24 B. C. EXTOMOLOGICAL PROCEEDINGS, 1911. 



half an inch below the surface of the ground, and ultimatel}' hatches 

 out, as mentioned previously. 



I will now mention the varieties of Narcissus most liable to attack 

 by the fly, in order of percentage in each \ariet\ observed. The true 

 Narcissus type is most susceptible, then come the intermediate season 

 daffodils. (Commonest varieties mentioned). 



Ren/rvus — most subject. 



Bfirii rrj/ispiciiis — nearly as bad. 



Orntitii): 



Poet arum 



Sir H'ntkin 



Airs. Laiigtry 



Von Sion 



Emperor 

 Earl\- daffodils, like "Henry Irving," "Golden Spur" and "Princeps," 

 are almost free, as are the late daffodils. 



In the true white Narcissi the easiest way to detect the grub is to 

 examine the root crown, and as these varieties rarely stop rooting, the 

 year round, it makes it all the easier. If there is a portion where the 

 roots have not sprouted and looks brown, it is almost sure to contain a 

 grub. The usual way of squeezing the bulb to see if it is soft does not 

 so readily apply in the case of daffodils, as the true white Narcissi are 

 very hard bulbs. (Only a very small percentage of affected bulbs have 

 any external puncture, except at base of bulb.) My reason for believing 

 that an entrance is made there is that the progress of the grub upwards 

 is registered on the root crown ( this is only apparent in the continual 

 rooting Narcissi, which, incidentally, is the class particularly attacked 

 by the Fly), consequently as each bulb layer is bitten or pierced, a 

 corresponding number of roots decay. 



Although the base is thus affected, and in advanced stages the root 

 growth ceases entirely before the dormant stage of the grub, a sporadic 

 growth of the flower spike and leaf crown often continues, with the 

 usual appearance (if strong enough to push through the earth) of a 

 sickly yellow leaf, nearly always single. This is an infallible sign of 

 the previous habitation of the grub in the month of February and 

 March. 



The next point is the appearance of the grub in the bulb. The grub 

 seems to develop much more rapidly and healthily on damp spots (damp, 

 I am persuaded, is essential), as in harvested bulbs out of the ground 

 the grub is practically quiescent and torpid, starting to attack the bulb 

 vigorously when planted in the ground. 



The fact that the grub has had a check is noticeable in this way: if 

 the grub is pure white and vigorous, it has received no check or shock ; 



