1927] Notes on the Mite Pediculoides ventricosus Newport 157 
NOTES ON THE MITE PEDICULOIDES VENTRICOSUS 
NEWPORT. 1 
Raymond L. Taylor. 
The mite Pediculoides ventricosus Newport, attracted my 
attention when it completely destroyed several hundred para- 
sites, which I was rearing. This acarid has been described as 
both beneficial and noxious, but this difference of opinion appears 
natural when one considers its wide range and the large number 
of insect species which it attacks. Moreover, it has been defini- 
tely shown to cause an irritating form of dermatitis in man. 
Pediculoides ventricosus was observed by Newport in 1849 
in the nests of Anthophora retusa at Gravesend, England, and 
was described by him in a published record in 1853. In 1879, 
Geber observed in Lower Hungary an eruptive epidemic coming 
from barley, and his investigations showed an acarid responsible 
for the dermatitis. Webster says that it would seem quite 
probable from Geber’s illustrations, that the mite involved in 
the epidemic might have been Pediculoides ventricosus. The mite 
was first recorded in America in 1882 by Webster, who held that 
it had probably not only occurred as early as 1830 in Massa- 
chusetts, but it had also, at that date, become noxious to man. 
Harris in the second edition of his “Insects Injurious to Vege- 
tation” refers to an observation he made in 1844 at Cambridge, 
that straw bed ticks had proved very troublesome to children 
sleeping on them because of insect bites. Harris ascribed the 
bites to Isosoma hordei, but Webster believes that it is more 
likely that Pediculoides was the cause of the dermatitis. Since 
1884, many notes on the attacks of the mite upon both man and 
insects, have been made. 
Pediculoides is widely distributed. It has been reported 
throughout the United States and Canada, especially in the 
regions where grain is grown, in virtually all of Europe, parts of 
Africa, notably Egypt, and in India. 
This mite feeds principally upon larvae and pupae of such a 
Contribution from the Entomological Laboratory of the Bussey Insti- 
tution, Harvard University. No. 285. 
