January.'] HOT-HOUSE INSECTS. ETC. 141 



Several spo.'ies and varieties of the same gpnus, Aphis, can 

 be destroyed in the like manner. 



Acaris tellurius, or red spider, is caused by a dry atmo- 

 sphere, and its havoc generally is obvious before it is arrested. 

 With its proboscis it wounds the fine capillary vessels of the 

 leaves. If they progress in their destructive work, the 

 leaves will prematurely decay. On this appearance turn up 

 the leaf, and you will see them running about with incredi- 

 ble swiftness. Their body is of a blood colour, and their feet 

 light red. When very numerous, they work thick webs on 

 the underside of the leaf, and frequently all over it, forming 

 a mass of half-dead plants, decayed leaves, and thousands of 

 spiders. The most effectual remedy is a thorough syringing 

 with water, 'and profusely under the foliage. This being 

 done every evening, will subdue and eventually banish them. 

 Had the house been syringed two or three times per week, 

 these intruders would not have appeared. It is said by 

 some writers that watering only reduces them to a temporary 

 state of inaction, and will not destroy them. Laying aside 

 the many prescribed nostrums, we assert that the pure ele- 

 ment is the most effectual cure, as well as the most easy to be 

 obtained.* 



Tlirips, order Semiptera, are insects so minute as 

 scarcely to be perceptible to the naked eye. They generally 

 lurk close to the veins of the leaves of plants, and frequently 

 attack esculents. When viewed through a glass they are 

 seen, when touched, to skip with great agility. The larva is 

 of a high brown or reddish colour. The thrip has four wings, 

 and walks with its body turned upward. It frequently attacks 

 the extremities of tender shoots or young leaves, which be- 

 come shrivelled, brown, and will rub to dust easily between 

 the thumb and finger. When any leaves or shoots are per- 

 ceived to be so, if you do not observe the green fly, expect 

 the thrips. They may be destroyed by a fumigation of to- 

 bacco, in the same manner as the green fly. By the simple 

 and expeditious method of fumigation, these insects and 

 several others may be destroyed effectually at any time they 

 appear. 



Cocus hesperiduS) or mealy bug, has appeared in the hot- 



* Fumes of sulphur is instant death to them ; but it has to be used 

 with great caution and experience. 



