251 



-Eggs are laid in a single row along the twigs of plants and hatch in 

 -about two weeks, the nymphs spending most of their lives on the same 

 spot on their food-plants. Very little injury to cotton has been 

 ■observed from this species, though boll disease has been fomid follow- 

 ing the ]3nnctures of the adults. A related species, L. gonogra. was 

 also found on tomato and bonavist bean, but no injury by it to cotton 

 has been observed. Females of L. balteatus lay small batches of eggs 

 «very few days, with the result that broods of all stages of the bugs 

 are to be seen in the field. It seems probable that Leptoglossus spp. 

 are attacked by egg-parasites ; though none have been foimd, it is 

 reasonable to suppose that they are checked by natural enemies as 

 they would undoubtedly prove injurious to cotton, tomato and legu- 

 minous crops if allowed to increase undisturbed. 



Phtliia picfu (red tomato bug), which greatly resembles species of 

 ■Leptoglossus in appearance, has been found in St. Vincent on tomato, 

 bona\dst bean, and Physalis sp. P. picta is normally not sufficiently 

 ■abmidant to be considered a pest, but breeding experiments indicate 

 that the bugs are capable of puncturing cotton bolls and infecting 

 them A\ith internal boll disease. In the event of a sudden increase 

 in numbers, the young should be collected and destroyed. 



Edessa meditabimda, like Nezara viriduh, is a common bush bug 

 in St. Vincent, the tw^o species being collectively known as pea chinks 

 in Barbados. E. meditahwida has a wide range of food-plants, inclu- 

 •ding nearly all those of N. viriduh. As a pest of cotton it is almost 

 negligible, since the adults hardly pierce the outer covering of the 

 bolls and do not infect them ^\-ith disease. Eggs are laid on the 

 underside of leaves of such plants as Polanisia viscosa, tomato and 

 various legumes, and on the inner side of the bracts of cotton. There 

 are two egg-parasites of this species, one of them being the same or 

 •closely related to that infesting N. viridula. Control measures include 

 the collection of adults, particularly at the time when they may be 

 fomid swarming and mating on certain plants such as pigeon peas, 

 Tephrosia spp., Indigofera spp., etc., and the encouragement and 

 distribution of parasites. 



Other plant bugs observed in St. Vincent, many of which have been 

 fomid attacking cotton in the southern United States and other 

 countries and must therefore be regarded with suspicion by cotton 

 growers, include the Coreid, Acanthocerus lohatus, and an unidentified 

 species ; the orange variety of the Lygaeid, Oncopeltus fasciatus ; 

 the Pentatomids, Thyanta perditor, Arvelius albopunctatus, Piezodorus 

 guildingi, and Euschistus crenator ; and the Scutellerid, Sp)liyrocoris 

 obJiquus. 



KowELL (W.)s Mycologist's Report on a Visit to St. Vincent, October 

 17— December 9, 1917.— Colonial Office MS. [Received 2nd May 



1918.] 



In this report the diseases of cotton are dealt with, and in particular 

 the action of insects in encouraging the dissemination of infection. 

 The damage done to cotton by the insects known as bush bugs, of 

 which Edessa meditabimda (jjea chink) and Nezara viridula (green 

 bug) are the commonest, are described in detail. It is probable that 

 N. viridida, the favourite food-plants of which are Leguminosae, is 



