330 



THE AGRICULTURAL NEWS. 



October 1G, 1909. 



INSECT NOTES. 



COTTON STAINERS. 



Cotton stainers have been discussed at some length in 

 the i)ubUcations of the Imperial Dei>artmeiit of Agriculture 

 during the past few years. In the West Indian Jiidhtui (see 

 Vol. VII, p. 6.5) an article on this subject gives an account 

 of the characters of the genus, the distribution of the 

 American species, and descriptions of three new species. In 

 the ABC of Cotton P/untinif, and in various articles in the 

 Agricultural News, are given the remedies to be emplo3'ed 

 against these insects when they become aliundant. 



It will be remembered by readers of the Agricultural 

 Xeu'S that the cotton stainer of the Northern Islands and 

 that of the Southern Islands are diflerent from one another 

 and from the species which are most abundant in Trinidad 

 and in the South-eastern States of America. 



The accompanying illustrations, which are three times 

 the natural .size of the insects, will serve to give a good idea 

 of the appearance of these three cotton stainers. They have 

 been prepared from drawings made by Mr. .John Belling, 

 B.Sc, late Science Master at, the St. Kitts Grammar School, 

 while he was tem]K)rarily attached to the Staff at the Head 

 Office of this Department. 



It will always Ije well to destroy, as far as possible, the 

 wild or native food-plants of these insects, and their breeding- 

 places. Waste cotton and cotton seed scattered about the 

 ginneries and store-houses are responsible, in many instances, 

 for the carrying over of enormous numbers of this trouble- 

 some pest from one season to another ; thus means for the 

 early infestation of the neighbouriiig cotton fields are provided. 



Fk;. 3.5. Dysdkrcu.s del.vuneyi. 



Fn 



31. DysDKRCU.S ANDRHAE. 



Di/sdercus andreae (Fig. 34) occurs in the Virgin Islands, 

 St. Kitts-Nevis, Antigua, i\Iontserrat, and Guadeloupe. The 

 parts dotted in the figure are bright yellowish-red, the black 

 parts are black and reddish-black, in nature: the St. Andrew's 

 cro.Ss is whitest. Di/sden-Ks ifdauuei/i (Fig. 35) has been 

 recorded from Moutserrat and Guadeloupe, and is the cotton 

 stainer of the islands south as far as Grenada. Jn this 

 island, there also occiu-s 7>. fcrna/di. The parts dotted 

 in the figure are pinkish-red in the natural insect, those 

 in black are black or reddish-blai'lc, and those left white 

 are whitish or while. Bi/xi/Aviis hairardi (Fig. 3G) occurs 

 ill Trinidad and Tobago, together with D. howari/i, var. 

 ■minor, in the former island. ' The parts left black in the 

 figure are black in the insect, those dotted arc piidvishred or 

 ferruginous, and the cross-shaVled parts arc brownish yellow. 



( 'otton stainers will feed on other, closely related plants, 

 in addition to cotton plants. The seed of the silk cotton 

 tree, all parts of the ochro and musk-ochro, and the fruit of 

 the orange arc attacked by these insects, and it is likely that, 

 in places where sucli plants are not abundant, the cotton 

 stainers have other food-plants. 



Many planters in the West Indies do not find the cotton 

 stainers a serious pest, but on the other hand, these insects 

 have been the cause of serious loss in many instances. The 

 following extract from the letter of a correspondent ia 

 Tobago shows what one planter's experience has been : — 



' Cotton stainers in the West Indies, Tobago in particular, 

 do a great deal more harm to the cotton crop than has 

 been assigned to them. They puncture the very young bolls, 

 causing them to drop off. The first-planted cotton does not 

 suffer much, but any later-planted, which is producing 

 flowers and young bolls when the stainers become more 

 numerous, suffers to a great extent. Last year, I lost a lot 

 from this cause. I did not know how much labour I should 

 be able to command for pi('king, so I planted over a very 

 long period, with the result that the last planted cotton gave 

 me very little fibre indeed. This season, I have begun to 

 catch the stainers at' once, and hope to be able tn control 



^S..-^^^''^ 



'-^""•^^k^ 



%y 



Fi<;. 3G. Dy.siiKRcus iiowARni. 



them. When the first crop has been picked, I shall cut 

 down the plants close to the ground, burn the tops, and 

 while the new growth is coming on, trap all the insects I can.' 



