Eight Pelecorhynchus species are known for Tasmania: fusconiger (Walker), igniculus Hardy, nigripennis Ricardo, olivei Hardy, eristaliodes (Walker), albolineatus Hardy, occidens Hardy, and montanus Hardy. All Tasmanian species, except P. fusconiger, belong in the personatis-Group of Mackerras & Fuller (1942):
Sexes similar; scutum never with sharply defined yellowish dorsocentral lines; wings with or without dark markings, but never with a bright flavid tint; abdomen tomentose dorsally and ventrally, but never orange in colour, always fasciate, and frequently with a median dark vitta, but never with lateral dark vittae.
Key to Tasmanian Pelecorhynchus – adapted from Mackerras & Fuller (1942):
| 1. | Abdomen black, shiny, devoid of tomentum or pattern dorsally (black hairs present, and laterally white tufts present); scutum brown with pale obscure dorso-central lines; wings without spots (Fig. 1) …………………………………..fusconiger (Walker) | P._fusconiger |
| Abdomen not shiny black, usually with distinctive pattern of bands and/or spots (if without pattern, then wings spotted); wings with spots or not; scutum usually with distinctive pattern (Figs 2, 3, 4) …………………………………..2 | →couplet_2 |
 |  |
 |  |
| 2. | Wings with dark spots, arranged in groups (Figs 3, 4a, 4c); abdomen with or without distinct bands or spots; abdomen with or without reddish hairing …………………………………..3 | →couplet_3 |
| Wings without spots, at most with an obscure darker mark at the apices on the basal cells; abdomen black, with the 2nd, 3rd, and 4th visible tergites with a pale band that are narrowly interrupted in the middle; abdomen lacking red hairs, instead those of colour being yellowish (Figs 4b, 11) …………………………………..8 | →couplet_8 | |
| 3. | Abdominal pattern very obscure, the pale bands on the 2nd, 3rd, and 4th visible tergites barely visible and never interrupted medially; abdominal sutures with conspicuous firey red hair; wing spots small and discrete; scutum brownish, with two black stripes each of which are divided longitudinally by a thin white line in the anterior half (Fig. 2) …………………………………..igniculus Hardy | P._igniculus |
| Abdominal bands or spots clearly defined; red hair present or not; wing spots generally larger, confluent in areas or not …………………………………..4 | →couplet_4 | |
| 4. | Pale abdominal fasciae (transverse bands) complete, dark fasciae partly interrupted by a pale median indentation (Fig. 3); wing spots blackish and confluent (forming bands) (Figs 5, 6) …………………………………..5 [Species with reddish hairing present on parafacials (next to face) and in patches on sides of the thorax.] | →couplet_5 |
| Abdomen with either a median dark vitta, or the dark abdominal bands confluent centrally, thus interrupting any pale fasciae there; wings spots not forming bands, and not strongly blackish (Figs 7, 8, 9) …………………………………..6 [Species lacking reddish hairing on parafacials or laterally on thorax (excluding infra-scutellar tuft).] | →couplet_6 | |
| 5. | Dark areas of scutum median and lateral areas blackish; scutum lateral areas lacking distinctive pale patches or streaks; wings with base of costa (between basicosta and humeral vein) with bright decumbent short hairing (Figs 3, 5) …………………………………..nigripennis Ricardo [The bright red short hairing on base of wing costa is not described or figured in the literature but all other characters agree with this species as presented by Mackerras & Fuller (1942). Only mainland field sightings could be found for this species (as interpreted here), though Tasmanian specimens are recorded in Mackerras & Fuller (1942).] | P._nigripennis |
| Dark areas of scutum median and lateral areas deep brown; scutum lateral areas with additional pale grey patches, including a large grey patch across and forward of the transverse suture; wings with base of costa (between basicosta and humeral vein) lacking short reddish hairing (Fig. 6) …………………………………..nr. nigripennis (undescribed species?) [Pelecorhynchus that shares the reddish hairing on parafacials and wide pale banding on abdomen with P. nigripennis, with scutum patterning and colour more in line with P. mackerras from WA. This form appears to be present also on the mainland.] | P._nr._nigripennis |
 |  |
 |
| 6. | The dark abdominal bands confluent centrally, and enclosing a conspicuous white spot at the centre of each segment (Fig. 7) …………………………………..olivei Hardy | P._olivei |
| Abdomen with a median black vitta, not enclosing a white a series of white central spots (Figs 8, 9) …………………………………..7 | →couplet_7 | |
| 7. | Dorso-central lines of scutum black, enclosing a white spot at the suture; infra-scutellar tuft and abdominal apical tergite fringe hairs red (Fig. 8) …………………………………..eristaloides (Walker) | P._eristaloides |
| Dorso-central lines of scutum black, enclosing a white line which ends posteriorly at the suture; infra-scutellar and abdominal hairs pale gold (Fig. 9) …………………………………..albolineatus Hardy | P._albolineatus |
 |  |
| 8. | Posterior margin of scutum with a median dark brown triangular spot, which is continuous with the similarly coloured mark of the scutellum; thorax with dark brown dorso-central lines discontinued just before the scutellum, these lines interrupted at the mesoscutal suture by a greyish-white spot, the internal margins of each line rather straight (Fig. 10a) …………………………………..occidens Hardy [P. occidens is very similar to P. montanus, being originally described as a variation of that species.] | P._occidens |
| Median part of posterior margin of scutum entirely pale; thorax with dark brown dorso-central lines discontinued just before the scutellum, these lines interrupted at the mesoscutal suture by a slate-coloured spot, the internal margins of each line ‘shaped’ irregularly, leaving the line largely wider where they shape inwards (Figs 10b, 11)…………………………………..montanus Hardy | P._montanus |
 |  |