66 INSECT PESTS 



called Black or Thunder Fly, They are less than ^ inch 

 in length ; an enlarged drawing of the adult insect is 

 seen on Plate 15. 



The eggs are laid in June, and hatch out into a larva 

 which is very similar in appearance to its parent but 

 without the wings. They are active on the plants for 

 about four weeks, subsequently passing into the earth 

 to pupate, and emerge the following season as full-grown 

 thrips. The damage done by these insects consists of 

 maiming the flowers and often preventing fertihzation 

 altogether. The soil is the best place in which to meet 

 them, ploughing deep and hming in the winter. On small 

 areas some such soil fumigant as napthalene may be used 

 effectively, but the burning of the haulm is not of much 

 avail for thrips as they have usually left before the plants 

 are up. Change of site will of course happen in any case. 



We now come to the Aphis {A, rumicis). Plant 

 lice are the most common form of blight and are met 

 with all over the country. Each plant has as a rule its 

 own particular species. On Plate 1, Figs, 17 and 18, 

 will be seen the Black or Bean Aphis and also the 

 Rose Aphis, which represent the general form of these 

 Hemipterous insects. 



The female Aphis passes the winter on furze clumps, 

 where she deposits eggs, which produce winged individuals. 

 These proceed to the scene of action as soon as the warm 

 weather comes. 



I always find there is a weird suddenness in the appear- 

 ance of Mrs. Aphis, against which it is well to be prepared 

 by getting emulsions and sprays in working order long 

 before the usual time. Every spring there is that 

 psychological moment when there is not the slightest 

 indication of anjrthing untoward likely to happen. You 

 are absolutely charmed, on some warm, still evening, 

 with the limpid air suggestive of a vesper bell. Mrs. 

 Aphis ? Good heavens, there is no such person. You 

 are all right this year at any rate. 



