2 INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



CRUSTACEA (Class) 



SOWBUGS, CRAYFISH, LOBSTERS, CRABS, ETC. 



At first thought few persons in California would think of any mem- 

 bers of this class as injurious to the crops grown in the State and 

 would probably need to lie reminded that the common sowbugs so 

 very abundant in gardens and greenhouses belonged in this class. It 

 is because of the much alleged serious damage done by these sowbugs 

 that it has been thought best to include a few words relative to at 

 least one of the common species. 



THE DOORYARD SOWBUG 



Porcellio Icevis Koch 1 

 (Fig. 1) 



Description. — The photograph (Fig. 1) gives a very good idea of 

 the general appearance of sowbugs. The color is dull slate above and 

 light grayish beneath. The outer covering is rather hard and resem- 

 bles a number of articulating plates. There are seven pairs of legs. 



Fig. 1. — The dooryard sowbug, Porcellio Iwvis Koch. Enlarged twice. (Original) 



The antennas are 7-jointed. The length varies from one eighth inch for 

 the very small young to over one half inch for the largest fullgrown 

 specimens. 



Life History.— The sowbugs are not aquatic, but are always 

 found in wet or damp places, and therefore become especially abun- 



'A very closely related species, Porcellio apinicornis Say, is usually associated with 

 this species in the central part of the state. Both species were determined by Miss 

 Rathhurn, U. S. Nat. Museum, through the kindness of Dr. L. O. Howard. 



