IODRNAL OF AGMCCITIAL RESEARCH 
Vol. XXVIII Washington, D. C., June 21, 1924 No. 12 
MORPHOLOGY OF THE HONEYBEE LARVA 1 
By James A. Nelson 
Collaborator , Bureau of Entomology , United States Department of Agriculture 
INTRODUCTION 
The observations here recorded seem desirable for several reasons. In the 
first place, it has been the policy of the Office of Beekeeping Investigations to 
secure, as far as possible, comprehensive and detailed information regarding all 
phases of the life history of the honeybee. An account of the development of 
the honeybee in the egg already having been completed ( 86 ) 2 , a study of the 
postembryonic development appears next in order, and this involves necessarily 
a thorough and intimate knowledge of the structure of the larva. Moreover, 
an account of the structure of the bee larva ought not to be entirely without 
interest to intelligent beekeepers. Finally, such an account will unquestion¬ 
ably prove valuable to investigators of the pathology of brood diseases of the 
honeybee. 
No complete description of the structure of the larva of the honeybee has yet 
been published. This is especially surprising in view of the attention bestowed 
on the structure of the imago. Leuckart and Nitsche (31) have included the 
bee larva in the series of types illustrated by their wall charts. These illustra¬ 
tions, however, convey but a meagre amount of information on this subject and 
in some respects are incorrect. Anglas ( 1) gives a description of the bee larva 
in his account of the metamorphosis of the wasp and that of the honeybee, but 
here again the description of the morphology of the larva is only incidental and 
for the most part brief and superficial. Moreover, some organ systems, such as 
the nervous system, are left almost untouched. 
In the following account the larva has been treated as if it constituted a single 
stage. The larval period, it is true, embraces a series of stages, differing from 
one another and representing a continuous process of development, but the 
principal morphological features peculiar to the larva as such remain surpris¬ 
ingly constant. Since a sketch of the structure of the newly-hatched larva has 
already been published by the writer in connection with the embryonic develop¬ 
ment, and, since it is especially important to know the structural conditions 
immediately preceding pupation, especial attention is here paid to the larva which 
has virtually attained its full growth. The following descriptions therefore 
apply to such a larva, unless otherwise stated. Wherever important changes in 
larval structures accompany growth, these are taken into consideration. 
EXTERNAL FORM 
In general appearance the bee larva much resembles many other cruciform 
larvae. When removed from the cell the full-grown larva (PI. 1, D) is fusiform, 
the posterior end being the larger. Younger larvae are more slender and more 
nearly cylindriform, while the head is much larger in proportion to the trunk. 
In those recently hatched the body differs in its proportions from the bodies of 
1 Received for publication Apr. 22,1924—issued Nov., 1924. 
* Reference is made by number (italic) to “Literature cited,” pp. 1208-1212. 
Journal of Agricultural Research, 
Washington, D. C. 
Vol. XXVIII, No. 12 
June 21,1924 
Key No. K-141 
