3o2 



THE AGUlCOLTUliAL NEWS, 



NOMIMBEE 15, 1919. 



INSECT NOTES. 



ENTOMOLOGY IN PORTO RICO. 



Th? AiiniKvl Keport of the Insular ExperiuieDt Stafioa 

 t^i the Departraeni cf Aariculture and LaVwur of Porto Rico, 

 for the period .July 1,' 1^1'? to .lune 30, 191S, contains 

 a review of the entomological work carried out l>y tha 

 Experitrent Station since its establishment in 1910 by the 

 Jiugar Producers' Association <f Porto Rico. In 1914 this 

 station was transferred to The People of Porto Kico, and 

 for three years it was adminir-tered by the Board of Com 

 niissioners of Agriculture (1914-16 inclusively), and in 

 1917 it became a part of the Department of Agriculture and 



Labour. 



The report of the Division tif Entomology for the year 

 1917-18 records principally, the work on the pests of sugar- 

 cane. In addition, there is an account of a rhinoceros beetle 

 attacking coco-nute. A number of young coco. nut trees 

 ■were seriously injured by the adults of this large beetle. 

 Older liees aic sometimes attacked also. The larvae of 

 these beetles live in rotting wood, and the adults are attracted 

 to the rotting husk of the seed coco-nut at egg-laying time 

 and find their way to the grepn leaf-bases, through which they 

 tunnel into the growing centre of the stem, sometimes kill 

 iug the plant, and often seriously injuring it. 



The remedy suggested for the control of this beetle is 

 based on the attraction of the adults to rotting wood. It 

 consists in the collection of che trash, dead logs and stumps, 

 which accumulate in coco-nut plantations into piles din- 

 tributed through the groves to attract the beetles at egg 

 laying time These piles should be turned over and examined 

 monthly, and all grubs and beetles found in them des- 

 troyed. 



Among miscellaneous insects dealt with in the report 

 arethehTn By {Haematobia serruta, Desv), garden pests, 

 certain scale insects, and white-ant.?. 



1 he horn lly seems to be on the increase. An attempt 

 •was to have been made to introduce a scarabeid beetle from 

 Santo Domingo to help to control the horn fly, but on 

 account of the conditions incident to the war, it could not be 

 done. This beetle. Canthon Tiolaceus, belongs to the dung- 

 rolling class, which are active agents in the quick disposal of 

 , cattle dung, and thus prevent the hatching of flics— the eggs 

 of the horn fly are deposited in cattle dung and the larval 

 and pupal stages are spent there. Such beetles are said to 

 be totally lacking \:. P.-rtoPi'-o. 



Hedges of orange jessaraine (Afurraya cxotifa) were 

 attacked by the Colifornia red scale{ Chrysotnphalus aiiriDitii), 

 the citrus purple scali; {Lcpidosophes heckii), and the brown 

 , shield scale {Sdlsseiia. hcmisphncrica). Peanuts were attack 

 ed by itn uiideterii'tned si>ecles of mealy-bug {Psciidococcus sp. ), 

 which was attended by a large brown ant {Proiolcpis sp. ). 



Sugar -cane cutiings used for planting were attacked 

 by wood ants (RiiUrincs mntio). Tlies.' attacks resulted 

 from Iciving thr- ciutings on the (iround for some time, and 

 they were infested before planting. 



The tables showing the results of I'lant Qiiaranti- 1 



., Inspection givi; in' renting information in regard to the 



. source from which plant material of all kinds are received at 



the several ports of entry, and particulars as to the insects 



interceptet^ in the course of this work. 



A rigid quarantine wos maintained. a.s in previous years 

 against the imporlatiou of ■ all citrus nursery stock, or 

 citrus (ruiUor seeds from the United States, and from foreijra 



jountriet^ and islands, on account of .he luuoh dreaded citroB- 

 canker, and also on account of auch insects as the white fly, 

 the black fly. the Mediterranean fruit fly, and the Mexicaa 

 orange maggot, none of which occur in Porto Rico. The- 

 insular laws require that no fruits from other tropical 

 countries shall be iutroijluced. A new regulation promulgated 

 in February 1916, by the Commissioner of Agriculture and: 

 Labour, prohibits the importation of pine-apple fruits or 

 slips from all foreign countries or islands, on account of the 

 recently discovered pests and diseases found to occur in 

 .Taiiiaica, Hawaii, and the Philippine IsUads. 



The mcjttliug disease of sugar-cane is one of the most 

 serious trnubles of the sugar planter in certain districts in 

 Porto Rico. The means by which the disease is spread and 

 communicated to healtby plauts is not known, and the pi'ssi- 

 bility of this trinsmission being due to the action oi insects- 

 is under oonsideration. The insects which are under .-uspi- 

 cion are a green leaf topper \Teitigonia similis), and the 

 .sugar cane shot Ijorer, (Xylebortis perforam) The leaf 

 hopper ociur.s in I'ara grass in the traces between cane fields, 

 and to someeytent on' young cane, and is often encountered 

 where the disease is spieadint^ The shot borer wa.? found 

 abundantly ia decayihg stalks under ground in a lield 

 which had been badlj' attacked by the disease, and in a dis- 

 trict where the disease was spreading rapidly. 



The probleui of white grub control is also a most serious- 

 one. Tha white grubs of augar cane fields in Porto Kico are 

 similar r.nd closely related to the. brown hardi'acks wnicU 

 are seri'His pc-jt* in Barbados and Antigua. They have 

 been incea^ing in importance in Porto Rico for several 

 j'oars pait, Mnd rrt-nt studies indicate chat there are at 

 least live species eon'.erued in the attacks cc the roots of 

 sugarcane plants. 



lu two districts where the white grub.s have not attracted 

 attention until the previous year or two, they were .su itiimer- 

 ous during tlie 1917-18 period under review, that on one 

 estate in a single sea.*ion over a million beetles and grub» 

 were c"llected, and cane growt-rs assert that if the white 

 grubs continue to increase in these districts, cane grow- 

 ing '.nil ceAse to be profitable. 



The only reliible and economically p>ying method of 

 cf'ntrol of while gru'is yet devised is the hand collection of 

 grubs and beetles, which is costly and iabr.rious and serves 

 at best only as a palliative. In spite or all efforts at col- 

 lection, white grub,s are on the increase, imditis evident that 

 there is great need of some better and cheaper m'^aos of 

 white grub control in sugar plantations. 



'A betier an i more economical means of «hitegrab 

 control which hws suggesteci itself to tlie writer, is the 

 permanent introduction into theislanlof two spucies of 

 .'vnimals from the mainland l hat live almost exclusively upon 

 iusfcl.'', ami are know n to »at large numbers of white grubs 

 and l\tay beetles These are the skunk and the toad. Roth 

 of them are distributed over a wide range of climate on the- 

 North ,:\ nierica coniirtent from Canad.n. to Central America, 

 occurring; as dittVrcnt species and rans and both are absent 

 on this island and might be readily accliraaied if introduced 

 here artificially, I'oth of these are noctura\l in habits, and- 

 would iheiefore do their foraging at a time when th" .May 

 beetles ((a/iulos ) are active, . , . , 



' The skunk is an atiim<l about the size of the mongoose, 

 but quite without its bloodthirsty taste for eggs and yoilng 

 birds. It protects itaelf from its enem'es'by the ."jectifu of 

 an pfiEensive smelling liquid on it.i pursuer ; an'd fchiW would 

 .serve to protect it from slaughlier by either man ir the 

 mongoose It is ,vlmost wholly ibHectlvbrona, and has b«en 

 known to roi)i; up the aoil over whole acres of grass land io. 



