ON METHODS OF PREVENTING INSECT ATTACK 55 



Finally, to prevent pests such as caterpillars moving from tree to tree 

 up or down the trunk, bands composed of a thick greasy material or of a 

 sticky material such as molasses should be painted on the tree, the band 

 being at least eight to twelve inches deep. These bands can be utilized 

 efficiently against another pest in the case of mango-trees. The Mono- 

 phlcbus scale insect which sucks the sap from the leaves and later from the 

 twigs of the tree, often thereby spoiling the fruit crop, when intent on egg- 

 laying crawls down the tree-trunk to oviposit in the soil below. It does not 

 appear to oviposit on the trees. Therefore, if in a severe attack broad 

 sticky bands are painted on the trunks about four to five feet above the 

 ground, the insects will be caught on these as they crawl down the tree, and 

 another bad infestation of the pest may be prevented the following year. 

 Care must be taken to scrape down inequalities of the bark at the point 

 where the bands are put on, otherwise deep crevices may not be properly 

 coated with the stuff, and insects finding them will escape through the band 

 to oviposit below. 



Aphidae and Coccidae such as Chermes, Lachinis, Coccus, etc., occasionally 

 prove serious pests to trees. In the case of valuable avenue, garden or park, 

 and orchard trees, methods of treatment inapplicable in the forest are possible. 

 For instance, in cases where the eggs are deposited in crevices on the bark 

 of the main stem and large branches, it is often effective to brush them down 

 with hard bristle brushes dipped into a paraffin emulsion, or to spray these 

 parts with the mixture. A good emulsion consists of paraffin, 2 gallons; 

 soft soap, lilb. ; caustic soda (98 per cent.), 6 Ib. ; water, 28 gallons. 

 Dissolve the soap in a gallon of boiling water, add the paraffin, and churn 

 thoroughly till a cream-like mass is obtained. This thorough mixing is 

 essential. Dissolve the caustic soda in 27 gallons of water and pour into 

 the paraffin emulsion, and mix the whole intimately. The mixture should 

 be used as soon as made. The emulsion should not be applied to the green 

 parts of trees or to unripe wood, nor should it be allowed to get on to the 

 skin of the operator. 



. XZ X2 



Cryptorhynchns bramtisi, Steb. a, larva ; /', pupa : . , weevil from i 



, Maymyo, Upper Burma. 



