154 



THE AGRICULTURAL NEWS 



M w 8, 1915. 



INSECT NOTES. 



A METHOD OF FUMIGATING SEED. 



What appears to be a i parture in the practici 



fumiga I struction of insects which mig 



hem, is described in Bulletin of the U. S. Depart- 

 ment "i Agriculture, X". 186, issued Februarj 27, 1915. 



The authors i bal a perfectly reliable method of 

 insects pn i ported into this country 



[United States] is much needed. The exclusio 

 a careful selection oi apparently uninfested seeds at the port 



:,.rt is impracticable, because many injurious 

 their larval and | iges and a portion of the adult stage 



sed within the seed, and on this account might easily 

 escape notice when the seeds were inspected. Furthermore, 



red tV localities where injurious 



. ;ir,- not d, and also, insects which are 



only slightlj injurious in their native habitats occasionally 



structive pests when established in this country. 



The ordinary methods of destroying insects in stored 



seeds, such as subjecting them to heat (with or without mois 



m bisulphide, and hydrocyanic acid in the presence 



of air, have been tried and found unsatisfactory for this 



purpose. 



The experiments recorded in Bulletin 186 were trials of 

 fumigating with hydrocyanic acid gas in a close chamber 

 from which the air had been exhausted. The fnmi 

 chamb i thesei xperiments consisted of an iron tubing, 



36 incl - and 12 inches in diameter. The air was 



exhausted i p driven by a motor. Arrangements 



were made so that after seeds "ere in place and the air suffi- 

 ciently exhausted, tb o amount of dilute acid could 

 be introduced toact on the cyanide which had 'nei n placed in 



position before the chanilier was rinsed. l'.y this contrivance 



the poisonous gas was generated within the tightly closed 

 chamb i ts penetration was much greater than as 



ordinarily 



It ig stated in the summary of these trials that 



the method de cribed in this bulletin was 



found to kill insects without injury to the seed and with 



a considerably shorter exposure than is necessary in the usual 



method of seed fumigation. 



PEA AND BEAN WEEVILS. 



At ' ■ en directed in the West Indies I 



other parts oi the British Empire to the necessity for 



the cultivation of minor f 1 crops, among which are peas 



. as one of the coi equences of the upset in 



iltural conditions resulting from the great I 

 war. 



I ise in the areas devoted to the 'cultivation of 



crops will naturally result in an increase oi the pests 



Which "I. and ill!- latter limy lie for the lir-t 



( ,r twi iropoi t ion to the former. 



p i tnd beans are attacked by leaf-eating caterpillars, 

 ips of the shoots, and by the group of 



picuous as a result of the injury 



they d I Specimens recentlj received from 



>r of the Botanic Gardens, Montserrat, with the 



rioll injury to the 3< I ds 



of pigeon | erve to call attention to these insects in 



sion with the development of the pea and bean crops. 



larged. {From 

 U. S. Dept. 

 AgriculU 



The ed as thi 



This is distinguished from 

 .iily relati bright, ivory- 



whiti iots at thejbi ia\. and bj the deeply 



antennae of the .scale. These characters are shown 

 in th There are several species of 

 Bruchus which attack peas and Weans, 

 and although thej maj have preferences 

 as to i be bi an or p> i .■. hich 



liny infest, tiny probably all attack the 

 differ . and they 



have 'ii reporte i as itt ick 

 seeds of other kinds. 

 The insect-, of the genus Bruchus, 

 the pea and bean weevils, are not 

 weevils in the sense oi being members 

 l'i>. 6. The Cow of the Rhynchophora, the si ties, 



in \ Weevil. En in which the front of the head is pro- 

 ved definite beak, as for 

 nee the sweet potato weevil and 

 the cassava stem borer. They probably 

 got their name because of the weevily 

 they produce in the sti red s I. 



The usual manner of attack oi tl ects is this. The 



are laid in the flower or on the very young pod on the 



plant. The grub on hatching bores into the young seed, 



where it develops and changes to pupa and adult. The 

 i.cks nl these insect, render the seeds unfit for t 1 or for 



planting. 



The remedy to be adopted against me pea and bean 



weevils consists of planting onlj seed which is free from 



weevils, and in destroying the insects in the stored seed and 



keeping it free f i them. 



When peas or beans are harvested they should !„• 

 fumigated with carbon bisulphide and stored with naphtha- 

 lene. Fumigation with carbon bisulphide i- accomplished 

 by placing the seed in a tight red i box, barrel 



or tin, and placing a small quantity of carbon bisulphide in 

 a shallow dish. After several hours, the • may be 



id and tile seed aired and further dried if uece--ary. 



In storing, naphthalem I in small muslin 



should be placed among the seed. One pound of naphtha- 

 lene in .[ -Hi. lots should be sufficient to give protection tn 

 abo 1 1 liels of grain. 



1 lirections for the use of carbon bisulphide will be found 



in Pamphlet No. 71, Insect Pests of the Lesser Antilles, 



p. L58, and on reference to the Agricultural A i ws, Vol. XIII, 



p. 360 (November 7, 1914), an account of the use of 



ior the protection of stored grain will he found. 



The leal ■ ' ei pillar-, of which the Lean leaf-roller 



(Eudamus proteus) and the Woolbj pyrol moth (Therm, 



.\ill probably prove the most abundant, are 

 likely to become troublesome. In tin- past thej have gener- 

 ally been controlled by their natural enemies except for local 



outbreaks d this condition maj he expected to prevail 



U one or two seasons in which a fairly 

 uiui - i niiimus crops is cultivated in 



locality. Trials have been made recently with Paris green 

 mo of lead in order to observe the efiect of these 



ecticides on the foliage oi bean plants of several kinds. 

 It was fanal that Paris green, in mixture with lime or flour 

 always seriously injured ih whilst dry arsenate of 



lead applied as ;, dust, either by it-elf or mixed in various 

 ons with (lour or lime, ca little injury to the 



leave-, and, SO far as trial- hue been made, tin- appears to 



he tl orreel insecticide t" use against these insects. 



