50 



of June. The California specimens, collected July 31, 1889, have not 

 hatched and it is quite possible, in view of the prior hatching of the 

 eggs from similar localities in Montana, that the former eggs, either 

 from severe cold or other causes, have been killed, although they are 

 still fresh and healthy in appearance. 



Professor Comstock found nearly full-grown specimens at Salt Lake 

 City on apple trees iu «Tnly, together with eggs and young, which would 

 indicate two broods there at least. 



In Indiana, Iowa, Ohio, and Massachusetts large numbers of the last 

 brood of mites winter over, and the fall and spring wandering of these 

 in search of food or shelter doubtless accounts for the invasion of dwell- 

 ings so frequently reported. The swarming or massing in Europe of an 

 allied species, Petrobia lapidum, is referred to by Mr. Webster in the 

 article cited above. 



In Vol. I, No. 10, of Insect Life we mentioned the record by the New 

 Zealand Farmer of the damage occasioned by a congeneric insect to the 

 leaves of the Apple in New Zealand ; and our agent, Mr. Webster, in 

 the course of his recent Australian mission, had his attention called to 

 the work of a similar mite on various fruit-trees in Victoria (see Insect 

 Life, Vol. I, p. 363). 



At Washington, the mites abandon the clover and leaves of trees 

 early in October and secrete themselves, especially, in crevices in the 

 bark and under loose bark of various trees. In these situations they 

 may be found abundantly during the fall and winter in connection with 

 eggs and (sparingly) young of various stages. It is thus seen that 

 breeding IS hardly interrupted in this latitude during the winter months. 



Food-plants. — The foregoing notes indicate that this mite is a very 

 general feeder. Many of the trees on which it has been found, how- 

 ever, evidently serve but to furnish winter quarters, and are not espe- 

 cially attacked by the young and adults during the summer months. 



Of the forage plants, Clover and Timothy (?) are especially attacked ; 

 the former being perhaps the ordinary food-plant of the mite. Of ti ees, 

 the Apple and Arbor-vitte are frequently infested with all stages during 

 summer, and the occurrence of eggs and adults in fall and winter on 

 Almond, Plum, Prune, Poplar, Elm, and other trees would indicate that 

 these are also attacked. 



Remedies. — In the case of its occurrence on fruit or shade trees it can 

 doubtless be controlled or destroyed by spraying with the kerosene 

 emulsion, to which sulphur may be profitably added at the rate of 2 or 

 3 ounces to the gallon of the wash. In the case of forage crops, spray- 

 ing would be impracticable and no efiective method of combatting the 

 pest can at present be given. 



The importance of this mite arises chiefly, however, from the annoy- 

 ance occasioned by its infesting houses, and this " inconvenience," to 

 put it mildly, can be avoided, or the mites that may have effected an en- 

 trance may be destroyed, by the use of the following measures which 



