INSTEUCTIONS FOR COLLECTING INSECTS. 173 



the following observations of Dr. Schiener (Wiener Entomol. Monat- 

 schrift, 1858, p. 175) may prove useful : 



"From manifold and repeated experience I have arrived at the con- 

 clusion that whenever one sex of a Dipterous insect appears in great 

 numbers, the other is always to be found somewhere in the immediate 

 neighborhood. 



"If the males soar in the air we can generally predict with certainty 

 that the females are not far off quietly reposing on trunks of trees, as 

 is the case with the AniJwmyzidce, or on the under side of leaves, as 

 witli the SyrpMdie. 



"If every indication of the resting place fails, I then commence 

 catching everything living and flying in the immediate vicinity, 

 sweeping in the air and shaking or beating the leaves and grass, and 

 in this way I have generally succeeded in obtaining, among one hun- 

 dred specimens of the one sex, at least one of the other. 



"The males soaring on the tops of mountains are generally isolated, 

 but on descending several hundred feet w^e will seldom look in vain for 

 the other sex resting on leaves or the heads of umbelliferous plants. 



"I have even succeeded, by patient perseverance, in discovering 

 single males among the numerous female horse-flies (Tahani) which 

 attack cattle." 



Those who wish more detailed information about the localities where 

 rare species of Diptera have to be looked for will find them in Bremi's 

 excellent paper on this subject, (Isis^ 1846, p. IGo,) as well as in an 

 article of Mr. Hoffmeister, in the "Entomologische Zeitung" of 

 Stettin, 1844, p. 360. 



INSTRUCTIONS FOR COLLECTING LEPIDOPTERA. 



BY BRACKINRIDGE CLEMENS, M. D. 



This order of insects includes the butterflies, sphinges, and moths, 

 and is divided by systematists into two very distinct and easily recog- 

 nised sections. 



The members of the first are known as diurnal Lepidoptera, or 

 Bhopaloccra, and are characterized by possessing a7itennce that are 

 always club-shaped at the extremity, by their diurnal Jiight, and the 

 wings being held elevated during repose. They are commonly desig- 

 nated butterflies, and their diurnal habits and beauty render them 

 familiar objects to the most casual observer. Their natural history, 

 also, is much better known than that of the members of the second 

 great group under this order, the great majority of those belonging to 

 the United States having been described in Boisduval and Leconte's 

 Iconographie dcs Lepidoptercs de I'Amerique Septentrionale, and in 

 the works of the older entomologists, Cramer, Drury, &g. There 

 are, however, doubtless, many species still undescribed, but the writer 

 wishes to direct special attention to the individuals of the following 

 group, which, being far more unfrequently the objects of attention, 



