474 REPORT OP THE COMMISSIONER OF AGRICULTURE. 



Pepper. 



Grape. 



Rose. 



Castor-bean. 



Spearmint. 



Rose-geranium. 



Mr. Koebele, avIioso observations bave been close and extensive, 

 found tbat tbe Quince is always tliicldy infested, as is also the Pome- 

 granate, while on Pear, Apple, Peach, and Apricot the scales were 

 not numerous in the adult state. Only a few scales, and these nearly 

 always small, were found upon the Castor-oil bean. Some Pecan- 

 trees were noticed on which some of the branches were completely 

 covered with scales. A Willow hedge surrounded by plants which 

 had been infested for over two years did not itself become attacked 

 until the past summer. The Fig he states to be a favorite food-plant. 

 On Eucalyptus he found young scales all summer, and in October 

 he found twigs full of scales of all sizes. A few full-grown individ- 

 uals were found upon a single Pepper tree {Schinus molle) growing 

 in the orchard. The following is a supplementary list of plants upon 

 which Mr. Koebele reported the scales most noticeable: 



Portulaca olef^acea — Scales often numerous. 



Malva rotundifolia. 



Grape ( Vitis spp. ) — Scales occurring principally on petiole and leaf. 



Medicago denticulata. 



Helianthus spp. 



Rose {Rosa spp.) — Scales growing often to an unusually large size, 

 and very numerous on some varieties. 



Epilohium coloratum. 



Erigeron canadensis. 



Bidens pilosa. 



Artemisia ludoviciana. 



Ambrosia psilostachya — Hundreds of scales on each plant during 

 July, August, and September. 



Sonclius oleraceus, 



Plantago spp. 



Mentha piperita. 



Stachys cequata. 



Solatium tuberosum. 



Solanum douglasii. 



Chenopodium murali. 



Chenopodium album. 



Amarantus retroflexus. 



Polygonum persicaria — Stem often entirely covered by scales. 



Rumex crispus. 



Urtica holosericea — A favorite plant, on which the scales devel- 

 oped with unusual rapidity and to large size. 



Carex spp. 



Paspalum spp. 



Panicum crus-galli. 



CHARACTERS AND LIFE HISTORY. 



The genus Icerya was first described by Signoret in the Annales de 

 la Socidte Entomologique de France" for 1875, pp. 351, 352, and was 

 founded on the single species I. sacchari (Gu(^rin), which occurs on 

 sugar cane in the Island of Bourbon. He knew only two stages, the 



