January.'] HOT-HOUSE — insects, etc. 137 



Several species and varieties of the same genus, Aphis, can 

 be destroyed in the like manner. 



Acaris tdlurius, 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 color, and their feet 

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

 the under side 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.* 



Thripsj order Hemiptcra, are insects so minute as 

 scarcely to be perceptible to the naked eye. They gene- 

 rally 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 color. The thrip 

 has four wings, and walks with its body turned upward. It 

 frequently attacks the extremities of tender shoots or young 

 leaves, which become shriveled, brown, and will rub to dust 

 easily between the thumb and finger. When any leaves or 

 shoots are perceived to be so, if you do not observe the 

 green fly, expect the thrips. They may be destroyed by a 

 fumigation of tobacco, 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 hesjjerichis, 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. 



12* 



