186 



THE AGRICULTURAL NEWS. 



June 13, 1908, 



INSECT NOTES. 



Insect Pests in Foreign Lands. 



Mr. W. \V. Froggatt, F.L.S., Government Entomolo- 

 gist of New South U'ales, started last year on a mission 

 tor the Governments of New South Wales,. Queensland,' 

 South Australia, and Vietoria, to invisti.^ate the fruit- 

 Hy and other insect pests, and their natural enemies, in 

 Europe and America. Mr. Froggatt was in Barbados 

 in January last, and was an honorary member of the 

 West Indian Agricultural Conference. The notes given 

 below are taken from Mr. Fruggatt's Progress Reports, 

 vhich have appeared in the Journal of Agriculfun' 

 of Victoria under the title ' Insect Pests in Foreign 

 Lands', and may be of interest to the readers of the 

 Agrtcaitund Newf<. The lantana scrub (similar to 

 Wild sage in thi' West Indies) which is a serious 

 nuisance in Hawaii, is attacked by a number of insect 

 pests, some of which have been introduced into the 

 Hawaiian Islands for the express purpo!-e of killing it. 

 Mr. Froggatt states : — 



It ha.s been claimed that the lantana i.-; entirely dastioyed 

 in some districts through these iiiuect parasites, but, though 

 there is no doubt under certain conditions its growth ha.s been 

 checked and great <|uantities of the Howers and seed buds des- 

 troyed, the scrub is not dead and the bulk of it will 

 have to be removed when clearing, by mechanical methods. 

 Quite a number of ditterent insects were propagated on 

 lantana ; e.g., two moths, a leaf mining Hy, a gall- 

 making Hy, and a small leaf bug. The latter is one 

 of the most cH'ective insect enenues of the scrub), attacking 

 the under-surfaces of the leaves and causing them to drop otf. 

 This bug, however, is very closely allied tii the native olivi' 

 ling of New South Wales, which destroys the foliage of the 

 cultivated olive, and we could never allow it to be introduced 

 into Australia under any conditions. The jiest, however, that 

 in my ojiinion, after very clo.se ob.servation, has efl'ected the 

 most destruction to the lantana, and is still at work, is the 

 ' Maui Blight ' (Orlhi-xia uiitii/uiii). This is one of the Mealy 

 liug.s, and is known as a very destructive pest to the tea plant 

 and other shrubs in India and the Kast. Jt must be stit{>d, 

 however, that the entomologist did not introduce this doubt- 

 ful nest ; it was accidentally introduced on the island of Maui, 

 but has been widely spread all over the other islands by the 

 lanch men, and is attacking other plants an'd'niay be a very 

 grave plant pest to reckon with in th<- future. 1 therefore 

 strongly ad\i.se that under no conditions should we introdncc 

 any of these insects into Australia for the purpose of killing 

 lantana. Kven if they killed every laish, our conditions of 

 ]ilant life arc so ditfercnt that it is hard to .say where the pest 

 vvonld stop after the original host plant had died out.' 



Orihezia insigiiLs is fairly common in the West 

 Indies, but is more conspicuous as a pest of certain 

 useful plants than of lantana. L;uitana, of which we 

 have several species, known as sage and rock SMge, 

 is not a Serious post in these ishuids. 



With regard to the leafdiopper of the sugar-cane,, 

 and the effect of the.^otroduced parasite, Mr. Froggatti 

 states : — 



Some years ago, a small leaf-hopper {Perkinse/la 

 s'lcc/idn'ri'la) made its ^gjjearance as a pest in the cane fields, 

 and, about the year 1902, .swaniied in such numbers — sucking, 

 up the sa[), and depo.si^ing their eggs both in the leaf .stalks 

 and the cane .stems — that the whole fields were black with 

 fumagine, and throu^i^i. the injuries they cau.sed, rust and 

 fungi damaged the tissues of the stalk. These injuries cau.sed 

 a great loss in the yield of juice, and Messrs. I'erkins and 

 Koebele came to Australia (whence much cane had been 

 introduced into Hawaii) to see if they could find the home of 

 the pest, and its parasites, if there were any. In the middle 

 of 190-1, they found this pest common in the North t^ueen.s- 

 land Plantations, and also discovered a .small hymeno[)terous- 

 parasite destroying its eggs. The infested eggs were sent 

 in cane steins to Honolulu, and the parasite is now .so well 

 established that the leaf hopper is ke()t in check. Still 

 there is a good number of the destructive leaf hoppers to be 

 found, and it will be interesting to watch later developments. 

 It seems incredible that the parasites have mastered the 

 hoppers in such a short space of time as two years, 

 however carefully they have been spread by the entomolo- 

 gists of the Sugar Planters' As.sociation. There can be 

 no question about the value of this parasite and another 

 since introduce<l from Fiji, but there may be also other 

 agencies at work in checking leaf hopjiers, one of which is 

 the return of .some of the companies to the old method of clean- 

 ing the cane fields by burning u^i all rubbish. Harder- 

 stemmed varieties of cane are also not .so subject to the 

 attacks of leaf h(jp[iers in the stem. 



In California, Mr. Froggatt visited the ilift'erent 

 fruit-growing sections, and he found that the intro- 

 duced parasite of the Codlin Moth has been of very- 

 little service, if any, to the apple growers. 



In the orange districts it was found that scale- 

 insects were more or less kept in t'heck by the native 

 and introduced predaceous and parasitic insects, but 

 that up to the present time the control by this means 

 has not been sufficiently complete to render spraying 

 and fumigating unnecessary, though without doubt 

 very large numliers of scale insects are destroyi'd by 

 their natuifd enemies. 



In Ijouisiana it was found that the control of cattle 

 ticks by a system of pasture rotation was effective. 



Mr. Froggatt visited Texas and made a visit to- 

 IMexico. The account of the trips beyond that country 

 has not yet been received. The report of Mr. Frogg.-itt's- 

 visit to Cuba, J.imaica and Barbados should contain 

 notes of interest to the readers of the AgriiuUd red 



Prize Holdings Scheme at Dominica. TIk- 



K.xpcrimcnts Conunittee at, Dominica propo.se that a Prize- 

 llol. lings Scheme in connexion with cacao cultivation 

 shall be tried in two districts of the i.sland, and that in 

 awarding the prizes, the holdings shall be divided into two 

 ilas.scs. 'I'lic first class, it is piopo.sed, shall consist of hold- 

 ings over 1 iicre, bu't not exceeding 4 acri's, while the second 

 cla.ss shall consist of holdings which .shall be less tlian 1 acre 

 in extent, but shall include at least 100 trees. The prizes 

 suggeste(l for award in the first class arc £4, £■_' 10.s., and 

 £1 res[pcctively, with jirizes of half this value for the .second, 

 cla.ss. 



