278 COCOA 



fields was not large enough, or the nests had not been 

 made carefully enough so as to make the ants feel at 

 home and increase quickly in number. But in spite 

 of these failures the method of introducing the black ant 

 into the cocoa fields may be regarded as being very 

 promising, and it will probably become still more 

 popular. 



(2) The Rind bug (Sahlbergella singularis) l is the 

 worst insect pest in Kamerun. It was first noticed in 

 1902 as a dangerous enemy of the cocoa, and since 

 that time has inflicted serious damage every year. It 

 attacks the young juicy twigs, and penetrates into the 

 rind with its sucker. As with the Hdopeltis, dark spots 

 appear on the twig, and as the twig grows, the spots 

 become larger and the rind shrivels. The leaf-stalks 

 and the fruits are also damaged. The tree becomes 

 defoliated, and large parts of the branch-system die out. 



The fight against this insect is not so difficult as in 

 the case of Helopeltis, because it does not move or fly 

 so quickly. In this case, therefore, spraying meets 

 with more success. Good results have been obtained 

 by spraying with a mixture consisting of Paris green 

 (40 grams), kerosene (3 litres), soap (1 kilogram), lime 

 (1 or 2 kilograms), and water (100 litres). A 1 per 

 cent decoction of tobacco has also been used with 

 success. It is further advisable to use torches in the 

 same way as in the case of the Helopeltis, as the rind 

 bug is easily killed by fire. 



(3) The Mosquilla (not yet determined). The 

 worst enemy of the cocoa in Ecuador is a sort of bug, 

 called there " Mosquilla," which seems to belong to the 

 family of Phytocoridae. A short description of this 

 pest has been given by Rimbach. 2 



The male insect is about 7 mm., the female about 

 8 mm. long ; the head and antennae are black, the 

 rest of the body reddish yellow. The adult insect 

 feeds on the fruits of cocoa, and sucks the juice of the 



1 Von Faber, Die Krankheiten und Parasiten, etc., p. 304. 



2 Rimbach, " Durch Wanzen verursachte Schadigung des Cacao im Kusten- 

 lande von Ecuador" (Zeitschrift fiir Pflanzenkrankheiten, v., 1895, p. 321). 



