1988] 
Buschinger et al. — Chalepoxenus brunneus 
259 
Tab. 2. Production of five Chalepoxenus brunneus colonies collected in the 
field (1st brood May/ June, 1987; 2nd brood in April, 1988) and three founded in 
the laboratory (1st brood in April, 1988). 
Production of sexuals 
1st brood 
2nd brood 
total 
Field col. no. 
< 5(5 
29 
( 5(5 
29 
( 5(5 
22 
1 
15 
56 
5 
8 
20 
64 
2 
4 
8 
2 
2 
6 
10 
3 
1 
1 
4 
4 
5 
5 
4 
— 
— 
6 
16 
6 
16 
5 
3 
9 
8 
6 
11 
15 
Sex ratio < 5/9 = 0.44 
48 
110 
1st brood 
Lab col. no. 
( 5(5 
22 
1 
9 
15 
7 
5 
10 
9 
3 
15 
17 
40 
( 5/9 
= 0.42 
All colonies 
65 
150 
< 5/2 
= 0.43 
Brood production and sex ratio 
In laboratory-founded colonies the C.b. females usually develop a 
somewhat swollen gaster even during the second week after having 
penetrated a host colony. Egg-laying apparently begins soon after, 
since higher egg numbers were recorded about 2-3 weeks after the 
colony founding, when the C.b. female survived that long. Egg- 
laying continues until the fall; the female of col. no. 1 was seen to lay 
an egg on day 73 after colony founding. 
Evidently there is no “rapid brood” production since in all colo- 
nies the first C.b. sexual pupae appeared in the “summer” after 
colony founding and hibernation, having developed from hiber- 
nated larvae. 
No C.b. workers were ever produced, neither in the field-collected 
colonies nor in the laboratory-founded ones. Only in one field col- 
ony a worker pupa with ocelli, perhaps an intermorph, was 
recorded; however, a week later it was destroyed. 
The number of C.b. sexuals produced was highly variable, cer- 
tainly in part dependent upon the numbers of host workers in the 
