4 ORTIIOPTERA 



Bionomics. — Very little is known as to the food of the majorit}- of the species of Blattida' ; 

 Eciobia lapponica in Northern Europe is said to feed largeh' on dried fish and Brunner states that dead 

 animal matter is the natural food of this order of insects. The species found in human habitations are 

 very catholic in their tastes and the Panesthinae seem to derive nourishment from the decaj'ed wood 

 in which they burrow. Many species are nocturnal in their habits and the majority of species spend 

 much of iheir life hidden under leaves and stones. The genera Nudicola and Spelaoblatta occur in caves: 

 according to Bolivar these two genera constitute a separate sub-famih' the Nocticolinte, but they may be 

 regarded rather as aberrant members of the sub-family Penplanetina; ; the eyes are simple or absent in 

 the three known species. Some species of minute cockroaches have been found in the nests of ants in 

 North and South America and another species has been taken from the nest of a wasp of the genus 

 Polvhia, occuring in French Guiana. The apterous females of the genus Rhicnoda and the larvffi of some 

 species oi Epilampra are amphibious, diving and swimming with great readiness. Certain genera of the sub- 

 family Perisphserinje are remarkably like millipedes; Ensieg'asta biiprestoides closely resembles a Buprestid 

 beetle and some of the species of the genus Prnsoplechi mimic Coccinellidas and Galerucidae; it has been 

 stated by two independent observers that the South American Achrobhitfa luteola mimics the Eampyridae. 

 Polyzostena mUchcllii from Australia is most brilliantly coloured and is probabh' highh' distasteful to 

 insect enemies. Gromphadorhina portentosa from Madagascar is said to stridulate loudly, but no apparatus 

 adapted for this purpose has yet been ilemonstrated. 



Distribution. — Owing to human agency certain species (e. g. Blatta uiiciitalis, Pen'planeia ainei icaiia, 

 Leucopktea siiriiiameiisis. Rhyparohia madcrac) have now a world-wide distribution and uidividuals of other 

 exotic species are continually making an appearance at European ports, whither they have been 

 transported by ships in the foreign trade. The geographical distribution of the different sub-families of 

 Blattidse will be noticed under their separate headings. The lUattidae are of considerable geological 

 antiqmtv as their remains have been found in abundance in beds of the C ai bonilerous period; a 

 fragment which is considered bj' some authcjrities to be a portion of the tegmcn of a cockroach has been 

 found in a Silurian sandstone. 



Classification. — Linnaeus ( i jOb-hS) described twelve species ot Blattida', ten of which were 

 included ui the genus Blatia ; these have now been referred to eight genera and oriaiialis has been selected 

 by almost universal consent as the t\pe of the genus Blatta. Thunberg (1826), Serville (iS3i-3g), Blan- 

 chard (1837). lUu'meister ( i<S3q). Stal f i856-()i ). de Saussure ( t86j ) added considerably to our know ledge 

 of this group ot insects, but it was not till the appearance in iS63 of the Xoiiveaii Sy^^teiiie des Blattaires by 

 ]-5runner von M'attenwyl that anything approaching a scientific classification oi the i^lattida- was 

 attempted. This classic was followed three \-ears later by Francis Walker's Catalogue of the Blattarix in the 

 British Mnseuvi. in which a large number of new species were described; it is a sufficient commentary 

 on the relative values of these two memoirs to state, that whilst the latter is practically useless to those 

 who have not access to the actual specimens described, the former remains at the present day the most 

 comprehensive and the most useful guide to the Blattidse that is extant. Stal (1874) submitted Brunner's 

 scheme of classification to some criticisms, but was unable to improve on it to any great extent, and in 

 1893 Brunner in his final revision of the tribe left it with but few alterations of the first impcjrtance. The 

 important memoirs of de Saussure, entitled Melanges. Orthopterologiques, his account of the Orthoptera of 

 Mexico and the memoirs by de Saussure and Zehntner on the Orthoptera of Madagascar and Central 

 America have added so largely to our knowledge that it can be said that the study of the Blattidae 

 now rests on a sound basis of scientific classification. The Synonymic Catalogue of Orthoptera by Kirby, the 

 two volumes of which have appeared recently, renders the task of the recorder much less difficult than 

 in the past. The characters which are of chief value in distinguishing the sub-families of Blattidae are, the 



