RED SPIDER. 219 



The **Eed Spider" has difficulty in moving on perfectly 

 smooth surfaces, but, by means of its claws and the pin-headed 

 bristles with which they are furnished, it moves readily on 

 the under side of the leaves, and fastens its threads to the 

 hairs or slight prominences, thus gradually forming a coating 

 of web, amongst which it lays its eggs, fastening them by 

 some glutinous secretion to the threads ; and under this shelter 

 a colony, consisting of many of both sexes in maturity, and 

 young in all their ages, feed and multiply with rapidity. 



The colour is various, depending, as far as present observa- 

 tions show, on the colour and nature of the food within ; 

 possibly also in some degree on the age of the individual. 



The attacked leaves may be known by their greyish or 

 yellowish, somewhat marbled appearance above, whilst be- 

 neath they are whitish and shiny from the covering of web. 

 This kind of Eed Spider has been found sheltered, as if for 

 the winter, beneath stones. 



The above observations give as much of the general life- 

 history and habits of the " Spinning Mites," commonly known 

 with us as "Eed Spiders," as is needed for practical pur- 

 poses, without distinction of the different kinds of species 

 that may possibly be present. But the following descriptions 

 of TetranycJius telarius, translated from the works respec- 

 tively of Donnadieu and of Berlese, special writers on the 

 Tetranychi; and also fromDonnadieu and Canestrini regarding 

 a very similar and common kind known by the former of 

 these two writers as Tetranyclius ruhesccns, and by Canestrini 

 as T. telarius of Dufour, are added, as probably serviceable 

 for reference. 



The following paper is extracted from the 'Eecherchespour 

 servir a I'histoire des Tetranyques,' par A. L. Donnadieu, 

 Professeur au Lycee de Lyon, 1875 (p. 151) : — 



" Tetranyclius telarius, Donnadieu. 

 Acarus telao'ius, Linne. 

 Tromhidium telarium, Hermann. 

 Tetranyclius telarius, Duges. 

 Tromhidium tiliarium, Hermann. 

 Flexipalpus tilics, Scheuten. 

 S- Leptus autumnalis, Duges. 



attribute to the Tetranychi glands placed near the anus, and recognize in these 

 creatures an anal spinning apparatus for the formation of their webs." Clapa- 

 r^de noticed the glandular apparatus of some Tetranychi as being placed at 

 the anterior part of the body, but was inaccurate in giving the excretory canals 

 as opening through the palpi ; and other writers have variously described the 

 position of the glands and their excretory canals ; but a reference to the page 

 above quoted of Donnadieu's work, and reference to fig. 78 of his plate s., and of 

 my reduced copy, fig, 1, p. 217, ante, will put the reader iu possession of very 

 full information on the subject. 



