50 PSYCHE [June 



NOTES ON THE INHERITANCE OF VARIATIONS IN THE COLOR 

 PATTERN OF CRIOCERIS ASPARAGL' 



BY FRANK E. LUTZ, COLD SPRING HARBOR, N. Y. 



Crioceris asparagi is the ordinary asparagus beetle. Both males and females 

 hibernate as adults in the stalks of dead plants — chiefly asparagus. They emerge 

 about the middle of INIay, and eggs are laid in a few days. These hatch in 2 to 4 

 davs. The larvse feed on the asparagus for from 1 to 3 weeks and then go into the 

 ground to pupate. The pupal stage is from 4 to 10 days in duration. The maxi- 

 mum number of offspring I was able to rear from a single pair was 57. Copulation 

 is repeated and frequent. There seem to be, normally, two generations a season, 

 although a few of a third generation can be procured. It is comparatively easy to 

 keep the adults over winter in glass vials loosely stuffed with paper. 



In doing pedigree work with Crioceris much time can be saved by growing 

 asparagus seedlings where beetles can not get at them. Otherwise, one must look 

 over the "leaves" of the food plant very carefully to guard against the introduction of 

 wild eggs or larvpe. If a branch of asparagus be put in a vial with a gravid female 

 she will lay freely upon it and the larvre may be fed in the vial by supplying fresh 

 food daily. When full grown, they will pupate in the vial even without earth to go 

 into. However, I found the following plan much easier. Asparagus seedlings were 

 grown in pots. Then a lamp chimney was put over the seedlings and partly sunk into 

 the earth. The top was covered with netting. Into this the mated pair was put. 

 After ten or a dozen eggs were laid the pair was transferred to another similar cage. 

 The larvfe which hatched fed on the growing seedlings and when full grown went into 

 the earth to pupate. By that time most of the asparagus had been consumed, so 

 that when the beetles emerged they could easily be seen and removed for recording 

 and mating. 



The elytra of Crioceris are blue-black in ground color with a reddish anterior 

 and distal border. There are three yellow areas or "spots" on each elytron. These 

 spots are frequently united in various ways giving quite a range of variation in color 

 pattern. The character whose inheritance was studied was the joining of the anterior 



> A study of the inheritance of variations in the color pattern of this beetle was started several years 

 ago, but owing'.to the press of other work there is little likelihood of the present writer's completing it in 

 the near future. Tliese notes are submitted in the hope that some one may take up and solve the several 

 important problems which are involved. The cut is kindly loaned by The Carnegie Institution of 

 Washington. 



