288 



[September, 1909. 



PLANT SANITATION, 



ENTOMOLOGICAL NOTES. 



By E. Ernest Green, 

 Government Entomologist. 



It has sometimes been stated by- 

 opponents of the burning or burying of 

 tea primings as a check upon the spread 

 of ' shot-hole borer,' that the mere 

 drying up of the primings on the surface 

 of the ground is equally efficacious. To 

 settle this question, I obtained a large 

 bundle of freshly pruned tea branches, 

 badly infested by the borer, and spread 

 them on the floor of an open verandah. 

 A few of the branches were examined 

 day by day. The living beetles, in gra- 

 dually decreasing numbers, were found 

 within their galleries, until the tenth 

 day, when no further insects could be 

 seen in the branches. During the whole 

 of this period I did not find a single 

 dead beetle inside the branches. They 

 simply disappeared, one by one, as the 

 branches became desiccated. It can 

 only be presumed from this that the 

 insects emerged from their retreat, 

 when they found their surrondings un- 

 suitable, and made their escape in search 

 of more congenial quarters. These 

 would be found, in the field, in the 

 nearest living tea bush. It was notice- 

 able that the larvse also disappeared ; 

 but I was unable to trace their migra- 

 tions. They probably crawled away 

 and died. 



Seeds of Manihot piauhyensis have 

 been received, with the report that they 

 were being attacked in the nursery, 

 by a species of ant. Specimens of the 

 ants were subsequently submitted and 

 proved to be the common species (Myrmi- 

 caria brunnea) that throws up circular 

 funnel-shaped embankments around the 

 entrance to its nests. The superinten- 

 dent writes that he has seen the ants 

 attack the seed and has watched them 

 clean out the shell as soon as it splits. 

 In one instance they bit up and carried 

 off the young germinating shoot. In 

 other instances they devoured, all the 

 supporting parts until the shoot fell 

 over. The addition of ' Vaporite ' (in 

 the proportion of 2 ounces to the square 

 yard) to the soil, when making up the 

 seed beds, should prevent any trouble 

 of this nature. The nests of this" ant, 

 being conspicuous objects, can be easily 

 destroyed in the neighbourhood of the 

 nurseries, either by means of the patent 



•Ant Exterminator,' or by pouring 

 dilute Phenol into the nests. * 



A bad attack of Helopeltis on tea has 

 been reported from the Nawalapitiya 

 district. 



I am constantly receiving sections of 

 Hevea rubber stems said to have been 

 killed by Scolytid beetles allied to the 

 ' shot-hole borer.' Sure enough, the bark 

 is liddled by the small beetles and, in 

 some instances, latex has oozed from the 

 perforations. But I have always been 

 sceptical of the ability of any boring 

 insect to penetrate the latex-bearing 

 tissues of a healthy tree. I have recently 

 had the opportunity of examining one 

 such tree in situ, I was accompanied by 

 the Government Mycologist who was 

 prepared to detect any signs of the 

 presence of a fungus disease which 

 would account for the original injury. 

 In this case the fungus was apparent 

 even on the surface. A large area of 

 the bark was killed outright and a 

 conspicuous network of mycelium was 

 spreading over the surrounding parts. 

 The presence of latex, oozing from the 

 holes of the borers, can be accounted 

 for by the supposition that the insects 

 have made their entry during a dry 

 spell when the already diseased bark 

 had been deficient in latex. Subsequent 

 wet weather has induced partial revival 

 of the tissues, with a consequent flow 

 of latex from the perforations. 



The common cotton-boll worm of Cey- 

 lon is the small pink maggot-like cater- 

 pillar of Gelechia gossypiella. I nave 

 recently bred out another moth (Earias 

 fabia, Stol.) f rom diseased bolls grown 

 both at Peradeniya and Maha Illu- 

 pallama. Both of these moths are well- 

 known cotton pests in India, where yet 

 a third species {Earias insulana) also 

 occurs. The Plant Quarantine Ordi- 

 nance has now been amended to permit 

 of the compulsory fumigation of cotton 

 seed imported for purposes of cultivation. 



Specimens of the caterpillar of a 

 Noctuid moth (C adrina reclusa) have 

 been received from the Ra&wana district 

 where this insect is reported to be 

 defoliating tea plants. This is not one 

 of our common tea pests. I have re- 

 ceived it only once previously, from the 

 Talawakelle district, in July, 1903. It is 

 unlikely to prove a serious pest. 



Cacao trees of the Nicaragua variety, 

 on the Peradeniya Experiment Station, 

 are being seriously damaged by Helo- 

 peltis. This variety appears to be 



