294 J. A. G. REHN 



Superfaniily Blattodea 



The superfamily Blattodea or cockroaches is represented in 

 North America by twenty-seven genera, of which eleven are re- 

 garded as adventives. Some of these were probably introduced 

 several centuries ago in the early historic periods of the Atlantic 

 states and provinces. Others were brought in during the early years 

 of the present century, particularly from the West Indies. The 

 original home of a number of these adventives was Africa, and the 

 early transport was by cargo or slave ships. Of these eleven ad- 

 ventives, six are now known to be present in western North x'\merica, 

 namely Supella, Blattella, Neostylopyga, Blatta, Periplaneta, and 

 Pycnoscelus. Of these Periplaneta was doubtless brought in by the 

 slave trade, as the genus, while now almost cosmopolitan in the 

 warmer regions, is clearly a native of Africa, where feral species 

 of the genus also occur. Supella probably had a similar history in 

 reaching the West Indies, as it was not known from the United 

 States until the early years of this century, although its dominant 

 species, 5. supellectilium, the only one that has reached America, 

 had long been established in the West Indies. The genera Blatta and 

 Blattella reached America in much the same way as the black rat 

 {Rattus rattus) and the Norway rat (Rattus 7iorvegicus) , and their 

 spread westward across Europe coincided very much in sequence and 

 time with the spread of the two species of domiciliary rats. Both of 

 these cockroach genera are probably natives of northeastern 

 Africa, where a number of feral species of each genera occur. 

 Pycnoscelus is of Oriental origin, and wild species of the genus 

 are known from Farther India. Today the domiciliary species, 

 P. surinamensis, is frequent in subtropical, as well as tropical, 

 America. It presents another case of usual parthenogenesis. 



The Oriental genus Neostylopyga, very readily recognized by 

 its form and coloration, is common in the Philippines and also over 

 much of Indo-Malayia, and west to Madagascar and the eastern 

 coast of Africa. The first report of its one domiciliary species, 

 A^. rhombifolia, in America was made in 1865. It was reported from 

 Acapulco, Mexico, and from Venezuela and Argentina. From 

 Acapulco it has spread to the Cape Region of Baja California, 

 northward over Sinaloa, and even to the railroad entry port of 

 Nogales, southern Arizona. Acapulco was the port at which in 

 colonial days the Spanish galleons from Manila landed their cargoes 



