112 



ON THE SCALE INSECT OF MULBERRY TREES. 



is pretty thick and tenaceous, but is gradually thinned out 

 towards the peripheries. The surface of the scale is of a 

 brownish grey color, and bears on its apex always two oval 

 areas of orange yellow. These two areas are really two 

 moulted skins, and the smaller lies over a portion of the larger. 

 The former is somewhat lighter in color than the latter (Fig. 9 

 PL. I.). The average diameter of ten large scales is 2 mm. 



II-) Manner of Copulation- 



From June to the beginning of November, both sexes of the 

 scale insects appear, the females remaining tightly attached 

 to the bark of the mulberry tree, protected by a patella-like thick 

 scale, which may be formed by the secretion from their 

 bodies. The males, on the contrary, being active and provided 

 with a pair of developed wings, can either walk or fly. When 

 we watch carefully the scales on the bark at this season, we find 

 that many winged males approach the scales on their wings. 

 When the male finds the scale, the former rests quite close to 

 the latter, and then it bends its long bristle-like genital append- 

 ages (caudal filaments) towards the margin of the scale, and 

 projects them inwards under the scale, and copulates. Although 

 I am unable to state exactly how the male conveys the male 

 elements to the female, yet that such action of the male against 

 the scale, that is, the penetration of the male genital appendages 

 under the scale is a process of copulation, is proved by the 

 examination of the contents of the female insects, in which there 

 may be found a large number of actively moving spermatozoa 

 which are received from the male. The males generally die at 

 the end of a few days after copulation, while the females pass 

 the winter under a scale. Thus our scale insect increases by 

 sexual reproduction which can not be observed in Diaspis penta- 

 gonia, as Mr. Contagne has mentioned. 



Ill ) Metamorphosis of the Scale Insects 



About March, the body of the female insects is more or less 

 swollen by a large number of developed eggs within the body. 

 The ovarian eggs are numerous, but the large eggs contained, 



