THE LEPTOCORISINAE OF THE WORLD 



147 



■- = Boundary line 

 of species 



x: Leptocorisa lepida 



W luzonica 



M >■ pseudo lepida 





yv\ 



473 



Fig. 473. Distribution map of Leptocorisa spp. 



The two tribes Leptocorisini and Noliphini are clearly distinct on the form of 

 head and pronotum, whereas in the Noliphini there are distinctions in the shape and 

 form of the body in the different genera, the body form in the Leptocorisini is 

 remarkably uniform and the taxonomic distinctions are mainly based on characters 

 of the genitalia. It may be that evolutionary pressures due to the habitat (various 

 Gramineae) of the Leptocorisini has restricted the modification of the form of the 

 body ; the other large groups of Heteroptera that share this habitat, Stenodemini 

 (Miridae) and Blissinae (Lygaeidae), are also both relatively uniform in body form. 

 The habits of the Noliphini are unknown. Alternatively it may be that the 

 Leptocorisini are more recently evolved and so less differentiated than the Noliphini. 



The Noliphini have an interesting distribution, similar to, but rather more exten- 

 sive than that of the Marsupials : Neotropical region (Lyrnessus) and Australian 

 region and Malayan and Philippine sub-regions of the Oriental region (Cosmoleptus 

 and Noliphiis). The centre of evolution of the tribe was clearly in the Australian 

 region, perhaps in the Papuan sub-region ; the farthest west that the tribe has 

 spread is north east Sumatra (C. sumatranus) but it does not seem to have crossed 

 the Strait of Malacca or the South China Sea. C. bakeri is found in the Philippine 

 Islands. Noliphus spinosus has the widest distribution of any member of that 

 genus ; Java, Phillippine Isands, Solomon Islands and north Australia, but the 

 remaining species are, so far as present records show, restricted to the Australian 

 region (i.e. east of Wallace's Line). 



In contrast the Leptocorisini are almost world-wide and some of the species have 

 very wide ranges, e.g. Leptocorisa acuta, the " Gandhi rice bug ", is found throughout 

 the Oriental and Australian regions (except New Zealand). It is considered that 

 Stenocoris (Pseudoleptocorisa) erratica retains more primitive characters than any 



