AN INVASION OF BRITISH GUIANA BY LOCUSTS. 



353 



this has caused the lighter areas, which have now become a pinkish brown, to be 

 reduced somewhat. This is particularly noticeable in the lateral markings of the 



Fig. 7. Sixth stage nymph. 



thorax and abdomen. The hind femora now show a lunule of a lighter colour on 

 the genicular lobes which is only to be found in this stage. 



Length 3-2-3 3 cm. 



Length of hind femora .. .. .. 2'Oc.m. 



No. of segments to antennae. . .. .. 26 



The Adult. 



In general appearance this insect resembles the sugar-cane locust, Schistocerca 

 fallens, Thunb., but differs from that insect in a few well-defined ways which, 

 once known, are easily recognised. Perhaps the most noticeable and distinct 



Fig. 8. Schistocerca sp., adult $. 



differences are to be found in the markings of the thorax and tegmina. On the 



lateral areas of the thorax S. fallens possesses a very well defined diagonal 



(C541) f 



