REPORT OF THE STATE ENTOMOLOGIST 1907 — ROY 
The following is Mr Ferguson’s summary of his results: 
The table shows at a glance that prac- —— 
tically all the food of lot 1 consisted of ive) 
silt and algae. The explanation for this ,| Ce 8 
is that other food, such as midges and oy r 
worms was scarce so early in the year. ‘N/ y~ 
Spring rains had not yet brought down the > IN a Me 2. 
earthworms. About half of the food of ae \ al \ 2 
lot 2 was silt and algae, while the other | ON Ve 
half was pupae and adult midges. In Lj ny 
only three of the fish was it possible to Uy SA 
say how many midges they contained, ic 
hence the stars in the table. Only 
three out of 16 fishes of lot 3 contained 
midges, while all but four contained 
earthworms and half of them contained 
a large amount of silt. Lot 4 shows a ( 
large number of adult midges of the 
genus Chironomus (apparently most of 
them of the species of which the ap- 
pendages are shown in figure 4a) and 
many earthworms. And one of them 
contained a single large mass of Chiro- 
nomus eggs—the only instance in’ 7 
which these were found. Lot 5 shows / 
one adult Chironomus, and earthworms 
and silt predominate again in lot 6. 
Out of 92 stomachs examined, 38 (41 * 
per cent) contained midges in one stage 4 h 
or another, 27 (29 per cent) contained ", 
earthworms, 6 contained beetles— all | 
adult beetles of nonaquatic habits. ae 
Three Gomtaimad Iyakomesteacams, KO sce auga eecomeo cee 
eomtamed ams, amc omby u Contained 2 EOsteme OR ey ceeiticlll Bio 
pendages of the adult male, dor- 
May fly nymph. This clearly proves Sail Viet: b one half of tip of 
0 ; abdomen o t : 
that Chironomus was by far the most half of the Ree AT Rea OA HES 
important food. fringe 
Q 
i 
) 
\ 
Ky, 
h 
Nin, 
Wn, 
After discovering the importance of midge larvae in the food of 
this minnow, Mr Ferguson began a feeding experiment to deter- 
mine how many such larvae could be disposed of by the fish 
-as a regular diet. He divided the tank of an aquarium table 
into two compartments, placing two full-grown Chrosomus in 
one of them and three others about half as large in the other. 
A piece of board was kept floating on the surface of each to 
furnish congenial shadow, and the white enamel bottom of the 
tank was kept clean so that uneaten food could be found. Midge 
larvae (nearly all those of Chironomus viridicollis, 
