13 



divided into the three usual divisions — head, thorax, and abdomen. 

 In fact, it is often difficult exactly to determine the line of division 

 between these parts. The eyes, when present, are simple, never 

 compound. The external mouth parts consist of a short tabular 

 labium functioning as a guide for the four long slender filaments 

 which represent the maxillae and mandibles. 



The adult males may be apterous or provided with a single pair 

 of wings, usually supplemented by a pair of hooked halteres which 

 engage with the wings (fig. 1). The alate condition is by far the more 

 usual. The wings have two simple nervures only. The head is 

 more or less clearly difterentiated from the rest of the body, but is 

 devoid of any vestige of mouth parts. The eyes may be either 

 compound or simple (usually the latter). 



In both sexes the limbs (when present) terminate in a single claw 

 and the tarsi are, normally, one jointed (fig. 2). 



The females pass through from four to five stages, and the males 

 from five to six, liz. : — Female. Egg: 1st stage nymph (or larva); 

 2nd stage nymph ; [3rd stage nymph] ; adult, ^]ale. Egg : 1st 

 stage nymph ; [2nd stage nymph] ; pre-pupa ; pupa; adult. (The 

 stage included in square brackets is the one that is suppressed in the 

 degenerate forms in Avhich the number of moults is restricted. A 

 few species are ovoviparous, in which case the egg stage is passed 

 within the body of the parent insect). 



Coccidae are to be found in every conceivable situation ; on the 

 foliage, stems and roots of plants. There are many gall-making 

 species, but none of these have been recorded from the British Isles. 



It will be convenient to adopt the arrangement given in New- 

 stead's Monograph, commencing with the subfamily IHaspinae. 

 Four genera only come within our category. They all agree with 

 each other, and are distinguished from members of other subfamilies, 

 in the possession of a separate covering scale composed partly of 

 cast skins (exuviae) of the previous moults, supplemented by a 

 secretionary appendix. The females undergo three moults only ; the 

 first, from the egg stage (fig. 8 a), disclosing the young larva ; the 

 second disclosing the nymph ; the third, the adult insect. The males 

 undergo an additional moult, a pre-pupal and a pupal stage being 

 interposed between the larval and adult stages. The adult female is 

 without either limbs or antennae, and the anal orifice is without a 

 setiferous ring. The larva (3 h), as in all Coccidae, is active, 

 possessing well developed limbs and antennae; but, having once 

 settled down to feed it remains on the same spot for the " term of 

 Its natural life." After the next moult it loses its limbs (3 c), 

 remaining attached to the plant by the rostral filaments only. It is, 

 at first, completely covered by the larval exuviae ; but, as the nymph 

 increases in size, this covering becomes inadequate and is supple- 

 mented by an extension (the appendix) secreted from special organs 

 on the compound terminal segment (the pygidium) of the body. 



