Changes in Body Melanisation and Not Body Size Affect Mating Success in Drosophila immigrans 33
Table 3 Data on no-choice tests based on isofemales varying only in body melanisation (dark—D and light—L) but
not in body size (A), and varying in body size (small—Sm and large—La) but not in body melanisation (B). For each
mating trait results of contingency χ^2 test are also shown
Traits (A) Body melanisation (B) Body size
L × L D × D L × D D × L Cont. χ^2 Sm × Sm La × La Sm × La La × Sm Cont. χ^2
% MP 10.3 ± 2.05 40.0 ± 2.84 23.8 ± 3.01 25.9 ± 2.73 10.3 ± 2.50 11.2 ± 2.83 12.0 ± 2.66 12.5 ± 3.14 ns
ML 23.4 ± 2.92 5.5 ± 1.72 16.5 ± 2.10 14.3 ± 1.60 23.4 ± 2.92 24.0 ± 2.78 25.3 ± 3.14 21.2 ± 3.01 ns
CD 38.0 ± 2.61 64.5 ± 2.42 47.0 ± 2.56 53.2 ± 2.44 39.0 ± 2.61 41.5 ± 3.20 44.5 ± 2.13 40.1 ± 2.46 ns
MP mated pairs, ML mating latency, CD copulation duration, ns nonsignificant
p < 0.001
Wing length (mm)
Number of Isofemale lines
0
2
4
6
8
10
12
14
3.5 3.6 3.7 3.8 3.9 4.0
Light
Mean = 3.80
SD = 0.09
Dark
Mean = 3.78
SD = 0.10
a Mating Latency ( min )
Number of Isofemale lines
0
2
4
6
8
10
12
14
0510 15 20 25 30
Dark
Mean = 5.36
S.D. = 1.95
Light
Mean = 22.35
S.D. = 2.10
c
Melanisation ( % )
Number of Isofemale lines
0
2
4
6
8
10
12
20 30 40 50 60 70 80
Light
Mean = 37.60
S.D. = 2.32
Dark
Mean = 76.09
S.D. = 2.27
b Copulation duration ( minutes )
Number of Isofemale lines
0
2
4
6
8
10
12
14
20 30 40 50 60 70 80
Light
Mean = 42.20
S.D. = 1.46
Dark
Mean = 63.35
S.D. = 1.68
d
Fig. 2 Isofemales similar in body melanisation (a) but differing in body size ( large vs. small; b) show lack of differ-
ences in mating latency (c) and copulation duration (d) in D. immigrans