282 



THE AGRICULTURAL NEWS. 



Septkmbkk 5, 1908. 



INSECT NOTES. 



The Trinidild Bulletin of Miscellaneous Infurnvi - 

 fliin for July 190S contains various short notes dealing 

 with observations on several insect pests of cacao, 

 and on a small weevil which inhabits the fiovvcr-bud of 

 a certain tree that has now been identified. The 

 accompanying note.<, which appear in small type, have 

 been e.\traeted : — 



CACAO liKK.rr.K AITACKS I'llDS. 



Oil line of the trees at St. Clau' a pod was found which 

 ;i|i|icai-eJ to be rotting from the base as if attacked \>y 

 'bniwnrot.' Exaniiiiatioii proved that the pod was attacked 

 by the larvae of the coiniiion ca'^ao beetle (StfirnxtoiiKi 

 (Icpri'ssinii), and that it was fei'dinj^ ])rincipally upon the 

 .•sweet pulp of the interior. The pod was secured and placed 

 under observation. It was noted that tlie larvae, after destroy- 

 ini; the pulj), attacked the seeds, which had begun sprouting, 

 and devonred more than 7-5 per cent, of the number in the 

 j)od. 'J'lie hirvae ultimately developed into the imago form 

 which enabled the in.sects to be deternuned. 



.As at times insects change their habits, and from one 

 food take ti)) another, it is .seen what a serious matter it 

 wonld be. if pods were generally attacked by the beetle, and 

 planters should be most careful to keep the pests under 

 control hy every means in their jjower. 



The cacao beetle is well known as a borer in the 

 wood and bark of cacao trees, but does not appear to 

 have been previously reported as attacking the pods. 

 This insect — larva and adult — -was figured in the last 

 issue of the Af/riiudtural Kewts, p. 2(i(). 



A BAO-WOK.M ox CACAO. 



Oni' ot tliese i-urious inseet.s is reporteil as occurring on 

 cacao at Trinidad, hut it is not stated that any .serious 

 damage has been done. The hag-worms belong to the 

 bc|iido|it(r;i. Although a moth, the adult female is wingless, 

 and lives in the bag or covering dui'ing the whole life. The 

 male is provided with wings. In the ]>esser Antilles iieacia 

 trees are fi-ei|uently seen on which are se\eral of these large 

 bags. At Montserrat the citru.s trees at the Botanic Station 

 have been attacked hy hag-wnrni« from time to time. These 

 insects are not often numerous, ;uid ean generally be con- 

 (rollrd liv hand ])icking or the use of I'aris green. 



A iinKrr.K i)i:.s-ri;iicTivK to tuk cacao tkek. 



A beetle whicdi had previously been re)'iir(<l to in 

 the liulleliii is in this number mentioned as having 

 been identified at the United States Department of 

 Agricidture as Ju'tlinfu (luadricor'nis, Oliver, of the 

 family Ceiambycidae, sub-family Lainiinae. In writ- 

 ing to Mr. Hart on the subject. Dr. L. (). Howard, 

 Chief of the Bureau of Entomology, U.S. Department 

 of Agri<-ultiire, states : 



The genus is elo.sely allied to oni' own twig-girdlers of the 

 genus Oiicitlcnx, and the girdled twig you send plainly indi- 

 cates that Krtliocd does not difi'cr in habits from our eomnion 

 OiiridctiK riiii/iilatiix which is sri often referred to in tin- 

 literature of economic entomology. There is apparently 

 nothing recorded as to the earlier stages or life history of 

 Jict/ioca. La Cordaire, in his (ienera de.t C'o/eopiere.i, states that 

 the species is by no means connnoh in the collections, but the 

 insect occurs from Peru to the (iuianas. According to the same 

 authoiity the colour of the species is variable, and greenish 



specimens are occasionally met with. The male of A', i/iiadri- 

 vornix is very remarkable l)y having four hornlike projectures- 

 on the head. 



In St. Lucia and St. Vincent another twig-girdler 

 {(hiciderest amjnit^itor) occurs which is reported to 

 frequently attack the cacao shade tree known as Pois- 

 dou.\ ( I ji>/it 1(1 iiri tilt), and also sometimes to attackcacao. 

 This insect was dealt with in the A(iric alt ural Neica for 

 May 20, 190.5 (see Vol. IV, p. 1.5.5), where an account 

 was given of the work of girdling twigs supposed to be 

 attributable to the Hercules beetle. 



In the case of the twig-girdling beetles such as- 

 (Jiiridercs and Evthnea the females gnaw thi' wood of 

 the twig to make the cut, and before the twig falls aa 

 egg is deposited in it. In this way the larva, on hatch- 

 incr in the wood of the twig, finds itself surrounded 

 with dead or decaying matter which it utilizes as food 

 material. 



.lUMPIN*; sKEns. 



In a note on the so-ealled ' jumping seeds, ' it i& 

 mentioned that these again made their appearance in 

 the Botanic Gaidens on March 27 last. They were 

 observed on the ' Roble ' tree (Fhit i) niisciiim platyxla- 

 vlii/nm, Benth.). ' Jumping seeds' are not seeds at all, 

 but are a portion of the plant inhabited by a small 

 weevil or snout beetle. Thej' have a seed-like appear- 

 ance, and gained their name on account of the fact that 

 they are sometimes seen to spring a considerable 

 distance from the ground into the air. This is, of course, 

 <bie to the presence of the living beetle. 



'I'he manner in which the insects get into the 

 tissues of the plant is explained in the following (piota- 

 tion from the Bidletin : — 



It has now been observed that the larvae of the 

 beetles enter the unopened flower-bud, and after eating out 

 its interior, change into the impa form, using the caly.\ of 

 the flower-bud as a (jrotective case during the dormant 

 period. As they fall from the trees, the larva is apparently 

 full-grown, and about to assmne the pupa form, and can at 

 this time jump as much as -f inches fron; the ground. The 

 insect is as yet undetermined, hut evidently In-longs to the 

 snouted beetles or weevils (l!hynco|ihora), perhaps to the 

 family t'urculionidae. 



The in.sect is an inteiesting one, seeing tliiit it takes 

 possession of a ready-made vegetable covering in which to 

 undergo its transformation to the imago form.' 



Dressing for Cuts on Cacao Trees. 



The Agricultural Sujicrintendent of (irenada at an Agri- 

 cultural Meeting lately held in the island stated that trials- 

 made by Mr. Malins Smith at Diamond estate, (!rena<Iii, and 

 liy other cacao ]proprieto|-s, with a mixture of resin oil and tar, 

 in the iirfijiortion of one ]iart of tar to four jiarts of oil, for 

 aliplication as an anti.septic dressing for cuts and wounds on 

 cacao trees have given sati.sfactory results. Jiesin oil 

 is a good dres.sing for wounds and was rei'onunended by 

 Mr. (). W. Barrett, when visiting Trinidad. It is, however, 

 colourless and, therefore, it is ilitticult to .see which wounds- 

 have been treated and which have not. The admixture of 

 a little tar colours the oil, and by this means the objection is 

 removed. Further trials with resin oil, as against tar, might 

 be made in other cacao-producing districts in these i.slands. 



