BR. J. ENT. NAT. HIST.. 13: 2001 



Fig. 1. Outline of pronotum. a. R. litura. b. R. chrysomeloides. 



However, there is often some individual variation in this character, so it may not 

 always be as clear-cut as the illustrations suggest. The colour of litura is usually 

 pale orange-brown, often with a U-shaped dark mark, although darker individuals 

 can also occur. The background colour of chrysomeloides is somewhat darker and 

 the dark marks are more strongly developed, sometimes with additional spots 

 inside the U-shaped mark. Fursch states that litura is shortly oval and somewhat 

 arched, while chrysomeloides is more elongate and flatter. 



The above differences are comparative and slight but the male genitalia are quite 

 distinct (Fig. 3). In chrysomeloides, the median lobe is more slender, elongate and 

 parallel-sided, and is distinctly longer than the pair of parameres, while in litura, the 

 median lobe is much shorter and stouter, and not longer than the parameres. The 

 median lobe of litura also has a strong protruberant prong on its dorsal face, between 

 the parameres, which is lacking in chrysomeloides. This prong is clearly visible when 

 the genital capsule is viewed from the side. Fursch also illustrates differences in the 

 genital plates of the females, in that the coxites are more slender and elongate in 

 chrysomeloides than they are in litura. 



Comment 



The presence of the first British specimen of R. chrysomeloides on a motorway 

 bank brings to mind the delightful possibility that it might, quite literally, have fallen 

 off the back of a lorry. At present about one million lorries and over five million 



Fig. 2. Prosternal carinae. a. R. litura. b. R. chrysomeloides. (after Bielawski, 1959) 



