DESCRIBE THE DAMAGE CAUSED BY THE BLACK BEAN APHID
- stunting of new growth by sap sucking of aphid
- foliage becomes curled and distorted
- plant becomes susceptible to virus
- black sooty mould grows on honeydew exuded by aphids and excludes sunlight
NAME 2 METHODS OF CONTROL OF THE BLACK BEAN APHID
- chemical with sprays containing fatty acids
- remove overwintering host plant e.g. Viburnum opulus
- physically remove soft growing tips
- hose off aphids
- encourage natural predators
- sow early cultivars
NAME 2 PESTS THAT CAUSE DAMAGE BY BITING
- rabbits
- large cabbage white butterfly larvae
- adult and larval forms of vine weevil
- mice
NAME 2 PESTS THAT CAUSE DAMAGE BY PIERCING
- aphids
- two spotted spider mite
- whitefly
DESCRIBE LIFE CYLE OF POTATO CYST EELWORM
- each cyst (dead swollen female bodies) contains 200-600 eggs and can stay in soil for 10-20 years
- egg hatching is stimulated by exudate from solanaceous plant or associated weed roots in spring
- male and female larvae swim short distance through soil to locate roots which they bore into to start feeding
- females are fertilised
- males die following fertilisation
- female bodies swell with eggs and develop into cysts which fall off back into soil in autumn, females die
- cysts (1mm) overwinter in the soil and usually hatch within one year
DESCRIBE 3 METHODS TO MINIMISE THE EFFECTS OF THE POTATO CYST EELWORM
- control solanaceous weeds e.g. Solanum nigrum
- use certified seed potatoes
- use resistant cultivars e.g. ‘Maris Piper’
- do not import infected soil on plants or equipment
- use early crop potatoes so that eelworm has less chance to develop
- sow Solanum sisymbriifolium which will trigger the eggs to hatch, but the eggs cannot develop in the roots. Live eggs population is reduced.
DESCRIBE THE LIFE CYCLE OF LARGE CABBAGE WHITE BUTTERFLY
- Butterfly emerges from overwintering pupa in April/May
- Butterflies mate and lay 200 eggs in batches of 10-20 on undersurface of brassica and Tropaeolum leaves
- larvae (caterpillar) hatch in about 2 weeks and feed on brassicas and Tropaeolum majus (nasturtium)
- larvae pupate on vertical surfaces such as woody stems when fully fed (about 1 month)
- butterfly emerges in July /August, producing many caterpillars in August/September
- one or more cycles per year
DESCRIBE HOW KNOWLEDGE OF LARGE CABBAGE WHITE BUTTERFLY CAN CONTRIBUTE TO CONTROLLING IT
- net the crop before butterfly lays eggs in Spring
- remove eggs from underside of leaves
- look for eggs on Tropaeolum plants
STATE ONE METHOD OF CONTROL FOR EACH OF 3 NAMED GLASSHOUSE PESTS
- Glasshouse whitefly controlled by Encarsia formosa (biological)
- Peach potato aphid controlled by pinching out soft plant tips (physical)
- Vine weevil controlled by Thiacloprid (chemical)
- 2 spotted spider mite by removing infested plant from glasshouse before females seek shelter to overwinter (cultural)
NAME 2 EXAMPLES OF DAMAGE CAUSED BY 2 SPOTTED SPIDER MITE
- mottling of leaves
- reduction in photosynthesis and plant growth
- silk webbing on the leaves
- leaf droop, loss and plant death
NAME 1 PHYSICAL AND 1 BIOLOGICAL METHOD OF CONTROL OF PEACH POTATO APHID
- fleece covering of crop is a physical method
2. ladybirds and parasitic wasps (Aphidius colemani) are biological methods
NAME 1 PHYSICAL AND 1 BIOLOGICAL METHOD OF CONTROLLING RABBITS
- rabbit proof fences and tree guards are physical methods
2. cats, dogs and ferrets are biological methods
NAME 1 PHYSICAL AND 1 BIOLOGICAL METHOD OF CONTROLLING SLUGS
- slug traps and physical removal are physical methods
2. hedgehogs and birds are natural biological methods;
DEFINE A PLANT PEST
A plant pest is an organism that damages a plant
NAME 3 METHODS OF PHYSICAL CONTROL OF 3 NAMED PESTS
- The use of enviromesh on brassicas to prevent large cabbage white butterfly laying eggs on leaves
- Tree guards to protect against rabbits
- Beer traps to protect against slugs
DESCRIBE THE LIFE CYCLE OF THE BLACK BEAN APHID
- aphid overwinters as eggs in cracks of branches of winter host ; Viburnum opulus and Euonymus europeaus
- eggs hatch in spring and young wingless females feed on winter host plant
- winged females are born in overcrowded conditions and migrate to summer host with soft succulent foliage (e.g. bean plant)
- winged females and males produced in late summer migrate to winter host and mate; females lay fertilised eggs
DESCRIBE USE OF BLACK BEAN APHID LIFECYCLE KNOWLEDGE TO CONTROL IT
- young shoots, known to be site of infestation can be pinched out
- sowing early will allow plants to have passed soft new growth phase before migration from winter host
DESCRIBE THE STAGES IN THE LIFE CYCLE OF THE VINE WEEVIL
- all adults are female
- adults lay hundreds of eggs (<1mm) from April to September around the base of the plant
- eggs hatch into larvae which are white with brown head
- larvae (10mm) remain in soil and eat and destroy plant roots
- larvae pupate deep in the soil
- adults are female, black/grey in colour, nocturnal and feed on foliage
- particularly problem with container plants
DESCRIBE DAMAGE CAUSED TO PLANTS BY VINE WEEVIL
Larvae destroy roots causing yellowing of older leaves, wilting and collapse of plant
Adult weevils damage foliage of evergreen leaves typically, leaving notches on leaf margins or holes in leaves
Adults affect Rhododendrons, Hydrangea and strawberry for example
DESCRIBE LIFE CYCLE OF GLASSHOUSE WHITEFLY
- 200+ pale coloured eggs are laid on underside of leaves (often in circles) without the need for fertilisation
- eggs hatch into flat, scale-like, crawling sap-sucking nymphs
- 2nd, 3rd and 4th instars are immobile, sap-sucking and exude honey-dew
- pupal stage is pale, flat and fringed
- adults emerge 10 days later and are mainly female, with pale flat wings
NAME ONE BIOLOGICAL AND ONE CHEMICAL CONTROL OF GLASSHOUSE WHITEFLY
- Biological:
Encarsia formosa (parasitic wasp) parasitises the whitfly nymph
2 Chemical:
- Deltamethrin, contact insecticide, used as spray
-Thiacloprid, systemic insecticide, used as spray
- Fatty acids, contact insecticide, used as s[ray
NAME ONE BIOLOGICAL AND ONE CHEMICAL METHOD OF VINE WEEVIL CONTROL
- Biological: pathological nematodes watered into soil in August/September when soil warm enough, before larvae have done too much damage
- Chemical: Acetamiprid or thiacloprid drench applied to the compost in mid to late summer
DESCRIBE ONE PHYSICAL ,ONE CHEMICAL AND ONE BIOLOGICAL METHOD OF CONTROL FOR LARGE CABBAGE WHITE BUTTERFLY
- physical:
- pick pale yellow butterfly eggs and caterpillars off leaves
- cover crops with fine netting to prevent adult butterfly from laying eggs - chemical:
- spray with pyrethrum or deltamethrin to kill at larval stage - biological:
- spray with Bacillus thuringiensis bacteria to infect larvae
HOW DO PESTICIDES TARGET INSECTS
- plant oils are used to block the spiracles of insects and mites
- fatty acids destroy the waxy coating of exoskeletons
- poison may be eaten
