BEES 197 



BEES WHICH VISIT ONLY ONE SPECIES OF FLOWEE 



By JOHN H. LOVELL 



WALDOBORO, MAINE 



ONE warm afternoon on the twentieth of July I was collecting in- 

 sects from a boat on the Medomac Eiver. A thunder- shower 

 was coming up in the northwest. The air was very still and in that 

 peculiar condition which precedes an electric storm. At such times 

 insects are very sluggish and seek shelter against the approaching 

 tempest. The silence was broken only by the rumbling peals of the dis- 

 tant thunder, following the bright flashes of lightning, which illu- 

 mined the dark thunder-heads of the advancing clouds. It became 

 necessary for me to hasten homeward. To my surprise I noticed on 

 almost every one of the violet-blue spikes of the pickerel-weed (Ponte- 

 deria cordata), a species of water hyacinth, which in countless numbers 

 fringed the winding stream on both sides, one to several small bees. 

 They had crept within the bilabiate flowers as far as possible, and were 

 evidently intending to await there the passing of the storm. They were 

 so inactive that no net was required, and I could easily knock them off 

 into the cyanide jar. I collected about forty specimens and could have 

 easily collected hundreds. This phenomenon has never been repeated 

 to my knowledge. 



On examination the bee proved to be Halictoides novae-anglice, or 

 the pickerel-weed bee. Every season when the pickerel-weed is in 

 bloom I find both sexes of this bee on its flowers, and though I have 

 carefully observed the visitors to many other plants in this locality I 

 have never met with it elsewhere. Apparently in this region it never 

 visits any other flower — it is a monotropic bee. When a female bee in 

 gathering pollen for brood-rearing visits but one kind of flower it is 

 termed a monotropic bee, or if only a few allied species an oligotropic 

 bee; but if it visits many flowers it is called a polytropic bee. These 

 terms were first proposed by Dr. Loew, and signify adapted to one, few 

 or many flowers. 



It is impossible not to feel some curiosity as to why this little bee 

 restricts its visits to the inflorescence of the pickerel-weed. Notice that 

 it flies only at the season of the year when this aquatic plant is in bloom, 

 and that it finds within the perianth both food and shelter. Very likely 

 its nests are built not far away. The flowers of the pickerel-weed 

 strongly attract insects by their great numbers, bright hues, pleasant 

 fragrance and abundant nectar and pollen ; and consequently are sought 



