BIOLOGICAL NOTES ON RAPHIDIA MACULICOLLIS. I 



the mandibles and the last remnants were removed and eaten 

 up. The adults also readily drank drops of water which I put 

 in. During feeding the female frequently wagged her ovipositor 

 as if in appreciation, and after every meal the antennae were 

 cleaned with the tarsus of the front leg, in a way similar to that 

 described above for the head. 



A piece of rotten wood, deeply cut with a knife, was put in 

 with them, and on this the female was seen probing with her 

 ovipositor, from the end of which drops of black excreta were 

 often expelled. 



On May 28th the male died (after nearly four weeks), and on 

 June 17th, the female being still alive, the rotten wood was re- 

 moved and examined for eggs, of which many were found in the 

 cuts in the wood, together with very small larvae. The eggs were 

 slightly transparent, very pale yellow in colour, and about 

 12 mm. long by 0'3 mm. broad. In shape elongate cylindrical, 

 slightly more pointed at the tail end than at the head ; at the 

 head end with a small white globular appendage.* A few eggs 

 which were removed to a microscope slide for examination began 

 to hatch immediately, and I was fortunate in being able to ob- 

 serve the whole process. The shell first split behind the globular 

 appendage and the young larva emerged with the head bent 

 downward along the ventral side of the prothorax. In one case 

 four and a half minutes after the first signs of hatching the 

 head was free, and in three minutes more the larva was walking 

 about on the slide. 



The young larvae were about 1*5 mm. in length and pale 

 brownish white in colour. The head was about 0*25 mm. long, 

 with rather stout three-jointed antennae of slightly over half its 

 length. Unfortunately all these larvae have died, but others 

 which I have readily drink water, as did the adults, and will eat 

 killed house-flies as well as aphis, in the former case eating only 

 the softer parts. 



On July 11th the original female died, after having lived two 

 and a half months. The whole time that the male was with 

 her she made no attempt to attack it, yet on an occasion when I 

 put two females together for a few hours one of them bit the 

 head off the other and ate its abdomen. The larvae also are 

 canuibalistic, if given the opportunity, usually leaving only the 

 head of their victim. 



Some time during April a parasitic grub came out from a 



* Mr. C. T. Lyle, in describing the egg of Eaphidia notata (Entom. xli. 

 1908, p. 233), says "the eggs .... had a very short pedestal at the thicker 

 end. They stood erect on this, and were in contact with one another, as is 

 the case with the eggs of Sialis." The eggs which I describe were lying in 

 the cut in the decayed wood and could not be said to stand on any end in 

 particular, bnt as the " pedestal " is at the head end in these, and in Sialis 

 eggs also it is at the apex and not at the base, I think Mr. Lyle must be 

 mistaken in saying that the eggs stood on this end. 



