252 



this is so, many colourless dead mites may be en- 

 countered in these which have been dead for some time. 



Vitality of Tarsonemus Woodi. 



(a) Away from the Bee. — While discussing the 

 question of the recognition of dead mites the following 

 brief summary of experimental results so far obtained 

 concerning the vitality of Tarsonemus woodi may be 

 suitably given here. Mites which have been maintained 

 in moist, deep-welled, glass slides at ordinary room 

 temperature cannot usually be stimulated into activity 

 after about twenty-four hours. Rarely, a mite has 

 been found a short time beyond this period, which 

 could move it-- limbs, but the majority of tiicso ra^iin- 

 tained under the condition stated died before the end 

 of the period. They have been maintained under 

 observation and periodically moistened up till about 

 seventy hours but no signs of life have ever been ob- 

 tained during these later stages of experiment. Whilst 

 recording these results I recognise fully the artificial 

 conditions of such experiments. They should be ac- 

 cepted as giving only a general indication of the vital 

 powers of the mite away from the bee. It is probable 

 that mites which leave the tracheae of the bee naturally 

 are capable of surviving longer outside its body. This 

 is suggested in the results referred to in the following 

 paragraph. 



(b) T. woodi in Dead Bees. — Up to about 24-30 

 hours after the death of the host bee, living mites of 

 both sexes may be readily encountered, although the 

 majority appear to be dead by this time. While this 

 is so, I have found living Tarsonemus woodi within bees 

 which had been dead for five days. In accumulations 

 of dead bees of much longer date I have never found 

 them alive although mites of various other species may 

 be very abimdant. 



Summary of Examinations. 



By way of illustrating the results of examinations of 

 bees made in accordance with the scheme already out- 

 lined, I give herewith a summarised statement of a 

 few recent examinations which, while omitting all 



