R2103 3.1 Explain why pests need to be controlled

Question 1

What is a plant pest?

Answer 1

• Pest are animals (mammal, bird, insect, mite, mollusc or nemotode) which cause damage to plants
• May damage or destroy sections of or entire plants
• Eat leaves, flowers, stems, roots, bulbs and suck sap

Question 2

Damage: Rabbits

Answer 2

1. Young turf and ceral crops most affected, particularly at seedling stages
2. Carrots, lettuce and annual bedding plants often targets
3. Will ring-bark stems of fruit and trees (removal of cambium, xylem and phloem tissues)
4. Can dig holes and scrapes in lawns and flower beds

Question 2

Damage: Rabbits

Answer 2

1. Young turf and ceral crops most affected, particularly at seedling stages
2. Carrots, lettuce and annual bedding plants often targets
3. Will ring-bark stems of fruit and trees (removal of cambium, xylem and phloem tissues)
4. Can dig holes and scrapes in lawns and flower beds

Question 3

Damage: Cabbage white (large white) butterfly larvae

Answer 3

1. Holes in outer leaves of all brassicas and damage may also be seen in inner leaves of cabbages when heart is cut through
2. Can result in skeletonised leaves

Question 4

Damage: Black bean aphid

Answer 4

1. Can see infestations with naked eye
2. Cause stunted growth with curled /distorted leaves
3. Excrete a sugary honeydew on foliage, stems and fruits which allows growth of black sooty moulds
4. Some aphids transmit viruses
5. Often attacks broad beans

Question 5

Damage: Peach potato aphid

Answer 5

1. Feed on flowers, fruits and vegetables
2. Directly piercing the leaf with feeding tube and sucking the sap
3. Infecting the plant with a virus
4. Honeydew can cover the leaves of the plant which then gets a black sooty mould - this blocks stomata and reduces photosynthesis

Question 6

Damage: Two spotted spider mite

Answer 6

1. Piercing mouthparts inject poisonous juices which cause localised death of leaf cells. Results in fine mottling on the leaf.
2. Underside of leaves have many tiny yellowish green whites and white cast skins and egg shells
3. May have fine silk webbing in heavy infestations

Question 7

Damage: Glasshouse whitefly

Answer 7

1. Sap feeding pest
2. Thrives in warm conditions thus often seen in Glasshouses (harbour pests overwinter)
3. Can see whitefly on infested plants
4. Adults and nymphs secrete sticky honeydew on foliage allowing growth of sticky moulds
5. Flat oval, creamy white scale like nymphs on the underside of leaves

Question 8

Damage: Vine weevil

Answer 8

1. Irregular shaped notches in leaf margins during the summer
2. White legless grubs found among roots
3. Plants wilt, above ground yellowing seen and dies during autumn to spring as a result of grubs devouring roots
4. Like strawberries, grapes, rhododendron

Question 9

Damage: Slugs

Answer 9

1. Leave slime trails - silvery deposits on leaves and stems
2. Irregular holes in plant tissue.
3. Kill off young seedlings
4. Black keeled slugs live underground and tunnel into potato tubers
5. Generally feed at night. Damage can be severe during warm humid periods

Question 10

Damage: Potato cyst eelworm

Answer 10

1. Affects potatoes and tomatoes
2. Overall growth reduced and crops dimished
3. Bad attacks - leaves turn yellow, then brown, dying from bottom of the plant upwards in mid-late summer
4. Dead female eelworms with eggs can survive in soil for ten years
5. Use a hand lens needed to identify the female cysts attached to plant roots