78 



HARDWICKE'S SCIENCE-GOSSIP. 



circular, with a slight inclination to be triangular, 

 less than 2 millim. diameter (Fig. 59, J). Its colour 

 is greenish-yellow, with the fringe pinkish. Immature 

 scales (Fig. 59, H) are broadly oval, and more or less 

 longitudinally keeled. The surface of the scale 

 presents many gland orifices, some single, others 

 double (figure-of-8), which secrete waxy rods, similar 

 to those which compose the fringe. Round the 

 margin is a distinct row of figure-of-8 glands, secret- 

 ing the fringe ; these, on the thoracic margin, are 

 accompanied on their distal side by a row of simple 

 glands. 



The adult female is oval, attenuate towards the 

 hind extremity, and showing on the dorsum many 

 round gland-spots. The segmentation is still in- 

 dicated, though indistinctly. The mouth-parts are 

 ordinary (Fig. 59, d). The posterior extremity (Fig. 

 59, b) shows distinct tubercles emitting the rather 

 stout caudal setre. The colour of the female, as seen 

 after immersion in caustic soda, is bright crimson. 



In a young individual (second stage) the antennae and 

 legs are present, and yellow in colour. The fringe is 

 colourless, and remarkable in appearance (Fig. 59, 1), 

 resembling a number of hoops placed side by side. 

 This appearance is produced by the bending-back of 

 the wax rods, so that they diverge from one another, 

 and the ends of each pair meet the ends of the nearest 

 rods of the neighbouring pairs on the margin of the 

 scale. In the adult scales, the rods of each pair only 

 slightly diverge (Fig. 59, K) ; a further degree of diver- 

 gence is seen in the marginal rods of Asterolecanhim 

 pahna (Fig. 59, Q) ; and the extreme is reached in the 

 second stage of the species under consideration 

 (Fig. 59, M). 



The larva, which turns scarlet on being placed in 

 caustic soda, is long oval, and has no fringe. The 

 legs are set far back, the first pair being about one- 

 third of total length from the anterior margin. There 

 is a tendency for the cephalic portion to be distinct. 

 The segmentation of the abdomen is distinct, and the 

 caudal tubercles emit moderately long filaments. 

 The legs are rather long ; the femur of the middle 

 pair (Fig. 59, c) is broad and notched, that of the first 

 pair narrow and normal. The antennre appear to 

 have six joints ; they are stout, the last joint not at 

 all accuminate, but rounded, emitting two long hairs, 

 and two or three shorter ones. 



The eggs (Fig. 59, G) are oval, greenish. 



This species occurs on a variety of plants, and is 

 very destructive. In British Guiana it is found on 

 the akee, on Castilloa, etc. In Kingston, Jamaica, I 

 find it abundantly on akee, infesting the leaf-stalks 

 and twigs, and producing a pustular appearance. Dr. 

 Riley informs me that it is found in Florida, on 

 Hibiscus. In Montserrat it is abundant and injurious : 

 Mr. C. A. Barber sent me specimens collected in 

 that island on pigeon-peas and white oleander. It is 

 also found on oleander in Jamaica. 



It has been confounded with P. fimbriate, which it 



resembles. Except the difference of locality and 

 food-plant, and the double row of figure-of-8 glands 

 in fimbriata, there would not be much difference so 

 far as one could judge from published descriptions ; 

 but Dr. Riley informs me that there are in the col- 

 lection at Washington, specimens cf P. fimbriata 

 received from Lichtenstein, and that there is no 

 question as to the distinctness of P. pustulous. 



A yellowish-red mite was found among some scales 

 taken from an akee in Kingston ; it may very likely 

 be predatory upon the eggs. There is also a Chal- 

 cidid parasite. Some specimens on oleander, in 

 Kingston, show parasite-holes, but the parasite was 

 not obtained. In the case of a parasite of this 

 species in Montserrat, I was more fortunate, as I ob- 

 tained a fragmentary imago. This was with the scales 

 on pigeon-peas, and although it no doubt belongs 

 to the sub-family Encyrtina, the genus can hardly 

 be ascertained. I made the following descriptive 

 notes : — 



Parasite of P. pustulans from Montserrat. Thorax 

 brown, minutely reticulated. Head brown. Abdo- 

 men shovel-shaped, colourless. Antennas pale (Fig. 

 59, r), club pubescent, funicle joints with whorls of 

 hairs. Middle tibia with a moderately long stout 

 spur, and a small short one. Wings hairy, stigmal 

 vein moderately long. 



(10). Planchonia oncidii, n. sp. 



Found in Kingston, Jamaica, on orchids. I first 

 received it on a leaf of Oncidium tetrapetalum, from 

 Dr. Henderson ; later, I found a plant of Broughtonia 

 sanguinea in Dr. Strachan's garden, badly infested 

 by it. It closely resembles P. pustulans, but is, I 

 am convinced, distinct. The food-plants are dif- 

 ferent, and the scale is a little smaller, and bright 

 yellow, with the shrivelled body of the female 

 appearing dark brown at one end. The fringe is 

 rather long, and pale pinkish. In shape, the scale is 

 inclined to broad-oval, and there is a slight median 

 keel. 



The young larva, which is quite active, is elongate- 

 oval, bright yellow, with the segmentation fairly 

 distinct. The cephalic margin shows a few hairs. 

 The antenna; (Fig. 59, a ) are stout, the last joint 

 emitting two very distinct airs of moderate length. 

 The terminal segment emits two caudal filaments as 

 in other species, but these are short, not much longer 

 than their distance apart, and much shorter than the 

 maximum width of body. Legs well-developed, tarsi 

 with slender but long-knobbed hairs. The larva, as 

 in P. pustulans, has no fringe. 



The Lecanium epidendri of Bouche seems to be a 

 Planchonia, and it may even be the same as the 

 present species. The female scale is said to be 

 rounded, depressed, greenish-yellow, the margin 

 ciliated ; the male is dark yellow, with the head 

 brown. It was found on Epidendricm cuspidatum. 



