THE BLACK PERIL.

Pukekohe & Waiuku Times, Volume 1, Issue 41, 5 November 1912, Page 4

THE BLACK PERIL.

Blackberry's Natural Enemy I F<.rm:rs whose lan s have become over-ran with the death-.:efying blackberry will be pa:ticularly interested i.l an article published by Mr A. H. Cockayne, Government Biologist, which arti.le lives a iay of Lope to those wl o h..ve lor years Le.n battling to k.ep the p.st in check. Up tili quite recen.ly, says Mr Cockayne, the blackberry a s singulaily Iree from the attacks of any nutuial en.'try th.t be of value in its control. For a number of yea s pi-st several parasitic lu:>ki, notably oraige-ruit (Lacoma nit ns), have b en noted iis cccuriii g hpotaoicilly, but i.i to casts have Ibeir tfleets justified the opinion th.t any of them would prove ellica iouj as control ngtr.ts Durir.g th. patt ;wo ytars, however, a hith^re 1 o rare native moth, "Larjosii.a adreptella," btluriging to the io.trix g;oup, has beej found attacki.g the young ehoots of the blackberiy. The immense cumbers iu which this moth has bctn pieser.i, and the lefclly tlfective work tha; it has alieany aecur pliihed, indicate that i ; - may prove an exceedingly valuable t iu controiiiig (hi ipread of the blackberry. A' fiisi bight its mode of attack might lead one to th:r.k that its action would have out little permanent benefit. 1 lie of the moth are laid in the leaf-btses of the young cr in the bud itsell. The larvae, after hatching rapidly, penetrate the soft tissue, and boie through the pith for a distance of perhaps two inchee. 'ibis L followed by the complete death of the leuniiial s;.out. 'he blackbfiry sprea: s exteniivtly by means of pendent branches which, ihtn they reach the ground, root and give ri-.e to new plan s. If a blackberry plant has the terminal portions of these branches destroj.d before ihey reach the uroutd the power to spread is entirely eliminated, and the plant remains small in size, and will not be able to coal.see wiLh its neighbours ana form a dens', rl.'-e thicket. Ih.sis exactly what is o-eunitg wherever "Caiposina" has atta ked the plant, and, n.orecvc, affected plants appear io be losing their powc.r of producing fiowe.s and fruit to a. ything like the same extent as unaffected ones. Mr Cockayte be--1 evej that "Carpotina" also attacks the young fLwer-buda before they expand, but ti.is is a point that has i.ot b.e:i yet investigated. The extraordinary part in the «o.k of "Carpoair.a," ;nj one haul to believe, is that this moth should f.r so many jears occupy auch an unimportant position in our launa, and that within the tpace of two seasons it sh.uld become o;.e of our commonest insects. The number of the larvae preset cn a single blackberry bush is almost incon- [ ceivable, and Mr Cockay. e has seen whole arias of t is weed with nta.ly every teiminal LuJ eaien o.t and de.t:o\e 1. 'the distribution of the moth is very widespread, a.d iu eveiy ciistiict the biologist examined the ett'ects of its work have been most lo.iceabl-. If it continues to extend there is not the least doubt, hi ad s, that it will completely prevent the blackberry from spieadug vegetativelj. Present it.dica ions point to iis cauar.g a great diminutioa in the amount of seed prod Ccd.