. Diagnosing bee diseases in the apiary. Bees Diseases Diagnosis. 26 CIRCULAR 3 9 2, U. S. DEPARTMENT OF AGRICULTURE wings and held at abnormal angles. Such bees are capable of only feeble fanning with the wings. The abdomen is often distended with feces and may appear shining or greasy. APPEARANCE OF THE INTESTINAL TRACT The intestinal tract of bees infected by Nosema apis is fre- quently swollen and discolored. When favorable specimens are at hand this symptom can be used for diagnosis in the apiary. If the bees are alive, or have just died, the entire intestinal tract can be removed as foll
. Diagnosing bee diseases in the apiary. Bees Diseases Diagnosis. 26 CIRCULAR 3 9 2, U. S. DEPARTMENT OF AGRICULTURE wings and held at abnormal angles. Such bees are capable of only feeble fanning with the wings. The abdomen is often distended with feces and may appear shining or greasy. APPEARANCE OF THE INTESTINAL TRACT The intestinal tract of bees infected by Nosema apis is fre- quently swollen and discolored. When favorable specimens are at hand this symptom can be used for diagnosis in the apiary. If the bees are alive, or have just died, the entire intestinal tract can be removed as follows: Remove the head and hold the thorax with the thumb and forefinger, then grasp the tip of the abdomen with a pair of forceps and pull gently. By this procedure the entire intestinal tract can frequently be withdrawn from the abdomen. In healthy bees the long, cylindrical mid-intestine is usually of a brownish-red, yellowish, or grayish-white color. Circular constric-. Figure 17.—Nosema disease : A, Intestines from healthy bees ; B, Intestines from bees infected with Nosema disease. tions show for nearly the entire length of the intestine (fig. 17, A), and the tissues are fairly tough and of a healthy appearance. When Nosema disease is present the mid-intestine swells (fig. IT, B) but finally shrinks to about normal size. Heavily infected intestines are usually of a dull grayish white, and some or all of the circular constrictions disappear (fig. IT, B). The tissues become soft and watery and are more easily crushed than are the tissues of healthy intestines. The fluid that flows from heavily infected intestines when they are crushed is whiter and more turbid than is the fluid from healthy intestines. After experience has been gained, it is often possible, when favorable specimens can be obtained, to make a diagnosis of Nosema disease in the apiary. There is considerable variation in the appearance of the mid-intestine of healthy as well as infected bees, however, and in m
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