LIFE-niSTOKY OF THE LADY-B]ltD liEETLK. 



481 



male and female are isolated in a box, mating takes place at 

 intervals during a period of two to nine weeks. Copulation lasts 

 from half to three-cpiarters of an hour. It takes place when no 

 eggs are laid and when the egg-laying pei'iod of the female is 

 finished. Palmer states that the female lays fertile eggs three 

 weeks after fertilization. Mating takes place in Statfordshire 

 and Warwickshire during the whole summer, but the principal 

 season is May to June, with a subsidiary season from the middle 

 to the end of August. Probably only a very few of the newly 

 emerged Lady-birds breed until the following year. The insects 

 have been found mating on sunny days in late (September, but at 

 that time no eggs were laid. 



b. The Eggs. 



Table I. 

 Detailed Record of Family, 33 (1919). 



Mating took place on 17.7.19 between two Red " iyxic" Adalias. In batches (1) 

 and (8) the larvas bad light rings around all the abdominal and thoracic 

 tubercles : hence these larva; appeared much lighter than the larva; of the 

 remaining batches, which only had light rings around the lower lateral 

 tubercles. The resulting imagines were all red, those from these two batches 

 being indistinguishable from the others. 



The eggs are spindle-shaped and laid in batches of from three 

 to fifty. The outer shell is coloiu-less and covered with numerous 

 protuberances. The colour of the eg§, is due to the yolk, which 

 is usually yellow but may be orange — a range of sliades similar 

 to those of the yolk of the hen's egg. Usually the whole batch of 

 eggs laid on a single occasioii is of the same uniform coloiu-, but 

 they may vary (see Table I.). In several batches the eggs shaded 

 from yellow at one end to orange at the other. The eggs do not 

 change in colour until a few hours before the lai'v;e are to 

 merge, when they become a greenish grey. 



