The Bee Louse 



DESCRIPTION OF THE SPECIES 



Braula coeca is a wingless, reddish-brown insect having a length of 

 about 1.5 millimeters and a width of about 0.75 millimeter, males 

 being somewhat smaller, on the average, than females. The entire 

 body is covered with numerous stiff, spinelike hairs, at least some of 

 which are said by Massonnat {28) to be connected with nerve endings. 

 These hairs are especially numerous on the head, except on the 

 clypeus and the low^er side of the head. The head is flattened from 

 front to rear and is oriented vertically on the thorax, bringing the 

 mouth parts toward the ventral surface of the insect. The antennae 

 have a peculiar structure and are articulated in a deep fossa on each 

 side of the head. Eye rudiments are present, but there are no ocelli. 

 The thorax is discoid and very short on the dorsal surface and is in- 

 serted throughout its width on the abdomen. There is no trace of 

 either wings or halters. The legs are of equal length and are long in 

 proportion to the size of the insect. The last tarsal joint of each leg: 

 carries a remarkable chitinous comblike structure, divided in the 

 middle with 15 or 16 teeth on each side of the median line, these being 

 modified claws. These combs are serviceable in permitting Braula 

 to attach itself to the branched hairs of its host, which is especially 

 necessary for an animal living on a rapidly moving and flying insect 

 like the honeybee. Each terminal tarsal joint also carries two pear- 

 shaped pul villi of delicate structure, covered mth fine hairs. The 

 abdomen has five visible segments and occupies about 60 per cent of 

 the whole length of the body. It is cylindrical in general shape,, 

 tapering to the posterior end, and is flattened less than in most 

 Pupipara. The abdomen of the female when eggs are in formation 

 is terminated by a transparent prolongation in which have been recog- 

 nized the rudiments of three additional segments, but unless eggs are 

 being formed these segments are invaginated. 



Braula is found only on honeybees, although there are statements 

 in the literature that it occurs on bumblebees, doubtless due to incor- 

 rect identification of parasitic species thus observed. 



CLASSIFICATION OF BRAULA 



This insect was first described by Reaumur (33) who briefly dis- 

 cusses the species and its relation to the bee colony. The genus 

 and species ^vere described by Nitzsch (30) who gave the name 

 Braula coeca, classified it with the Diptera on account of the structure 

 of the mouth parts, and allied it with the Pupipara. Various dis- 

 cussions have appeared regarding the exact classification of this 

 species in the series of Diptera of the group Pupipara, and Egger (15) 

 erected for it a special family, Braulidae. Egger corrected certain 

 erroneous statements made by Nitzsch regarding the structure of the 

 antennae and thorax and thereby removed the last doubt as to the 

 alliance of Braula with the Diptera. Miiggenburg {29) shows the 

 relationship of Braula to the Hippoboscidae in the structure of the 

 head vesicle. Until recently the position of Braula with the Pupi- 

 para has not been seriously questioned, although, as will be explained 

 later, Braula is not pupiparous. Bezzi (7) was the first taxonomist 

 definitely to remove Braula from the Pupipara and he places it as a 



