330 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



Scientific Notes 



An Acrobatic Fly. While collecting in Hocking County, Ohio, during the sum- 

 mer of 1911, the writer met with An interesting species of fly. In carefully scrutin- 

 izing the sandstone wall near the bottom of a gorge, he was surprised to observe 

 a number of small insects, strung out in a row apparently floating in midair. A 

 closer inspection afforded a novel sight. Thirteen minute flies were seen arranged at 

 intervals along a long spider's thread which extended from one rock prominence to 

 another. Each insect was hanging by the anterior pair of legs and careful inspection 

 with the magnifier showed that they were using the terminal claws to grasp the fine 

 thread. There they hung quite undisturbed by the swaying of the delicate line. 



Upon lightly toucMng one with a small twig it would fly away a short distance, 6 

 to 10 inches, then begin to hover in the vicinity until it found the thread again. With 

 one exception, each of the thirteen flies succeeded in regaining the thread which it 

 would grasp much in the manner of a horizontal bar performer, its body swaying to 

 and fro after the impact. 



This interesting colony was observed frequently after its discovery. The num- 

 ber of insects present was different each time an observation was made, though 

 there were never less than five or six. Whether the insects left at intervals in 

 search of food and returned was a matter quite impossible to determine. There were 

 very few long or short independent spider threads present in the vicinity and of 

 those in use the longer invariably had the larger number of flies. It seemed to the 

 writer probable that the insects did find their way back to their peculiar perch. 



Specimens of the midges taken from the spiders thread have been found to belong 

 to different genera. Dr. E. P. Felt has kindly examined them and refers them to 

 the genera Microcerata and Bremia. 



B. W. Wells. 



A Probable Parasite of Scapteriscus didactylus in Cuba. Having received 

 several inquiries about this insect from Messrs. Van Dine, Tower, Grossman, Jones 

 and Hooker, entomologists of Porto Rico, I have been waiting for an opportunity to 

 find out for them something about this insect in Cuba with a special watch for a 

 parasite, for the situation stands thus: Scapteriscus didactylus Latr. known in Porto 

 Rico as "changa" is quite a pest there, it exists in Cuba but is rare, although we 

 have similar climatic conditions to those of Porto Rico, and its principal plant food, 

 which is tobacco, is cultivated on a large scale. All this induces us to believe that 

 here mui^t e.xist a natural enemy that controls this insect. 



Through Mr. G. N. Wolcott of the Bureau of Entomology, who at the time was 

 doing special work here on tobacco insects and who went to San Juan y Martinez in 

 the tobacco section of Pinar del Rio Province, we were able to find that Scapteriscus 

 was known there and called "berraquito de la tierra" (little ground hog). With 

 this information at hand I took advantage of a trip made to that section on account 

 of a serious pest of wireworms on tobacco, being accompanied by Mr. Wolcott, and 

 we found that what the people there called "berraquito de la tierra" wag really the 

 "changa" of Porto Rico or Scapteriscus didactylus Latr., and that the fire ant, Solen- 

 opsis geminata Fab., and tjie common red ant, Pheidole megacephala Fab., were their 

 most dreaded enemies in high and dry land. To the attacks of these ants we partly 

 attributed the fact that Scapteriscus has not proved a serious pest. 



On a second trip made to San Juan y Martinez I paid attention to this matter of 

 the "berraquito de la tierra." I had specimens brought to me, collected in high land 

 where ants were veiy abundant, but evidently they had evaded them. Then I 



