SUBFAMILY DIASPIDINAE 223 



bounding them are obsolete. The females of the conchaspids have 

 been described as having a pygidium, but between all of their 

 abdominal segments distinct coriae can be identified. While the 

 pygidium of the Diaspidinae has probably been derived from a 

 progenitor with an abdominal structure similar to that of the 

 Conchaspinae, yet the form of abdomen found in this latter group 

 can not properly be designated as a pygidium. 



The wax in the great majority of the Diaspidinae is poured out 

 through openings which are located in the external cuticle. They 

 are the external outlets of cuticular tubes. These tubes vary 

 greatly not only in length and diameter but in the size and shape of 

 their external openings. Each of these tubes is known as a cera- 

 tuba. It is not known just how the ceratubae function, whether 

 they serve simply as passage ways for the wax or whether they 

 serve as reservoirs into which the wax, as it is elaborated, is stored 

 until the insect is ready to use it. The ceratubae are formed by an 

 invagination of the body-wall. The inner end is truncate and 

 always bears on its ental surface a minute knob or nipple, the bulla. 

 Whether the ceratubae and the cuticular wax tubes found in the 

 Eriococcinae, Kermesiinae, Lecaniinae, and Asterolecaniinae have 

 a common origin is not known, but the presence of the bulla in the 

 ceratubae readily distinguish those of the Diaspidinae from the 

 wax tubes of the other subfamilies. There is a lumen extending 

 through the bulla which connects with the lumen of the ceratuba 

 and it is through this lumen the wax is poured into the ceratuba. 

 The ceratubae and their external openings are also known as fusi, 

 filiere isolate, filiere separee, filieres isolee, tubuli, tubular spin- 

 nerets, dorsal tubular spinnerets, orifici delle grosse filiere margin- 

 ale, fuse marginales, elongated pores, oval pores, marginal pores, 

 spinnerets, dorsal glands, dorsal gland orifices, wax ducts, elongated 

 pores, marginal gland openings, semi-lunar marginal pores, mar- 

 ginal lunar pores, or dorsal pores. 



There are several types of ceratubae in the Diaspidinae and 

 each type seems to be more or less characteristic of certain groups 

 of genera. The external opening of each ceratuba, located in the 

 external cuticle, is an oraceratuba. This opening, which is usually 

 small, is the external opening of the ceratuba and not a ceroris or 

 wax pore or pygidial wax pore as it has been generally considered 

 and described. The ceroris of the ceratuba, if present, would be 

 located at the opposite or inner end adjacent to the bulla. The 

 great majority of the oraceratubae are located on the dorsal aspect. 



