1913] 
Burrill: Lake Michigan Swarms of Chironomids 
55 
mate proportions of the kinds of midges about the porch. When 
midges were not flying, all species were captured with equal ease 
by placing small cyanide -bottles used in relays, over the flies as 
they rested on the screens. This method avoided all handling 
of the delicate forms, on whose frail legs the tarsi are a most 
important feature in identification. Catching in nets is not ad- 
vised, since enough specimens can be caught by the more careful 
method using vials. Thus six or ten midges can be successively 
captured in a vial before there is much danger of one of them 
trying to escape from the tube. The increase in midges noted 
above was accompanied by other forms, as Tipulids, a large yel- 
low-brown Ophion, Curculionids, Coccinellids and Cerambycids, 
a Sepsid, and a Scatophagid, May 27 to 28. 
On May 28 other less common midge species resting or flying 
included a whitish winged black form, two different species of 
tinier black midges, the greenish or straw-white species of larger 
size than the common black one, and a very few Tipulids and 
Culicids. Two clear winged Tipulids were also taken, four Psy- 
chodids, a Trichopterid and a Meloid beetle. 
During the close of the cold spell, May 29 to June 5, a Bibio, 
two species of Tipulids, two Staphylinids, two Cerambycids, a 
Carabid and a Chrysomelid appeared, besides Myriapod forms. 
With the warmer weather on the evening of the 6th and morn- 
ing of the 7th, the beginning of midge convention week, one might 
say — -there were captured specimens of black Chironomids of 
the various species collected before. One brown species was taken 
with a red mite on the right mesothorax, and one green midge 
with a mite elsewhere on the body. Twenty-two greenish-brown, 
quite small midges of a distinct species were taken and tinier 
ones of many different species, if one may judge by the variety 
of colors and forms. These figures indicate that June 7 marked 
a new period in the emergence of insects generally since nearly 
twice as many kinds of midges were noted as during the previous 
month and also more mosquitoes, new Tipulids, a leaf hopper, a 
Hemerobiid, a stone fly, and an Ichneumonid. Thus three cy- 
•clonic storm periods were successively followed by a greater var- 
iety and abundance of midge and other insect species. In the 
very backward spring of 1912, I duplicated these observations 
near Lake Mendota, Madison, Wis. The first swarm of midges 
