Miscellaneous. 275 



MISCELLANEOUS. 



Leaf-ivlnged Locust. By J. J. Quelch, E.Sc. 



Op all the many varied and really wonderful contrivances to be met 

 with in nature tending towards the protection of various harmless 

 creatures which are preyed upon by other forms, perhaps none are 

 as wonderful as, certainly none are more remarkable than, the con- 

 dition of the anterior pair of wings in certain of the Locustidoe, 

 such as Pterochroza and other closely allied forms. In many genera 

 of the family the front wings are elongated and narrow, like the 

 wings of the grasshoppers, and are not only coloured green, like the 

 ordinary leaf of a plant, but are furnished with a large subcentral 

 vein like the midrib of a leaf, with small veins springing therefrom. 

 In Pterochroza and the other special forms referred to, of which a 

 few different examples have lately been added to our museum collec- 

 tion, the leaf resemblance is carried to a most perfect degree. In 

 shape they are ovate, and generally, as in the common elm-leaf, the 

 one side is somewhat wider than the other, according to the depth 

 of the curve of the central vein, which is thickened like a midrib. 

 From this side-veins pass off in all directions, branching and reticu- 

 lating, exactly as in the case of the leaf of an ordinary dicotyledo- 

 nous plant. The colouring of the wings is even more remarkable, 

 the tint varying according to the species. In one the shade varies 

 from reddish brown or reddish yellow to a dull purple, and closely 

 resembles the shades to be found on the young leaves of many of 

 the forest-trees, and more especially on the mora {Mora exceha). 

 In another the tint is of a deep green, which is said to fade away 

 gradually on continued exposure to light after the death of the 

 insect. In a third it is of a very pale yellowish brown, much like 

 the colouring on an old and fading leaf about to fall from the 

 plant ; while in a fourth it is a dull dead brown, like that of a sere 

 and fallen leaf. 



As though to give a more complete naturalness to the already 

 seemingly quite natural leaves, variably sized spots of brown or 

 yellowish white are sparsely scattered about the surface, just as are 

 to be found so commonly upon leaves. 



Observations upon the growth, life-history, and habits of these 

 forms are much needed ; but the specimens seem to be extremely 

 rare — though it is much more likely that, inhabiting the foliage of 

 trees and bushes, they are seldom, and then only accidentally^ 

 discovered. It is suggestive that the forms in the museum were 

 only obtained when they had strayed into houses in or by the forest 

 on the Mazaruni River. — Journal of the Royal Aijrlcidtural and 

 Commercial Society of British Guiana, June 1890, p. 141. 



