Ladybirds and Icerya Purchasi.

Otago Witness, Issue 2173, 17 October 1895, Page 8

Ladybirds and Icerya Purchasi.

Residents of Hawke's ftxy will remembar that, 15 or 16 years ago, gardeners were in despair at the spread of a disgusting cottony scale commonly known as tho acacia blight (Icerya purchaai).' It was popularly supposed to have been introduced with the acacia, or wattle, from Australia. However it came it spread with alarming rapidity. Hardly anything was fto3 from it ; it even panotrated well-kept vineriee, and was found in musses on tho grapes. Then it began to disappear, and in a few years there was practically none left. It is still cccasicnally seen, hxti its appearance is invariably followed by lights of ladybirds, which quickly clear it off. Ib was, we believe,* Mr Hamilton, then curator of the muicum here, who first detected the particular variety of ladybird which fed on the pest. About that time the 6amo blight made i!s presence felb in the United States, particularly in California. It was said to have been introduced there also from Australia. It toon made i(st)lf at home, and there, as hero, did immense damage, cxtengive orasgo pltntat : ons being practically ruined. Tfee Amwicsa Department of Agrioaltwe in i

" lira " body, which paya special attention to the natural enemies of girden aid orchard — pefts, and he* ring what was being done here by tho ladybird, one of its naturalists, Mr Koebele, was scot to Efawkft's B*y to investi- ? g^'o. Under the guidance of Sir Hamiltou he .' secured a number of la^j birds ond took th m to California, whera they sot to woik with such ' vigour that Mr Koebelo paid ns a second visit r g to get a large number of the insects. But by that time the b'igUt had all but disappeared, and with it thfc parlioula? variety cf ladybird . whioh was hi natural enemy. However, ho j^ maiiftgi-d to g«t a few ep^cimens, ond theee wera not liberated ai the firs'; !oi were, but wero } j kept by the dcpartmtn.t to breed from. Teas c j of thousands of them h*va been raised and dhtributad ; no fewer than 85 generations have been reared, and they are being sent all through the State*. The ladybirds are placed on soft ' moss in small bixep, 50 in each, aud an» mniied * to orchard i>ts, and every yaar Borne 500 b^ xas V' are srnb cu 1 ;. They are, we »re told, considered j one of the most valuab'o enemieß of tha black scale a.3 well as the acacia blight, and the department sets great store by them.