THE UBIQUITOUS BLACKBERRY.

Taranaki Daily News, Volume LV, Issue 141, 1 November 1912, Page 6

THE ÜBIQUITOUS BLACKBERRY.

CONTROL BY AN INSECT. Farmers whose lands have become over-run with the death-defying blaek j berry will be particularly interested in an article published by Mr. A. 11. Cockayne, Government Biologist, which article gives a ray of hope to those who have for years been battling to keep the pest in check. Up till quite recently, says Mr. Cockayne, the blackberry was singularly free from the attacks of any natural enemy that might be of value in its control. For a number of years past several para-

s-itie fungi, notably orange-rust (Cacoma nitons), have been noted as occurring sporadically, lint in 110 eases have their effects justified the opinion that any of theni would prove efficacious as control agents. "During the past two - years, however, a hitherto rare native moth, "{Jarjosina adreptella," belonging to the Tortrix group, has been found attacking the young shoots of the blackberry. The mmense numbers in which this moth has leen present, and the really effective ,vork that it has already accomplished, lidieate that it may prove an exceedingy valuable agent in controlling valuable "gent in controlling the spread of the liaekberry. At first sight its mode of attack might ead, one to think that its action would lave but little permanent benefit. The :ggs of the moth are laid m the leaflases of the young shoot or in the bud tself. The larvae, after hatching rapdly, penetrate the soft tissue, and' bore hrougli the pith for a distance of perlaps two inches. This is followed by rhe complete death of the terminal shoot. The blackberry spreads extensively by neans of pendent breaches which, when ;hev reach the grpund, root and give rise ;o 'new plants. If a blackberry plant las the- terminal portions .of . these tranches destroyed before they reach the ground the power to spread vegetatively'is entirely eliminated, and the plant remains small in size, and will not be able; to coalesce with its neighbors and form a dense, close thicket. This is exactly what is occurring wherever "Car- • posina" has attacked the plants, and, moreover, affected plants, appear 'to be losing their, power of producing flowers

and fruit to any tiling like ■ the same ex-, tent as unaffected ones! Mr. Cockayne believes that "Carposina" also attacks the young flower-bttds before they dxpand, but this is a point .that has not been yet investigated. The extraordinary part in the work of "Carposina," arid one hard to believe,■ is that.this moth should for so many years occupy such an ] unimportant position in our fauna, and , that within the space of two seasons it should become one of, our commonest insects. ; i The number of the larvae present on a single blackberry: bush: is' al-Y ■tost. inconceivable," and : 'Mr. ! 'Gfoakayne < Hak whole areas''of this weed with nearly 'every termini!! fcud eaten-out: arid destroyed. The 1 ; distribution' of the moth is very widespread, and in every district the biologist Examined'the effects: of its "v/ork/ have mbst rioticeablfen K it Continues to 'extend' there is -not the leaist doubt, he adds, that it will com« pletelyj prevent the - blafekberry from: spreading vegetatively. Present indicas tions point to its causing a great diminution in the amoi}n£:; 9f ;Seed_'p^od^ced.