Fruit Tree Pests And Their Control

Press, Volume CI, Issue 29909, 24 August 1962, Page 8

Fruit Tree Pests And Their Control

Not everybody follows a spray programme in their fruit garden. It pays, therefore, to be on the look-out for signs of pest activity and disease symptoms. Specific sprays to halt the menace before more damage is done can thus be quickly implemented. Periodic inspection, at least once a week, is important where no spraying schedule is maintained and should be done thoroughly. A hand lens will prove useful as well as adding interest to the job. This allows for the spotting of early outbreaks of red spider attack, for instance. The following descriptions of some common insect pests will help in identifying the various pests:

Codlin Moth.—This is the most commond, and probably most troublesome, pest which fruitgrowers have to contend with. It is the pinkish maggot-like caterpillar of the moth that does the damage by boring holes into the fruit of apples and pears. A darkish red irregular ring often surrounds the point of entry. This discoloration becomes more conspicuous a few weeks after the caterpillar has tunnelled into the flesh of the fruit through to the core where it devours the, seeds. The adult moth is seldom seen and is an inconspicuous light brown insect which flies by night. Eggs are laid on leaves, twigs, and fruit of apples or pears and the resulting caterpillar begins to bore into the fruit. Many people are of the opinion that they invariably enter by means of the eye of the fruit This is not a fact, since it is just as common for them to enter by boring into the side of the fruit

Good control can be achieved by the use of lead arsenate (plus hydrated lime), D.D.T or Gusathion.

Red Spider.—This is a tiny red-brown sap-sucking pest that is just visible to the

naked eye. It is found on most kinds of tree fruits, black and red currants and raspberries. Severe infestations can cause the foliage to lose its natural colour and assume a silverybronze appearance. This becomes particularly noticeable towards the end of the season, especially after a prolonged dry summer. In winter and early spring the egg masses can be seen on twigs and bark as a red dust-like covering. The red spiders die after laying the eggs These will hatch in spring and the young spiders immediately begin feeding. A winter clean-up spray of red oil will deal with the wintering eggs while summer oil, malathion and particularly metasystox will give control in the summer.

Woolly Aphis.—Very well known and widely distributed, it can be found on apples and pears. It derives its name from the white waxy secretions in which it lies and which, in a severe infection, resembles cotton wool They can destroy buds on the new growth which will reduce the yields in future crops. Woolly aphis will cause hard blister-like swellings on wood of branches.

There is a natural parasite ot this pest. It is a wasp that lays its eggs in the body of the aphis. The growing larvae feed on the aphis and eventually cause its death. Aphis that have been affected in this way can easily be picked out by their black discoloration among the normal grey. Where the presence of woolly aphis is noticed in the winter, spray with winter oil. In the summer, severe infestations can be controlled with lindane or malathion plus a suitable spreader The spreader is particularly necessary to give maximum adhesion to the insecticide 'because of the protective waxy cone in which they lie embedded.