110 



TDK AOUK'ULTl'KAI. NEWS. 



M 



1915. 



S NOTES. 



THE EFFICIENCY OF FUNGOID PARA- 

 SITES OF SCALE INSECTS. 

 IV I ile insects 



I I rable 



attention in the Le ser Antilles, .1- elsewh 

 subtropi 



Our I Ii 



tin fui lieirrel 



1 ji 1 1 certain gei by now 1 niergi d. 



u what might have been 



intelligi ntl] iej are valuable 1 eing the 



alts of exj I bio \ - ch, they may be 



worth stating in vievi of tl hopes which still 



lingi i to tl irl ificial disti ibu 



tii'i, thi 



Speal all quite bi ladlj . it maj be said thai 



the efficiency of the fungi is proportional to the humidit] 

 of the air am 1 - hich theii tcur. 



Their relative abu 1 the islands of the Windward and 



Leeward groups follows pretty closely the amount of rainfall 

 usual i" each island, though the distribution of rain is so 

 local that the wettei islai 1 ■' have areas in which 

 the fungi are of little hm-, and the driest island has sheltered 

 me list situations in which thej are effective. Still speaking 

 broadly, it may be said that in Dominica, in normal years, 

 the control is as efficient as natural -can well produce, 



ditions ai illy such that the red-headed fungus 



(Sphaerostilbe coccophila) the white-headed fungus (Ophin 

 nectria coccicola), the Mack fungus {Myri/rngium Duraei) 

 certain Aschersonias, ami the shield-scale fungus (Gephalos- 

 check established colonies of scale, 

 and follow so closely on new infestations that the effects of 

 the insects are negligible. In most parts of St. Lucia, and in 

 the wetter districts of Grenada and probably of Sfc. Vincent 

 and Montserrat, the control approaches to that in Dominica. 

 In tin drier districts of these islands the fungi, while present, 

 are not so effective, or are more restricted to a seasonal 

 activity. With reasonable accuracy it might be said that 

 epting the shield-scale fungus and one on sugar-cane 

 K bugs, tin- Limits of successful cacao and lime cultiva- 

 tions arc the limits of the effectiveness of scale-destroying 

 fungi. It is not suggested that there is in this a relation of 



cause and effect, bul lather that in the islam I- under COnsid 



eration, the neces arj conditions as to climate are about the 

 ne in both respects. A case might indeed be rgued with 

 regard to Montserrat, that the depressed condition of lime 

 cultivation in some parts of that island is due quite as much 

 t.i the checking 1 >i at drj 3 ears 8 - to 



the direct action of such c lifions on the plants t hem-elves. 



This leads to tl n ablation of the fact thai the 



matte) is m>t quite so simple as has been assumed for the 

 pui 1 neral >ve. The n effective 



reproduction b} the insects has to n into account as 



well 1 he fungu d in 



this the cond 1 of the plant is usually, perhaps always, the 



determining facti '1 



■"This i- a subject « hich lark 



ed H|i..n. does not aj ft om 



becau 1 get beyond 

 simpl di 1 dited if it cannot he 



expressed in til 11 ot 



hemist. In ..ne sucli ense it ha- hi 



1 A. r. Woods, Bull / t J CS.D.A.) 



ieci.i 



I en in the favoured distrcts oi Dominica and St. Lucia, 

 plants transferred from the nursery to the field may becon 

 badly infested until they get established, and require, or would 

 '"' the better foi spraying, [n connexion with older tree-, the 



infl 1 of otl irs stands out \ jus conl i"l is 



less complete, .1.- in casi Grenada, ti ben 



particulai n 1 won hi ivily infested, though the 



shield scale fungus was present in e, while 



"i hei - near bj wer* qnib lean 



Eti uming tl ■ 1 < ler it ii « 1 if humiditj 



the fungi in question, th bul in Barbados is instruc- 



tive. The rainfall 1- low. and 1 I in general is 11 



and windswept. With the two exceptions noted, the fungi 

 enumerated abovi ii save in a very lew sh I ered 



ts. In deep gullies and in -mall on the hills 



where the rainfall is greatest, the writer h the red 



beaded fungus and one of the Aschersonias, th with 



tricted range "t hosts, : pre 



cariously. A similar. 1 li ition 



seems to prevail in Antigua, St. Kitts, and \. ■■. .- islands of 

 relatively low rainfall. 



('nming to the fungi men bove as exceptions 



whose distribution is not so strictly limited, 01 i them, 



Aspergillus parasiticus the sugar-cane mealy-bug fungus, is 



lily accounted for. It is not less dependent on moisture, 



but finds it accompanying its hosts in the enclosure formed 



by the base of the leaf-sheath around the I the cane, 



a situation in which water collects and lingers. The shield' 

 scale fungus is mure remarkable. Even in Barbados it per- 

 sists through the driest season with little shelter, and becomes 



very active with - ewhat small encouragement in the 



wetter months. 



The only relevant difference known to the writer between 

 its spores and thus.- of the other scale fungi i- that they are 

 enclosed in a drop of mucilage. Whether this or some 

 constitutional factor accounts for its hardiness would be 

 difficult to determine. 



This discussion will be continued in the uexl issue of the 

 Agricultural News. 



W.N. 



His Honour the Administrator of St. Vincent has 

 furnished this Office with a copy of the report of tin- 

 Directors of the St. Vincent Agricultural Credit and Loan 



Hank, Limited. This is not an agrii liberal credit society 

 under the Act, nor is it nm on I; liffeisen lines. But the bank 

 continues to do excellent work, and is in a very thriving 



ei.nditii.il. The net profit for the past twelve month- was 

 $l,049 - 49. In spite of last year being one of industrial 

 depression, the ban! has not failed to make financial progress. 



An inexpensive and thoroughly efficient tyj f drain 



■ n evolved to m in the Fedi 



Mala\ Stat ion with the prevention of malaria. 



1] I 11 n\ II. 1915, says that thi- i- formed ot 

 !i dt egg shape laid 



The bl 1 1: lent foundal ion even on bad ground 



in Bo« it Should tl 1t.1t 



them correctly when the surroi 

 . after « hi ive no trouble; but 



