WINDS AND INSECTS

Timaru Herald, Volume CXXXVII, Issue 19750, 17 March 1934, Page 15

WINDS AND INSECTS

FERTILISATION OF PLANTS. The fertilisation of plants by winds and insects was interestingly described by Mr. R. Nairn during the course of a lecture on ‘‘Pollination,” which he gave to members of the Christchurch Tomato and Stone Fruit Growers’ Association at its monthly meeting. Mr. Nairn based his lecture on popular lines and eschewing technical details, described how flowers were equipped in a wonderful way by Nature with scent and colour to attract the insects which carried pollen for fertilisation. With the aid of several blooms he demonstrated the way in which insects were dusted with pollen when they came to seek honey. Mr. Nairn said that plant life could be divided intq two sections, those fertilised by the wind, and those fertilised by insects. Naturally the first method had preceded insect fertilisation in the history of plant life. Wind fertilised flowers were inconspicuous and without petals, colouration or scent to attract insects. They produced and distributed an enormous quantity of pollen, and were entirely dependent upon the wind for their pollen to meet its affinity elsewhere. Examples of wind fertilised plants were grasses, firs and sedges. Insect fertilised flowers, said Mr.

Nairn, were conspicuous in Nature owing to their colours and perfume, which attracted insects. Competition among insects insured fertilisation, but those flowers which could put the strongest attractions generally survived. The night flowering plants were the only ones not highly coloured, being usually white or yellow. They, however, were very highly perfumed to attract night-flying moths.

An example of the wonderful provision made by Nature was given by Mr. Nairn, when he described how both the objectionable and sweet smelling flowers possessed the power of withholding their scent on cold days when no insects were about. He also pointed out on several blooms the white markings on the petals, which were intended as guides to direct insects to the honey, and ensure that they passed underneath the pollinators.