357 



We are able to publisli herewith a satisfactory figure of this species 

 which was drawn by Miss Sullivan some months ago at Professor 

 Eiley's direction. We believe it important to publish this figure as 

 early as possible in order to assist entomologists in recognizing the 

 species should it be found to have established itself at any jioint in 

 this country. 



A REMARKABLE MIGRATION OF BUTTERFLIES. 



Through the kindness of Mr. Geo. W. Knight, of San Marcos, Tex., 

 we have received reports of a remarkable migration of the so-called 

 snout butterfly, Hi/patus hachmani, a species which belongs properly 

 to the Carolinian fauna, but which has been occasionally found as far 

 north as Ontario. On September 1 Mr. Knight sent specimens of the 

 insect to the Department, and reported that they were flying in an 

 eastward direction in vast numbers. At our request he instituted 

 inquiries in the surrounding counties as to the occurrence of the spe- 

 cies, and ascertained that at about the time mentioned swarms of the 

 butterflies were observed flying in a general eastward direction over a 

 territory almost one hundred miles square. Taking the city of Austin, 

 Travis County, as the northeastern corner of this territory, it may be 

 bounded as follows: Westward 75 miles to Fredericksburg, Gillespie 

 County; thence due south 100 miles to Pearsall, Frio County; thence 

 eastward to Karnes City, Karnes County, 75 miles. The butterflies 

 were also reported from the following towns lying within this territory: 

 Boerne, Kendall County; Castroville, Medina County; New Braunfels, 

 Comal County, and San Marcos, Hays County. 



At our suggestion a part of Mr. Knight's inquiry was directed ta 

 ascertaining the abundance of the hackberry, Celtis occidentalism 

 throughout the territory covered by this migration. This is the only 

 food plant known for the species, and the reports received by Mr. Knight 

 show that it grows more or less plentifully at nearly all the places 

 where the migration was observed. 



Hypatus hachmani is a common butterfly throughout Texas wherever 

 the hackberry tree grows, but migratory movements of this species 

 have never been reported before. It would appear to us that the flights 

 observed this season in Texas were brought about by the rather 

 abnormal weather of the past season. Mr. Schwarz, who visited Texas 

 in August, tells us that during the months of June and July there was a 

 period of severe drought all over the State, which was suddenly followed 

 in the first week of August by an equally i)rouounced rainy season of 

 several weeks' duration. This very moist and at the same time hot 

 weather must have favored the simultaneous issuing of an unusually 

 large number of specimens from their chrysalids and thus brought 

 about the primary condition under which migratory instinct is developed 

 in many insects. 



12283— No. 4: 6 



