429 



Wilson (C. E.). Report oJ the Entomologist. — Rept. Virgin 

 Islands Agric. Expt. Sta. 1920, Washington, D.C., 18th April 

 1921, pp. 20-35, 2 tables. 



The names and food-plants of scale-insects collected in the American 

 Virgin Islands are given in a table. 



Kerosene-fusel oil emulsion [R.A.E., A, v, 397], unhke other 

 contact insecticides, requires no heat when mixing, and in the W est 

 Indies fusel oil is cheap. Scales of the subfamilies Dactyloptinae 

 and CocciNAE were killed with one part diluted with 15-20 parts water. 

 One part with 10 parts water was successful in killing scales of the 

 subfamily Diaspinae ; Euscepes hafafae (West Indian sweet-potato 

 weevil) ; Heliothrips rubrocinctiis (red-banded thrips), attacking 

 Mangifera indica (mango tree) ; and Targionia hartii (yam scale) 

 infesting yam tubers, which were immersed in the solution before 

 planting. 



Owing to the increasing numbers of Aleurodicus cocois and Aleiiro- 

 thrixus floccosus (whiteflies), the red fungus, Aschersonia aleurodis, 

 was introduced as a control measure. The introduction was un- 

 successful, owing to high winds and drought, but it will be resumed 

 with the establishment of windbreaks. In the larval stage a small 

 Coccinellid beetle {Exoplectra sp.) attacked A. cocois. 



Sugar-cane was infested with Diatraea saccJiaralis (sugar-cane moth 

 borer). The tunnels of larvae in the stalk permit the entrance of 

 fungi, and cause direct loss in sugar and reduction in puritv of juice. 

 Parasitic and predaceous insects and the fungus Cordyceps harberi 

 partly control the larvae. Other measures recommended are : planting 

 non-infested cuttings, clean cultivation, collection of e^^ clusters, 

 cutting out dead hearts, and burning all infested canes. 



The most injurious sugar-cane pests in 1920 were Metamasius 

 sericeus and Lagochir us araneiformis. All dead canes should be burnt. 

 A table is given of the damage caused by each of these pests. 



Pseudococcus calceolariae and P. sacchari are controlled by natural 

 enemies and a parasitic fungus, probably Aspergillus flavus. Young 

 canes are seriously damaged by the root grubs, Ligyrus sp. and 

 Strategus titanus, probably introduced in bagasse and pen manure. 

 Targionia sacchari caused only slight damage. Xyleborus sp. (shot- 

 hole borer) attacked diseased canes, which should be collected and 

 burned. 



Cotton pests include Nezara viridula (green stink bug) and Dysdercus 

 andreae (cotton stainer). Hand-picking, or knocking them into 

 water containing a film of kerosene, is recommended, and D. andreae 

 may also be trapped by placing handfuls of cotton seed every 15 or 

 20 ft. between the rows. Against Eriophyes gossypii (blister mite) 

 the control method is a close season, regulated by the Cotton Pest 

 Commission, when no planting is done or old plantsallowed to remain. 

 Aphids attacking cotton are controlled by parasitic and predaceous 

 insects and a fungus, probably Acrostalagmus albus. Kerosene 

 emulsion will control scale-insects if necessary. The larvae of 

 Alabama argillacea (cotton worm) are the most serious cotton pest, 

 as they defohate the plants. Their presence can be detected by the 

 odour produced when feeding. The plants should be dusted with one 

 part Paris green and eight parts air-slaked lime. This mixture 

 also controls Heliothis {Chloridea) obsoleta (cotton bollworm). Other 

 cotton pests are Diaspis [Aulacaspis] pentagona (West Indian peach 

 scale), Saissetia hemisphaerica and S. oleae (black scale). 



