100 ARACHNOIDEA. 



CASE Veitch's Chelsea Blight Composition, Frettingham's Liquid Com- 

 pound, are all good. Sulphur, in any form, seems potent. Laying 

 flour of sulphur upon the pipes in the greenhouse or hothouse is 

 much recommended. It has been used with very decided success 

 also against the growth of microscopic fungi, as in the case of the 

 Oidium Tuckeri (vine fungus). Mixed with soap, as is done in 

 Gishurst Compound, and applied to the leaves by the syringe, it 

 is also very useful. Even plain soap and water is said to be an 

 effectual remedy if it reaches the insect. A quarter of a pound of 

 soft soap whisked until it has become dissolved, is to be applied 

 with the syringe so as thoroughly to wet the leaves ; but in water- 

 ing and bathing the leaves, we must remember that if we content 

 ourselves with watering the upper side of the leaves we have done 

 nothing, because the mites remain very quiet during the opera- 

 tion and in perfect security on the low^er side. It is necessary, to 

 secure success, to use a bent syringe to send the water upwards, 

 and to wet the under side of the leaves well with the decoction used. 

 The gardener is assisted in his war against them by other mites 

 and insects, that help to keep them in check by preying on them. 

 The grub, or larva, of the Hemerobiidae, or lace-wing flies (the 

 same which prey on the Aphides), devour them in such numbers 

 and so fast that entire colonies quickly disappear before them. 



Tetranychus telarius Var.; cinnabarinus {Boisd.\ Ent. Hort,, p. 88. 



We can see nothing in the following account of this species^ 

 which is from the pen of M. Boisduval, to distinguish it from the 

 red spider, Tetranychus telarius : — 



" It was in the warm greenhouses of M. Savage that we 

 became acquainted with this acarus on the tufts of Dracaena, 

 australis. Thanks to that able horticulturist we have been able 

 to observe it from the egg stage to that of the perfect insect. 

 When it hatches it is then green or a yellowish green ; later it is 

 variegated with black and green ; after its last change of skin, it 

 becomes a beautiful aurora red in colour. It is a little larger 



