Vol. XIV. No. 3»l>. 



THE AGRICULTURAL NEWS. 



187 



rence for the leaves oi the Para grass, and to be ready 

 also to eat other grasses after the I'ai i grass are 



eaten down. 



In one infested grass field whii it examined 



patches of Para grass were growing amongst Guinea 



. which in turn was bordered by sour grass {Paspalum 



conjugatum). When first examined rhe Para grass was 



ly without leaves, the Guii i . was somewhat eaten, 



while the sour grass merely showed small bits eaten oul of 



i leaves. 



Mr. Watson summarized the life-history of this insect 

 tie following tabular form, showing the length of time 

 occupied in each stage of development, and how and where 

 this lime is spent: — 



Egg 5 days Attached founder side of leaf near mid-rib 



Larva 20 ,, Feeding on leaf. 



„ 2 „ Building cocoon and pupating. 



Pupa 6 ., In cocoon which is partly enclosed by leaf. 



2 i o ., Pairing and flying abbul to deposit eggs 



19 days 



The eggs are deposited in masses of forty to sixty close 

 to the mid-rib: these masses are easily to be seen. 



The larva is a slender caterpillar about 1J inches in 

 length when full-grown. It is one of theloopers or measur- 

 ing worms. 



There are three pairs of thoracic legs, and only three 

 pair- of prolegs. The larva walks by taking a grip with it.s 

 thoracic legs, bringing its abdominal or prolegs up, by 

 arching its body, taking a grip with them and straightening 

 it- I" dy out, 51 tting a new hold with the thoracic feet. 



The head is rather large in proportion to the body. The 

 colour of the larva is gray and brown in longitudinal bands; 

 there is 1 broad dark dorsal stripe which is nearly black for 

 part of its length, broken only by very fine, delicate, light 



The lighter, broad, lateral I inds are -ecu to be 

 made up of very fine -tripe-: the head markings are very- 

 fine, wavy -tripe-. 



The pupa is about | inch in length, of a light amber colour 

 at first, growing darker as it gets more mature. Many of the 

 pupae are covered with a delicate bloom such as is seen on 

 certain fruits. This is easily noticeable when, on account of 

 lack of suitable leaf material for the purpose, no cocoon is 

 made. The moth is a delicately marked brown insect with 

 a spread of wings of about I J inches. In this species there 

 ■ . great range of varieties even in the same batch i 



fr larvae which appear to be all alike. 



This insect (Mori* repanda) is widely distributed, rang- 



iroughout the American hemisphere and being found in 



other part- of the world. In the West Indies it appears to be 



m I controlled by natural enemies, which keep it in check for 



long period- at a I ime. 



The remedy which suggest- itself is that of cutting the 



grass as soon as the attack is seen t 1 be >ugh to 



sitate action being taken. If the grass en be cut as the 



first brood of caterpillars is nearly mature, that is, when 



ii the cocoons are being formed and 1 1 ■ > ■ being 



laid, the attack would lie completely checked; if, however, 



a few moths escape, and caterpillars are seen on the young 



as they spring after the cutting, an application of 



Paris green might be made. The leaves which r< :eive the 



poison would not persist and be harvested with the main 



crop- oi grass, and consequently there would be 00 I mger ol 



poisoning the stock to which the grass was fed. 



Black bird-, turkeys, Guinea ad the comm n Fowl 



are all very useful enemies of such insects as this. 



SOIL LOSSES BY LEACHING. 

 The following conclusions are drawn 1>\ Messrs. 

 Crawley and Cad} in regard to fertilizer losses in 



Porto Etican soils. Tl unplete paper will be found 



in Bulletin No. 8, oi th< Board oi • !ommissi - t 

 Lgriculi ure, Porto Rico: 



From a consideration • 1 the data as a whole, it is indi 

 cated that phosphoric acid is very quicklj and very firmly 

 fixed by all classes of soils, but that there is an ible 



loss from the light sand} soils, when the application is 



followed by repeated applications of wati i 



There is the greatest ess of nitrogen, but this is not 

 of material consequence, except in the sandy soils. The 



• day soils fix the nitrogen quickly and hold it firmly 



Potash is lost from a ll soil,-, but in small quantities, 

 except in the case of the sandy soils. Heavy rainfall- or 

 irrigations may wash this substance out before it is fixed, 

 especially from sandy soils, but after becoming fixed it is 

 washed ou1 only in small quantities. 



The application of the data lias a very practical bearing 



on plantation practices. I n the case of clay soils there is 

 very little loss of fertilizers even from very heavy rains 

 or very heavy irrigations. The only wax that losses 

 occur is by the water washing off the fertilizers from the 

 surface and carrying them off in the running waters, 

 or by washing off the soil and carrying the fertilizers with 

 it. There is a practical suggestion in this also as to the 

 method of application or fertilizers. Inasmuch as they 

 become fixed so quickly, it is suggested that they do not get 

 thoroughly mixed with the soil, nor filter down readily when 

 applied on the surface, and that they should be mixed is 

 well with the soil as can conveniently be done. 



While the loss of phosphates from sandy soils is s tall, 

 nitrogen and potash are lost in appreciable quantities in 

 underdrainage. It is suggested that there is not the same 

 reason for thoroughly mixing the fertilizers with these soils 

 as in the case of clay soil-, tor there is a tendency for the 

 moisture to diffuse the ingredients. It is suggested also that 

 fertilizers should be applied in small and frequent doses to 

 sandy soil rather than in large doses at long intervals, for in 

 this way there would be a more constant supply in the soils 

 for the use of the plants. 



deference is made in Tropical Life lor April 1915 to 

 the ideas put forward in the Agricultural A'etvs early this 

 year regarding the work done by various committees and I il 

 departments of agriculture to make the islands, and 

 cially the crops produced by them. Wetter known at purchasing 

 and consuming centres. Mention is made also of the views 

 put forward in regard to Wesl Indian exhibits at the Imperial 

 Institute. In this connexion Tropical Liu -. ii 



would be of greater advantage if the exhibits were in I 



in the city near to the big business houses and ma 

 rather than when the} are in South Kensington. Thei 

 a great deal to support this suggestion. While d ig 



the matter, it may be mentioned that the Daily A 



(Demerara) reports that many of the samples at thi 



Institute gallerie- are going to be supplemented anil in - ime 



cases renewed, but the British Guiana Go 1 is not 



prepared to increase the amount of $720 ai present 



expended at the Imperial Institute for exhibition purpo 



