1915] Andrews: Survey of Lake Butte Des Morts Boa 
201 
Halictus hortensis Lovell. This small wasp was found in great numbers 
flying about the coarse grass. It is preyed upon by many of the larger 
insects. 
Coleoptera 
Tetraopes tetraophthalmus Hancock. Often seen resting singly, or in 
pairs, on the leaves of the swamp milk-weed — Asclepias incarnata. 
Pyropyga fenestralis Melsh. Always seen late in the afternoon resting 
on the leaves of the water plantain — Alisma Plantago aquatica. 
Pyropyga decipiens Harris. Smaller than the Pyropyga fenestralis, and 
not as numerous. 
Calopteron reticulatum Harris. This beetle is found on the water plan- 
tain. It feeds on small insects, such as leaf hoppers. 
Pterosticus lucublandus Comstock. Two of this species of ground 
beetle were found under a plank August 4. No others were found at any 
time during the observation. 
Diptera 
Scatophaga callopistra annulipes Comstock. This species was common 
everywhere on the bog. 
Stomoxys calcitrans Meig. This fly was very common in August. 
Phormia regina Meig. Seen almost everywhere on the bog throughout 
July and August. 
Lucilia sylvarium Meig. Very numerous in July; rather rare in August. 
Lucilius caesar Comstock. Found near the shore. Not many flew far 
out over the bog. 
Chrysops Niger Comstock. These flies which are powerful flyers were 
very abundant during the hottest days of July. 
Chrysops sackeni Hine. Two of these flies were seen the last week in 
July. No others were observed. 
Dolichopus lobatus Loew. Present in moderate numbers during the first 
weeks of July. 
Dolichopus brevimanus Loew. This fly, present in moderate numbers 
all through July, did not seem to do anything except fly about — pausing 
to rest every now and then on the leaves of some plant. 
Psilophius ciliatus Comstock. Often seen pursuing smaller insects 
which it ate head first. 
Toxomerus (Mesogramma) germinatus Say. This small fly, which was 
very abundant about the seeds of the Sagittaria, was the prey of several 
species of damsel flies. 
Toxomerus (Mesogramma) marginatus Say. Not quite as numerous as 
Toxomerus germinatus. Also the prey of the damsel flies. 
Platychirus quadratus Say. Found in small numbers during July. 
Sarcophaga sp? Meig. This is a large fly, and a powerful flyer. Only a 
few were seen. 
Winthemia quadrupus tulata Tabi. Very plentiful; especially during 
July. 
