Diptera.info

Thread subject: Diptera.info :: Chironomidae - Hong Kong

Posted by Clive Lau on 30-01-2013 03:18

Found in Hong Kong on 12.i.2013. Grateful for its identification.

Posted by Clive Lau on 30-01-2013 03:19

Abdomen

Posted by Clive Lau on 30-01-2013 03:20

Lateral View

Posted by Clive Lau on 30-01-2013 03:20

Wing

Posted by John Carr on 30-01-2013 04:39

Do you have a dorsal closeup of the genitalia (at the tip of the abdomen)? What is the ratio of length of length of fore tarsomere 1 to fore tibia? Are eyes hairy?

Posted by Clive Lau on 31-01-2013 05:00

Dorsal closeup of the genitalia

Posted by Clive Lau on 31-01-2013 05:01

Genitalia of another specimen

Posted by Clive Lau on 31-01-2013 05:03

Ration of tarsomere 1 to fore tibia

0.925 mm : 0.382 mm = 2.42 : 1

Posted by Clive Lau on 31-01-2013 05:05

I'm not familiar with Chironomidae taxonomy. As such, the whole foreleg is included here for your checking of measurements.

Posted by Clive Lau on 31-01-2013 05:06

#10

The eyes do not appear hairy to me.

Posted by Clive Lau on 31-01-2013 05:07

#11

Alternative view of the eyes from different angle.

Posted by John Carr on 31-01-2013 13:05

#12

The ratio 925:382 (basitarsus:tibia) is the "leg ratio". The front leg ratio is usually over 1 in Chironominae and 1 or less, usually around .6, in other subfamilies. So you have a Chironominae. This is confirmed by genitalia: the gonostylus is not freely articulated in this subfamily but more or less fused to the gonocoxite.

Is the base of tergite 8 constricted naturally or crushed? It is constricted naturally in Polypedilum but the genitalia do not look like that genus. Most Chironomini have additional pairs of appendages between the outer claspers. It is also constricted in many Tanytarsini but other factors argue against that ID.

Posted by Clive Lau on 31-01-2013 14:37

#13

Tergite 8 is constricted naturally. The genera belonging Chironominae known from this part of the world (Guangdong Province) include:

Chironomus
Cladopelma
Dicrotendipes
Einfeldia
Glyptotendipes
Harnischia
Kiefferulus
Microchironomus
Nilodorum
Polypedilum
Rheotanytarsus
Robackia
Shangomyia
Stenochironomus
Tanytarsus
Xiaomyia

Will this help to further narrow now the possible ID of this fly?

Edited by Clive Lau on 31-01-2013 23:50

Posted by John Carr on 01-02-2013 02:39

#14

Possibly Polypedilum (Pentapedilum), Tanytarsus, or Rheotanytarsus. I have difficulty interpreting the genitalia. There may be damage. I know nothing of Xiaomyia. The rest can be ruled out for various reasons: tergite 8 is not triangular or the eye does not have a strong extension over the base of the antenna.

Your antennae have more than 11 flagellomeres. Chironominae primitively have 13 flagellomeres. This number is reduced to 11 in a large group of Chironomini including Chironomus, to 12 in many Tanytarsini, and to 11 or fewer in several smaller groups.

Pentapedilum was revised recently. http://insects.um...lum%20.pdf