48 ENTOMOLOGICAL NEV/S. [Feb., '03 



must record another observation, which perhaps partly ac- 

 counted for my success the past summer. This fall I had 

 occasion to beat the milkweed Asclepias verticillata for the 

 beetle Doryphora rogersii and its larvae. During the middle of 

 the day I had no success at all, but near sundown, while get- 

 ting the' cows, I had the luck to capture one of the adult bee- 

 tles and four of the larvae. The next day I revisited the 

 locality where my captures of the previous evening had been 

 made, with the hope that I might take more specimens, but 

 without success. Then I thought, perhaps, the time of day 

 might have something to do with my capturing the beetle and 

 its larvae, so that evening I returned to the milkweed patch, 

 and was rewarded with four additional larvae. This set me 

 to thinking why only at evening the species was taken, and I 

 concluded that the species kept low down during the heat of 

 the day, but when the sun had got low down and the dew com- 

 menced to gather on the lower grass the larvae were driven 

 from their retreat by the growing coolness caused by the gath- 

 ering dew and climbed up higher where it was warmer. My 

 captures along the stream, mentioned further up, were made 

 near sundown, while getting the cows home, and I think the 

 same cause was at work which made my collecting there so 

 fruitful. 



Riley, in his "Directions for Collecting and Mounting In- 

 sects," recommends the use of mucilage made of gum-shellac 

 dissolved in alcohol, for mounting specimens on cardboard or 

 pin-points. When I made my first attempt to dissolve some of 

 the gum in alcohol, I was fortunate in making a perfect solu- 

 tion of the gum, with which I mounted many of my earlier 

 specimens. After the lapse of a year or so, my mucilage had 

 evaporated so much that it had become too thick for use, and 

 I put in a little alcohol to thin it when, instead of becoming 

 more fluid, it seemed to curdle and became unfit for use. I 

 tried to prepare a new supply by using fresh gum, and was 

 again disappointed, as the the gum instead of dissolving as- 

 sumed a jelly-like state, which was useless for my purpose. I 

 made several other attempts to make a supply of the shellac 

 mucilage, but always without success. In desperation, I wrote 



