3U 



THE AGRICULTURAL NEWS. 



OCTOBEE 2, 1909. 



INSECT NOTES. 



ENEMIES OF THE COTTON WORM. 



Several articles have apjjeared iu the A'jricultiiial Xews 

 dealing with parasitic insects and the beneficial effects of 

 their attacks on the pests of various crops. 



There are several well recognized pests of the cotton 

 plant, some of which are attacked by parasites, while others 

 are immune from such attacks, so far as is known. AVith 

 regard to predaceous insects, also, certain pests are much 

 more liable to attack than others. The cotton stainers for 

 instance, which occur in all thc-islands where cotton is grown, 

 are not attacked by parasites and are rarely attacked by 

 predaceous insects. The cotton worm, on the other hand, is 

 attacked by several [jarasitic and predaceous insects. 



The small egg parasite, Trichojraiama pfetiosa, is record- 

 ed as a i)arasite of the eggs of the cotton worm ; Chalcis 

 ovata (see Agriculiural JVeii's, Vol. VIII, p. 74) attacks 

 the larvae and pupae ; a fly, Sarcophwia triviftnta, attacks 

 larvae and pupae, also. 



The ordinary practice of killing the cotton worm by 

 means of Paris green or other arsenical poison kills at the same 

 time any parasites that may be living in the tissues of the 

 caterpillar. It is suggested that the [ilanter should ascertain 

 whether these parasites are abundant in his cotton fields, and 

 if they are, that he .should adopt measures to increa.se their 

 numbers. 



Fig. .32 shows an observation box intended for use in 

 this coanexion. In its con.^truction, it is a small, deal box 

 with an opening in the top; over, or under, the opening is 

 a wire mesh too small for the cotton worm to get thvouirh, 

 and large enough to let para-ites escajje. If the ordinary 

 house fly could pass through it would be sufflciently coarse. 

 Over the opening a glass is inverted. 



Fig. 32. OasERV.A.Ti0N Box foi: P.u:asites. 



The method of use is this : Full-grown cotton worms and 

 pupae arc collected and confined in the box. If any para- 

 sites are present they will escape in the course of a few days, 

 and come up into the glass. If 100 pupae are i)ut into the 

 bo.x the percentage of infestation can easily be calculated. 



Planters might have several of these boxes, and by use of 

 them ascertain in which cotton fields the parasites are most 

 abundant. If the percentage of parasitized pupae is fairly 

 high, it would be good policy to have boxes made for use in 

 the field, so that tne parasites could escape and return at once 

 to the attack of other cotton worms. This might be calleil 

 the field box, and it should be made with openings, covered 

 with the wire me.sli, at two ends, so that the rain may not 

 get in too freely, and the parasites would be able to escape. 

 No glass would bo reijuired, of course, in this case. 



The use of the observation box will very quickly show 

 how long a time is necessary for the emergence of all the 

 parasites. When that time has elapsed, the moths, dead 

 jnipae, etc., should be thrown out, and fresh pupae collected. 

 In this way the planter will be able to do a great deal to 

 help in the control of the cotton worm by means of natural 

 enemies. 



It should be borne in mind, however, that the 

 ob.servation box should be used first, for it is evident that if 

 there were no parasites present that it would not pay to 

 collect on a large scale. If, on the other hand, they are 

 fairly numerous, it would be worth doing. 



In a recent article entitled 'Some Parasites of the Cotton 

 Worm '(see Agricultural Scwx, Vol. VIII, p. 7-i) three insects 

 are mentioned, and fi^^ures are given which show the appear- 

 ance of two of these parasites. The third of those mentioned, 

 Sj'iruchalcis, is a pu-asite on the Sarcophagid fly, and is 

 consequently harmful, and should be killed if possible. 



The predaceouV' insects which attack the cotton worm 

 have often been mentfoned in lUe Agricultural News. Amoni' 

 the most imiiortantof these are the wasps or Jack Spaniards^ 

 In Barbados, the two most common are the wild bee (Polistes 

 awndari:i) and the cow bee (Polistes bellicosus). In St. 

 Vincent, Polistes annularis is known as the Jack Spaniard • 

 it probably occurs in all the other islands, but the term .Jack 

 Spaniard is al.?o given to another species, Polistes fuscitus- 

 iiistithHis. These are all much alike in form, the last being 

 slightly smaller than 'the other two, but they vary in colour 

 and markints. 



Fi'j. .'Jo. FiEKV CiiouND l!iaTi,K. (U. S. Department of 



Agricullure.) a, Lai;va ; />, Bketi.e. 



Fig. 33 .shows llie fiery ground beetle (Colisomncalidiim), 

 which has been leported at Barbuda (see Agricultural ]\'eivs 

 Vol. V, p. 10) and 'at St. Vincent (.see Agricultural Keivs, 

 Vol VII, p. 2.50) as attacking the cotton worm. This beetle 

 is known in the United States as an active enemy of cater- 

 pillars, and in any locality where it is abundant it wouhl 

 probably prove of great value as an enemy of the cotton 

 worm. 



MILLIONS 



MALAY STATES. 

 for the Federated .Malay 



FOR THE 



The consignment of million 

 States, mentioned in the last number of the Agricultural 

 Ni'ins (see p. 298) has reached its destination. 



The Acting Director of Agriculture for that Colony, in 

 a letter dated July;2S, 1909, writes to the Imperial Com- 

 missioner of Agriculture : ' I wish to thank you for the 

 eonsigninent of million!?, which arrived last week in •rood 

 order. I shall let you know later how they progress 

 here.' 



The.se fish wi're shipjpcd from Barbados, on May IS, to 

 the Zoological fJardens London, whence they were liter 

 reshipped for the remainder of the journey. From this it will 

 be seen that only about S or 9 weeks were occupied in transit; 



