68 SANITARY ENTOMOLOGY 



shown to act as intermediate hosts, but insect-like animals commonly 

 known as sow-bugs apparently act as intermediate hosts, Piana (1897) 

 having found larval nematodes in an isopod (Porcellio Icevis) that corre- 

 sponded in morphology with immature nematodes found in chickens 

 harboring also the adult worms. Furthermore these larval nematodes 

 occurred in sow-bugs only in the locality where the chickens were found 

 to be infested. Although Piana identified the parasites that he found in 

 chickens as Dispharagus nasutus (Rudolphi), it is apparent from his 

 description and figures that they belonged to the species Acuaria spiralis 

 (Molin). 



FUaria gallvnarwm Theiler, 1919 



Theiler (1919) has recorded the occurrence of larval nematodes in a 

 species of termite (Hodotermes pretoriensis). Among the termites only 

 the workers were found to harbor these parasites, no infested soldiers 

 having been discovered. Infested termites can easily be distinguished 

 by the swollen abdomen which gives the insect a sort of balloon-like 

 appearance. According to Theiler, on many South African farms the 

 custom exists of digging up nests of termites and allowing the chickens 

 to feed on the insects, and the droppings of chickens running in the fields 

 are naturally scattered about and serve as food for the termites. Infested 

 termites were fed to young chickens that had been hatched in an incubator. 

 Adult worms that had evidently developed from the larvas parasitic in 

 the termites were found in the intestine or stomach in 15 out of Ifi 

 chickens that had been thus fed, but none were found in control chickens.- 

 The proper generic position of this nematode described by Theiler as a 

 Filaria remains to be determined. 



Ascaris lumbricoides Linnaeus, 1758 



This common parasite of man has been definitely shown to have a 

 direct life history without intermediate host. The opinion of Linstow 

 (1886) that a species of Julus (guftulatus) acts as the intermediate host 

 is without foundation. The common house flj"^ may swallow eggs of this 

 parasit3 as well as those of various other parasites which occur in the 

 feces of infested human beings. The eggs pass through the intestine of 

 the fly unhatched. Flies may thus scatter the eggs of Ascaris but there 

 is no evidence that mechanical carriage of the eggs in this way assists 

 materially in the spread of the parasite. There are various other natural 

 agencies more effective than insects in spreading infection with parasites 

 such as Ascaris. -Stiles, however (according to Nuttall, 1899), fed 

 females of Ascaris lumhricoides containing eggs to fly larvae (Musca 

 domestica) and afterwards found the eggs in later stages of development 



