186 



THE AGRICULTURAL NEWS. 



.Iim 5, 1915. 



INSECT NOTES. 



CORN EAR WORMS. 



In the West [ndies there are two insects which attack 

 I > < < i i.i ii corn, injuring the leaves and eating into the ears. 

 These insects cause a large amount of injury, and sometimes 

 seriouslj affect the value oi the crop. 



The more i mon, and consequently the more injurious, 



of these is the corn ear worm (Laphygma frugiperda), and 

 ih' other is the cotton boll wonn {Hehothit obsoleta) 



In the United States both these insects occur, but they 

 are kii"\vn by other common names. The former, Laphyyma 

 frugiperda, is called the fall army worm, and the latter, 

 Heliothii obsoleta, is called the corn ear worm: this is because 

 the latter is the timst serious of the caterpillars attacking 

 con ' 



These two caterpillars are alike in their habit of eating 

 leaves and ears of com. The moths differ in the habit of 

 egg laying. The Heliothis female distributes the eggs, 

 depositing them singly "n the food plant, while the Laphygma 

 fei deposits eggs in clusters which are covered with 



down from the body. 



On Indian e.'i ii, Heliothis deposits eggs on the silks of 

 the ear, and the newly hatched caterpillar eats it- way at 

 once into the tip "I the ear. This of course can happen only 

 if the ("in is in the right condition at the time when the 

 eggs are being laid. At other times, the eggs are laid in 

 other places and on many different plants, and the young 

 larvae feed on foliage, or fruits other than corn. 



In consequence of the habit of the moth of laying eggs 

 in the corn silk, experiments in the control of this insect 

 by means of poison carried out at the Kansas Agricultural 

 Experiment Station were confined to the application of 

 insecticides to the silks. 



These experiments were made the subject of a paper 

 ' the meeting of the American Association of Economic 



Entomologists at Philadelphia, in December last, entitled 



I . Results iii tic I'.,- of Dust Sprays for Controlling the 

 Con Ear Worm, by James W. McColloch.* The results 

 obtained indicate that powdered arsenate of lead was the 

 most suitable poison for this purpose, and in this case 

 a mixture of (!.", parts by weight of arsenate of lead and 

 •"'.7 parts of sulphur was used. The sulphur was used to 

 prevent the development of those fungi which follow the 

 injuries caused by the worms. 



Powdered arsenate of lead was dusted on the com silks 

 at intervals of three days during the time the silks 

 remained fresh. Tic poison was applied by means of 

 ;i bag '■! cheese cloth. This treatment resulted in a very 

 considerable reduction of the injury, but it was found 

 i jive. The use of unslaked lime instead of sulphur 



would probablj cheapen the cost, and less frequent appli 



cations would be likely to give nearly as g I results in 



the control of the Worm, and this also would help to keep 

 I In- cost 

 It is likely that with a considerable extension ol coin 

 cultivation in the West Indies, the pests of this crop, 



especially the corn ear worm and the cotton boll worm, will 

 inci •' in abundance. If powdered arsenate of lead is 

 , £fii .it in killing these insects, and if it can be used in 



mi ire with Iim ' sulphur, without injury to the corn 



plant, planters may be ready with a weapon in hand to meet 



iIh attack. In dealing with these insects under local 

 conditions the whole plant, especially while it is young, 



*SeeJourn. Ecou /■;„/,„„., Vol. V1H, p. 211, April 1915. 



will have to I.,- dusted, iii order to destroy those caterpillars 



which feed on the leaves, and special effort will need to be 

 made to destroj tin/ larvae in the centre, the throat or curl 

 of the plant. 



The use of a mixture of Paris green ami corn meal has 

 1 "'•■!! suggested in Departmental publications, as affording 

 a remedy against caterpillars in the throat of the plant. 

 Arsenate of lead x- ill probably entirely replace Paris j 

 for Use on corn, sh ce the latter is liable to injure the plant, 

 while the arsenate of lead doe- not appear to do so. 



THE PINK BOLL WORM OF COTTON. 



The pink boll worm {Gelechia gossypiella, Saunders) is 



a very serious pest of cotton in practically all the cotton- 

 growing districts of. the old world, and it is also established 

 in the Hawaiian Islands. The following quotation from the 

 Annual Report of the Hawaii Agricultural Experiment Station 

 l"i 1913, indicate- how serious a pest this insect is in those 

 islands: 'The pink boll worm still continues its ravages and 

 there is little hope of a cotton industry in Hawaii until some 

 remedy has been found for this pest. The cotton area in the 

 Islands are growing less instead of greater.' 



In the West Indies, every effort should be made to pre- 

 vent the introduction of the pink boll worm, which should be 

 regarded as being almost, if not quite, as serious a pest as the 

 boll weevil. 



How easily this pest may be introduced is shown by the 

 following sentence quoted from a paper entitled. Important 

 Insect Pests Collected on Imported Nursery Stock in 1914, 

 read before the American Association of Economic Entomolo- 

 gists, by Mr. E. 1!. Sasscer, and published in the ■tournal of 

 Economic Entomology for April 1915: 'Larvae of the [link 

 boll worm {Gelechia gossypiella, Saunders) were found in three 

 shipments of Egyptian cotton seed, one of which exhibited 

 a 20-per cent, infestation, and was to be for warded to Arizona'! 



Such a shipment of infested cotton seed, if admitted into 

 any cotton-growing region, would almost certainly result in 

 the introduction of a most serious pest. 



THE GUINEA GRASS MOTH. 



MOCIS [kBMIGIa] RAPANDA, FA BE, 



An account "I this insect was given in the West Indian 

 Bulletin, Vol. 3 . p. 238 (1902), In an article which recorded 

 the occurrence in Barbados of the Guinea grass moth in 

 in 1901 and 1902 when both Guinea grass (Panicum 

 maximum) and Para grass (Panicum muticum) were rather 

 seriouslj attacked by caterpillars. During 1901, grasses at 

 San Fernando, Trinidad, were injured to an estimated extent 

 of Tii per cent., ,md at Government Eouse, Grenada, grassed 

 were also attacked bj caterpillars. 



The caterpillars concerned in those attacks were the 



larvae of the moth {Moris [Remigia] repanda. Fabr.). 



During May, June and. Inly 1902, the Guinea grass 

 caterpillar was abundant in Barbados and caused a consider- 

 able amount "i injurj to grasses grown for stock food. The 



article in the West Indian Bulletin referred to above 



tained a complete record of the life cycle of this insect, by 



the I lev. X I'.. Watson, B.A., F.E.S. 



The Guinea grass moth Ins been scarce in Barbados 

 since 1902 until the present season, when il has appeared in 

 large numbers in certain localities. It is noticeable that 

 while this insect is called the Guinea grass moth or (iuinea 

 grass worm, lie j caterpillar appears to have a strong 



