1870.] EITICHU — INSECTS BY ARTIFICIAL LIGHT. 63 



Thirdly, and lastly. — Is it on dark or moonlight nights that 

 insects are attracted to artificial lights ? 



In answering these questions, our opinions are based upon 

 actual observation and experience. 



To the first question, viz.: What species of insects are gener- 

 ally attracted to our open windows by artificial lights? we suggest 

 the following reply : We have taken representatives of nearly all 

 the orders of insects in our rooms by lamplight during the past 

 ten years, — but mainly Lepidoptera (or moths). The following 

 is a statement taken from notes of captures on an evening in 

 July, 1869. Working with the microscope at an open window, 

 with the lamp burning on the table, the following insects were 

 attracted by the light : — First, a beetle (^Harpcdus Pennsylvanicus), 

 rather a strange fellow to be about at this hour; next visitor, a 

 water beetle (^AcUius frafernns), then followed several moths, 

 principally small species ; the mosquito also made its appearance, 

 and some small Ephemeroe. They flew out and in at the window, 

 and in the reflected light across the street, numbers of moths 

 could be seen as they crossed the rays from the lamp. Compara- 

 tively few rushed into or against the lamp, — evidently finding the 

 light too strong for them, they flew out of the window to join in 

 the dance going on outside, where the greatest number appeared 

 to be. This answers the question in regard to the species gener- 

 ally attracted. 



We shall now consider the second question, viz. : — What are 

 some of the habits of those species, and for what purposes are 

 they attracted ? Without going into particulars about the habits 

 of the several species, we will confine ourselves to the several 

 orders as regards their being attracted by lights. Nearly all the 

 specimens we have seen are nocturnal, — these feed and seek their 

 mates by night. There are exceptions to this, as to most other 

 rules, for in the case of some of the insects named, e.g., Harpalus 

 and Acilius, — both are diurnal species. The first named was 

 abundant last summer, flying into lighted rooms in numbers, 

 perhaps awakened by the light shining from the window on the 

 side-walk, under which it had retired for the night, and so got up 

 a little ahead of time. The other, Acilius, has been found at 

 fault before, as also some of the large species of the family 

 Dytiscidce. They have been seen to pitch themselves on the 

 glass roofs of conservatories, probably taking the shining glass 

 for the surface of a pool or pood. 



