662 



is still unsettled [see this Review, Ser. A, i, p. 370]. Green assumed 

 the existence of "winter eggs" which only hatched with the first 

 rains ; according to Zehntner, on the approach of the dry season the 

 females retire to low, damp spots, often near streams running through 

 the plantations, and this agrees with the observed fact that this pest 

 generally first reappears in the neighbourhood of such places. Control 

 is difficult because the insect infests many other trees, including tea, 

 cinchona, kapok, pepper, Bixa orellana (often used as a hedge plant 

 in Java), tamarind, cinnamon and camphor. Catching the insects 

 regularly by a special gang of women and children is practised in 

 Java. A light bamboo 8 to 16 inches long, mth a ring of bamboo at 

 the end 3 or 4 inches in diameter, is used and this ring is covered with, 

 cobwebs or smeared with the adhesive sap of the jak tree ; another 

 method is to burn the insects with kerosene torches made from bamboo ; 

 many insects are thus destroyed, but neither method is really satis- 

 factory. Spraying has not been very extensively tried, but the results 

 so far are not encouraging. Insect enemies are few, but an ant, 

 Dolichoderus bituberculatus, Mayr, has proved very useful in driving 

 away this pest. The rind bug or cacao bark-sapper, Sahlbergella 

 singularis, is the worst insect pest of cacao in the Cameroons, Gold 

 Coast and Congo [see this Review, Ser. A, ii, pp. 141, 634, 670]. In 

 Ecuador, the " mosquilla," probably a Phytocorid bug, causes very 

 serious damage. Pods of all ages are attacked and the insect lives on 

 them throughout its whole life. Few Lejjidopterous caterpillars eat 

 the leaves of cacao ; in Surinam, the very yovmg foliage is attacked 

 by an unknown Geometrid and in Java the larvae of the Limacodids, 

 Orthocras'peda trima, Belvppa lohor and Parasa lepida feed on the leaves. 



The cacao thrips (Heliothrips rubrocinchis) does great damage in 

 Surinam and the West Indies by attacking the leaves and causing 

 defoliation. In Surinam spraying with kerosene emulsion, tobacco 

 decoction or Paris green was unsuccessful, but in Grenada kerosene 

 emulsion is reported to have given good results. This thrips damages 

 mangos {Mangifera indica), canary trees {Canarium commune), cashews 

 {Anacardium occidentale), guavas {Psidium gnayava) and will also live 

 on Liberian coffee, apparently without doing much harm. The cacao 

 moth, Acrocercojjs (Zaratha) cramerella, is perhaps the worst enemy 

 of cacap ; its life-history has been partially worked out by Zehntner ; 

 the eggs are laid in the furrows on the fruit and hatch in 6 or 7 days. 

 The larvae begin to bore at once and, for from 15 to 18 days, live in 

 the fruit and tunnel in the pulp ; they then bore their way out and 

 pupate, generally on the leaves, but sometimes on the fruits under a 

 slight cocoon ; the adult emerges in from 5 to 8 days. The method 

 of control by " rampassing " is the only one which has been found of 

 practical \aiue [see this Review, Ser. A, i, pp. 57-62]. The reduction 

 in the market value of cacao due to this pest is very serious ; in one 

 case 45 healthy fruits yielded 36 oz. of cacao of first quality, while 

 the same number of attacked fruits only produced 12 oz. of second 

 quality. Ephestia elutella (the chocolate moth) attacks the skin of 

 the cacao bean in the West Indies, Ceylon and Java. 



There is an excellent index to this book and the illustrations are 

 well chosen. 



[Other insect pests of cacao which are not mentioned by the 

 author, include : —Sahlbergella theobroma and the grey moth borer, 



