836 I'KOCEEDINGS OF TUB THIRD ENTOMOLOGICAL MEETING 



47.— THE LIFE-HISTORY OF CALIGULA CACHARA. 



By J. Henry Wat.son, F.E.S. 

 (Plate L30.) 



The following notes on the partial Life -History of Caligula cachara 

 are not complete as no larvae sui-vived longer than the middle of the 

 fourth age. It was most disappointing as they appeared to be thriving 

 to the end of the third age, but no doubt it was due to the food they 

 were fed upon, the common English Hawthorn, Crataegus oxyacantha, 

 which was evidently unsuitable for them ; but of course that is one of 

 the points one has to contend with in breediag exotic larvae, the natural 

 food plant of which is unknown . The species is for the present included 

 in Caligula but I think it should not be included in this genus, nor in the 

 genus Didyoploca to which C. simla and C. japonica are now referred. 



Unlike Caligula japonica, where the ovipositing is like our British 

 Salumia carpini (that is, laid in closely-packed sheets or regularly round 

 twigs), the ova of C. cachara are in httle groups irregularly laid and un- 

 evenly covered with brown cement giving them a streaky appearance. 

 The size of the egg is about 2'5 X 15 mm. 



The ova were laid from a female paired to the same male for two 

 successive nights but which separated each night before dawn. They 

 were laid 19th to 23rd March. Tho.se laid on the 22nd and 23rd were 

 without cement and quite white and were deposited at a foot away from 

 where the female was caged, evidently by propulsion ; none of these last 

 ones hatched ; the others hatched 13th to 17th April. 



The larvae on first hatching are about 3'5 mm. long and are pale 

 milk-blue on the dorsal surface shading down the sides to greenish- 

 blue, more prominent on the first four segments and reminding one of 

 the last two stages of D. simla and the last stage of some larvae of D. 

 japoiiica. During feeding in the first stage the larvae changed from 

 milk-blue to green, yellowish on moultiag. 



Head, glossy black with a few scattered forward projecting creamy 

 hairs. Carapace yellow, kidney-shaped ; with a black glossy kidney- 

 shaped mark, on anterior edge of which on both sides of the median line 

 a similar yellow mark ; anterior edge of each havmg a flat spindle-shaped 

 yellowish tubercle with forward projecting hairs similar to those on the 

 head ; on lateral posterior edge of this segment an oval black spot 

 surrounding the first spiracle ; m front of it in a line with the lower 

 edge of black carapace, a small yellowish flat tubercle with a few hairs 

 longest in the middle. Feet black, glossy and with very few hars. 

 The oval black spot and the aforementioned tubercles form the lateral 



