364 
Psyche 
[December 
Number of Generalized 
Feeders * 
latituc 
Number of Species 
e 
A 
B 
c 
Percentaae 
. Generalized 
i Feeders 
e World Papiltonida 
D 
tota 
60-70 
4 
2 
1 
3 ! 
42.86 % 
50-60 
^ 19 
2 
7 
9 
47.37 % 
40-50 
2 
10 
2 
14 
26.42 % 
30-40 
ifiM- 
1 
4 
17 
4 
26 
22.61 % 
20-30 
125 
5 
13 
5 
23 
18.40 % 
10-20 
A 160 
7 
9 
5 
21 
13.13 % 
0-10 
iiifif 
- J224 
8 
9 
6 
23 
10.27 % 
0-10 
iiifiP 
256 
8 
11 
4 
23 
9.02 % 
10-20 
155 
10 
10 
3 
23 
14.84 % 
20-30 
j 89 
1 
10 
7 
2 
19 
21.35 % 
30-40 
> 
3 
6 
1 
10 
38.46 % 
40-50 
f 2 
1 
1 
1 
50.00 % 
1 
50 ' 150 250 
Fig. 4. Latitudinal gradients in species richness and percentage of gen- 
eralized species of Papilionidae of the world. A — Parnassini ; B = Lep- 
tocircini; C = Papilionini ; D = Troidini. 
land (Australia), the larvae are unsuccessful and eventually die when 
left to feed upon leaves of this relatively recent introduction (Ed- 
wards, 1948; and Straatman, 1962). It appears thus that in at least 
some populations metabolic specializations or adjustments may have 
coevolved along with the regional restriction in food-plant choice such 
that Citrus is perhaps in some way no longer physiologically suitable 
for those individuals. It should be pointed out that individuals fiom 
some Australian populations can and do successfully utilize the native 
rutaceous Alicrocitrus australis (D abrera, I 970 > an d those in New 
South Wales can be reared successfully upon Citrus (see Stiaatman, 
1962) . 
It is interesting that in Africa Papilio demodocus (Esper), a spe- 
cies which is very closely related to and once consideied a race of 
P. demoleus, is primarily a Rutaceae-feeder over most of its range. 
It is however polymorphic (Clarke, et al. 1963) and also utilizes the 
Umbelliferae in South Africa w^here the richness of this plant family 
is relatively high (Dethier, 1941). Similarly, the P. machaon group 
of Umbellifer feeding species in Sardinia, East Asia, and North 
America are also close to P. demoleus in ancestry (Munroe, i960). 
