Dilasia Reuter 1871
Creators: name: Carpintero, Diego Leonardo
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Anthocoridae
Dilasia

description: 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)
description: Published as part of Carpintero, Diego Leonardo, 2014, Western Hemisphere Lasiochilinae (Hemiptera: Heteroptera: Anthocoridae) with comments on some extralimital species and some considerations on suprageneric relationships, pp. 1-87 in Zootaxa 3871 (1) on pages 17-18, DOI: 10.11646/zootaxa.3871.1.1, http://zenodo.org/record/4947859