1932] 
SERVICE AND REGULATORY ANNOUNCEMENTS 77 
B. P. Q.— 338. July 8, 1932. 
ADMINISTRATIVE INSTRUCTIONS— NARCISSUS INSPECTION AND CERTIFICATION 
(Issued under Notice of Quarantine No. 62) 
These instructions are issued to assist inspectors and collaborators of the 
United States Department of Agriculture in making inspections for bulb flies 
and eelworms under the domestic narcissus-bulb quarantine. They are sup- 
plemental to B. P. Q. — 337, which is primarily prepared for the use of both growers 
and inspectors in carrying out the treatment of infested bulbs. All inspectors 
should familiarize themselves with the provisions of both circulars, as well as 
with P. Q. C. A. — 324, relating to the use of bulb disinfectants. 
FIELD INSPECTION FOR EELWORMS 6 
Method of inspection. — Whenever possible, the inspection is to be made row 
by row over the entire planting. In case the available force of inspectors is not 
large enough to carry out this plan in full in extensive plantings, an intensive 
inspection of a part, such as one-third or one-half of each lot and variety, is 
preferable to a less careful examination covering the entire premises. Such an 
intensive fractional inspection should be made over different parts of the field. 
If a general infestation is found to exist in any block or variety it is, of course, 
not necessary to complete the examination of that particular planting. When 
only one or two small spots involving a few bulbs each are found to have eelworms, 
the field examination may be continued in order to aid the grower in determining 
on such field sanitation measures as may be needed. Such sanitation is considered 
on page 79 of this circular and on page 76 of B. P. Q. — 337. 
Eelworm symptoms can not be detected successfully when the direct sunlight 
is shining on the plant being examined. The inspector should carry a full-sized 
sunproof umbrella to shade the plants being inspected. Otherwise, the reflec- 
tion of light rays from the surfaces of the leaves confuses the detection or identifi- 
cation of the lighter green or yellowish, raised areas known as "spikkels" (fre- 
quently as small as the head of a pin), which are often the only evidence of the 
presence of eelworms. Occasionally the rows will be found to run in such direc- 
tions as to permit the use of one's own shadow as shade. The use of a stick to 
move the leaves about to show both sides will be found helpful. 
Mosaic increases the difficult}- of finding eelworms. Plantings heavily infested 
with mosaic should not be certified as free from eelworm without treatment if 
there is any record of eelworms on the premises, unless a thorough, complete 
storage inspection can be made. 
It is of great importance that the inspector use every precaution to avoid 
transporting nematodes from one planting to another or from one block to another. 
Care in cleaning knives, shoes, etc., is essential. A disinfectant such as formalde- 
hyde should be carried for this purpose. The inspector's caution along this line 
should be so apparent as to constitute a model for the grower to follow. 
Gross diagnosis. — The bulb nematode or eelworm (Tylenchus dipsaci) is a small 
round worm only about one-twentieth of an inch in length when full grown, 
so its presence is first determined through signs of the damage done, or the 
physiological reaction of the plant being attacked, rather than by sight of the 
pest itself. Unfortunately, no single character or malformation definitely and 
invariably records the presence of parasitic nematodes in a narcissus planting. 
The most nearly definite indication is the presence of small swellings on one or 
more leaves of the infested plants. These swellings, called ''spikkels" in the 
Netherlands, appear to represent a physiological reaction caused by the eel- 
worms' presence, which is destroyed or overcome as the infestation of eelworms 
increases. Apparently, a spikkel may result from the presence of only one or two 
eelworms, especially if the tissue is growing rapidly. The spikkel enlarges as 
the number of eelworms present increases, and finally bursts forming a longi- 
tudinal lesion, the edges of which turn brown with adjacent tissue yellow\ Leaves 
from bulbs definitely infested with eelworms the previous season sometimes show 
no spikkels but instead have distinct yellowish streaks of a diseased or leathery 
appearance, usually near the base. Somewhat similar whitish streaks, however, 
occur from other causes. 
• "Eelworm" as used herein refers to Tylenchus dipsaci. In the case of infestations with other parasitic 
nematodes, specific instructions are to be obtained from the Bureau of Plant Quarantine, Washington, 
D. C. The method of inspection for other parasitic nematodes is similar to that described here. 
