PROCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 667 



The actual breeding data are briefly summarized in the following 

 table :— 



Moths 

 emerged 



1st August to 

 13th Novem- 

 ber 1917. 



20th February 

 to 27th Feb- 

 ruary 1918. 



11th May to 

 14th May 

 1918. 



12th August 

 to 21st Octo- 

 ber 1918. 



Eggs 

 deposited 



J2nd October 

 1917. 



20th February 

 to 14th Feb- 

 ruary 1918. 



l;3th-17th May 

 1918. 



20th- 22nd Oc- 

 tober 1918. 



Eggs 

 hatched 



31st October 

 to 2nd No- 

 vember 1917 



5th March to 

 10th March 

 1918. 



21st-27th May 

 1918. 



31st October 

 to 2nd No- 

 vember 1918 



Larvie 

 pupate 



12th Decem- 

 ber to 15th 

 December 

 1917. 



21st April to 

 23rd April 

 1918. 



17th- 27th 

 June 1918. 



7th-llth De- 

 cember 1918. 



Length of 

 the whole 

 life-cycle 



Over 120 days. 



Over 100 days. 



Over 120 days. 



Over 120 days. 



The above shows that the duration of the pupal stage of the second 

 brood varies to a great extent from 21 days to 110 days, and that the 

 season of deposition of the third lot of eggs is in October. It is a rather 

 curious fact that the moths which emerge in August or September are 

 always fruitless as they die without any deposition of eggs. The multi- 

 plication of this insect is rather rapid but the larva? of the second brood 

 are usually' infested by several still unknown Bacteria and die in the 

 fifth instar. The sudden disappearance of this insect, after reaching 

 its chmax, is almost always due to the work of these useful Bacteria, 

 though sometimes a Tachinid-fly is still more effectual in the work of 

 extermination. The remainder become full-grown larvae and begin to 

 form their cocoons below shelters on the ground or below the twigs 

 near the stem or rarely between or on the leaves. The pale brownish 

 cocoons are usually aggregated together in some numbers, the united 

 structure showing a flat face. After pupation the moths emerge in 

 from 18 to 114 days and the females deposit their eggs in five to 

 fourteen days. The newly hatched larvae remain on the underside of 

 the leaf in a mass, and begin to eat the under epidermis and 

 chlorophyll, leaving the upper epidermis until they first moult ; in this 

 case the caterpillars usually extrude fine silky threads and form a web- 

 like skin on the under surface of the leaf, this serving as a resting place 

 for the delicate larvae. After the first moult they move from leaf to 

 leaf, and eat it from the margin. The caterpillar is not hke that of a 

 Bombycid, but it is densely covered with very fine hairs and the 

 appearance of the skin seems velvety. The duration of each instar is ■ 

 from about three to ten days.. 



