58 



Talxiiiufi llneola Fab. is a widel}" distributed species and everywhere 

 is of especial economic importance. It was common at Cameron, and 

 is one of the three species referred to abo^^e as })eing especially 

 iniurious. 



TdJjimus costaUs Wied., the common greenhead, was abundant and 

 appeared to be more persistent in its attacks than any of the others. 

 When sucking- blood it is usually located on the under parts or on the 

 fore legs, where an animal has most diiliculty in reaching it, and once 

 it alights it is pretty sure to satisfy its appetite before leaving. 



Tdhanus (julnquemaculatus Wied. has not been reported from the 

 United States heretofore, but the commonest species observed at 

 Cameron agrees very closel}^ with Wiedemann's description. Besides, 

 it is reported from Mexico b}^ both Wiedemann and Bellardi, so it 

 would not be strange to find it in Louisiana. This species appears 

 much like costalis, but is larger, has two purple bands on the eye 

 instead of one, and the costal cell is hyaline. It is also close to llneola 

 in appearance, but the color of the vestiture of the body is decidedl}^ 

 more yellowish, and the upper purple band of the eye is noticealjl}' 

 narrower than in that species. Besides, it averages larger than either 

 cosUdis or lineola, but undersized specimens are often met with. 



Since no sj^stematic experiments were carried on at the Gulf Bio- 

 logic Station, what the writer has to say regarding remedies may be 

 considered as suggestions, derived partl}^ from observations on the 

 conditions existing in that section, and partly from work and experi- 

 ence in Ohio. 



NATURAL ENEMIES. 



The natural enemies of the Tabanidge is an interesting subject for 

 investigation at the Gulf Biologic Station. The writer is under ol)li- 

 gations to Messrs. Ashmead and Coquillett for the names of most of 

 the species mentioned ])elow. 



Monedula carolimi Fab., a large and attractive species of the familj'^ 

 Bemliecida^, is common, and its habit of flying ai'ound horses and 

 cattle for the purpose of catching Tabanids and other stock pests is so 

 noticeable that it has received the common name of horse-guard." 

 One commonly sees from one to three or four of these at work 

 around a single animal. 



Bemhex helfmgei Cr. belongs to the same family as the last and like 

 it is an important enemy of horseflies. It has ditt'erent hal)its, how- 

 ever, for instead of capturing prey around animals, it flies about the 

 fields in the vicinity of marshes and captures males and females at 

 their breeding grounds. It is a common occurrence to see a specimen 

 carrying an adult Tabanid. 



Both the above species deposit their eggs in burrows which they 



«A name which it shares with the great digger wasp {SpheduK \_StizuH\ Hpcciosua Dru. ). 



