346 



THE AGRICULTURAL NEWS. 



October 22, 1904. 



INSECT NOTES. 



Insects of the Cacao Tree. 



I'lidertlic title of 'A preliminary Bulletin on Insects of 

 the Cacao,' the Departnient of tlie Interior for the Philippine 

 Islands publishes an account of the insects attacking cacao 

 in those islands. 



The injuries to cacao in the Far East would seem to be 

 much the same as those of the We.st Indies, although in mast 

 cases the insects causing the injury are not the same. This 

 being a preliminary report, the technical names are not given, 

 and Ihe insecticides recommended for dealing with the pests 

 are general and not the result of experience under the local 

 condttions. The illustrations, of which they are a large 

 number, are mostly from photographs and are very good. 

 Thrips, aphis, borer, leaf-eating caterpillar.s, ants, termites, 

 and .scale in.sects are all dealt with, and several benefii-ial 

 insects are also mentioned or described. 



This Is, perhaps, the first publication on the economic 

 entomology 'of the Philippines, and will serve an excellent 

 purpose in helping the cacao planters to understand and deal 

 with the cacao iiests. 



An Enemy of the Mexican Cotton Boll Weevil. 



Professor O. F. Cook, of the United States Depart- 

 ment of Agriculture, visiting Guatemala in April this 

 year, discovered an ant which destroyed the Mexican 

 cotton boll weevil. This was recognized at once as 

 a very important discovery, since the boll weevil is at 

 present the most serioiis pest of cotton known (see 

 Af/nrvUvral Xews, Vol. Ill, p. 298). 



Reports of this ant and its work were ]3ublished 

 in certain American newspapers at the time (see 

 Agricultural X>'vs, Vol. Ill, p. 204) which, though 

 based on fiict, were yet without authentic detads, and 

 many extravagant statements were made. Since that 

 time careful ' investigation has been made by the 

 United States Dci)artnicnt of Agriculture and the 

 results have been published in a report on the habits of 

 the Kelep. or Guatemalan cotton boll weevil ant, by 

 O. F. Cook, {Bulletin No. 49, Bureau of Entomology). 



The following notes are taken from this bulletin : — 



The kelep was discovered on cotton on April 20, 1904, 

 at Alta Vera Paz, Guatemala, and its efficiency as a destroyer 

 of the cotton boll weevil {Anihonomvs rjrandi^, Boh.) was 

 demonstrated the next day. Kighty-nine colonies numbering 

 together about 40,000 ants have lieen taken to Texas in 

 healthy vigorous conilition. Although the journey with the 

 various delays occupied more than a month, .scarcely more 

 than a dozen ants died on the way. This indicates that Uie 

 ants are hardy, and argues well for their successful establish- 

 ment under new conditions. 



The kelep, like many wasps, has the power of stinging 

 its prey and paralyzing it, thus making it easier for them to 

 carry it to the nest. 



The introduction of any insect or other form of life to 



a climate and locality where it is not known is always 

 attended with risk, and many objections are naturally raised. 

 The objections in the i>resent case have been met and 

 disposed of : — 



(a) The kclcii is entirely carnivorous and predaceous 

 and does not attack jilants. It feeds to .some extent on the 

 .secretions of the honey glands on the leaf of the cotton. 



(b) The keleji does not excavate large chambers in the 

 ground to serve as pit falls for men and farm animals. The 

 chambers are dee]) and consist of narrow passages and 

 tunnels running to a depth of 3 feet. 



(c) The kele]) never attempts to sting human l>eings 

 unless actually held or injured, and theii' sting is neither 

 jiowerfnl nor dangerous. 



In addition to preying on the Ixill weevil, the kelep 

 attacks several other insect.s, the boll worm among them, but 

 so far does not attack the larvae of the lady -birds. It also 

 attacks and kills a large stinging ant which is a serious pest 

 in some parts of Texas. 



The kelep is as yet the only ant known to attack and 

 destroy healthy, adult boll weevils, just as the cotton grown 

 with the protection of the ants is the onl}- field culture 

 permanentlv maintained in the weevil-infested regions of 

 Central America. 



The present .status of the boll weevil ant investigation 

 may be summarized by .saying that three of five crucial 

 4ue>tifins have been met and answered and that the two 

 others arc still to be reached, but with no insurmountable 

 obstacle in sight. 



(1) An ant has been discovered in CJuatemala which 

 attacks and kills the adult boll weevil, and thus holds this 

 most injurious insect in check and permits the regular 

 harvesting of a crop of cotton, even under conditions 

 favourable to the weevil. 



(2) This ant is carnivorous and predaceous ; it injures no 

 form of vegetatifiii, aiid takes nothing from the cotton plant 

 exceiit the nectar secreted for it on the leaves and floral 

 envelopes. 



(.1) The habits and temperament of the in.sect are such 

 that it is readily capaVile of domestication, transportation, 

 and colonization in the cotton fields of Texas. 



The issues which remain to be determined are : — 



(4') Whether the keleps will survive the winter climate 

 of Texas. 



(•")) Whether they can be obtained or propagated in 

 sufficient numbers to serve the practical [lurpose for which 

 they have been introduced. 



Scale Insects on Cocoa-nuts. 



In iiis report, referred to on p. 849 of this issue, on 

 plant diseases in Porto Rico, Mr. F. S. Earle makes the 

 following observations on cocoa-nuts; — 



Cocoa-nuts are widely planted in Porto Rico. For the 

 mo.st part they seem quite healthy. No trace of either of 

 the serious diseases found in Jamaica * was observed. In 

 the neighbourhood of Ponce many of the trees were yellow 

 and some were dying. Imspection showed that the trouble 

 was caused by scale insects. Fortunately a lepidopterous 

 larva was present in some numbers feeding on the scales. 

 Specimens were secured by Professor Barrett, and it is hoped 

 ho will succeed in rearing them. Unle.ss this or some other 

 enemy of the scale multiplies very rapidly, a number of trees 

 in the neighbourhood of Ponce will be lost, as they are 

 badly infested. 



See West Indian BtiUefin, Vol. IV, pp. 4-6. 



