31C 



THE AGRICULTURAL NEWS 



October 25, 1913. 



INSECT NOTES. 



AN ENTOMOLOGICAL VISIT TO THE 

 UNITED STATES. 



Mr. G. E. Bodkin, Jl.A., GoverDineiit Economic I'.iolo- 

 ^st of the Department of Science and Agriculture, Kritiah 

 CJuiana, recently viaited the United States and Porto llico 

 as a Carnegie Entomological Scholar. The report on this 

 visit has just been received, and the following article has 

 been abstracted from it: — 



Early in 1912, the Entomological Research Committee 

 (now the Imperial Bureau of Entomology) made an offer to 

 the Government of British Guiana of a Cirnegie Scholarship 

 in Entomology, which was accepted, Mr. Bodkin being 

 chosen as the recipient. The scholarship provided for 

 a subsistence allowance for six months and a sum to cover 

 travelling expenses. Mr. Bodkin left ]!ritish Guiana on 

 August 7, 1912, and returned on January 22, 1913. 



During this time some thirty entomological stations 

 and museums were visited. These included the Head- 

 quarters of the U.S. Department of Agriculture, and the 

 U.S. National Museum at Washington, museums in several 

 other large cities, several universities, agricultural colleges. 

 State experiment stations and the special field laboratories 

 of the United States Department of Agriculture in ditferent 

 parts of the country. 



In addition to studying the insect pests of many crops 

 and plants which are grown in the Tropics, and the methods 

 of controlling them, Mr. Bodkin had opportunities for 

 becoming familiar with nearly all the large entomological 

 projects which are being worked upon in the Fnited States. 



SUi;.\R C.\NE PE.STS. 



Sugar-cane was studied in Louisiana and in Por-to Rico. 

 In the former of these places the insect pests observed were 

 the moth borer (Diatraea saccharal's), the sugar cane mealy- 

 bug (Pstiidoroccus sacchari), the sugar-cane beetle borer 

 {Luiynis nigiceps), and the May beetle {Lachnostcnia sp.). 

 The Argentine ant {Iridotat/rme.c humilis), which is a serious 

 household pest, is also a factor of importance in connexion 

 with sug.'ir-cane cultivation, because of its relationship to the 

 su^r-cane mealy-bug which it protects from its enemies and 

 estaBlishes in suitable i)laces for feeding. The sugar cane 

 mealy-bug of Louisiana is the one known as tie 'grey' mealy- 

 bug (F. mcc/i'iri), while the common form in the West Indies 

 is the 'pink' (P. cxlceolariae). The injury to the canes in 

 Louisiana by mealy-bug is stated to result from the habits 

 of this insect of collecting in numbers under the leaf sheaths 

 and causing the death of the eyes. 



Insect attack in the sugarcane fields was seen to be 

 much less than in British Guiana. The definite winter 

 season probably has a very beneficial effect by checking 

 develoi>ment of pests at a certain time. Mr. Bodkin 

 discovered clusters of moth borer eggs parasitized by either 

 the .same insect (TvidtdyniiKinn /)re^ios«) which occurs in the 

 West Indies, or a closely related species. This was the first 

 time this bad been observed in the United States. Since then, 

 parasitized moth borer egg clusters have been found io 

 several localities 



The Argentine ant is a serious [lest. When introduced 

 into a new locality it kills out the species of ants already 

 established there. It is a nuisance in dwelling houses and 

 causes much loss by its attacks on stored food stuffs. 



In addition to its protection of the mealy-bug of 

 sugar-cane, it has become a serious pest of citrus trees. 



The ants visit the Mossoms of the orange trees for the- 

 nectar, and they also destroy the young embryos, and con- 

 sequently little or no fruit is produced. Extensive experi- 

 ments in poisoning these ants by means of a dilute solution 

 of arsenic (sodium ^rsenite) in a sugar syrup have bean carried 

 out. Small pieces of sponge are saturated with the poison 

 mixture, placsd in tins or glas.< jars to prevent the access of 

 rain water, and distributed in situations frequented by the 

 ants. (This sy>tein was described in the Aqrtcidtvral A'ews, 

 Vol. .\, p. 316.) - 



In Porto Ivico, many of the same insect pests of sugar- 

 cane were found. The small moth borer was everywhere 

 present but not particularly abundant. The white grub was 

 also present and caused a considerable amount of injury. 

 J'igs have been found useful enemies of the grubs in newly 

 ploughed fields. Several parasites are known also to attack 

 them, viz; two wasps, Caiiijisonieris [Dielis] dorsata and 

 Elis sexcinota; and ^wo parasitic flies of the family Tacliinidae. 

 Another wasp, Tiphia inornata, is being introduced from 

 the United States; a parasitic fungus, Isaria pensa, is being 

 introduced from France, and a toad from Texas. A species 

 mole cricket is also a pest in fields of young plant canes. 

 The mealy-bug P. mlo-olaviae is generally present and at 

 times very numerous. 



I'E.STS OK laCE. 



In Louisiana, rice is cultivated on a fairly large scale 

 and here were seen important pests. The rice weevil 

 {Lissor/ioptrvs simple.'; Say) is an aquatic insect, the larvae- 

 of which attack the roots of the rice jilants. A small bug 

 (Oehalus jiiignai) of the family Pentatomidae attacks the 

 fruiting heads of the rice, sucking the juice from the develop- 

 ing grain. The larvae of the small moth Chilo pleje- 

 ddlus bores into the stems, and the sugar-cane beetles 

 {Ligi/riis rug{crj:s) attacks the roots. 



The rice weevil is captured successfully by means of 

 light traps and the application of crude petroleum to the 

 surface of the water appears to give good results, so far 

 as the experiments with this method have been tried. 



IN.SECIS ON <IT1U'S PLANTS. 



In California the principal pests are four species of 

 scale insects.- the black scale (Saissi'tia oUa), the red scale 

 {C/iri/somp/ialiis atariniii), the yellow scale (C. aumiitii, var. 

 c/>trinus) and the purple sjale {Li'jiido$ap/ies lieckii). Several 

 other pests of minor importance also occur. 



The methods employed for the control of scale insects 

 ki California are fumigation and spraying. Much valuable 

 work has also been done in the importation and use of natured 

 enemies, but it is found profitable to resort to artificial means 

 of control at times. Fumigation with hydrocyanic acid gas 

 is most generally practised. This method involves the use 

 of expen.sive tentg, but with the valuable nature of the crop 

 the percentage of cost is not great. The distillate (heavy 

 petroleum oil) spray is also used to a considerable extent. 



The black scale has been controlled to a large extent by 

 the imported natural enemies, the parasite, Scute/lista 

 ci/aiiea, but in spite of this, scale insects have been sufficiently 

 abundant to give rise to black blight and sooty mould to 

 such an extent as to necessitate washing or scrubbing of the 

 fruit before packing, and as this injures the keeping qualities 

 of the fruit the attempt is made by means of fumigation tft 

 obviate the necessity for this washing 



Fumigation must be carried on at night as the poison- 

 ous gas is injurious to the leaves in daylight when they are 

 actively performing their natural fuctions. The cost o£ 

 fumigation is estimated to average about 50c. per tree 

 and it will need to be repeated at intervals of three years. 



