Pests and Diseases Viewer
Caused By:- The insect larvae of Contarina pyrivoraDescription
Pear Midge is a tiny fly (Contarina pyrivora), the larvae of which damage immature pears. This pest is widespread and can be quite damaging to the crop. The adult is only 2.5-4mm long and darkly coloured and emerge from the soil in April and May, during the peak of the pear-blossom season. It lays between 10 and 30 tiny elongated eggs in each open flower. After four to six days, the eggs hatch and the grubs emerge. Since more than one fly will lay eggs in each flower, there can be up to 100 larvae in each developing fruitlet. These feed inside the fruit as it develops, forming a black cavity filled with seething larvae. When fully grown they are 4-5mm long. The pest is usually first noticed when the fruits start to turn black and fall off and the larvae eat their way out and into the ground to overwinter and pupate ready to emerge in the next spring flowering.
There is not much you can do once an outbreak has occurred, but picking up the fallen fruitlets before they fall or as soon as they fall and destroy them. Putting plastic sheets under the trees to catch fallen fruitlets will prevent them from entering the soil. Cultivating the ground beneath the tree, up to 7.5cm deep, without damaging the roots in late summer and winter will help as this will exposse the grubs for birds to eat. Spraying is possible with a contact insecticide, but care must be taken not to damage benificial insects. Probably the best time to avoid killing benificial insects is at the white bud stage. Keeping chickens under the trees will help as they will aslo eat the grubs. Early and late varieties may miss the emergance of these pests therefore some varieties show some resistance to attack. Early flowering varieties are prone to frost which also gives blackened fruits.