THE PRODUCTION OF NARCISSUS BULBS 
23 
under good conditions. This also is not as deep a yellow as Golden 
Spur, which has supplanted it for that reason. 
ENEMIES 
The enemies of daffodils are few in number, and only one really 
serious pest has been observed in this country. 
The injury by the larger narcissus fly (Merodon equestris Fab.) 4 is 
done in the larval stage, the grub burrowing through the bulb and 
destroying it. The grubs can be detected and destroyed at planting 
time. They are about half an inch long and one-fourth of an inch 
in diameter and occur singly in the bulbs (fig. 3). The adult, which 
is seldom seen, somewhat resembles a bumble bee. A practical 
method for destroying the insect has not been 
completely worked out in this country. Hand 
picking the bulbs is quite efficacious in maintain- 
ing a measure of control, but it does not eliminate 
the pest. This is not so difficult a process to 
apply as it may seem, for there is usually some 
evidence, such as a rotten base or perforated apex 
to the bulb, to suggest visually the presence of 
the insect. To the feeling, bulbs occupied by the 
grub are light in weight and mostly soft to the 
touch. Some of these evidences are sufficiently 
pronounced to enable one to cull the stock and 
throw out most of the infested bulbs. 
The most approved Dutch method of general 
treatment of narcissus bulbs for this fly as well 
as for the nematode is known as the hot-water 
treatment. In its simplest, most approved ap- 
plication a tank heated by steam or hot water is 
employed. Suspended within this is another 
tank in which the bulbs are placed for treatment. 
A constant temperature of the water in the inner 
tank is maintained at 110° F. for 1J to 3 hours, 
depending on the size of the bulbs treated. 
Experience shows that if the grower has 
planted bulbs infested with this fly he can do a 
great deal toward getting rid of the pest very 
early the next spring as the plants are coming up. Bulbs infested by 
the fly will be weak, throwing up only one or two weak leaves. Such 
bulbs can be rogued out and destroyed. This work must be done 
early before the grubs leave the bulbs and while the evidence is clear. 
The lesser narcissus fly (Eumerus strigatus Fall.) in the writer's 
opinion does not attack healthy narcissus bulbs although commonly 
found not only in these bulbs but in many other genera as well. The 
hot -water treatment will kill the larvse of this insect also. 
The status of the lesser narcissus fly has not been studied suf- 
ficiently in this country to establish its relations to other crops, 
such as the onion. In an experience of seven years with it the 
Fig. 3. — The grub of 
the greater narcissus 
fly in a bulb which it 
has about destroyed 
4 The information here given has been approved by the Bureau of Entomology. In case 
fui'ther information on the bulb flies is desired, consult Weigel, C. A., and E. R. Sasscer, 
Insects injurious to ornamental greenhouse plants. U. S. Dept. Agr., Farmers' Bui. 1362, 
81 p., 91 fig. 1924. 
