128 Insect Pests. 



the opening and then commences to make at the top of the hole 

 (or ^Q to -|- inch below the top) a covering of the dust, and apparently 

 some liquid. I also found one crawling along a branch." 



The genus Emphytus, to which this pest belongs, has thirteen 

 representatives in Britain. The larvae are all somewhat similar, 

 being greenish on the back, paler at the sides, and sometimes covered 

 with a white powder. No definite cocoon is formed. Most bore, as 

 described above, into the steins of plants to pupate. For this purpose 

 rosaceous plants are mostly sought after. A few, however, are 

 found on the oak, birch and willow, and on Geranium robcrtianum. 



I think there is no doubt that the species attacking the apple in 

 Herefordshire was the Emphytus carpini of Hartig, as the larva most 

 closely approaches the description of that insect. 



The mature larva? (Fig. 102) I examined varied from ^ inch to a little 

 more in length. In colour the dorsum varied from rich deep apple- 

 green to dull olive-green. The sides and venter much paler, varying 

 from dull greenish-white to pale yellowish-green, a few pale spines 

 on the back of the segments ; the spiracles black with a pale area 

 around them. Head, deep brown to almost black above, paler 

 beneath. The true legs pale, with deep brown apices ; the seven 

 pairs of prolegs the same colour as the venter. 



When taken from their chambers, the larva- curl themselves up 

 in the characteristic manner of their genus. 



The last two or three abdominal segments are paler than the rest, 

 but darken to the same colour during the winter. The young larva 

 is said to be pale, dirty olive-green above, and the posterior segments 

 are seen to be clearer than the rest. 



They remained in the larval stage until the end of March, and 

 then changed into pallid pupa?. 



Emphytus carpini is a common English and Scotch insect. The 

 larva feed in shady places on Geranium robertianum, also on the 

 mountain ash (tiorbus aucuparia} and hawthorn (2). 



There are two generations : one in July, August and September, 

 which feed on the radical leaves ; the second in October and 

 November, and which feed on the other leaves, eating them down 

 to the thick mid rib. They feed on the lower surface. 



The adult fly is black and shiny, the legs mostly white, but there 

 is black on the middle of the femora, on the apex of the hind tibite ; 

 the hind tarsi and the fore and mid tarsi dusky. Length inch. 



The only other species it might be is Emphytus cinctus, Linnaus, 

 whose larva 1 feed on the common rose, eating the leaves along the 

 edges. Those from the apple differ, however, in not having the 



