126 



HARDWICKE'S SCIENCE-GOSSIP. 



[June 1, 1867. 



Gossip will remember that allusions have been 

 made to a curious little red mite which deposits its 

 white eggs on stones, and similar substances. This 

 " Stone Mite " (fig. 93) is Tetranychus lapidus, and 

 the extract from the Entomologists'' Monthly Maga- 

 zine alluding to it, which was quoted (Science- 

 Gossip, 1865, p. 22), need not be repeated here. 

 Gervais states that the eggs may be seen in autumn 

 on the stones of the public promenades in Paris. 

 These eggs (fig. 91) were observed and figured in 

 one of the earliest numbers of Loudon's excellent 

 Magazine of Natural History. 



Fig. 93. Tetrunychus lapidus. Fig. 94. Eggs of the same. 



M. Duges has described another and smaller 

 species, ;with similar habits, under the name of 

 Tetranychus glabrus, but which he says is so very 

 minute that it is scarcely visible to the naked eye. 

 A figure is given (fig. 102) belonging to the present 

 species, and is copied from the one furnished by 

 M. Duges. 



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Fig. 95. Tetrunychus major. 



Another species, which may be called the Laurus- 

 tinus mite, having a long appendage (Tetranychus 

 caudatus), is found in colonies on the lower sur- 

 face of the leaves of the Laurustinus, but has not 

 yet been recorded in Britain. 



Already allusion has been made to the " Social 

 Mite " (Tetranychus socius), of which a figure is now 



given (fig. 96). It is of a pale colour, and also 

 prefers to consort in colonies. 



The "Plum-tree Mite" (Tetranychus prunicolor) 

 is said by Gervais to be found in the months of 



Fig. 96. Tetranychus socius. 



July and August, on the leaves of the pear and plum 

 trees in some parts of Erance, and when mature is 

 of a violet-brown colour, but when young, greenish. 

 One species, affecting elm-trees, is called by 

 Koch — Tetranychus ulrai, and is of a bricky red 

 (fig. 97). 



Fig. 9/. Tetranychus ulmi. 



Another attaches itself to willows, and has ac- 

 quired from hence the name of Tetranychus salicis 

 (fig. 98). In general colour it resembles the last. 



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Fig. 98- Tetranychus salicis. 







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Fig. 99. Tetranychus Tiburni. 



The guelder-rose also cherishes its sociable mite, 

 which is called Tetranychus Viburni (fig. 99), and 

 is orange- coloured when mature. 



Upon the poplar a greenish mite has been dis- 

 covered, belonging to the same genus, and which is 

 named by Koch— Tetranychus populi (fig. 100). 



