31 



Some years ago, Mr. C. W. Nash, one of the directors of the Entomological 

 Society of Ontario, exhibited, at a meeting of that society, a like fungus, growing 

 from another root-feeder, the Wire-worm. 



(b) Of insects working in the stems of plants we have a remarkable instance 

 in the larva of that fine moth Sphida obliqua Walker. It affects the Cat-tail 

 Flag (Typha latifolia L.) and causes' its decay. It forms a cell in the thickened 

 base of the plant, and feeds on the pithy portions of the stem. The Cat-tail Flag 

 grows in marshy ground which is liable to be flooded, and the larva resorts to dry 

 ground to undergo the pupal change. It is formed for swdmming, and moves easily 

 through the water, with undulations like those of an eel or water-snake. At such 

 times its spiracular line is below the surface and the creature would drown but 

 for a strange provision : the last pair of its spiracles are placed higher than the 

 rest, and through these the larva breaths w^hile on its watery way. 



Can any foe reach this larva when working in the heart of the flag? Yes — I 

 have raised, again and again, from maggots that I found preying upon it there, the 

 beautiful little two-winged fly Chetopsis oenea Wied. 



In September, thirty-one years ago, I was driving from Stanbridge East to 

 Cowansville. In one part, my road led through a dense alder-swamp of considerable 

 extent. I was driving slowly, and I noticed a small butterfly fluttering from bush 

 to bush. I stopped my horse and left my vehicle to examine the insect. It was of 

 the kind that was then know'n as Polyommatus crataegi — Boisduval & Le 

 Conte — someone having found the insect on a thorn-bush. A few days after- 

 wards, I drove back to the spot, equipped wdth net and pill boxes, and captured a 

 number of the butterflies. 



I was at that time in correspondence with that grand old entomologist, the 

 late W. H. Edwards. I mentioned my captures to him, and he asked me to try 

 to obtain particulars as to the food-plant and larva of the insect. I did try, 

 both that season and the next, and all that I could write to him concerning the 

 species w^as that I thought the name crataegi a misnomer, for there was not a 

 thorn-bush in all the district in which I had taken the butterflies. 



It remained for a lady to trace the life-history of the species. 



Feniseca tanquinius Fab., as the insect is now called, is predaceous. Its 

 larvae lie hidden in the white patches of the Woolly Aphis, which are so often seen 

 on the stems of Alder, draining the sap of the plant. The larvae feed upon the 

 aphides. I have raised the perfect insects from them many times since the days 

 1 have spoken of. Their pupae closely resemble diminutive mc nkeys' heads. 



