CABBAGE APHIS. 17 



The young, when first hatched, are yellow. In the next 

 stage (which answers to the j^upa one, and whilst as yet they 

 are without wings) they are much wrinkled, of a dirty green 

 colour, with olive-green or grey-black wing-cases. The wing- 

 less females which produce living young arc mealy, and when 

 this meal is rubbed off they are of a greyish green, with black 

 spots on each side of the back ; eyes and legs black ; antennae 

 (horns) green or ochreous, with black tips. 



The winged viviparous female is of a yellowish green, with 

 head and markings between the wings black, and some dark 

 marks across the abdomen. The legs and antennae dark 

 brown, and a mark on the fore edge of the wings also dark. 

 The male is given by Curtis as pea-green, otherwise it is much 

 like the winged female, excepting in the mark on the wings 

 being green ; the antennae longish and black, and the cornicles 

 or honey-tubes black at the base. — (' Farm Insects,' and 

 ' Mon. of Brit. Aphides.') 



Prevention and Eemedies. — In garden cultivation, drench- 

 ing the infested plants with soap-suds is practicable and of 

 service, especially in killing the young Aphides. 



Syringing with an infusion of tobacco mixed with lime- 

 water has been found very useful, and the following mixture 

 is also stated to be serviceable : — Four ounces of quassia 

 boiled for ten minutes in a gallon of water, and a piece of 

 soft-soap about four ounces in weight then added ; and the 

 mixture syringed over the plants. In this application the 

 soft-soap is the important matter. From the mealy or 

 powdery nature of the coats of the Aphides, mere waterings 

 are apt to run off from them harmlessly, and adhesive 

 applications like syringings of soft-soap are much surer 

 remedies. 



Thorough drenchings of water with the garden-engine, 

 however, are of service, by forcibly clearing many of the 

 Aphides from the plants and also by encouraging growth. 



We all know the overwhelming increase of Green Fly 

 that often happens when the plants are stunted by heat or 

 disease, — or by the Aphis attack itself ; and it is noted (see 

 ' Mon, of Brit. Aphides,' by G. B. Buckton, F.R.S., vol. i. 

 p. 72) that when the juices of the infested plants begin to fail 

 and become sickly from excessive numbers of Aphides, a 

 change commences in larvae subsequently born. Signs of 

 wings appear, and the viviparous females from these pupae 

 are winged ; this different development, with its increased 

 power of spreading attack, following apparently on the altered 

 food. 



This is curious as a scientific observation, and, if always 



c 



