488 



MRS. O. A. MERHITT HAWKES ON THE 



5. Nummary. 



1. Adalia hipunctata has so many varieties that it is highly 

 suitable for tlie needed study of inheritance of normally occurring 

 variations. 



2. Adalia can be mated in captivity with ease, but their canni- 

 balistic habit makes it very difficult to rear them satisfactorily 

 in large numbers. 



3. The time passed in the various stages is variable, depending 

 not only on the food, but also on the temperature, to which all 

 stages, but especially the pupal, make a rapid response. 



4. Little is known of either hibernation or migration, but 

 apparently both septempunctata and hijnmctata tend to collect in 

 numbers in the spring and autumn, and may at times be found 

 hibernating, piled upon one another, similar to the "masses" of 

 Hippodamia found in the western U.S.A. 



5. There is no evidence of dominance in crosses between the 

 two main forms — the Red "type" and the Black (var. 4-maculata 

 and var. 6-pustulata). 



6. Eleven matings of Red x Red produced only the Red type. 



7. Black and Red forms also occur in C. variabilis, and, as in 

 hipunctata, neither is dominant. 



8. The pronotum of the Black form is darker than that of the 

 Red, but there is no progressive blackening of the pronotum of 

 the Red coincidentally with the increase in the size of the black 

 spots of the elytra. 



9. Although it is possible to make a series from pure red 

 elytra on the one hand through various patterns to pure black on 

 the other, this cannot be regarded as proof that the variations 

 are merely fluctuating. The percentages of the variations is, as 

 far as is known, approximately stable, and certain types are far 

 more common than others. These facts, combined with the 

 observation that the children tend to show the variations of 

 the parents, strongly suggest that there are probably certain 

 points of genetic stability, and that only analysis is needed to 

 show that there is some regular method of inheritance. 



I have much pleasure in thanking Dr. A. D. Imms for naming 

 several of the aphis species and Mr. W. B. Grove for naming the 

 mould, Cladosporkim aphidis, which he believes has never before 

 been recorded as British. 



Literature. 



1. Burgess, A. F. 1903. — Economic Notes on the Family 



Coccinellid^. U.S. Dept. Agric. Div. Ent., Bull. 40 

 (New Series), pp. 25-32. 



2. Burgess, A. F., & Collins, C. W. 1911.— The Value of 



Predaceous Beetles in destroying Insect Pests, U.S. Dept. 

 Agric. Year-Book, pp. 453-466, 



