Diptera.info - Discussion Forum: Platypalpus

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Platypalpus
John Sankey	#1 Posted on 21-05-2012 01:56
Member Location: Ottawa Canada Posts: 156 Joined: 24.04.12	5 mm 20 May 2012 John Sankey attached the following image: [74.2Kb] Edited by John Sankey on 15-10-2012 22:40


John Sankey	#2 Posted on 21-05-2012 01:56
Member Location: Ottawa Canada Posts: 156 Joined: 24.04.12	head John Sankey attached the following image: [68.68Kb]


Roger Thomason	#3 Posted on 21-05-2012 02:15
Member Location: Mossbank,Shetland Isles. Posts: 3994 Joined: 17.07.08	Looks like Hybotidae: Platypalpus sp.


John Carr	#4 Posted on 21-05-2012 02:38
Member Location: Massachusetts, USA Posts: 1437 Joined: 22.10.10	Resembles Platypalpus harpiger Melander, 1924, described from Massachusetts. I can't see all the details and it is a notoriously difficult genus.


John Sankey	#5 Posted on 26-05-2012 17:31
Member Location: Ottawa Canada Posts: 156 Joined: 24.04.12	John, what details do you need to improve the chances of an ID?


John Carr	#6 Posted on 27-05-2012 04:28
Member Location: Massachusetts, USA Posts: 1437 Joined: 22.10.10	The problem is not the pictures. The ones you added on BugGuide should be good enough for ID by an expert. The problem is the latest reference I have is from 1928. Platypalpus harpiger was described based on a single specimen and as of 1965 was known only from that specimen. I have identified several flies as that species based on Melander's 1928 revision. That makes me very suspicious. The fly could be commonly photographed now yet rarely collected in the past. Or I could be wrong. Here is the original description. The fly matches very well except for antennae and the single pair of yellow hairs on the head instead of two pairs. **** Platypalpus harpiger, sp. nov. [Female] -- Length 5 mm. Body black, head and thorax closely gray pollinose, legs including coxae entirely yellow, the tip of the long tibial spur alone black; base of abdominal segments with narrow interrupted pollinose fasciae; antennae yellow, the third joint short; cross-veins separated, the posterior oblique. Front and face with parallel sides, the ground-color of the face yellow; epistome pollinose; one pair each of ocellar and vertical bristles yellow; proboscis black; palpi large, securiform, pale yellow, with a few pre-apical white hairs; antennae entirely yellow, the outer joint triangular, twice as long as deep and two-thirds as long as the black, moderately thick arista. Pollinosity of mesonotum dense, the setulae of the acrostichal and dorso-central rows and the bristles yellow, four scutellar bristles, center of sternopleurae polished; last two segments of the abdomen opaque, the stiles linear. Front femora with about a dozen outstanding flexor yellow hairs; middle femora with twenty-eight black setulae in each of the flexor series and with about six yellow bristles in front toward the knee and about a dozen longer yellow bristles in the posterior row; middle tibiae more than two-thirds the length of the femora. Calypteres, fringe and entire halteres pale yellow. Veins yellowish becoming slightly darker toward the tip, the second, third and fourth sections of the costa proportioned 7:6:1; third vein gently swinging back and ending a little beyond the tip of the wing, fourth vein quite strongly bowed, the first posterior cell widest at the middle where it occupies two-sevenths of the wing-width; cross-veins at two-fifths the wing-length, distance between the cross-veins two-thirds the length of the anterior cross-vein; base of anal vein very weak. Holotype.--Boston, Massachusetts, June, 1914 (Melander).


John Sankey	#7 Posted on 27-05-2012 13:09
Member Location: Ottawa Canada Posts: 156 Joined: 24.04.12	Many thanks, John. Maybe Bugguide will leave the photos up long enough for another expert to weigh in. I'll keep a watch here and there.