unknown wormlike parasite

Jack J. O'Brien jobrien at JAGUAR1.USOUTHAL.EDU
Mon Aug 25 16:01:15 EST 1997


Dear Ginhu:

I agree with Steve Upton and believe that the "worms" that you have seen
in your bathtub are probably larvae of flies of the family Phoridae or
humpbacked flies.  The larvae of some species of this family are commonly
found in the drains of sinks, toilets and bathtubs in houses.  The larvae
feed upon mold and fungus growing in the pipes are are quite harmless to
humans.  Adult flies can be recognized by their characteristic humpbacked
shape causes a swollen thorax, the area where the fly's wings attach to
the body proper, and gray, rounded wings with few veins.  

Although no phorid as far as I know has been known to parasitize humans,
some members of this group parasitize other insects, especially ants and
termites.  M.R. Orr and colleagues [Nature, vol. 373, 1995, p. 292]
suggested that one species of phorid might be a biological control agent
for fire ants. This prompted Kathirithamby and Hamilton {Nature, vol. 
374, p. 770] to point out that fire ants in the southern U.S. are already
being parasitized by yet another introduced species (a strepsipteran)
which apparently does not parasitize fire ants in Brazil where both
species are native. Interestingly, it is the male strepsipteran that
parasitizes fire ants; females parasitize some other, as yet unknown, 
species.

Jack O'Brien

Dept. of Biological Sciences
University of South Alabama
Mobile, AL 36688
334-460-7525



More information about the Parasite mailing list