1922] 



Synopsis of Panurgidce 



167 



Phenologically the sexes begin and end as follows: 



Begin 



d" first 



57.5 



cf 9 together 



25.0 



9 first 



37 



End 



9 last 



75.0 



cf 9 together 



ci^ last 



25.0 



The males which are first precede by 6.1 days and the females 

 which are last are later by 29.2 days. It is probable that all of 

 the species are proterandroiis, but the males precede by so few 

 clays and are so much harder to observe that it is not easj^ to 

 prove the proterandry. My dates give the earliest ever observed 

 and it is probable that, in the year in which the earliest date 

 for the female was recorded, the male really preceded. The 

 records show 124 flower visits for the females and 92 for the 

 males, which indicates how much more likely the flight of the 

 female is to be correctlj^ made out. 



Taking the cases in which the males were first and the 

 females last as normal examples we have for the average number 

 of days: 



cf precedes 



9 follows 



cf 



9 I Species 



I 



4 normal 

 12 others 

 Total 



7.2 



27.5 



32.5 

 46.0 

 42.6 



52.7 

 66.3 

 62.9 



59.5 

 68.6 

 66.3 



The oligoleges are 85. 5 per cent, of the species. They 

 average 55.3 days, while the two polyleges average 143.5 days. 



FLOWER VISITS.— In the following lists the pollen 

 visits of the female ( 9 c) are separated from the nectar visits 

 (9s). The pollen visits do not exclude nectar visits to the same 

 flowers. Visits of the male (d^s) not made by the female also 

 are in italics. Visits to Composit^c are distributed under An- 

 themidese, Asterese, Eupatorieae, and Heliantheie. 



