112 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



Tarsonemus ananas Try on was determined by Tryon to be the 

 primary cause of a disease of pineapples in southern Queensland. 1 

 The mite infests the pineapple plant quite generally, as the stem of 

 the fruit, deep between the bases of the leafy bracts, forming the tuft 

 at top of plant, and especially the fruitlets, where, by its puncturing 

 with its styliform mandibles at the base of the cavity containing the 

 essential organs, an injury is produced which may be followed by the 

 invasion, of a fungus, resulting in the so-called "fruitlet core rot." 

 The mites are never very abundant and shun the light, inhabiting 

 principally the deeper recesses of the fruit. 



Two species of Tarsonemus have been reported by Mr. A. D. 

 Michael as injuring sugar cane in Barbados. 2 One species, which he 

 calls Tarsonemus bancrofti Michael, also occurs in sugar cane in Queens- 

 land. The mites were exceedingly abundant in all stages on the canes 

 observed by Mr. Michael, living principally under the leaf sheaths. 

 They are thought to be present in other sugar-producing countries, 

 but have thus far escaped notice. The infestation of cane by mites, 

 according to Mr. Bovell, superintendent of Dodds Botanical Garden, 

 reduces the annual yield of sugar from 3 tons to 1 ton per acre. 



Another mite, Tarsonemus culmicolus Reuter, produces a silver-top 

 disease of grasses in Finland, 3 occurring especially on Plnleum y pratense, 

 Agropyron repens, and Festuca rubra. This species has been well 

 treated by Dr. Enzio Reuter. The mites are present on the grasses 

 from early spring to faU, infesting the interior of the leaf-sheath, 

 living on the tender stem above the highest node. While no deformity 

 results, the extraction of the juice occasions the drying up and death 

 of the inflorescence, which remains filiform and turns white. 



Tarsonemus latus Banks was found by Banks in some small mango 

 plants in one of the department greenhouses in Washington. 4 Some 

 plants had stopped growth, and the mites occurred principally 

 on "the swollen and partially discolored tips. 



Tarsonemus pallidus Banks was found on a chrysanthemum in a 

 greenhouse near Jamaica Plain, N. Y. 5 



There are numerous other species, but those cited will serve to 

 show the importance from an economic standpoint of this group of 

 small creatures, and adds additional evidence, by reason of its rela- 

 tionship, that our peach bud mite is responsible for the injury to peach 

 herein described. 



1 Fruitlet core rot of pineapples. Queensland Agr. Journ., 1898, p. 458. 



2 Report on diseased sugar cane from Barbados, etc. Bull. Royal Gardens, Kew, 1890, p. 85. 



3 tiber die Weissahrigkeit der Wiesengraser in Finland. Acta Soc. pro Fauna et Flora Fennica, vol. 19, 

 No. 1,1900, p. 77. 



* Journ. N. Y. Ent. Soc, vol. 12, 1904, p. 55. 

 5 Proc. Ent. Soc. Wash., vol. 4, 1898, p. 294. 



