4 ORTHOPTERA 



Bionomics. — Very little is known as to the food oi the majority of the species of Blattidas; 

 Ectohia lapponica in Northern Europe is said to feed largely 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 Panesthina? seem to derive nourishment from the decayed wood 

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

 much of their life hidden under leaves and stones. The genera Nocticola and SpeLroblaita occur in caves; 

 according to Bolivar these two genera constitute a separate sub-family the Nocticolinse, but they mas In- 

 regarded rather as aberrant members of the sub-family Periplanetina? ; 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 

 Polvbia, occuring in French Guiana. The apterous females ot the genus Rhicnoda and the larvae of some 

 species oiEpilampra are amphibious, diving and swimming with gteat readiness. Certain genera of the sub- 

 family Perisphserinae are remarkably like millipedes; Ensiegasta buprcstoides closely resembles a Buprestid 

 beetle and some of the species of the genus Prosoplecta mimic Coccinellidae and Galerucida 1 ; it has been 

 stated by two independent observers that the South American Achroblatta luteola mimics the I.ampyridae. 

 Polyzosterm mitchellii from Australia is most brilliantly coloured and is probably highly distasteful to 

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

 adapted for this purpose has yet been demonstrated. 



Distribution. — Owing to human agency certain species (e. g. Blatta orientalis, Periplaneta americana, 

 Leucophaa surinamensis, Rhyparobia maderae) have now a world-wide distribution and individuals 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 

 Blattida? will be noticed under their separate headings. The Blattidas are of considerable geological 

 antiquity as their remains have been found in abundance in beds of the Carboniferous period: a 

 fragment which is considered by some authorities to be a portion of the tegmen of a cockroach has been 

 found in a Silurian sandstone. 



Classification. -- Linnaeus (1766-68) described twelve species 01 Blattidas, ten of which were 

 included in the genus Blatla ; these have now been referred to eight genera and orientalis has been selected 

 by almost universal consent as the type of the genus Blatta. Tlninberg (1826), Serville (i83i-3g), Blan- 

 chard(i837), Burmeister (i83g), Stal (i856-6i), de Saussure ( 1862) added considerably to our knowledge 

 of this group ot insects, but it was not till the appearance in i865 of the IVouveau Systeme des Blattaircs by 

 Brunner von Wattenwyl that anything approaching a scientific classification of the Blattidas was 

 attempted. This classic was followed three years later by Francis Walker's Catalogue of the Blatiaria in the 

 British Museum, 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 Blattidas 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 importance. 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 ( >rthoptera of Madagascar and Central 

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

 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 Blattida? are, the 



