38 



INSECT8 AFFECTING THE ORANGE. 



Fkj. 9. — Paiiatnrln periiaiviii male. (After 



becomes dark purple at maturity. The serrated hind margin is thin 

 and tinged with yellow. 



The mature females do not entirely till their scales. When gravid 

 with eggs, their bodies, altliough much thickened, are reduced in cir- 

 cumference, and in laying they surround themselves with a nearly com- 

 jdete circk' of eggs. Length of mature female O.G'"™ (0.02 inch). 



Eijgii. — Tlie «'ggs are as large or larger than those of the Long Scale, 

 and resemble them in shape and color. They are nearly 0.2""" (0.008 

 inch) in k'ugth, and are more or h\ss amethystine in color. 



Young Larva. — The migrating larva is very broadly oval, and mottled 

 with pnrplt'. It dilfers from the larva of icdated sjjecies only in minule 

 details. 



Male. (Fig. 0.) — As soon as it be- 

 gins to form its i)erinanent scale, the 

 male insect becomes distinguishable 

 from the female by its more elongate 

 form, and it soon turns to a dark pur- 

 j)le-re(l color. The skin of the second 

 molt is pushed toward the mouth or 

 thrown out of the scale. After shed- 

 ding this skin the male insect becomes 

 CoiiistoL-k ) a pupa of dark red or purple color, 



and has the fVn-m of the fly with members folded or abbreviated. 



The perfect insoct emerges tVom the thin outer end of its scale, which, 

 however, has no hinge or flap. The fly is very similar to those of the 

 genus Aspidiofiis, but is shorter and stouter, and lias hirger eyes than 

 the si»e(:ie> of Mytihi.spi,s. Tiie color is i)urple, mottled, and somewhat 

 j) iler upon the large shield of the ujjper surface. Lengtli to tlie tij) of 

 llie stylet about equal to that of its scale, 0.0"'"' ((►.02 inch). 



Life hi.storij. — The young Chaff Scale re|)eats with slight variations 

 the history of tlie si)ecie8 already mentioned. After wandering a few 

 hours, it chooses a fixed position, Nery often underneath a pile of old, 

 dead scales, and in a few days covers itself with a circular shield of 

 white tissue, so thin as to be quite trausi)arent. This covering disap- 

 l)ears before th.- time of the first molt. After tlie molt the females con- 

 struct a circular and the males a linear scale. 



The number of eggs laid is variable. Professor Comstoek reeords in 

 one instance twenty-seven eggs. The average number is sixteen.. 



Number of Generations. — The earlier metamorphoses take place at 

 about the usual intervals of twoity days, but the latei- periods vary 

 with the seasons, and are greatly accelerated by hot weather. 



The Chaff Scale appears to have one more brood than the Long Scale. 

 There are four summer generations, but these broods are so greatly 

 confused by unequal development in the females that the limits of each 

 cannot be exactly defined. The first brood in si>ring and tlie last brood 



