1910 ENTOMOLOGICAL SOCIETY. 93 



ing plants. Two species of Red Spider, Tetmnychus himaculatus and T. telarius, 

 are the common species of the greenliouse of Ontario. They are found on suqji 

 plants as primulas, chrysanthemums, carnations, cinerarias, tomatoes, etc. The 

 bulb mite, Rhizoglyphus hyacinthi, is responsible for an enormous amount of 

 damage in hothouses. They burrow into the healthy tissue, thereby giving a 

 chance to the destructive soil bacteria to bring about decay. It is found on 

 hyacinths, narcissus, orchids, and other bulbous plants. Affected bulbs should 

 be burned as soon as the mite is discovered. T. pallidus is sometimes found on 

 leaves of Chrysanthemum and Rhizoglyphus heteromorphus, which cause injury 

 to the stems of carnations, are found in New York state. Other species are found 

 on the pistil of Banana flowers in the tropical greenhouses, and on the leaves of 

 Latania palm. 



As Pests of Flour Mills, Stores, Etc. 



Flour mills, grocery stores, dru^ stores, butcher shops, libraries, laundries, 

 restaurants, confectioneries, seed stores, furriers and furniture stores all afford 

 hospitality to a species or more of Acarid. The flour mites, Aleurohius farinae and 

 Tyroglyphus longior are the chief pests of the flour mill, the grocery store, the 

 seed store and confectionery store. The sugar mite, Carpoglyphus passularum is 

 chiefly found on raw sugar. 



TL— CLASSIFICATION. 



The mites belong to the Phylum Arthropoda, to the class Araohnida and to 

 the order Acarina. In a general way mites are readily identified by their one- 

 piece or sac-like bodies, but a much greater difficulty is encountered when it comes 

 to differentiate them from their allies, the spiders and scorpions. Scorpions have 

 segmented bodies and spiders have a marked constriction between the cephalo- 

 thorax and the abdomen, and when these characteristics are present they can be 

 easily separated from the Acarids. They are mostly very small and some are even 

 microscopic. It has been found that in the embryo eight legs are present, but 

 at birth and during larval development they have only six, and after moulting 

 a few times develop a fourth pair. Exceptions are found in the large family, 

 Eriophyidae — the worm-like mites — where they have but two pairs throughout life. 

 The legs are provided with hairs and spines, sometimes much modified, fitting 

 them for special adaptations in life. In some groups organs are found on the 

 anterior legs which are supposed to be sensory. The last Joint of the leg is 

 commonly terminated by from one to three claws. The mouth parts take the 

 form of a truncate cone or beak, and in some families it is partially or completely 

 reversible. The mandibles and palpi are of various types and peculiarly modified 

 according to the habits of the mite. In some families there is a lingula or tongue 

 which is usually not visible except by careful examination, but in the Ixodidae it is 

 large and roughened with sharp teeth. On the cephalothorax there are usually 

 one or more pairs of simple eyes which are sometimes elevated on short pedicels. 

 The reproductive organs open on the ventral surface of the abdomen, and in this 

 respect they are like their relatives, the Arachnids. 



