30 CIRCULAR 3 9 2, U. S. DEPARTMENT OF AGRICULTURE 



sis are also present in other disorders of adult bees and cannot be 

 depended upon alone for diagnosis. Trembling, weakness, and hair- 

 lessness, particularly when accompanied by dark, shining abdomens 

 and sprawled legs and wings, seem to be the most dependable symp- 

 toms of paralysis. Bees in this condition tend to collect on top of 

 the frames. A diagnosis can sometimes be made by carefully opening 

 the hive/ disturbing the colony as little as possible, and examining 

 the bees on the top bars of the brood nest. 



TRANSMISSION 



Beekeepers have found that they can give combs of brood from 

 colonies with paralysis to healthy colonies without spreading the dis- 

 turbance and that the bees emerging from these combs remain healthy. 

 In experiments by the Division of Bee Culture, combs of honey and 

 pollen from affected colonies were placed in a healthy colony without 

 paralysis being transmitted. When all the combs of an affected Italian 

 colony were replaced with combs of brood from a healthy Caucasian 

 colony, paralysis appeared among the young Caucasian bees within 

 2 weeks after the first of them emerged. Paralysis appeared to be 

 transmitted when sick bees and young healthy ones were confined in 

 the same cage. When young healthy bees were wet with water con- 

 taining the macerated remains of affected bees, paralysis also appeared 

 to be transmitted. The results of these experiments seem to indicate 

 that paralysis is slightly infectious and spreads directly from sick 

 or dead bees to healthy ones. 



SENDING SAMPLES FOR LABORATORY EXAMINATION 



If only a small amount of brood or a few bees are affected, or the 

 symptoms are unusual, it is sometimes difficult to make a definite 

 diagnosis in the apiary. Examination by laboratory methods is 

 then necessary. It is also desirable at times to have diagnoses made 

 in the apiary verified in the laboratory. 



How To Prepare Samples of Brood 



In sending samples for laboratory examination, the following in- 

 structions should be followed: (1) Cut a sample of comb at least 

 4 by 5 inches in size. (2) Be sure that the sample contains as much 

 of the dead or discolored brood as possible. (3) No honey should 

 he present, and the comb should not be crushed. (4) Mail the sample 

 in a wooden or strong cardboard box. Do not use tin, glass, or waxed 

 paper. 



Smears of dead brood and small crushed pieces of comb are fre- 

 uently unsatisfactory for diagnosis but will be examined in case 



3 



the foregoing instructions cannot be followed. 



How To Send Samples of Adult Bees 



(1) Select, if possible, bees that are sick or recently dead: bees 

 that have been dead for some time are not satisfactory for examina- 

 tion. (2) Send at least 50 bees in a sample; if poisoning by ar- 



