Powder- Wings.

Star (Christchurch), Volume LXVI, Issue 20510, 11 January 1935, Page 6

Powder- Wings.

Nature Notes.

By

James Drummond,

F.L.S.. F.Z.S.

u N ; KNOWN to the public on account of their smallness, inconspicuousness and retiring disposition, are very plentiful insects that have interested entomologists for a long time. Their wings are short and rounded, and are covered with powder as fine as flour, instead of with the microscopic scales that beautify moths’ and butterflies’ wings. They look like tiny moths. " The Illustrious Swede,” Linnaeus, was excused for classifying them as moths, a mistake rectified years later, when the powder-wings, white-flies, or snow-flies, as they are called, were found to be allies of the plant-lice and the scale-insects. New Zealand has at least seven species of powder-wings. It harbours an introduced species, the greenhouse white-fly, which damages plants in greenhouses. The life-histories of these humble insects are highly specialised. As in the case of all winged insects, they begin life in a wingless condition. Insects’ wings are never developed until late in life. There are four episodes in the life-cycle of a highly specialised insect like the powderwing. The complete life-cycle usually is passed through in one year, but it may occupy several years. The four episodes are: The egg, or embryo stage; the grub, or growing stage; the chrysalis, or resting state, a stage of inertia; the perfect stage, usually -winged, which alone is the sexually adult stage.