2t)(J ]3r, T. A. Chapman's 



Eggs kid August 3-4 

 Tliose (11) hatched 9-12 removed 

 The rest hatched August 13-15 

 Several in 2nd skin „ 17 

 All „ „ „ 19 



Some in 3rd „ „ 2(5 

 Some in 4th ,, „ 29 

 Nearly all in 4tli skin Sept. 2 

 All „ „ „ 4 



Full-fed „ 13 



Hatched September 18 

 Full-fed 2nd skin „ 27 

 All in 3rd skin October 4 



2 in 4th skin ,, 6 



All in last skin (4th) „ 12 

 Full-fed „ 15 



(joing down ,, 18 



Hatched September 13 

 Most in 2nd skin ,, 21 



3rd „ „ 27 j 



Many in 4th skin „ 30 i 



It may be useful to summarise tlie items of the life 

 history of 0. tristis noticed above. The beetles emerge from 

 the ground in May, and eating freely of the food-plant 

 {Ccntanrca sp.) and pairing frecjuently, lay eggs abundantly 

 during June, July and August, and even on to November, 

 some specimens living (in confinement) until tiie following- 

 March. 



The eggs are rarely laid singly, usually in small batches 

 up to twelve or twenty, or even considerably more. When 

 laid the eggs have already undergone some development, 

 sometimes only to the mulberry stage, usually the larva is 

 already largely developed, and more rarely the eggs may 

 be ready to hatch. This seems to be more frequent later 

 in the season. The eggs hatch by two slits forming, under 

 internal pressure caused by the secretion of air in the 

 alimentary canal of the young larva, their site being 

 determined by the presence of " hatching spines." The 

 larva; moult three times, the effete skin being similarly 

 split by pressiu'e from " inflation." 



They feed up in about a month, rather longer in cool 

 weather, shorter probably in hot, and then bury themselves 

 in the earth to a depth of one to five or six inches, remain- 

 ing unchanged to the following March or April, when the 

 further changes are rapidly gone through. It seems 

 possible, but I have no evidence whatever to make it 

 at all probable, that the earlier larvss feed up and may 

 emerge the same year. 



Postscript, June 11th, 1903. — As an indication of the 

 date of the appearance of the beetle, on April 27th, 1903, 

 at the habitat of the beetle at Pino, only two specimens of 

 the beetle could be found, these happened to be a male 

 and female ; the Centaurea was only some twelve inches 

 high. On May 30tli, 1902, it was three to four feet high. 



