1910 ENTOMOLOGICAL SOCIETY. 87 



Here it might be mentioned that the fruit grower may do much in the way 

 of avoiding diseases of the kind mentioned by frequent applications of the common 

 insecticides. 



In Grocery stores cleanliness cannot be too strongly emphasized, as this is one 

 of the favourite resorts of mites. A few examples of the spread of bacteria and 

 fungi will give an idea of their destructive habits to the groceryman. They crawl 

 underneath the lids of manufactured jams and jellies, carrying with them spores 

 which multiply and bring about putrefaction. In dried fruits, sugar, and other 

 sweets, flour, bread, cheese, etc., they carry a number of species of moulds and often 

 cause tremendous loss, which might easily be avoided if the proper care were prac- 

 tised. T. longior, T. Americanus, Aleurohtis forvnm, Carpoglyplivs sp. are ex- 

 amples of G-rocery pests. 



In horse stables and other buildings, mites are found abundantly, especially 

 where imperfect lighting and cracks and crevices of concealment are features of 

 the buildings. T. longior might be mentioned as the commonest house mite. It 

 is found from cellar to attic and practically on every object, thus we see the prob- 

 ability of its spreading spores of bacteria and fungi. The ensilage mite which 

 makes its home in the silo is a good example of a stable mite. It, no doubt, spreads 

 spores of some of the numerous bacteria and fungi found in ensilage. Another 

 example of how mites may spread disease from stable to house is the case of the 

 house-fly mite which travels on the backs of flies and may be transported from the 

 manure of the stable to the food in the pantry, ejg., Histiostoma Mtiscarum. 



Spread of Protozoan Diseases. Nearly all of the diseases belonging to the 

 genus Piroplasma are transmitted from animal to animal by means of these ticks 

 or mites. In the United States there are two very well known pathogenic diseases 

 which belong to this group. The Texas Fever {Pirdplasma higeminum) and Spot- 

 ted Eocky Mountain Fever (Piroplasma sp.) In Asia and Africa six other well 

 known diseases, Piroplasma ovis of sheep, P. canis known as Piroplasmosis of dogs, 

 P. equi, Piroplasmosis of the horse, Piroplasma Sp. — Rhodesia fever, and Haemo- 

 glohinurina of Finland. Space will not permit of discussion of this important 

 phase of the subject. At present we have no record of any diseases spread in this 

 manner in Canada, but since we have hete numerous species of ticks associated 

 with animals it is not unlikely that in time we shall find examples of diseases car- 

 ried in this way. 



As Parasites of Animals. 



Man. — Among the mites that are injurious to man might be mentioned, first, 

 those that are parasitic and spend the whole of their existence in the host ; second, 

 those like the ticks that are casual visitors; and, third, those that inhabit his house 

 and clothing and cause annoyance by their presence. The first is exemplified in the 

 follicle mite which lives on the secretions of the follicles of the skin, such as Demodex 

 follicularum and the " Jigger " of the Southern States. Examples of the second 

 class are the numerous species of ticks. These are found in the tropics, and are 

 abundant in fields, woods and pastures. They leave the herbage to attach them- 

 selves to man and other animals, where they burrow into the skin and create 

 considerable irritation. In Ontario ticks are not so abundant, but in some parts 

 the wood tick leaves its common habitat to attack man in the way just described. 

 The harvest mites, found in grass, hay and cereal crops, when found in large 

 numbers also cause much irritation. The species known as Carpoglyphus paS' 

 sularum found in sugar in grocery stores often leaves the sugar to attack man, 

 causing what is known as grocer's itch. The most common species found in 



