28 DiaspincB. 



one species from another, they are, nevertheless, constant in their 

 characters, and differ in the larvae of different genera.' A pair of 

 stout setae, sometimes more than half as long as the body of the 

 insect, spring from the posterior extremity. The anal orifice is 

 situated on the dorsal surface of the terminal segment. 



The antennae spring from the ventral surface close to the 

 anterior margin. Dr. Berlese has pointed out that, while the larvae 

 of some Diaspids have five-jointed antennae (//. \.fig. I2„a,d), in 

 others six free joints are distinguishable {fig. 13, b, c). The first 

 four or five joints are short ; but the terminal one, which Dr. 

 Berlese calls ' the funicle,' is usually as long as or longer than all 

 the others combined, and very much wrinkled transversely, Mr. 

 Maskell considers that six is the normal number of antennal joints 

 in all larval Coccids. When a smaller number occurs, it is, doubt- 

 less, due to the coalition of two or more joints. In the DiaspincB 

 the missing joint must be looked for in the funicle. Each of the 

 basal joints bears one or two stout hairs, and from six to eight 

 hairs spring from the long terminal joint. 



The eyes are minute, but usually distinct. In the larval pellicle 

 the corneae can always be distinguished on the anterior margin. 



The comparatively large rostral apparatus is situated between 

 the coxae of the anterior pair of legs. The very long sucking-tube 

 is either exserted, or withdrawn and coiled in a loop which some- 

 times extends far down into the abdomen of the insect. 



The legs are attached to the ventral surface at some distance 

 from the margin, but are sufficiently long to extend well beyond 

 the edges of the body. The leg consists of the usual parts, — 

 coxa, trochanter, femur, tibia, single-jointed tarsus, and single claw. 

 There are four longish knobbed hairs on the foot, two springing 

 from the base of the claw on the inner side, and two from the end 

 of the tarsus on the outer side. 



The female of the second stage differs but slightly from the 

 adult insect. The legs have entirely disappeared, and the antennae 

 are reduced to minute tubercles bearing one or two stout bristles. 

 The pygidium is well developed and provided with lobes, squames, 

 and tubular spinnerets as in the adult ; but there are no grouped 

 glands nor any external genital orifice. The body is at first alto- 

 gether soft and flexible ; but the dorsal parts become hardened at 

 the time of the second moult. Normally the insect does not 

 increase very greatly in size during this stage, the second pellicle 

 having usually not more than twice the diameter of the first. But 



