Dilasia Reuter, 1871

Carpintero, Diego Leonardo, 2014, Western Hemisphere Lasiochilinae (Hemiptera: Heteroptera: Anthocoridae) with comments on some extralimital species and some considerations on suprageneric relationships, Zootaxa 3871 (1), pp. 1-87 : 17-18

Dilasia Reuter, 1871

Dilasia Reuter, 1871: 563 . ( Reuter, 1884: 20, as subgenus of Lasiochilus ). Type-species by monotypy: Dilasia fuscula Reuter, 1871 (Generic rank restored by Carpintero, 2002: 27).

Lasiochilus (Dilasia) Reuter, 1884: 20 .

DESCRIPTION: Male: Dorsal view: Medium-sized species, oblong-oval, not flattened dorso-ventrally (excepting in sulcicollis ). Head: Antennal segment II nearly 2.5x the length of I with sparse pilosity, segment I and II with setae not longer than twice the width of segment; labium long and reaching to midcoxae or, in some species, to hindcoxae; segment I very short, not reaching base of antennal segment I. Thorax: Pronotum smooth, laterally carinate, with slightly elevated calli. Anterior lobe of pronotum smooth, sometimes with median longitudinal sulcus, never deep ( sulcata, sulcicollis ); posterior lobe rugose, sometimes smooth ( fuscula ), collar present, lateral margins not sinuate. Midfovea present. Scutellum rugose. Hemelytral margins not sinuate, commonly shorter (specially in females) than length of abdomen, not punctured or, if so, only slightly and never (exc. in punctipennis ) with a seta emerging from each puncture. Membrane not translucent. Cuneus smooth. Ostiolar peritreme short and slightly curved posteriorly ( Figs. 13–14 ); forefemora enlarged, sometimes unarmed, sometimes ( D. foveicollis ) with few spiniform teeth on inner margin of basal third or armed with long spines (especially in Old World species). Foretibiae with row of spiniform teeth. Foretrochanters also with row of spiniform teeth on inner margin. Pads well developed. Metasternum elongate (excepting in foveicollis and colludens where it is short and rounded); prominence narrow. Abdomen: Dorsal pilosity present only on outer margins. Genitalia: Left paramere slightly curved to nearly straight, short to medium-sized and apically not acute. Right paramere absent. Grouping of copulatory teeth on apical left margin of sixth sternite, apically acute, spiniform. Female: Similar to male in measurements and coloration; forelegs more slender and unarmed. Genitalia: parietovaginal gland absent or at least inapparent in most species (not easily distinguishable in slidemounted specimens). Seventh sternite not punctured centrally.

DISTRIBUTION: Worldwide, especially in tropical and subtropical areas.

DISCUSSION: In 2002, the author restored this group to generic level on the basis of “classic” external characters. For this reason, only species formerly described under Lasiochilus (Dilasia) were included. Now, following the analysis of a series of new characters, the group is redefined and the number of species increased to 19, including some new species. This genus is easily recognizable from Lasiochilus in having the secondary sexual characters on males consisting of groups of copulatory spines, spines on the inner margin of the foretibiae and on the foretrochanters,the shorter and weakly curved left paramere, and by the lack of deep punctures on scutellum and hemelytra. The author also had the opportunity to see some Old World Lasiochilinae and all could be placed in the genus Dilasia . Probably, future studies will show that most of the Old World Lasiochilus belong to this genus.

Key to Western Hemisphere species of Dilasia

1. Hemelytra with punctures on clavus and endocorion with a seta emerging from each of these punctures ( Fig. 133 ).................................................................................... punctipennis Champion, 1900

- Hemelytra without punctures ( Fig. 154 ).................................................................... 2

2. Smaller species (1.60–1.80 mm). Males with forefemora armed with spines on the inner margin ( Fig. 97 )............................................................................................. foveicollis ( Champion, 1900)

- Larger species (≥ 2 mm). Males with forefemora unarmed..................................................... 3

3. Labium long, reaching the midcoxae....................................................... neotropicalis n. sp.

- Labium shorter, usually reaching only the middle of mesosternum, or slightly beyond, but never reaching the midcoxae.... 4

4. Apex of ostiolar peritreme opening thickened and elevated................................... basalis ( Reuter, 1884)

- Apex of ostiolar peritreme opening thinner and flattened....................................................... 5

5. Hemelytra bicolored, dark brown with base of clavus and corion pale yellowish................ ashlocki ( Herring, 1966)

- Hemelytra unicolored, or sometimes with small areas paler or with clear spots.................................... 6

6. Males without secondary sexual characters; i. e. no grouping of copulatory teeth in left apical angle of sixth sternite and no teeth in the inner margin of foretibiae (fig. 74) or foretrochanters................................... cuscoensis n. sp.

- Males with secondary sexual characters or at least, some of them present.......................................... 7

7. Anterior lobe of pronotum sulcate medially................................................................. 8

- Anterior lobe of pronotum smooth........................................................................ 9

8. Flattened dorso-ventrally. Left paramere apically subquadrate ( Fig. 165 )..................... sulcicollis ( Reuter, 1884)

- Not flattened dorso-ventrally. Left paramere apically acute ( Fig. 162 )....................... sulcata ( Champion, 1900)

9. Only brachypterous forms present in both sexes ( Fig. 44 ).......................................... carvalhoi n. sp.

- Macropterous forms. If brachyptery, only in some females.................................................... 10

10 Antennal segment II of homogeneous width throughout length ( Fig. 60 )......................................... 11

- Antennal segment II thickened towards the apex ( Fig. 57 )..................................................... 12

11. Head black or at least darker than the remainder of body ( Fig. 89 )............................ galateae ( Reuter, 1884)

- Head of the same colour as pronotum ( Fig. 46 )................................................ crassicornis n. sp.

12. Males with left paramere “hammer-type” and bearing a transverse apical prominence ( Figs. 56 )...................... 13

- Males with left paramere linear or slightly widened apically................................................... 16

13. Hemelytra dark...................................................................................... 14

- Hemelytra pale...................................................................................... 15

14. Apex of metasternum not elongate ( Fig. 52 ) (as in Anaelia mirifica ). Hemelytra dark brown....... colludens ( White, 1879)

- Apex of metasternum elongate. Hemelytra reddish-brown ( Fig. 88 ).............................. fuscula Reuter, 1871

15. First antennal segment darker than others; head prolonged anteriorly from base of antennae; left paramere sinuate ( Fig. 169 ).................................................................................... unicolor Reuter, 1884

- Antennae evenly unicolored; head short and wide; left paramere slightly curved ( Fig. 148 )...... reuteri ( Champion, 1900)

16. Hemelytra dark brown with some areas and spots paler...................................................... 17

- Hemelytra uniformly dark brown........................................................................ 18

17. Left paramere slightly sinuate, not widened subapically and apically acute ( Fig. 85 )................. gracilicornis n. sp.

- Left paramere straight, slightly widened subapically, and apically rounded ( Fig. 158 )..................... similis n. sp.

18. Left paramere short and widened subbasally ( Fig. 173 )...................................... varicolor (Uhler, 1894)

- Left paramere longer and nearly linear ( Fig. 121 )...................................... microps ( Champion, 1900)

Figures

FIGURES 1–16. Left metapleura of different genera of Lasiochilinae showing the ostiolar peritreme and metapleural microsculpture. 1–2, Plochiocoris (350X and 1000X respectively); 3–5, Eusolenophora (350X, 1000X and 2000X); 6–9, two species of Lasiocolpus showing the small specific differences following a generic pattern: 6–7, L. minor (200X and 1000X) and 8–9, L. sinuaticollis (200X and 1000X); 10–12, Anaelia (200X, 1000X and 2000X); 13–14, Dilasia (200X, and 2000X); 15–16, Lasiochilus (200X, and 2000X).

FIGURES 132–136. D. punctipennis. Male. 132, Pronotum and foretibia showing the spines (Sp) on internal margin; 133, Scutellum and hemelytron; 134, Metasternum; 135, Copulatory spines (Csp); 136, Pygophore showing left paramere (LP).

FIGURES 149–158. D. similis. Male. 149, Head; 150, Pronotum; 151, Foretibia showing the spines (Sp) on internal margin and pad (Fos); 152, Apical half of foretibia; 153, Spines on foretrochanter (Tsp); 154, Hemelytron; 155, Sternum and base of abdomen showing the metasternum (Ms); 156, Copulatory spines (Csp); 157, Pygophore showing left paramere (LP); 158, Detail of left paramere.

FIGURES 95–101. D. foveicollis. Male. 95, Head and pronotum. Foretibiae showing the spines (Sp) on internal margin and pad (Fos); 96, Apical half of foretibia; 97, Spines on foretrochanter (Tsp) and base of internal margin of forefemur (Fsp); 98, Metasternum; 99, Copulatory spines (Csp); 100, Detail of left paramere. Female. 101, Genitalia.

FIGURES 163–165. D. sulcicollis. Male. 163, Copulatory spines (Csp); 164, Pygophore showing left paramere (LP); 165, Detail of left paramere.

FIGURES 159–162. D. sulcata. Male. 159, Apical half of foretibia showing the spines (Sp) on internal margin and pad (Fos); 160, Copulatory spines (Csp); 161, Punctures on dorsal surface on pygophore (PP); 162, Detail of left paramere.

FIGURES 43–47. Species of genus Dilasia. 1. 43, D. ashlocki Female, allotype (2.24 mm); 44, D. carvalhoi Female, holotype (2.24 mm); 45, D. colludens Male (2.27 mm); 46, D. crassicornis Male holotype; 47, D. gracilicornis Male paratype.

FIGURES 60–72. Dilasia crassicornis. Male. 60, Head, 61, Pronotum; 62, Foretibia showing pad (Fos) and row of spines (Sp); 63, Pad; 64, Foretrochanter showing spines (Tsp); 65, Hemelytron; 66, Sternum and base of abdomen showing metasternum (Ms); 67, Copulatory spines (Csp); 68, Pygophore; 69, Detail of processus penniformis (Prp) on aedeagus; 70, Detail of punctures on dorsal surface on pygophore (PP); 71, Detail of left paramere; 72, Prominence on pygophore beneath the paramere (Pro).

FIGURES 56–59. Dilasia colludens. Male. 56, Detail of left paramere (LP). Female. 57, Head and pronotum; 58, Metasternum; 59, Genitalia showing the parietovaginal gland (PG).

FIGURES 86–94. Species of genus Dilasia. 2. 86, D. foveicollis Male; 87, Idem. Male, holotype (1.75 mm); 88, D. fuscula Female, syntype (2.83 mm); 89, D. galateae; 90, D. microps; 91, Idem. Female holotype (2.53 mm); 92, D. neotropicalis Female holotype (2.65 mm); 93, D. punctipennis (2.56 mm); 94, Idem. Male holotype.

FIGURES 50–55. Dilasia carvalhoi. Male. 50, Fore leg; 51, Foretibia showing the row of spines (Sp) in the inner margin; 52, Metasternum; 53, Pygophore; 54, Detail of punctures on pygophore (PP) visible from above; 55, Detail on left paramere.

FIGURES 166–169. D. unicolor. Male. 166, Copulatory spines (Csp); 167, Pygophore showing left paramere (LP); 168, Detail of processus penniformis (Prp) on aedeagus; 169, Detail of left paramere.

FIGURES 145–148. D. reuteri. Male. 145, Copulatory spines (Csp); 146, Pygophore showing left paramere (LP) and processus penniformis (Prp) on aedeagus; 147, Detail of processus penniformis; 148, Detail of left paramere.

FIGURES 79–85. D. gracilicornis. Male. 79, Head and pronotum; 80, Foretibia showing a reduced pad (Fos) and the row of spines (Sp) on internal margin; 81, Apex of foretibia; 82, Hemelytron; 83, Sternum and base of abdomen showing the metasternum (Ms); 84, Copulatory spines (Csp); 85, Detail of left paramere.

FIGURES 170–173. D. varicolor. Male. 170, Copulatory spines (Csp); 171, Pygophore showing left paramere (LP); 172, Detail of processus penniformis (Prp) on aedeagus; 173, Detail of left paramere.

FIGURES 113–123. D. microps. Male. 113, Head; 114, Pronotum; 115, Foretibia showing the spines (Sp) on internal margin and pad (Fos); 116, Apical half of foretibia; 117, Spines on foretrochanter (Tsp); 118, Sternal area showing the metasternum (Ms); 119, Copulatory spines (Csp); 120, Pygophore showing left paramere (LP); 121, Detail of left paramere. Female. 122, Genitalia; 123, Detail of punctures (Pfg).