Vol. XIV. No. 353. 



THE AGRICULTURAL MEWS. 



■ 



riii cotton Wo r j icea inh bri in :i 



BEETLl I 



re has nol ireak of cotton worm 



i son, and an opportunity li;i> not pn 



itself of trying the effect of th( i above described on 



this worm, still there is no doubt but that it would prove 



effective. In the case of the bronze beetle which attacks 



Leaves, the poison has been successfully used against it. 



I loNCH SIONS. 



experiments shov oixtures of arsenical 



as with starch are extremely valuable in controlling 

 ,ks of worms; they are chc4per* than the lime 

 mixtures usually employed, and are more deadly. 



INSECT PESTS OF LIMA BEANS IN 

 ST. VINCENT. 



The following notes, by Mr. S. C. Harland, B.Sc 

 : continuation of those which appeared in 

 the last issue of the Agricultural A", ws: 



THE i;i \\ LEA! ROLLER (Eudamtoi proteus, I..). 



A general account of this insect is to he found in 

 Insect Pests of the Lesser Antilles (Ballou). The larval 

 parasite Urogaster leucosiignui, Ashm., lias been reared in 

 St. Vincent, but it isnot at all common. Three species of 

 Chalcid flies have been obtained from the eggs, one large, 

 and two small. It is thought that the larger fly is a primary 



te but that the others are hyperparasites, and there- 

 fore tn he viewed as harmful. In view of these natural 

 enemies it i- probable that Lima In uns will not suffer very 

 seriouslj from this pest. 



Food Pltints. 'The bean leaf-roller has been observed 

 to feed upon the following othei plants Bermodinm incanum 



nmon leguminous pasture weed), Clitoria sp., cowpeas 

 [ , ■ ,. and bonavist bean {Dolichox tablab). 



I hi LIM \ BEAN LEAF-BLOTCH MINER. 



Lima beans are attacked extensively by an undetermined 

 blotch miner, which is possiblj i oi Igi myza. 



Life-hutory, The lite-history of -.the miner has not 



been fully worked out, but s ime information has been gained 

 as to its habits. 



The Egg. The egg has not been seen, but as many as 

 nine may be laid in a single leaf. 



The Larva. In colour the larva i- pale greenish white, 

 ami is semi-transparent. The dimensions when mature are 

 aii. Hi- .'. mm. Ion.: by I mm. broad. The length of the> larval 

 peri,.,] is about six to nine days. When full-grown the larva 

 bites a hole through the epidermis and enters the ground to 



pupate. 



The Pupa. The pupa is aboui •"> mm. in length anil 

 1-5 mm. in breadth. It is oval in shape, ami is of a reddish 

 brown colour. The segments can be seen quite clearly. The 

 length ol the pupal period is about thirteen days. 



The Adult. The adult is a stoutly built dipterous fly 

 about 3 mm. long. 



Parasites. The pest was very abundant in tin- litter 

 part of August and a Chalcid fly was reared from tin- pupae. 



Control. The blotch-miner must he regarded as a 



i -tin the control of which ordinary methods would 



seem to find littie application. Many plants had more than 

 .'lit per cent, of their leaves attacked n I u ii larva is 



capable of destroying almost hall a ch <>' tis 



is evident that the metabolizing power -t tin- leaves must be 

 seriously reduced. \o suggestions for ttrol can at pri 



in- mad--, and it is hoped that the pest will he kept in 



by i iiri seasons of the year. 



\ si., i \ i i ei-il.i. u:. 



Lima beans are attacked by the larvae of an nniden 

 titled moth. The caterpillar is greenish in colour, is semi- 

 transparent, and possesses the leaf rolling Irtlut A full 



hie historj has not been worked, out, hut tin- length of the 



larval stage appears to he about eight to nine day-, and 



that of the pupal period -i\ to seven day-. Pupation takes 

 place in a fold of the leaf. The moth measures 

 15 mm. aero.---, tin- win- and is golden brown in colour, 

 with a few darker markings. 



Host Plants. Clitoria sp., honavist (Dolichoi lablab), 

 cowpeas (Vign\ catjang, var.), Bengal hems (Stizolobium 

 aterrimiirn), woolly pyrol {Phaseolus mungo), Lima 

 (Phaseolus lunatus 



Parasites. The pest completely disappears at certain 

 seasons of the year. This is due to the fact that several 

 parasites exist in St. Vincent. The following have been 

 reared, but have not been identified: — 



i a i Two I I. aleid parasites of the larvae. 

 i 01 A I'.raconid parasite of the larvae 



(e) A Chalcid parasite of the pupae. 



Control. During the greater part of- tin- year the pest 



is controlled by its parasites, hut at certain times li- 

 very numerous, and eats Bengal beans to the ground. At 

 these times Lima beans would certainly suffer badly. A mix- 

 ture of starch and arsenate of lead in the proportion 30 to 1 

 is a good means of control. 



St mm \i:v. 



b'our pests '-f Lima beans in St. Vincent are described 

 in a popular manner. Of these the first, third and fourth 

 are probably major pests. The second is held in check by its 

 parasites. Methods of control are suggested for tin- CryptO- 

 rhynchus borer and the last mentioned caterpillar. 



Variability in the rate of cure of rubber is, according to 

 Mr. Lewtou Brain and Mr. I!. J. Eaton of the Department 

 of Agriculture, Federated Malaya States, caused by a differ 

 ence in the quantity or quality of certain non-caouchouc 

 constituents of the latex, which remains in the rubber after 

 coagulation. There may he other factors, but the one 

 mentioned is considered the most important. The subject 

 referred to is fully dealt with in the India Rubber World 

 (October 1, 191")), in that interesting section 'What The 

 Luhher ( 'hemists an- Doing.' 



*. In St. Vincent, mading 'low grade arrowroot starch 



can be obtained at from LOs. to 12*. per 2f© ft., and the lowest 

 ,: . assava starch at Is. 2d. per LOO lb. 



The house centipede, although disagreeable in up 



feeds on small cockroaches, J thfi typhoid fly, arid othei -till 

 more disagreeable inserts, and therefore would not -■ m 

 altogether an undesirable visitor in one's house. However, 

 as one of the Federal Department of Agriculture's Ento- 

 mologists says it. a recent Farmers' Bulletin (No. ,; -7) 

 dealing witlt tin- insect, its uncanny appearance is hardly 

 calculated to inspire confidence, and it will unquestionably 

 bite in self-defence. It does not feed on household goods 

 and woollens, although many housewives hold this belief. 



