364 



festing the rose, Goccinella 9-notata Hbst., was more particularly selected 

 for the purpose of carrying out cue portion of the experiment, other 

 species being included in smaller numbers only. 



The experiment began July 26, by transferring fifty adults of C. 9- 

 notata from the fields to the conservatory. September 2i there were 

 added to these sixty-two, and two days later fifty-six others. These last 

 included also a very few Megilla maculata, Hippodamia convergens and H. 

 I'S punctafa. October 1, thirty-four more were placed as the others had 

 been, these being nearly all 9-notata, and were mating at the time. On 

 October 15. many young larvte were observed running about over the 

 potted plants, but despite these the Aphides increased so rapidly that 

 it became necessary to fumigate with tobacco smoke to protect the 

 plants, and a very light fumigation was applied. Although the smoke 

 did not appear to affect the larviie, they continued to decrease in num- 

 bers, though only a very few seemed to reach maturity, a single adult, 

 H. convergens, being the only evidence that any of the larvfe had de- 

 veloped. At present writing, March 15, of the two hundred and two 

 individuals placed in the conservatory, there remains not a trace, either 

 of themselves or of their progeny, while "green fly" has abounded, as 

 usual. 



For the other portion of this colonizing experiment Chilocorus bivul- 

 nerus Muls. was selected. A couple of white spruce trees Abies alba, 

 on the campus of Purdue University, became thickly infested by Myti- 

 laspis pinifoUce* which, as is usual in such cases, attracted myriads of 

 the Lady beetle. 



On October 22, several hundred of these beetles were transferred from 

 the spruce to another compartment of the same conservatory, devoted 

 exclusively to tropical and subtropical plants, ferns, etc., upon which were 

 large numbers of Coccidce. For a few weeks after being liberated an 

 occasional beetle would be observed, while dead ones gradually became 

 more numerous until no living beetles could be found. Outside, how- 

 ever, they were present about the spruces in great numbers on warm 

 sunny days, and continued to remain up to date of writing. Not a liv- 

 ing individual has been observed in the conservatory for three months, 

 yet the "Scale" and "Mealy bug" have in nowise diminished in num- 

 bers. This compartment has not been fumigated, nor has anything 

 been applied to the plants which could in any way affect the Lady- 

 beetles, and therefore both features of the experiment must be set down 

 as yielding information decidedly adverse to the colonization of either 

 of these species of Coccinellid;e in our conservatories. 



*I may perhaps be pardoned for stepping aside from the tenor of this notice in 

 •order to record the fact of this scale being attacked by the Inaidions Plant- bug, 

 Triphleps insidiosus, and which I several times detected with its beak thrust into the 

 body of the female Mytilaspis. 



