. Sacbrood. Bees. 18 BULLETIN 431, U. S. DEPARTMENT OF AGKICULTUEE. Middle third.—While the color of the middle third is similar to and often approaches in its shade that of the anterior, very frequently it is considerably lighter. The ventral surface of this third (figs. 18 and 7) is less convex from side to side than in the preceding stage, and the segmental markings, while still plainly visible, are less pro- nounced. The notches along the lateral margins are also less pro- nounced. Posterior third.—^The color of the posterior third (figs. 18 and 7; PI. II, p) equals or exceeds in depth of
. Sacbrood. Bees. 18 BULLETIN 431, U. S. DEPARTMENT OF AGKICULTUEE. Middle third.—While the color of the middle third is similar to and often approaches in its shade that of the anterior, very frequently it is considerably lighter. The ventral surface of this third (figs. 18 and 7) is less convex from side to side than in the preceding stage, and the segmental markings, while still plainly visible, are less pro- nounced. The notches along the lateral margins are also less pro- nounced. Posterior third.—^The color of the posterior third (figs. 18 and 7; PI. II, p) equals or exceeds in depth of shade that of the middle third and sometimes equals that of the anterior third. The surface marldngs are still pronounced and much resemible those of the normal larva. That the watery content of the sac is being lessened through evapo- ration is evidenced by the dinainution of the quantity of the watery-. Fia. 19.—Third stage: Larva dead of saobrood, lateral view. (Original.) appearing substance seen at the lateral marguis of the middle and posterior thirds and by the wrinkling of the cuticular sac. These wrinkles are small and numerous. The lateral view of the larva in the third stage (fig. 19) shows that it stiU maintaiQS, in a general way, the form and markiags of the normal larva (fig. 4), The turgidity is gone, although the position in the cell is very much as it is in the healthy larva. Consistency of the sac and its contents.—It is the appearance of the remains of the larva in the third stage of the decay that best character- izes the disease, sacbrood. The cuticular sac is now quite tough, permitting the removal of the larva from the cell with considerable ease and with httle danger of its being torn. The content of the sac is a granular mass, brownish in color and suspended in a comparatively small quantity of a more or less clear watery-appearing fluid. Upon noicroscopic examination the mass is found to consist of decaying tissues, chiefly fat cells. Condition
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Keywords: ., bookcentury1900, bookdecade1910, bookpublisherwa, booksubjectbees
