54 
Psyche 
[March 
(1966). Last instar nymphs were injected with twenty microliters 
of colcemid (in two instances adult parthenogenetic males were 
used), 16 to 24 hours later their gonads were dissected in an insect 
Ringer’s solution (Bodenstein, 1946) and transferred to 1% sodium 
citrate solution for 5 to 7 minutes. The gonads were placed in 
acetic alcohol (1 part glacial acetic acid to 3 parts absolute alcohol) 
for about 1 minute, then in a drop of 45% acetic acid, on separate 
albuminized glass slides, until they became clear. Coverslips were 
placed over the gonads, squashed between 2 pieces of highly ab- 
sorbent paper, and the slides were immediately placed on dry ice. 
After 5 to 10 minutes, the coverslips were flipped off with a single- 
edged razor blade, and the slides were immediately placed in acetic 
acid-absolute alcohol (1:1) for 10 minutes. The slides were quickly 
rinsed in absolute alcohol, placed in 2 changes of 95% alcohol for 
5 minutes each, removed, and allowed to dry. A drop of acetic- 
orcein was placed on the dried tissue, covered with a coverslip, and 
after about 1 minute, the excess stain was removed with absorbent 
paper. The slides were placed in 95% alcohol, the coverslip was 
removed, the specimen rinsed in 95% alcohol, then in 2 changes of 
Table 1. Chromosome numbers of Pycnoscelus indicus males a . 
Source 13 
Nymph 
Number 
Cells 
Examined 
the 
Number 
following 
of cells with 
chromosome counts: 
35 
36 
37 38 
Hawaii 0 
2 
5 
4 
1 
5 
4 
4 
6 
12 
12 
Hawaii^ 
8 
6 
6 
11 
17 
15 
1 
1 
13 e 
3 
3 
Hawaii 0 
4 
7 
2 
1 
4 
7 
6 
6 
9 
3 
3 
10 
9 
9 
Hawaii^ 
1 
20 
1 
19 
3 
5 
5 
12 
20 
20 
| 
14 e 
20 
1 
1 
17 1 
aThe chromosomes in a maximum of 20 cells per individual were counted. 
If this number could not be found, as many cells as possible were examined. 
bThe original source from which laboratory colonies were started. 
°From a culture of Hawaiian $ $ X Hawaiian $ $ . 
dFrom a culture of Bogor $ $ X Hawaiian $ S . 
e Nymphs reddish. 
