stiff setae and dorsally with lobe on either side of labial groove ( Figs 2 , 4 , 5 , e.g., O. duodentis sp. nov. and O. pristis sp. nov.).......................................................................... 4

- 1st labial segment not armed with stiff setae and dorsally without lobe on either side of labial groove ( Figs 2 , 5 , O. nudus sp. nov.)................................................................................... O. nudus sp. nov.

4 4th labial segment with heavily sclerotized proximal, lateral and sometimes more distal, dorsal processes ( Figs 2 , 4 , 5 , e.g., O. duodentis sp. nov., O. tridentis sp. nov.)................................................................... 5

- 4th labial segment without heavily sclerotized processes ( Figs 2 , 5 , e.g., O. nudus sp. nov., O. pristis sp. nov.)............ 8

5 4th labial segment anteriorly with pair of short, lateral processes ( Fig. 5 , e.g., O. parvidentis , O. yoderi )................. 9

- 4th labial segment anteriorly with pair of long, lateral processes ( Figs 4 , 5 , e.g., O. duodentis sp. nov., O. tridentis sp. nov.). 6

6 Proximal processes of 4th labial segment strongly curved, apices pointing proximad ( Fig. 5 )........... O. tridentis sp. nov.

- Proximal processes of 4th labial segment straight or slightly curved, apices pointing distad ( Fig. 5 )..................... 7

7 Proximal processes of 4th labial segment slightly curved, apices acute and unarmed ( Fig. 5 )........... O. duodentis sp. nov.

- Proximal processes of 4th labial segment straight, apices blunt and with serrated spines ( Fig. 5 )................................................................................................. O. ornatus (Carpintero & Dellapé)

8 Macropterous ( Fig. 1 , e.g., O. duodentis sp. nov., O. nudus ), abdominal spiracle 8 placed on fully sclerotized tubercle of tergum 8 process ( Fig. 6 , white arrow)......................................................... O. pristis sp. nov.

- Submacropterous ( Fig. 1 , e.g., O. parvidentis sp. nov.) abdominal spiracle 8 placed on fully membranous tubercle of tergum 8 process ( Fig. 6 , black arrow)............................................................ O. pillcopata sp. nov.

9 Enlarged 1st labial segment consisting of large lobe with 10 short, stout setae along dorsal margin and smaller coiled lobes with 2 long, stout setae at tips ( Fig. 5 ; O. parvidentis sp. nov.)................................ O. parvidentis sp. nov.

- 1st labial segment with single lobe, beset with many short, stout setae ( Fig. 5 ; O. yoderi sp. nov.)........ O. yoderi sp. nov.

Figures

FIGURE 1. Dorsal habitus images of Ommatides spp. males and females.

FIGURE 2. Lateral habitus images of Ommatides spp. males and females. Black arrows pointing our 4th labial segment processes (O. duodentis male, O. tridentis male) and sparse setation of foretibia (O. nudus male)

FIGURE 4. SEMs of Ommatides parvidentis sp. nov. (UCR_ENT 00057523); (A) Head and thorax lateral, white arrows indicate the lateral margin of the pronotum and the enlarged 1st labial segment, (B) Head and thorax (minus wings) dorsal, (C) Head and thorax frontal, white arrows indicate the short setae along the dorsal edge of the 1st labial segment, the large setae on smaller lobes at tip of large lobes, the pair of short, proximal processes on the 4th labial segment, and sparse setation of foretibia, (D) hind coxa, white arrow indicating adhesive pad consisting of microtrichia on medial surface.

FIGURE 5. Labial structures of Ommatides spp. males in frontal view. Shading indicating degree of sclerotization. bubuccula; ca—conjunctival appendage; cly—clypeus; els—enlarged labial segment; mdpl—mandibular plate; mxpl—maxillary plate; proc—process; set—setae; spn—spine

FIGURE 6. Male genitalia of Ommatides spp.in dorsal view. Arrow indicating location of (or estimation of) abdominal spiracle 8 on tergum 8 process. ano—anophore; anop—anophoric appendage; at—anal tube; ca—conjunctival appendage; lpleft paramere; rp—right paramere; s9—sternum 9; t8—tergum 8; t8p—tergum 8 process; v—vesica.