158 BULLETIN 15 7, U. S. NATIONAL MUSEUM 



Unusually large specimens were captured on the following dates: 

 Males with the fore wing 29 mm. long, August 6, 1927, and Septem- 

 ber 14, 1928; with the fore wing 30 mm. long, September 8, 1926; 

 with the fore wing 31 mm. long, October 7, 1928. Females with the 

 fore wing 32 mm. long, August 6 and 13, 1927; with the fore wing 

 33 mm. long, August 6, 1927, and October 6, 1928; with the fore 

 wing 34 mm. long, September 11 and 14, 1928. 



COLIAS PHILODICE (Godart) 



Yellow Clover 

 Plate 27, Figures 3 to 8 



Occurrence. — ^Abundant and generally distributed throughout the 

 District. It is, or rather was until 1930, the most numerous of the 

 medium-sized butterflies. 



The yellow clover butterfly is found everywhere in open country, 

 and is particularly abundant in fields with a luxuriant growth of 

 clover. 



There is a single male from the District in the National Museum 

 taken in 1915. The Schonborn collection includes six specimens, 

 two males, two yellow females, one lacking the spots in the black 

 border of the fore wings, and two white females, one with a yellow- 

 ish tinge. 



Habits. — On warm and sunny days the yellow clover is a rather 

 active butterfly, coursing about the fields usually about a foot above 

 the grass tops in a broad irregular zigzag the general direction of 

 which often changes suddenly. From time to time it rests upon a 

 flower, and when feeding is as a rule quite unsuspicious. The larger 

 males have a higher, faster, and stronger flight than the smaller 

 ones. They are also shier, and are sometimes rather difficult to 

 capture. The females are less active than the males; their flight is 

 less irregular, usually lower, and never very long. 



When two males meet they may flutter about each other for a sec- 

 ond or two and then continue on their way, or they may engage in 

 combat, gradually rising vertically to a height of sometimes 50 feet 

 or more. 



When a male and female meet the female may alight upon a leaf, 

 spread her wings almost to the full, the hind wings being more nearly 

 horizontal than the front wings, and constantly flutter them with a 

 tremulous motion, while the male actively flutters about her, in 

 front and on either side; or the female may rise rather slowly up- 

 ward at a steep angle with the male, as noticed by Mr. Scudder, just 

 above or in advance of her. A pair may rise in this way, according 

 to Mr. Scudder, for 60 feet or more, though usually they rise to be- 

 tween 10 and 15 feet. The performance ends by the male suddenly 



