Jan. 1907-3 



PLANT SANITATION. 



Entomological Notes. 



By E. Ernest Green. 



The ' Tea Tortrix ' {Capua coffearid), which has been a serious pest in Mas- 

 keliya for several years, is reported to have almost disappeared from that district. 

 An occasional caterpillar can be found, but the extensive fields of blighted bushes 

 are no longer apparent. This relief is to be accounted for partly by recent inclement 

 weather, but more particularly to the increase of the natural enemies of the insect. 

 The small Ichneumonid fly, described on p. 194 of the Tropical Agriculturist 

 Vol. XXV, No. 1, (July, 1905) is said to have been very busy in the infested fields. 



The Tortrix pest seems to have moved on to other localities. I have received 

 reports of damage from the Hatton and Nawalapitiya districts. Living specimens 

 of the parasite should be imported to these districts from Maskeliya, where it 

 has apparently gained the mastery and will be in danger of dying out for want 

 of food. 



An outbreak of the ' Morowak-korale Nettle-grub' (Thosea recta) has occurred 

 on an estate near Randy* The caterpillars had completely defoliated the bushes 

 over the infected area. As this pest has, on several occasions, proved a very 

 troublesome one to check, strong measures were recommended, namely, the imme- 

 diate pruning of the infested bushes and the destruction of the prunings by fire 

 A belt of quicklime round the pruned area will help to keep the caterpillars from 

 straying to the surrounding fields. 



A correspondent has sent me some young tea shoots thickly infested by the 

 common tea aphis (Ceylonia theaecola, Buckton) and expresses some alarm at the 

 prevalence of this insect on his tea. This is a pest of really little importance and 

 requires no special treatment. It has so many natural enemies that it is always 

 very rapidly checked. The specimens submitted were already badly parasitized, and 

 1 felt confident in predicting that within a week or ten days' time there would be 

 some difficulty in finding a single living insect in the fields now so strongly infested. 



The following letter, referring to the failure of Ceara seeds after planting, 

 has been received from an Indian correspondent: — " I have to report that some 

 Ceara rubber seed treated in the usual manner —namely, that of filing— was sown 

 in boxes raised from the ground to prevent the incursion of insect pests. A very, 

 small proportion has sprouted and the remainder are, I find, being eaten by hundreds 

 of small white hair-like ' hoolas ' (? worms) which seem to have bred in the seed. 

 These ' hoolas ' have got dark heads. The seed, on being opened, is alive with theml 

 The soil has been treated repeatedly with strong kerosene emulsion and, while all 

 other insects have been killed thereby, the treatment has had no effect on these pests. 

 I shall be glad to hear from you as to what I should do, and at the same time you 

 might inform me if this a known rubber pest." 



I replied that " This is not a recognised rubber pest and is probably not 

 confined to Ceara seeds. The worms must have entered the seed from the soil after 

 they had been filed. Possibly the filing was too deep and had injured the kernel of 

 the seed. I would suggest baking the soil before planting the seeds. But as this 

 treatment will more or less sterilize the soil, the addition of some suitable manure 

 will be necessary after the germination of the seeds. Well rotted leaf mould and 

 old cattle or stable manure (reduced to an earthy consistency) might then be spread 

 Upon the soil or dibbled into it. This will bring back a supply of the necessary 

 nitrifying bacteria which might not be introduced by purely artificial manures." 



