1980] Sivinski & Stowe — Kleptoparasitic cecidomyiid 341 
noted in Didactylomyia longimana; unidentified fly (McCook 
1889); and milichiids, (Champion-Jones 1937; Robinson and Robin¬ 
son 1977). The mouthparts of D. longimana are also somewhat 
pronounced for a cecidomyiid (R. J. Gagne, pers. comm.). 3 
Phylomyza sp. near securicornis, length 2.8 mm. A single female 
was found riding on a Nephila clavipes at the juncture of the 
abdomen and cephalothorax. This is the only species we en¬ 
countered that appeared to be phoretic, i.e., attached to a host who 
is not fed upon. Phoresy is reported in a neotropical Phyllomyza sp. 
(Robinson and Robinson 1977). Our sighting was made at night. 
Neophyllomyza species A, length 1.5 mm. A diurnally active 
species captured in Marion Co., Fla., on the prey of a Nephila 
clavipes. The mouthparts are as elongated as those of Paramyia 
nitens\ the rostrum is 1.3X the height of the head. The single female 
specimen was 1 of 5 flies on the prey (see below). 
Neophyllomyza species B, length 1.8 mm. A species taken from 
the same prey as species A. Mouthpart development is more 
conventional. The rostrum is 0.8X the height of the head. Two 
females were captured. 
Suspected Kleptoparasites 
The following were captured most frequently in traps baited with 
spider prey. Flies may be kleptoparasites or participants in a 
number of other symbioses, locating spiders, their eggs or webs 
through scents released by pre-oral digestion. 
Ceratopogonidae: Culicoides bauri, length 1.0 mm. Seven females 
were taken from spider prey discs, three on intact insects but none 
on controls. The two previous feeding records of C. bauri were from 
humans, suggesting catholic tastes (see Blanton and Wirth 1979). A 
considerable number of Ceratopogonidae are carnivores, sapro- 
phrages or ectoparasites of insects (Downes 1978; Downes and 
Smith 1969; Wirth 1956, 1971). Downes and Smith (1969) mention 
an Atrichopogon sp. feeding on dead insects in spider webs. 
Phoridae: Megaselia sp., length 2-3 mm. Seven female specimens 
of this genus were taken from spider prey-baited discs, none from 
intact insects or controls. Kleptoparasitism may not be the most 
3 In a more benign relationship probably derived from kleptoparasitism, Australian 
orb-web spiders spread their chelicerae to aid mutualistic milichiids cleaning their 
mouthparts (McMillan 1975). 
