40 NATURE SKETCHES IN TEMPERATE AMERICA 



viUic'5^^ The Selected Guests of 



J'iiiW.j \r?;''%,) THE BCTTERFLY WeED 



U-. 



1^ 



HOW l>rilliant '\ llie flowers of the orange 



huttordy weed appear in the field, when 



viewed in the bright sun of a July day! Under 

 these conditions they show with a splendor only 

 known to the flowers of this species. Not only the rich color 

 of the blossoms appear to have charms for insect guests, but 

 the pollen and sweets seem to meet their most exacting whims. 

 A veritable entomological garden is spread before us as we 

 approach. \'arious winged insects, from butterflies to small 

 flies, are all busily occupied among the blossoms. Nearby 

 are half-opened flowers of the goldenrod and the pretty, 

 scented, lace-like flowers of the wild carrot, but they are for 

 the moment completely ignored by these special insect guests. 

 I have alreatly considered the structure of the blossoms of 

 the common milkweed and have endeavored to show how the 

 delicate and weaker flies and bees sometimes fall victims by 

 having their feet entangled in the pollen masses of the flowers. 

 These pollen organs or corpuscula become clasped, as if animated, 

 to the feet of certain insects. Some of the weaker insects are 

 unable to disentangle themselves, and these captives either 

 die of exhaustion or fall prey to the ants, which often swarm 

 upon these plants. The larger insects, such as the wasps, 



