22 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



of Eupatorium, Benzoin, and Hamamelis leaves. Some of 

 the empty egg-cases (PI. I, fig. 6) usually clung to the leaf 

 after hatching, but in one instance not the slightest trace re- 

 mained of an eg-g-mass on a witch hazel leaf. A fly heard 

 by E. A. Schwarz giving its peculiar buzz on July 13, and 

 which undoubtedly was ovipositing then, was located by the 

 writer on July 17. On July 24 the female was absent and the 

 eggs were hatching. The larva?, dropping to the ground, im- 

 mediately burrowed in. 



These observations show that the female Goniops guards 

 the egg-mass sometimes for a week at least; that this precau- 

 tion does not always prevent parasitism; that the period of 

 incubation varies, and that the larva? are fitted for a subter- 

 ranean life, upon which they enter as soon as hatched. Eggs 

 have hatched in from 2 to 11 days from the date of collection. 

 But from the fact that eggs are added to the mass for several 

 days, and that all hatch at the same time, it must be inferred 

 that the eggs within the body of the female keep pace in de- 

 velopment with those laid. To determine the true period of 

 incubation, observations must cover the process from the lay- 

 ing of the first egg to hatching. 



All of the egg-masses found on Plummet's Island in 1910 

 were on the steep north slope of the principal elevation of the 

 island, which is a well-shaded, cool, and damp locality. The 

 finding of seven egg- masses in this area of less than an acre 

 in one season shows that Goniops chrysocoma is not uncom- 

 mon locally, even though little is known of it and recorded 

 captures are not numerous. 



The buzzing noise made by the female Goniops is very 

 characteristic and once learned will not be mistaken. The 

 fly makes the sound periodically when ovipositing and guard- 

 ing the egg-mass, and also usually makes it when disturbed 

 by motion nearby. Hence the insect almost always betrays 

 its presence to the passing collector. The sound is made fre- 

 quently if one remains near. In describing the method of mak- 

 ing the sound, Hine says 1 the wings "striking the leaf at each 

 downward stroke make a rattling noise which could be heard 

 plainly several feet away." According to the writer's obser- 

 vations, the sound is a true "buzz" and is made with the 

 wings lifted up and forward, from which position thev are 

 rapidly vibrated, but not to such an extent as to touch the 

 leaf. Hine speaks of finding the flies on the upper sides of 

 leaves; we have always found them on the under sides. 



1 Ent. News, XI, 1900, p. 392. 



