284 rniversitij of California Puhlicafious. [Entomology 



Adalia bipunctata Linn. 



This species is very abundant in the San Francisco Bay 

 Region, and is found in comparatively small numbers in other 

 parts of the state, though none were found by the writer in the 

 Sacramento Valley. During the winter the adults hibernate in 

 sheltered and protected places, as many as fifty having been 

 found in one colony under a loose strip of eucalyptus bark, this 

 being a location much favored by this particular species. All of 

 the common aphis species are preyed upon by this beetle and, so 

 far as observed, no particular one can be termed its favorite 

 food. 



Oviposition. — The period intervening between emergence and 

 mating w^as found in ten individuals to vary from one to two 

 days, with an average of 1.6 days, while the time from mating to 

 egg-laying ranged from eight to eleven days, averaging 9.6 days. 

 The complete period of oviposition required from 20 to 39 days, 

 and during this period the proportion of days upon which eggs 

 were actually deposited varied from 60.0 to 76.3 per cent. The 

 averages were 28.2 days and 69.4 per cent, respectively. The 

 maximum number of eggs deposited in one day was 23, while the 

 average daily production by the ten females was 6.7 eggs per day. 

 For the entire adult period, the variation in number extended 

 from 94 to 269, with an average of 190 eggs for each individual. 



Egg-Laying Records — Adalia bipunctata Linn. 

 Berkeley, 1914 

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