2 BULLETIN 1232, U. S. DEPARTMENT OF AGRICULTURE. 



ment. Such damage has been caused by Leucotermes tenuis Hagen, 

 Coptotermes niger Snyder, and Nasutitermes ephratae Holmgren. 



There is also a discussion of the possibility of termites acting as 

 mechanical carriers of the nematode Aphelenchus cocopMlus Cobb, 

 which causes " red-ring " disease of coconut palms. Although species 

 of Nasutitermes, Eutermes, and Coptotermes infest the trunks of 

 coconut palms or have runways on them, only Coptotermes niger 

 Snyder has been found with these nemas on the bodies of the workers. 



As in the Dietz-Snyder paper (0), all specimens were given num- 

 bers in the field. All field observations and photographs of nests, 

 galleries, damage, etc., are supported by numbered specimens of the 

 termites. This insures accuracy and avoids confusion; it affords a 

 check in case of wrong determinations, for the notes can then be 

 identified easily and properly placed. 



GEOGRAPHICAL DISTRIBUTION. 



Apparently more species of termites inhabit the Pacific slope than 

 the Atlantic slope of the Canal Zone. On the Atlantic slope the 

 rainfall is greater. Mr. Zetek states that at Colon, in 1913, there 

 were 246 rain} r days, whereas at Ancon there were only 180, and 

 the total precipitation was 131.22 inches and 65.98 inches, respec- 

 tively; h& has prepared a table (Table 2) giving the rainfall for 

 1921 for the 13 towns, with comments. This is particularly inter- 

 esting, especially since many termites are so dependent upon mois- 

 ture. 



Reference to a map of Panama (Pis. I and II) 3 will show the Rio 

 Chagres flowing practically southwestward, and receiving tributaries 

 from both the north and south sides. Along the Atlantic side are 

 rivers that empty into the Caribbean Sea and along the Pacific 

 coast are rivers that enter the Gulf of Panama. There are, then, 

 two more or less parallel divides, the first skirting the Atlantic 

 coast, the second skirting the Pacific coast. Most people seem to 

 have the erroneous idea that there is but one divide. 



The Hydrographic Office, Bureau of Navigation, Department of 

 the Navy, considers the central section as from Culebra (more or 

 less near Pedro Miguel) to Monte Lirio. This is based on the orig- 

 inal divisions made by the chairman of the Isthmian Canal Com- 

 mission when the canal was being built. The central region is not 

 considered by the present writers to extend beyond Darien. 



Zetek has thus divided the Canal Zone into three regions — the At- 

 lantic (as far as Darien), the central (from Darien to Pedro Mi- 

 guel), and the Pacific (from Pedro Miguel to Panama). The great 

 Gatun Lake has, of course, greatly altered this arrangement, and 

 it may be necessary to change these limits somewhat. The central 

 zone is a sort of transition zone, now less evident than when the 

 digging of the canal was begun. The flooding of Gatun Lake killed 

 the trees, and the insects had to. go elsewhere and adapt themselves 

 to new surroundings, or else die out. They emigrated in great num- 

 bers, no doubt, and a large proportion did well in their new abodes 

 after some fighting with those already in possession. 



3 The map shown in Plate II is adapted from Plate I in Mammals of Panama, by E. A. 

 Goldman (Smithsonian Miscel. Col., vol. 69, no. 5, 1920). 



