Nematodes: Minute eelworms, some of which cause destructive plant dis- 

 eases. 



Paleacrita vernata: One of the canker-worms found in the United States 

 and Canada prior to 1909. See Canker-worm. 



Pestalozzia sp.: An unidentified fungus of the genus Pestalotia (syn. Pes- 

 talozzia) that, under moist conditions, lives as a secondary invader 

 or as a weak parasite on dead plant material or on plants that are 

 growing under conditions of stress. 



Pierid: A common name for Pieridae, a large family usually of white or 

 yellow, medium-sized butterflies that in the larval stage feeds on 

 many types of plants. 



Pseudaulacaspis pentagona: A white scale insect, formerly called Diaspis 

 pentagona, that is widely found in the tropics and warmer temperate 

 zones. This pest is not known to be in North America at present 

 and, therefore, perhaps it never spread from the cherry trees sent 

 from Japan in 1909. 



Quadraspidiotus perniciosus: A scale insect very destructive to orchard 

 fruit trees that probably entered the United States from China 

 through San Jose, California, in 1870. This pest was known sci- 

 entifically as Aspidiotus perniciosus in 1909. 



Root Gall: A growthlike swelling resulting from the stimulation of tissue 

 by insects, fungi, bacteria, or nematodes. 



San Jose Scale: See Quadraspidiotus perniciosus. 



Sanninoidea exitiosa: A clearwinged moth that in the larval stage often 

 damages peach trees by boring into the wood just above the ground. 



Scale Insect: Any insect of the family Coccidae producing a secretion that 

 forms a scalelike covering of waxy or powdery substance over the 

 body. Several are pests of orchards and garden plants. 



Sesiid Moth: A common name for the clearwinged moth of the family 

 Aegeriidae (syn. Sesiidae). 



Shiny Black Ants: See Crematogaster sp. 



Weevil: These insects, as both larvae and adults, are often injurious to 

 fruit trees and other plants. A group of hard-bodied insects having 

 heads with long beaks that turn downwards. 



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