10 



SCALE INSECTS. 



Classification of the Coccid^. 



By Mon. V. Signoret, of Paris. 



I. Diaspides. — Species covered with a scale composed of successive moultings, and of a 

 secretion forming a shield, or sack, more or less independent of the body of the animal. 

 Kine genera are included in this sub-familj^, but the scales may all be reduced to two 

 principal types, viz.: those with rounded shields, liive an oyster shell, with the larval scale 

 in the center; and those with more lengthened shields, in the form of a large comma, or 

 of a large mussel shell, and having the larval scale at one end. 



II. Brachyscelides. — Species living in gall-lilce, or tube-like, excrescences. These insects 

 are, so far as known, confined to Australia. 



III. Lecam'des. — Species either naked or inclosed, or simply covered with waxy, calcare- 

 ous, or filamentous secretions, and in which the female, after fecundation, generally 

 acquires an entirely different form to that which she previously possessed, and becomes 



. fixed. Before pregnancy, they have the power to move, if necessary. A number of genera 

 are included in this sub-family, some of which approach in some characters to the Diaspi- 

 des, and have been separated by Targioni under the name of Lecanio diaspides. 



IV. C'occtrfes. —Species retaining to the end the body form, with all its joints distinct. 

 They never become necessarilj^ fixed, and are either naked or more or less covered with 

 waxy or spumous matter, arranged generally in filaments. 



In summing up the chief characteristics of the coccidse, I give Mr. Mas- 

 kell's words: 



The first principal character separating the coccidse from other Homoptera, and distin- 

 guishable without microscopic examination, is the absence of wings in the female in all 

 stages of their existence. 



The second principal character is the absence of any apparatus for feeding and digesting 

 in the viale. 



From these two characters it follows that the females can only extend their operations 

 by, at the best, crawling from plant to plant, or by being carried by birds, or other agen- 

 cies. Also that the males cannot enjoy more than a very short existence, their work being 

 entirely confined to impregnating the females. Hence, in an endeavor to destroj' these 

 insects, the males may be disregarded, and the females attended to. 



PERNICIOUS SCALE. 



Aspidiotus Perniciosus. (Figure No. 2.) (Comstock.) 



This is one of the worst and to-day the most widespread of the species 

 of scales which are found preying on deciduous fruit trees in California. 

 The work of this species is generally readil}^ distinguished from other spe- 



Figure No. 2. 



Descnplion.— Scale, about one sixteenth of an inch in diameter (scale of male insect 

 elongated); color, center, yellow; margin, dark-mottled gray; eggs, thirty to fifty pro- 

 duced by each female; color, yellow; form, ovate; larva, six legs; two antenna?, six- 

 jointed; two analsetse; body, color, yellow; form, oval. Male insect (perfect), winged- 

 wings nearly transparent; body, color light amber, with dark-brownish markings: anten- 

 nae, ten-jointed (hairy), and stylet nearly as long as body. 



