2 



laid a small wiiire catLTpillar hrcaks through outward and (om- 

 nieiiees to food ; for tliat pur})oso generally moving to tlie upper side 

 of the iincnrving leaf. It is shaped like most caterpillars are, except 

 for a tendency to draw its head under the body; it has relatively 

 long, pale, but not numerous hairs. Later it changes colour and 

 develops a fold down either side joined, each to the other, in a 

 kind of collar at the back of the head, which quite alters its 

 appearance; for now it is flattened, and the legs and head are 

 hidden. Tn tlie course of three Aveeks, it has grown to a length of 

 8 mm. with a l)readth of 3 nnn. It is more conspicuously flatten- 

 ed towards the head and towards the tail than at the center of the 

 body ; but nevertheless is flattened throughout. Its colour is a 

 reddish crimson, and the dorsal surface is covered with small black 

 l)ristles among which over eight segments there are four unde- 

 fined lines of smaller white clavate hairs ; towards the side the bristles 

 are colourless. From the flattened hinder end, two curious scent 

 organs can be exserted ; they are colourless and with a few colour- 

 less hairs; when exserted they are minute columns; and a kind of 

 irresolute movement is given to them by repeated retractions and 

 exsertions. This red grub can spin a thread at all times. 



When mature at 21 days it pupates, on the back of a leaf or 

 iu some other sheltered place, into a short plump light green pupa 

 hanging by its tail and girdled by a thread holding it against its 

 support. The eyes come to sliow reddish and the wing covers look 

 pale. 



By the time pupation has been reached tlie pinnae of the leaf 

 of the food plant have generally been utterly destroyed while the 

 grub has been feeding for the last part of its time by burrowing into 

 the fleshy young axis of the leaf. It moves about a little but never 

 far. What with the gumming resulting from the wounds, and with 

 the raggedness resulting from the dead scraps of pinnae left attach- 

 ed, the beauty of the plant has been utterly destroyed. The lower 

 block on the plate shows about 30 destroyed leaves and five that 

 have more or less escaped, — an evidence of the small distances 

 through which the grubs move, for they liad not wandered to the 

 pinnae which had not received eggs. 



The butterfly also appears not to move far. for Cycads at a 

 distance no greater than a quarter of a mile from attacked Cycads, 

 have been seen to escape repeatedly. 



Two species of Cjcas are attacked in the Botanic Gardens. 

 Cijcds Riniiphii, aiul Cycaft siafncnsis: 



Other food ])lants have been looked for but not found. The 

 cause of suspecting that the caterpillar has other foods is that 

 young C'ycad leaves are available only at intervals which it may be 

 that the insects cannot always keep. But the lengih of the life of 

 the butterfly on the wing has not been ascertained: it ma}' be so 

 long as to fill ill tlie interval between its emergence at 5 weeks 

 from the egg-laying and the ("ycad's alulity to ])roduce a new 

 foliage. 



An arsenical spray may ])>■ used as a remedy. 



T. H. Bl ]!KILT.. 



