34 



[July, 1909. 



HORTICULTURE. 



PETRiEA VOLUBILIS. 



No member of the vegetable kingdom 

 can surpass, and few can equal, the ex- 



auisite beauty of this plant when in full 

 ower. The blossoms which are helio- 

 trope with a violet centre, are borne in 

 loose pendant sprays (racemes), which 

 are hung gracefully from the slender 

 arching branches. These combined with 

 the rigid green leaves suggest almost a 

 perfect artificial blossom, and the beau 

 ideal of the milliner's art. The plant is 

 a woody climber, native of Tropical 

 South America and some of the West 

 Indian Islands. There is no record of its 

 date of introduction at Peiadeniya, 

 though this cannot obviously be far back. 

 It bears a few seeds occasionally at 



Peradeniya, but these need not be depend- 

 ed upon for propagation, as cuttings ; 

 if inserted iu the rainy weather, will grow 

 readily. The plant is seen to best ad- 

 vantage when allowed to ramble of its 

 free will amongst the branches of a low 

 spreading tree. But it may also be 

 grown, with much effect, by itself as a 

 bush, or over an old tree stump. A 

 white-flowered variety of Petrcea is 

 found in British Guiana, Trinidad, etc. 

 There is also a tree-form {Petrcea erecta) 

 indigenous to the same habitat. This 

 has been introduced and established at 

 Peradeniya, and promises to become an 

 acquisition to the Island's most beauti- 

 ful flowering trees. 



H. F. MACMILLAN. 



PLANT SANITATION 



ENTOMOLOGICAL NOTES. 



By E. Ernest Green, 

 Government Entomologist. 



Branches of Camphor, injured by a 

 small Seolytid beetle (allied to the ' shot- 

 hole borer ' of tea) have been received 

 from the Ambawella district. The same 

 pest was reported from Hewaheta in 

 November, 1906 (See T.A., December, 

 1906, p. 42). In the present ease the 

 trees had been killed by root fungus 

 (Rosalinia) ; but this little borer un- 

 doubtedly attacks healthy trees also. 

 The mycelium of a fungus subsequently 

 develops in the galleries of the insect, 

 penetrating the woody tissues for a con- 

 siderable distance and often killing the 

 bark round the entrance to the tunnels. 

 The branch may be completely ringed by 

 these diseased areas. The presence of the 

 pest is marked by dark brown patches 

 on the bark. The pest should be kept in 

 check by cutting out and destroying the 

 affected branches. If a still is in oper- 

 ation, there is nothing to prevent the 

 diseased branches (which still contain 

 camphor) from being utilized for distil- 

 lation. 



The cotton (Gossypium) plots, on the 

 Experiment Station, are badly infested 

 by the ' Pink Boll-worm ' (Gelechia gossy- 

 piella, Saund). Nearly every pod ap- 

 pears to be infected. This is the first 

 crop and the first occasion upon which 

 cotton has been grown here. Nor is there 



any wild — or half wild— cotton on the 

 place. This insect is— to the best of my 

 belief -confined to the cotton plant. Un- 

 der these circumstances, it is difficult to 

 understand how the pest has appeared in 

 such enormous numbers. It can scarcely 

 have been introduced with the seed,* as 

 the eggs are laid on the immature seed 

 pods. It is possible that the insect 

 breeds also in the fruit of some allied 

 malvaceous plant; but I have been un- 

 able to find any evidence of this. A 

 species of Abelmoschus, with a blossom 

 and fruit somewhat similar to that of 

 the Gossypium, is common in the jungles ; 

 but an examination of the locality shows 

 that these plants are not in either blos- 

 som or fruit at the present time. The 

 dried seed pods, of which a few were still 

 remaining on the plants, showed no siyjns 

 of having been tenanted by any borer. 



The bolls are also infested by myriads 

 of the small Lygaeid bug— Oxycarenus 

 Icetus, Kir by. The irritation of the 

 numerous punctures apparently causes 

 the pods to open prematurely, when 

 the insects swarm into the lint, fouling 

 it with theii excreta. After gathering 

 the crop, the insects may be driven out 

 of the lint by spreading it in the sun. 



A few examples of Helopeltis (antonii) 

 were captured on the foliage of the 

 cotton plants. No damage from this 

 cause was noticeable, and it is possible 

 that the insects were merely resting, 

 having wandered from the neighbouring 

 cacao. But, when confined with some 



* Mr. Maxwell Lefroy informs me that, in India, the borer winters in the seed, so it is possible that 

 the pest may have been introduced in this way. But, in that case, the larva must remain quiescent un- 

 derground, for several months, until the plants have grown up and commenced to fruit. The remedy 

 wlU be to fumigate the seed before planting.— E. E, U. 



