180 TRINIDAD AND TOBAGO BULLETIN. [NVIIL 3. 



Most of the scale insects and mealy bugs can be controled by 

 natural enemies by keeping away ants from the trees. When numerous 

 they can be sprayed with nicotine sulphate in combination with resin 

 wash or soap, see formulae Nos. 4 and 5. 



WEBBING CATEEPILLAES. 



{Stericia aUnfasciata). 

 Sporadic attacks by these caterpillars take place, and young leaves 

 and flowers of tall trees are destroyed. The caterpillars are gregarious 

 and live in nests made by webbing leaves and branches with a tough 

 silk, see fig. 2 which represents a single net while fig. 1 shows how a 

 tree can be affected. The caterpillars, see fig. 3, are about one inch 

 long when full grown, the general colour is dark brown with longitudinal 

 yellow lines, the head is black and yellow. As a rule the caterpillars 

 are controlled by natural enemies of which a Tacliina fly see fig. 5 is the 

 most important. 



The moth expands about an inch, its fore wings are light brown 

 with dark brown mottlings, the hind wings are white with a slight 

 purplish fringe. The male see fig. 4 has two conspicuous wliite spots 

 on the fore wings which are absent on those of the female. 



The caterpillars can be destroyed by cutting off and burning the 

 nests, but this has to be done with care and despatch as the caterpillars 

 when alarmed let themselves down to the ground by silken threads and 

 <lisappear in the grass. 



MINOR PESTS. 

 Selenothrips riibrocinctus, (the cacao thrips). 

 Heliothrips hcBmorrJwidalis. 

 Aleurodicus neglectus (White flies^. 

 White flies arc only serious when attended by ants, they generally 

 cause black blight under these conditions. For control use formula 4 or 5. 



Formulae. 

 No. 1.— ROSIN CASTOR OIL MIXTURE.* 

 This may be made according to the following formula :— 

 Rosin ... ... ••• pounds 5 



fluid ounces 48 

 Castor oil ... ••. ••• (or any fraction thereof). 



Place the rosin and castor oil in a pot and heat slowly until the 

 rosin is melted. Add more oil if too thick. 



These sticky bands are sometimes injurious to the tree but injury 

 may be avoided by spreading the adhesive on a strip of heavy paper 

 encircling the tree trunk. A form of band that has given satisfactory 

 results is made from cheap cotton batting and single-ply tarred 

 building paper. The cotton should be cut into strips about 2 inches 

 (3 inches would be better for Trinidad) wide and wrapp d around the 

 tree trunk so as to fill all crevices of the bark. Over the cotton is 

 placed a strip of tarred paper about 5 inches wide, drawn tightly and 

 securely tacked where it overlaps. The sticky material is then spread 

 on top of the paper. 



The sticky substance must be renewed from time to time, since 

 when it dries out or becomes covered with dust or insects it fails as a 

 barrier to crawling insects. If a combing instrument is occasionally 



