:U6 



THE AGRICULTURAL NEWS. 



IS'OVEMBBR 2, 1918. 



INSECT NOTES. 



WEEVILS ATTACKING SWEET POTATO 



AND YAM. 



Two papers dealing with weevils of the groups to which 

 the Scarabee and sweet potato weevil belong have recently 

 been issued. t)ne of them, by Dr. G. A K. Marshall, appeared 

 in the Biil/ctin i>f Eiitomi'/ogiia/ J^esrnrch, London, 

 Vol. VIII, February 'l91S, p. 2')9, entitled 'A New Weevil 

 Pest of Sweet Potatoes in Jamaica!. The other, by IJr. W. D. 

 Pierce, published in the Joiinnil of Agriadlura! Research, 

 Washington, Vol. XII, Nc. 9, March 4. 19 1«, was entitled 

 'Weevils which affect Irish Potato, Sweet Potato, and 

 Yam' Dr. Marshall describes I'fllneupus O'stied/is, a new 

 species sent in by Mr. A. H. Uitchie, Government Ento- 

 mologist. JamaicH, who found this insect doing serious 

 damage to swe^t potato. In general appearance it is ^> 

 much like the Scarabee {Eiiscefts. Imialae, that it might be 

 mistaken for thnt insect; the injury to the sweet potato is 

 similar to that of Scarabee also. It is considered likely that 

 the two insects have been confused under one name, and that 

 the injuries resulting form the attacks of both have been up 

 to the present time attributed entirely to the Scarabee. 



Two other specimens of weevils of this genus in the 

 collections in the British Museum, very similar in appearance 

 to P. eusfico/lis, proved to represent two new species, and 

 while nothing is known of their habits, it is suggested that 

 these will be similar also. 



These two species are /'. -re/ia//eits/s from Grenada, 

 and F su/'^ra»if/afi/s from St. Vincent. 



J )r. Pierce, in this paper, describes a new species of this 

 genus from Jamaica as a pe.st of yams. The name given to 

 this is /'a/iV/'/'iis dioscorene. It was described from two 

 specimens reared from tubers of yam {Diasairea //afafas) by 

 Mr. S. F. Ashby. in 1914. 



This indicates that the genus Palaeopus attacks yams as 

 well as sweet potatoes, and the new species described from 

 Grenada and St. Vincent may preve to be pests of yams, or 

 even of other starchy roots or tubers. 



Dr. Pierce als- deals with the sweet potato weevil 

 {Cr/as/m»!iairii/s,[¥a.hnc'niA) wd other species of the genus. 

 It would appear that there has been some confu.-«ion in the 

 identity cf certain species of this ►enus. Three species known 

 or supposed to be pests of sweet potato seem to be well 

 established. They are Cjlns Jonnkariui, Fab., C. tt/rdpemih, 

 Boheman, and C. femoralis, Faust: 



An account of C. furviicarius was given in the Ai^ri- 

 (-«//7/rrt/iV«w, Vol. XVII, p. 42. This insect has greatly 

 increa-sed in importance in the 1 nited States and the West 

 Indies within the [>*st few years. C- turcipcnnis occurs in 

 India, the Dutch East Indies, and the Philippine Islands, 

 while C. femoralis is recorded from T.,iberia and Kamerun, 

 Africa. 



nisTRIHI TION OK WEEVILS ArrACKIN(; .SWEET POTATO 

 ASH VAM._ 



.Jacobs or Scarabee {Euuepa hatatae, Waterhouse). 

 General throughout the West Indies. Occur." in Brazil, the 

 Hawaiian Islands, Guam, and New Zealan'i. 



ralaenpiis coitico/is, Marshall. Occurs in .(amaica, sim- 

 ilar in appearance to the Scarabee, and affects sweet potatoes 

 in the same manner. 



Sweet pouto weevil {Cylas formkariu^, labricius) 

 General throughout the E-isiern Tropics. ( (ccurs in the' 

 Southern Unictd States, I'orto Rico, the Bahamaa, and 

 Britiih Guiana. 



Cylas femoralis, Faust. A serious sweet potato pest 

 in Liberia. Occurs in Kameriin. 



C\las /«;r//itv/«/y, Boheman. Occurs in Java. Sumatra, 

 the Philippine Islands, Sarawak, and India. The f ood • of 

 C tincipciuiis is not recorded. 



Palaeopus dioseoreae. Pierce. Occurs in Jamaica; 

 attacks the tubers of yams. 



Palaeopus grenadensis, Marshall. Described from a 

 museum specimen from Grenada. 



Palacdpus sul,granulatus, Marshall. Described from a 

 museum specimen Irom St. Vincent. Feeding habits of the 

 two species last mentioned are not known; they may attack 

 sweet potatoes or yams. 



TERMITE INJURY TO SWEET POTATOES. 



A note on the above subject by E. W. Berger appeared in 

 the Quarterly Bulletin of the State Plant Board of Florida, 

 July 1918, which appears of interest to planters in the 

 West Indie?, and is reproduced below. 



Owing to the great importance of sweet potato weevil 

 {C\las formicarius, Fab.) sweet jiotato growers should be on 

 the watch for it everywhere, and especially in sections sap- 

 posed to be free from the pest. 



Among injuries (uost likely to be confused with the 

 work of the sweet potato weevil are those caused by termites 

 or 'white ants' The differences between the injuries done 

 to the tubers by the two pests are summarized as follows: — 



1. 'Absence of larvae (grubs) and pupae in the tunnels 

 when infested by termites, but their presence in apparent 

 abundance whenthe tuber is infested with the weevil. 



2. 'Absence of f^ass (excreta) when the injury is due 

 to termites, but an abundance "f this in the tunnels pro- 

 duced by the weevil 



3. 'Exit and entrance holes very apparent with ter- 

 mites, but tuber infe.sted with weevil may show little or no 

 outward evidence of its condition inside. 



4. 'The clean-cut outlines of the tunnels made by the 

 termites are in marked contrast with those made by the 

 weevil. 



5. 'If the plant3,are growitiif, tunnelling larvae (grubs) 

 in the stems near the ground indicate the weevit. , 



(;. 'The pre.sence of large (about j-inch lo>^g) ant- 

 like insects with black head and snout, brick-red thorax 

 (middle) and legs, and dark steel-blue end, is au alin|st cer- 

 tain sign of the weevil. 



7. 'The presence of whitish, rapidly running insects, 

 having much the appearance of ants, indicates terof/tes.' 



H.A.B. 



DEPARTMENT NEWS. 

 Sir Francis Watts. K.C.M.CJ., the Imperial Cora- 

 iiiissioiier of Agriculture, K;us returned to Marbados 

 after payinL' an ofliciftl visit to St. Vincent. 



Mr. V\'. Nowell, D.I.C , Mycologist on the Staff of 

 the- Imperial Department of Agnciilture, has also 

 returned to Harbadosaftei a visit to (irenada for the 

 purpose of inve.stigating a di.se.vie of coco-nuWrees in 

 that island. 



