Q Why are soft brown rotting areas appearing on the pears? They're soon covered with numerous creamy white, raised spot-like pustules. The fruit is rapidly reduced to either a soft or a dry mummified mass.

A The fruit have got brown rot.

Caption: Brown rot ruins the fruit.

Q Why do the pear fruitlets start to develop normally but then, a few weeks after the blossom has fallen, they become swollen and blackened at the eye end? If the fruitlet is cut open, you may see a very pale orange maggot-like larva, up to 2mm in length. The fruitlet becomes completely blackened and falls from the tree between the end of spring and early summer.

A The fruits have been attacked by pear midge.

Caption: Fruitlets affected by pear midge drop off.

Q Why does the pear blossom turns brown and die shortly after opening, yet remains on the tree? The infection often spreads into the adjacent leaves, which also turn brown and die, causing localised dieback. Look really closely using a magnifying glass and you can see pinprick-sized, raised, buff-coloured pustules on the infected areas.

A The plant has blossom wilt.

Q Why did some pears appear normal to start with, but soon begin to develop sunken or pitted areas on the skin? The flesh within is full of patches of gritty cells and the fruits are really unpleasant to eat.

A The fruit have stony pit virus.

Caption: Stony pit virus causes sunken or pitted patches in pears

Q What's causing red or orange spots, which are 1-2mm in diameter, to develop on the upper surface of infected leaves in spring, enlarging as the season progresses? Later, raised and almost horn-like spore-bearing projections appear on the lower leaf surface as the fungus really gets hold. 

A They've got pear rust.

Caption: The distinctive spots of pear rust.

Q Why does pear blossom suddenly wilt, discolour and die shortly after opening? During wet or damp weather, a white-coloured ooze may appear from infected areas. The infected shoot withers and dies. Infected areas may be randomly scattered over the crown of the tree. If the bark is peeled back, the wood beneath may show a reddish-brown discolouration.

A The tree has been hit by fireblight.

Q Why are some of the leaves on my pear tree binded together with webbing? Between bud burst and early spring, tiny yellowy-green caterpillars feed on the foliage. They also eat blossom and will even damage young pear fruitlets. This damage is not noticeable initially, but becomes much more obvious as the fruit
expands and becomes very distorted, often with deep fissures. 

A Winter moth has attacked your pear tree.

Q What has caused sunken, darkened patches to develop on the bark of my pear tree, that become flaky and loose?

A Your pear tree has canker.

Q What are the pink-red blisters on young leaves of my pear tree in spring? Later, they appear as small, raised bumps on the leaves, clustered around the midrib. They start green, redden, and eventually the whole leaf may blacken and fall. In severe attacks, the fruits and their stalks are also distorted and may fall
early. 

A They're caused by pear leaf blister mite.

Q What's caused the leaves of my pear tree to develop slightly raised patches of khaki-grey colour, and fall prematurely? The petioles or leaf stalks may also be attacked and, particularly during a wet spring, the fruits may develop scabby patches, which cause splitting as the pear expands.

A It's pear scab.

Q What are these small, yellowish, almost club-shaped caterpillars, covered with a black slimy secretion, that I found grazing on the foliage of pear trees from late spring until the middle of autumn? The damaged areas on the leaves turn brown and dry.

A They're slugworms.

Caption: Slugworms eat pear leaves.