NOTICES OF NEW BOOKS. 77 



bombi, and is allied to Nosema apis, the cause of the " Isle of 

 Wight disease " in hive-bees, of which so much has been heard 

 of late. Although Bombus agrorum is the chief sufferer, other 

 species of Bombus — hortorum, latreillelus, lapidarius, sylvarum 

 and terrestris — may suffer, especially the last-named ; while the 

 hive-bee, Apis mellifica, and A.florea may also be affected. The 

 medium of infection is bee-food and drink soiled by the dejecta 

 of infected bees, and even larvae may contract the disease. 

 Different species of humble-bees may also infect each other, and 

 both hive- and humble-bees may suffer at the same time both 

 from Nosema apis and N. bombi. Hive-bees become infected 

 from the attempts of humble-bees to rob them, and the patho- 

 genic action of the parasite is in them accelerated, while 

 similarly robber humble-bees contract the " Isle of Wight 

 disease " in a virulent form. 



The sick humble-bees infected by Nosema bombi generally die, 

 often previously crawling about unable to fly, and exhibiting great 

 irritability and readiness to sting. Artificially infected humble- 

 bees have shown the commencing infection in forty-eight hours, 

 and in some districts practically all individuals of B. agrorum 

 were found to be infected. 



The disease thus assumes considerable economic importance 

 in view of the known services of humble-bees in fertilizing red 

 clover, and the authors recommend as measures in keeping up 

 the humble-bee stock the destruction of all infected humble-bee 

 colonies and dead or dying bees, and the discouragement of the 

 taking of humble-bee nests by children. Considering the part 

 played by Field Mice also in such destruction of nests, the 

 preservation of Owls and Kestrels might also have been 

 recommended in this connection. Another paper with a 

 peculiar if rather gruesome interest is one written (in French) 

 by Dr. J. Schwetz on the morphology and biology of the larva of 

 the fly Auchmeromyia luteola, known as the "Congo floor 

 maggot." This is a blood-sucking maggot which infests the 

 floors of native huts, creeping out to attack people who are 

 sleeping on the ground or on low bedsteads. Dr. Schwetz has 

 been studying it at Kabinda, and though forced to leave his 

 investigations incomplete for the present, has yet succeeded in 

 establishing some interesting points in the habits of this 



