DOLICHOPODIDAE: CHRYSOSOMA GUERIN-MENEVILLE)
Igor Ya. GRICHANOV
Grichanov, I.Ya. Afrotropical species of the subgenus
Kalocheta Becker (Diptera: Dolichopodidae:
Chrysosoma Guerin-Meneville)
The first descriptions of the females of Chrysosoma
(Kalocheta) collarti and C. (K.) cucana
from Kenya and Uganda, catalogue and a key to Afrotropical
species of Kalocheta are given.
I.Ya. Grichanov, All-Russian Institute of Plant Protection,
Podbelskogo 3, St.Petersburg-Pushkin, 189620, Russia.
Key words: Diptera, Dolichopodidae, Chrysosoma (Kalocheta),
Africa, Kenya, Uganda.
The genus Kalocheta was established by Becker (1923) for two
females of Kalocheta passiva Becker from Camerun, and is closely
related to the genus Chrysosoma Guerin-Meneville, distinguishing only
by the widened lancet-shaped arista on the third antennal segment. As
in original description, the strap-like part of the arista is four
times as long as the hair-like portion. Later Curran (1925, 1927a,
1927b) and Parent (1929, 1933) found the species in Congo and Zaire
mentioning females and males but without concise descriptions.
A further four new species were described, mostly by males. Males
of Kalocheta liberia Curran (1929) have the hair-like part of arista
s long as the strap-like portion. This proportion was not defined
exactly for females. Males of Kalocheta collarti Parent (1933) have
the hair-like part of arista as long as the strap-like part. Females
were unknown. Males of Kalocheta villiersi Vanschuytbroeck (1970) have
the hair-like part 1.5 times as long as the widened part, and females
have filiform arista. The last statement is need cofirmation because
widened arista are characteristic of the genus. At last males of
Kalocheta cucana Negrobov & Kulibali (1983) have the ratio of
strap-like to hair-like parts of arista - 2.5:4.5. Females were
unknown. Bickel (1994) synonymized Kalocheta with Chrysosoma. Here I
consider Kalocheta as subgenus of Chrysosoma Guerin-Meneville, stat.
nov.
Revising the collection of the Natural History Museum (London) I
found two series of males and females of C.(K.) collarti, and one
female that is most nearly related to male of C.(K.) cucana. It
appeared that females had the strap-like part of arista 4 or more
times as long as the hair-like part, and males had the same part twice
as short as the filiform portion. The series of C.(K.) collarti
specimens also showed the sex and/or individual variability of such
characters as colour of antennae, halters, coxae, femora and tibiae
(from yellow in females to brown in males), shape and color intensity
of brown spots on wings, number and strength of dorsocentral bristles
(partly reduced in males) and postvertical bristles (partly reduced
in females).
Below are the first descriptions of the females of C.(K.)
collarti and C.(K.) cucana.
Chrysosoma (Kalocheta) collarti Parent
Female. Corresponds to male described by Parent (1933) with the
exception of the following characters. Antennae yellowish-brown.
Proportion of length to height of first flagellomere - 1.1:0.7.
Proportion of length of lancet-shaped part to thread-like parts of
arista - 8.4:1.2. Strap-like part of arista approximately 12 times as
long as width of arista. One pair of strong postvertical bristles near
the upper edge of eyes. 3 pairs of strong acrosticals and 5 pairs of
strong dorsocentrals. Legs yellow; fore coxae in basal forth, middle
and hind coxae and trochanters, hind tibiae near apex, hind tarsus,
apical segments of fore and middle tarsi brown. Length ratio of fore
coxae, femora, tibiae to tarsi (segments from first to fifth) -
7.4:11.0:12.2:8.0:2.3:1.3:1.0:1.3. Middle tibiae with 3 dorsal, 3-4
anterior and 2-3 ventral bristles, without long bristles. Length ratio
of middle femora, tibiae to tarsi (segments from first to fifth) -
14.2:18.0:14.5:3.7:2.2:1.1:1.1. Length ratio of hind femora, tibiae
to tarsi (segments from first to fifth) -
18.0:23.0:9.2:4.1:2.5:1.4:1.4. Halters yellow.
Length: body - 5.9 - 7.7 mm (with antennae - 9.0 - 10.7 mm), wing
- 6.6 - 7.7 mm.
Material examined: 8 males, 15 females, Kenya: 18.XII.1970 (A.E.
Stubbs), B.M. 1972-211. Kakamega, Forest, 5200 feet; 1 male, Uganda
Prot., S. of L. George, 3200-3400 ft, 17-19 Oct. 1911 (S.A. Neave); 2
females, Uganda Prot., Tero Forest, S.E. Buddu, 3800 ft, 26-30 Sep.
1911 (S.A. Neave) [The last 2 females det. by C.E. Dyte, 1963 as K.
passiva Beck.].
Chrysosoma (Kalocheta) cucana Negrobov et Kulibali
Female. Corresponds to male described by Negrobov and Kulibali
(1983) with the exception of following characters. Antennae red-brown.
Proportion of length and height of first flagellomere - 1.1:0.7.
Proportion of length of lancet-shaped and thread-like parts of arista
- 8.5:1.4. Strap-like part of arista approximately 11 times as long as
width of arista. One pair of strong postvertical bristles near the
upper edge of eyes. 3 pairs of strong acrosticals and 5 pairs of
strong dorsocentrals. Legs light-yellow; fore coxae in basal forth,
middle and hind coxae and trochanters, apical segments of tarsi brown.
Femora without long hairs. Length ratio of fore coxae, femora, tibiae
and tarsi (segments from first to fifth) -
6.2:10.8:12.9:7.9:1.9:1.4:0.9:1.0. Middle tibiae with 3-4
postero-dorsal, 5 antero-dorsal, 2 antero-ventral and 2
postero-ventral bristles, without long hairs. Length ratio of middle
femora, tibiae and tarsi (segments from first to fifth) -
13.2:17.8:10.4:3.4:1.5:1.0:0.8. Length ratio of hind femora, tibiae
and tarsi (segments from first to fifth) -
15.0:21.3:8.3:2.4:3.3:1.2:1.3. Halters yellow.
Length: body - 5.5 mm (with antennae - 8.5 mm), wing - 6.4 mm.
Material examined: 1 female, Uganda, Kigezi dist. Kayonza,
2-4.XI.1964 (R.W. Crosskey).
Analysis of sex variability in species of the subgenus Kalocheta,
especially analysis of ratio of parts of arista, leads to supposition,
that references of C.(K.) passiva from Congo and Zaire should refer to
other Kalocheta species, and the female description of C.(K.)
villiersi has nothing to do with Kalocheta. A new key to the species
of Kalocheta is proposed below, with the exception of sex variable
characters.
List of known species of Kalocheta
Kalocheta Becker, 1923:41. Type-species: Kalocheta passiva
Becker, 1923, by monotypy.
collarti Parent, 1933:35. - Zaire, Tanzania, Kenya, Uganda.
cucana Negrobov et Kulibali, 1983:1121. - Zaire, Uganda.
liberia Curran, 1929:5. - Liberia.
passiva Becker, 1923:42. - Camerun, Congo(?), Zaire(?).
villiersi Vanschuytbroeck, 1970:267. - Congo.
Key to the species of Kalocheta
Males and females
1. Wings transparent, slightly darkened along veins ............
.............................. C.(K.) cucana Negrobov & Kulibali
- Wings with brown spots.......................................2
2. Squamae with white hairs..... C.(K.) villiersi Vanschuytbroeck
- Squamae with black hairs or bristles.........................3
3. Face thinly whitish pollinose, propleural hairs black, fore
coxae with white hairs and black bristles.. C.(K.) liberia Curran
- Only epistome greyish pollinose, clypeus metallic green......4
4. Fore coxae without hairs, only with black bristles; apical and
median brown spots have crosspiece along R 4+5 and M 1+2 wing
veins...................................... C.(K.) passiva Becker
- Fore coxae with white hairs and black bristles; apical and
median brown spots have crosspiece near junction of M 3+4 and
posterior transverse wing veins........... C.(K.) collarti Parent
Males
1. Strap-like part of arista as long as hair-like part of
arista .................................... C.(K.) liberia Curran
- Hair-like part of arista 1.5-2 times as long as strap-like
portion.........................................................2
2. Wings transparent, slightly darkened along veins ...........
............................... C.(K.) cucana Negrobov & Kulibali
- Wings with brown spots .....................................3
3. Hair-like part of arista 1.5 times longer than strap-like
part, squamae with white hairs ......K. villiersi Vanschuytbroeck
- Hair-like part of arista twice as long as strap-like part,
squamae with black hairs ......................K. collarti Parent
Acknowledgement
I am sincerely grateful to Dr Brian Pitkin for his kindness in
giving me the opportunity to study the collection of the Natural
History Museum (London).
References
Becker Th. 1923. Dipterologische Studien: Dolichopodidae. D.
Aethiopische Region. - Entomol. Mitteilungen, 12, 1: 1-50.
Bickel D.J. 1994. The Australian Sciapodinae (Diptera: Dolichopodidae),
with a review of the Oriental and Australasian faunas, and a world
conspectus of the subfamily. - Rec. Austral. Mus., 1994, Suppl. 21: 1-394.
Curran C.H. 1925. The Dolichopodidae of the South African Museum.
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