300 



difficult to rear, and very few reared specimens are before me although 

 several species are not uncommon in this vicinity. 



I have reared one hymenopterous parasite from a breeding-cage 

 containing larvae of this family, but doubt its connection with Bibio 

 as its host. 



HABITS OF IMAGINES 



The imagines of Bibio fcmoratus fly in April in this latitude and 

 are sometimes very common. The name "March-fly", applied to 

 adults of the family by some writers, does not justify the natural in- 

 terpretation of the term, as they do not appear in this country until 

 later in the year than March. The term is probably due to a misin- 

 terpretation of the significance of the specific name of a European 

 species of Bibio, B. marci, supposed to owe its name to its occurrence 

 on the wing about St. Mark's Day (April 25). Popular names are 

 very frequently misleading, and no encouragement should be given to 

 the currency of any which may be derived from the characteristics of 

 a single species, which can never properly serve as a criterion by 

 which to judge of the remainder of the family. 



The species that occur early in the season are instrumental in 

 pollinating blossoms of various fruit-trees, upon which they occur 

 very commonly. They fly readily even on dull days, and on this ac- 

 count are more generally serviceable as pollinators than bees, which 

 are seldom active except during sunshine. 



Important Papers on Biology of North American Species 



Lintner, J. A. 



'85. Second Annual Keport of the State Entomologist of New York, 

 pp. 110-115. (Gives description of imago of Bibio albipennis 

 and notes on life history.) 



Needham, J. G. 



'02. A remarkable occurrence of the fly Bibio fratemus Loew. Am. 

 Nat., 36: 181. (Gives figures of larva and pupa.) 



Family SCATOPSIDAB 



Until recently the species of this family have been included in the 

 family Bibionidae, but all stages of the species herein dealt with pre- 

 sent good characters for their separation from that family. 



