2SI 



ensues in both sexes, and there is plenty of evidence 

 to show that in large measure this takes place within 

 the tracheae of the bees. There may be also from 

 diverse causes a certain amount of mortality amongst 

 immature forms as well. Since one of the tests of the 

 gravity of an acarine infestation in the bee is the recog- 

 nition of the number of living mites, it becomes im- 

 portant that the dead should be distinguished from 

 these. This is a matter of some difficulty and trust- 

 worthy conclusions can only be arrived at with care 

 and experience. 



The first and most obvious sign of death in the mites 

 is complete immobility. This feature alone is not to 

 be depended on unless proper care is taken in manipu- 

 lation of the bee, not to crush the mites while these 

 are under examination, and further, that the observa- 

 tion of the mite is maintained for a sufficiently long 

 period, during which no movement is detected. Living 

 mites under a coverslip may remain practically im- 

 mobile for hours, and unless these are closely watched, 

 slight movements indicsating that the mite is alive may 

 be overlooked. A second feature, not universal but 

 very common in mites which have died a natural death, 

 is contraction of the body and limbs. The former 

 becomes rounded and the latter are drawn inward and 

 appear quite short. The body is also shrunken to 

 smaller dimensions. 



Mites not long dead usually remain colourless. The 

 body eventually ceases to be granular and assumes a 

 homogeneous, waxy-like appearance, and may have any 

 tint from pale yellow to brown. The colouration is 

 frequently deepest in mites found a long time dead in 

 deeply bronzed parts of the tube. It rarely affects 

 the appendages of the body. The association of browned 

 tubes and bronzed mites is sometimes striking, where 

 the mite has been dead for some time. It is not clear 

 whether this deeper colouration of dead mites is caused 

 by a staining from the contents of the tubes or not, 

 but the association of yellowish or brown mites with a 

 bronzed area of the tube may be frequently noted. In 

 any case, the distinctly yellowish or brown mite is one 

 which has been dead for a longer period than one not 

 so discoloured but showing other signs of death. While 



