THE APHIDES OF GUERNSEY. 85 



" With regard to what we know at present of means of 

 prevention, our best course is, if we can, to nip the evil in the 

 bud by destroying the very first Aphides that appear. This 

 plan is constantly carried out in field management with regard 

 to the Bean Aphis. AVhen the Colliers, as they are called 

 from their black colour, appear on the tops of bean shoots, 

 these infected shoots are cut off. If the shoots and Colliers 

 on them are destroyed, the attack, or at least a great deal of it, 

 will be stopped ; but if, instead of carrying off the fragments 

 and destroying them, they are only thrown on the ground, the 

 Black Aphides will just walk or fly back again to the 

 growing beans, and the labour will have been in the great part 

 lost. 



" This same plan is useful throughout the summer for all 

 plants or trees, such as Apple, Plum, Cherry or others in 

 which Aphides collect in great numbers on shoots, which may 

 be cut off without hurting the plant. Thus if the shoots and 

 Aphides on them are properly destroyed at once, we get rid of 

 centres from which attack is constantly spreading to do 

 present harm. Also we may thus lessen the amount of next 

 year's attack. It is the autumn brood of males and females 

 which provide the eggs to start the attack of the following 

 year ; and therefore anything which lessens the production of 

 broods is useful. The shoots, however, should always be 

 destroyed at once ; not merely thrown aside to wither 

 gradually, whilst their infesting hordes gain wiugs to go home 

 again." 



The wonderful life history of the chief division of the 

 Aphidce has engaged the attention of the most celebrated 

 naturalists for centuries. Mr. Buckton says " It is now more 

 than 130 years since Reaumur and subsequently Charles 

 Bonnet began observing Aphides. Some think that the facts 

 to be obtained from such insects might soon be investigated, 

 and that the well of inquiry in this direction would soon 

 be fathomed. To disprove such ideas, we have only to turn 

 to the mass of literature which relates to the subject, and 

 notice how it embodies the labour of some of the most 

 acute natural philosophers of almost every civilized country. 

 The cause of this interest may be traced without difficulty to 

 two principal facts. In the first place, the study of these 

 creatures has presented to the embryologist questions for 

 solution of the greatest importance. Phenomena connected 

 with processes of reproduction occur, which even now some 

 physiologists consider to be abnormal, and concerning the 

 intei'pretation of which unqualified consent is by no means 



