OF INSECTS, &C. 335 



wards and forwards, that no part of the tree be 

 missed. This should be done in cloudy weather, 

 or when the sun is off the wall. If the trees are 

 on an East wall, you may begin to water them 

 about half past eleven o'clock ; if on a North wall, 

 you may water them the first thing you do in the 

 morning ; and if on a South wall, at four o'clock 

 in the afternoon ; repeating the watering for at 

 least six days successively. But if there be cold 

 Northerly and Easterly winds, or frosty nights, 

 the watering should be discontinued till the wea- 

 ther is milder. 



Be always careful that your trees get dry before 

 night, and be sure never to water when the sun is 

 on them, nor yet water them with the grounds of 

 the lime, which will make the trees look very un- 

 sightly, and also injure the leaves. 



When aphides are numerous at the ends of the 

 shoots, the leaves there will be curled up ; these 

 should be stript off, and the insects crushed with 

 the foot. 



Of the Acarus, 



The Acarus, or Red Spider, is one of the most 

 destructive insects that can infest plants, particular- 

 ly in forcing-houses. 



These insects have no wings, and the female is 

 oviparous. 



There are not less than 82 species of this genus. 

 The Acarus is very common on trees, particularly 



