THE RAT-TAILED MAGGOT. 



of tenax the Rat-tailed Maggot, a name which has stuck. 

 This creature is extremely interesting but one must be 

 interested in order to enjoy it, for it usually lives in foul 

 water, such as privy vaults and the fluid in decaying car- 

 casses. The yellow and black adults, Drone Flies, resemble 

 honey bees, and it was this which led Ovid, Virgil, and 

 other ancient writers to tell about bees originating from 

 dead animals. Plate LXVIII shows both adult and larva; 

 the larva's tail lengthens and shortens like a telescope so 

 that the tip may reach the surface of the water and the 

 larva breathe atmospheric air through it while feeding 

 on decaying matter under water. Pupation occurs out 

 of the water in the larval skin. This was originally an 

 Old World species but it is now almost cosmopolitan. 

 O-her species of the genus have similar habits. 



These (Plate LXVI) and the other aphid- 

 Syrphus eating Syrphidae should be classed among 



our friends. I have seen ants stop milking their aphid 

 cows to threaten a female Syrphus, and the ants even 

 ran from the upper to the under side of the leaf and back 

 again to keep her in sight but always she succeeded finally 

 in depositing a minute egg in the midst of the herd. I do 

 not believe the ants reasoned that here was an enemy of 

 their friends; they were merely naturally pugnacious to- 

 ward any intruder and, at any rate, they never noticed the 

 eggs, which doubtless hatched, in the course of time, into 

 flat, transversely wrinkled, green larva?, pointed in front 

 and eyeless, but able to search out the sedentary aphids 

 and to suck their juices. 



CONOPID^: 







Physocephala sagittaria (Plate LXVIII) gives a fair idea 

 of the family; some are even more wasp-like, some less; all 

 are "thick-headed." They feed on nectar and pollen 

 but the female, from time to time, leaves this sweet pas- 

 time to lay an egg on some bumble-bee, wasp, or grass- 

 hopper. The larval and pupal periods are passed in the 

 abdomen of the host. 



'7 257 



