18 



Parasites. Hosts. 



Microdus agilis Cr Gelechia ahaconditella Walk., on Polygonum 



acre. Washington, D. C, May 26, 1884. 



Microdus melanocephalus Riley, MS Pcedisca sp.? on SoHdago lanceolata. Wash- 

 ington, D. C, June 12-17. 



Microdus cinctus Cr Tineid on Cephalanihus occidentalis. Wash- 

 ington, D. C, June 3 and 28, 1884. 



Microdus bicolor ? Prov Cecidomyiid iv cone of Abies hracteata. Jo- 

 Ion. Cal., Sept. 8, 1880. 



Microdus simillimus Cr Pcedisca strenuana Walk., on Ambrosia. 



St. Louis, Mo., 1873. 



Microdus calcaratus Cr Cecidomyia on Sensitive plant. Fort Hua- 



cbuaca, Ariz., June 27, 1883. 



Microdus earinoides Cr Tmeiocera ocellana Schifif.,on Apple. Can- 

 ada, July 20, 1870. 

 Coleophora cinerella ? Cham., on Alnus. 

 Washington, D. C, Apr. 10, 1884. 



HOW ARE INSECT VIVARIA TO BE LIGHTED ? 



By A. H. SwiNTON, Bedford, England. 



Kuowledge means advance. Of late years the addition of an insect 

 vivarium to zoological collections has pressed itself on the public notice, 

 and, as the scientist knows and feels, the want of an efficient receptacle 

 in which to study the habits of winged insects has for long been with 

 him a desideratum ; but I can not think from those articles that I have 

 chanced from time to time to read that any one has been at much pains 

 to contend with the outstanding difiiculty, that of illumination. To 

 many this subject may appear futile, others may have reputed it, per- 

 haps impious, but experience teaches. As I have a fancy for a night 

 moth or a butterfly flying about my apartment when engaged in read- 

 ing, I have never failed to detect their invariable tendency to flutter 

 over the window pane, save when the evening lamp has diffused a radi- 

 ance, and then the moths circle around it or go a bumping against the 

 whitewashed ceiling, the geometrid moths, perhaps, of the undomes- 

 ticated kind appearing most at their ease. Evidently the second con- 

 ditions here are most favorable; a vivarium should be diffusely illumi- 

 nated, and probably the walls and ceiling should be blackened. But 

 what would happen were the illumination from the floor and the same 

 were covered over with flowering plants ? Would not such an arrange, 

 ment be congenial to butterflies whose glance is ever upward ; and in 

 the case of thick-bodied moths that are prone to flap along the ground, 

 ought not the source of light here to be central, raised, and masked by 

 a dark transparent shade ? 



It is a vulgar notion that the hot-house, lighted on its four surfaces or 

 five, is a suitable vivarium, when it is most palpable that the butterflies 

 and moths instead of displaying their habits merely flutter over the 



