CABBAGE APHISi 2l 



be found as males, winged and wingless females, and in young state 

 resembling the fully developed insects in shape, excepting in the 

 absence of wings ; these being known commonly as larvcB during the 

 first stages after being produced alive or hatched ; and afterwards, when 

 they have developed wing-cases, but not as yet wings, as pupcE. 



When first hatched the larvae are stated to be shinuig and bright 

 yellow ; with advance of age to be of a dirty grey much corrugated, 

 and the wing-cases of a dark or grey black. The wingless female pro- 

 ducing living young is given by Bucktou (when without the powder) as 

 of a greyish green, with eight black spots down each side of the back> 

 those nearest the tail being the largest ; horns green with black tips ; 

 eyes, legs, cornicles (honey-tubes), and tail, black. The winged egg- 

 laying female is given as having the head, neck, lobes of the thorax 

 black, and the rest of the body yellowish green ; horns and cornicles 

 dark brown ; tail dark brown or green ; legs dusky brown. 



There is much difficulty in certain identification of the difi'erent 

 kinds of Aphis infesting Cabbage and Turnip, but their method of life 

 is so far alike as to make them all fall under the same kinds of treat- 

 ment. The general rule is that the male Aphis does not appear 

 until autumn, a little before the appearance of the wingless egg-laying 

 female. Between these pairing takes place, and the wingless females 

 lay the eggs from which proceed the infestation of the following year. 

 Tiie appearance of the male only occurs in autumn. 



If we could get at the eggs, or find that the Aphides passed the 

 winter in any accessible shelters, then we could work satisfactorily 

 towards lessening the infestation ; but as the case stands, no method of 

 destroying them, on the scale of open garden or field work, appears to 

 be known excepting the use of washes. 



Soft-soap washes, or soap suds witli various additions to make them 

 more poisonous or deterrent, have long been used with greater or less 

 success for garden service ; but until lately there has been great 

 difficulty as to any reasonably practical method of appbjhif/ ivash in 

 field cultivation of root crops. In the last few years, however, much 

 improved soft-soap mixtures have been introduced, as soft-soap and 

 siilphur, soft soap and mineral oil, or other mixtures which must as 

 surely do good in lessening amount of these Aphides, or Plant-lice, on 

 Turnips or Cabbage, as the various and long-used soft-soap washes do 

 yearly as a preventive of Hop Aphis. But there is the very great 

 difiiculty still to be met of Iwiv to (jct at the infested plants. 



In very many cases the action of the large implements cannot be 

 brought to bear, from the method of arrangement of the crops, as Tur- 

 nip, Mustard, &c., which do not usually allow room for the washing- 

 machines, however much good they might do ; and the fine and gradual 

 work of the implements which can be carried on a man's back runs up 

 quickly in cost at the rate of field work. 



