M. A. Scheuten on some Mites and their young states. 475 



XXXVIII. — On some Mites and their young states. 

 By A. Scheuten*. 



[With a Plate.] 



Under the epidermis of the leaves of pear-trees, in black, 

 pustular, inflated spots, the author discovered some small vermi- 

 form animals, which were pronounced to be the larvae of Mites 

 by Professor Troschel. The author then examined the outside 

 of the leaves, and found mites, which had probably been deve- 

 loped from the little animals above mentioned. This appeared 

 not only from their common habitation, but also from the simi- 

 larity of the organs of the mouth, and the presence of two strong 

 bristles on the abdomen of both animals. On examining a large 

 number of spotted leaves in his garden, in which all the pear- 

 trees were similarly attacked (one tree having a third of its leaves 

 affected), the author always found the same larvse in the interior 

 of the leaves, and in most cases the mite on the exterior. On 

 one tree a very similar larva was found with a few specimens of 

 a different mite. This was at the end of July, and in August 

 the author detected the same mite and larva on pear-trees at 

 Harlem. He afterwards observed the leaves of a lime-tree, 

 which were covered with reddish-brown spots by Erineum ruhigOy 

 and found on them the same larvse and mites. 



Hence it would appear that the larvse and mites belonged to 

 the same species, and the question of their identity becomes the 

 more interesting, as Duges had already asserted that the mite 

 is produced from the larva, which was disputed by Dujardin, 

 because he supposed that he had seen eggs in the so-called 

 larva. 



In the ' Annales des Sciences Naturelles,^ 2me ser. tome ii. 

 p. 104, a larva of the same form is described by Duges, who 

 asserts it to be the larva of Tetranichus, Dufour, partly on ac- 

 count of the similarity of the organs of the mouth and of the 

 legs, and partly on account of their common habitation. Dujar- 

 din describes a third larva, so similar to that of Duges, that he 

 considers them to belong to the same genus. Duges saw the 

 larvse become motionless and converted into pupse; the body 

 contracted, leaving the extremities of its envelope. Two or three 

 times, in galls of the white willow and the lime-tree, he saw 

 short, nimble, eight-legged mites with the palpi and legs of 

 Tetranichus] they were perfectly similar to the large reddish 

 Tetranichus which he also found repeatedly in larger galls. 

 Dujardin described the animal in the 'Annales des Sciences 



* Abstracted from Wiegmann's Archiv, 185/, p. 104, by \V. S. Dallas, 

 F.L.S. 



