182 THE MOPANE-TREE. 



The mopane-tree (bauhinia) is remarkable for the little shade 

 its leaves afford. They fold together and stand nearly perpen- 



Mopane or bauhinia leaves, with the insect and its edible secretions. 



dicular during the heat of the day, so that only the shadow of 

 their edges comes to the ground. On these leaves the small lar- 

 vae of a winged insect appear covered over with a sweet, gummy 

 substance. The people collect this in great quantities, and use it 

 as food ;* and the lopane — large caterpillars three inches long, 

 which feed on the leaves, and are seen strung together — share the 

 same fate. 



* I am favored with Mr. Westwood's remarks on this insect as follows : 



" Taylor Institution, Oxford, July 9, 1857. 

 "The insect (and its secretion) on the leaves of the bauhinia, and which is eat- 

 en by the Africans, proves to be a species of Psylla, a genus of small, very active 

 Homoptera, of which we have one very common species in the box ; but our spe- 

 cies, Psylla buxi, emits its secretion in the shape of very long, white, cotton-like 

 filaments. But there is a species in New Holland, found on the leaves of the Eu- 

 calyptus, which emits a secretion very similar to that of Dr. Livingstone's species. 

 This Australian secretion (and its insect originator) is known by the name of wo- 

 me-la, and, like Dr. Livingstone's, it is scraped off the leaves and eaten by the abo- 

 rigines as a saccharine dainty. The insects found beneath the secretion, brought 

 home by Dr. Livingstone, are in the pupa state, being flattened, with large scales 

 at the sides of the body, inclosing the future wings of the insect. The body is 

 pale yellowish-colored, with dark-brown spots. It will be impossible to describe 

 the species technically until we receive the perfect insect. The secretion itself 

 is flat and circular, apparently deposited in concentric rings, gradually increasing 

 in size till the patches are about a quarter or a third of an inch in diameter. 



" Jno. O. Westwood." 



