found within one dead adult host varies from two to nine, usually 

 four to six. Infested beetles that have died are always found in 

 their burrows in the ground. 



Work on the life-histories of the two species is in progress now, 

 l)ut has not yet been completed. 



Neither species has been found to occur in the Guanica district, 

 where the damage from vandinei is most acute. Attempts to intro- 

 duce the flies at Santa Rita, using infested beetles taken there from 

 Anasco, were not successful ; and it seems probable that the flies do 

 not thrive in a dry climate like that of the south coast. 



Attacked bij miles and nematodes. — In the experimental jars and 

 boxes some difficulty was experienced in the rearing of eggs of van- 

 dinei because of attack by nematodes and mites, the latter appar- 

 ently a species of Tyroglyphus. The follomng brief notes may serve 

 as examples of the manner in which this loss of eggs occurred : 



No. 1016. — Augnst 25, elexen eggs, laid since August 17, were put into arti- 

 ficial cells at bottom of a jar. August 26, one egg destroye<l, feurrounded by a 

 myriad of young nematodes. August 27, two more similarly destroyed. August 30, 

 all the other eggs but four destroyed by the nematodes. 



A'o. lOSl. — August 26, fourteen eggs, laid August IS to 21, were put into 

 damp sifted earth at bottom of jar. August 27, one destroyed by nematodes and 

 mites. August 29, two more destroyed. September oO, last two killed by mites, 

 and being eaten by them. 



The injury from the mites was not limited to the eggs, grubs in 

 all instars often suffering badly, even dying, from their attack. The 

 following notes give specific examples of mite injury to grubs: 



No. 1049d. — January 28, a grub in second, molted about December 12, heavily 

 infested with mites. February 17, grub died as result, without being able to molt. 



No. 1049(1. — .Tanuary 18, a grub in second, molted about December 20, partly 

 ,.(>\ered with mites on head, legs, and front of body. February 2.5, jnolted. June 

 25, sickly, wdth many mites. June 30, dead, eaten up by mites. 



No. 119S. — May 3, grul) preparing to pupate put into box. May 22, died 

 before pupating; covered with mites. 



No. TiUM. — May 15, grub in first, hatched May 15, has mites. June 2. in- 

 jurcil by mites, and died molting to second. 



No. i:i09a. — .lune 18, grub hatched sinre yester.lay put into box. July 29, 

 half covered with mites, wiiicli prevent its growth. August '^>, sickly, with many 

 mites. August 14, died witliout nuJting to second. 



Eggs devoured by iviretrorm and titaphijlinid larvce. — Occasional 

 loss of eggs was experienced in experimental jars from wireworins 

 {Monocveiyidins sp., undetermined) and from larv;v of a small Sta- 

 phylinid beetle, introduced into the earth with manure. The follow- 

 ing extracts from notes give specific cases: 



87 



