Pests COPY COPY COPY Flashcards

1
Q

What is the definition of a plant pest?

A

Any insect or animal that causes unacceptable levels of damage to cultivated plants, making them unsuitable for the purpose of which they were grown. Pests may affect the aesthetic value or the crop yield.

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2
Q

Why do pests need to be controlled?

A

Commercially growers can lose a lot of money if crops fail due to pests.

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3
Q

What are the 3 methods that pests feed on plant material?

A
  1. Piercing/sap sucking - aphids & whitefly.
  2. Biting - caterpillars, beetles & rabbits.
  3. Rasping - Slugs. Rarest of 3 methods.
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4
Q

How do insects breathe?

A

Insects breathe through holes called spiracles along their abdomen.
These spiracles connect to a network of tracheae (air passages or tubes) which allows oxygen to permeate all tissues. Spiracles can be closed by valves.

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5
Q

Why is it important to understand the biology of pests and how they breathe and reproduce?

A

Understanding how pests breathe and reproduce helps us in choosing a control method and timing of these methods.

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6
Q

Which pests can be managed by attacking their breathing mechanism?

A

Red spider mite, aphids and white fly.

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7
Q

How can you control pests by restricting their breathing?

A

Refined plant oils block the breathing pores. (Spiracles).
Oils are also used on fruit trees and bushes to kill overwintering eggs.
Other chemicals such as natural Pyrethrum or Deltamethrin as act as a nerve toxin which affects movement and breathing.

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8
Q

What do fatty acids do?

A

Fatty acids (insecticidal soaps) dry out the insect cuticle so desiccation is the cause of death. Most affective on soft bodied insects like aphids.

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9
Q

What is diatomaceous earth?

A

A powdery natural occurring soft sedimentary rock.

Dust made from diatomaceous earth abrade insect cuticle and make them susceptible to dehydration.

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10
Q

What control method can you use the biology of flying/winged insects to reduce numbers?

A

Trap them with yellow sticky traps placed at flying height.

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11
Q

What should we do to manage nocturnal pests?

A

Pick them off at night time - eg. Vine Weevil and slugs.

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12
Q

What is a pheromone trap?

A

Pheromone traps monitor populations and allow lifecycle to be broken at the point when the male is searching for the female.
Pheromone traps contain the odour of females and will trap the males.
Pheromone traps main use is to indicate when is the best time to use sprays - ie. Codling moth.

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13
Q

Give 3 examples of how knowledge of lifecycle of pests can help us manage them and their damage?

A

Plant at time of year to avoid when pest is active. Eg. autumn sown broad beans against black bean aphid.
Apply physical barrier to prevent pest laying eggs. Eg. Brassicas protected from cabbage white butterfly.
Target immobile stage for removal - eg. remove eggs and lifecycle is broken.

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14
Q

Which insect overwinters on Vibernum opulus?

A

Black bean aphid.

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15
Q

What are Glue Bands used for and how?

A

Glue bands applied to the trunks and stakes of fruit and ornamental trees to prevent wingless females of winter moths and similar species reaching the branches of the trees and laying their eggs.
Bands must be kept sticky and in position between November - March.
Barrier glue can also be used around pots and greenhouse staging to deter vine weevil. Sticky traps combined with a chemical attractant.

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16
Q

What are the two types of insecticides?

A

Systemic or Contact

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17
Q

What are systemic insecticides best used for?

A

Best for sap suckers, as the insecticide is taken up through the plant - then when the insect sucks the sap it is poisoned.

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18
Q

How do Contact Insecticides work?

A

They depend on good plant coverage. The insecticide is absorbed by the insect body or is eaten.

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19
Q

What are the two distinct types of insect lifecycle?

A

Complete and incomplete.

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20
Q

What is Complete Metamorphosis?

A

It means that there is a complete difference/change between the young and the adult.

  • Egg
  • Larvae (caterpillar/maggot/grub)
  • Pupa
  • Adult
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21
Q

Give 6 examples of insects with a complete lifecycle?

A
Ladybird
Moth
Butterfly
Flies
Vine Weevil
Beetles
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22
Q

What is incomplete metamorphosis mean?

A

Incomplete metamorphosis means there is more of a gradual change between the young and the adult.
After hatching the younger insect gets bigger and bigger and sheds it’s exoskeleton several times. The adult may or may not have wings.
There are 3 main stages to incomplete metamorphosis.
- Egg
-Nymphs (bigger and bigger)
-Adults

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23
Q

Give 4 examples of insects with an incomplete metamorphosis life cycle?

A

Aphids
Earwigs
Crickets
Cockroaches.

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24
Q

What is the chemical control of pests?

A

Use of pesticides to reduce pest problem. They may be synthetic or naturally occurring compounds. They may be applied directly to the pest or to the plant, and then ingested from the sap by the pest

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25
Q

What is the physical control of pests?

A

The physical removal or the exclusion of pests.
Eg. Netting/barriers/traps.
Pinching out bean shoots covered in aphids and removing them.
Squishing aphids with fingers, or washing off with a powerful jet spray of water.

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26
Q

What is the biological control of pests?

A

Use of natural organisms which prey on the pest and reduce it’s numbers.
Biological control may be parasitic wasps, nematodes, mites.
The garden has lots of natural biological controls such as ladybirds eat aphids and ground beetles will eat slug eggs.
The gardener can introduce biological control to an enclosed environment in the greenhouse.

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27
Q

What is Integrated Pest Management? (IPM)

A

A pest control strategy that relies on multiple control practises.
Population levels are monitored and action is taken. Usually organic methods are favoured before chemical control but this depends on the scale of the problem.

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28
Q

What damage can rabbits be responsible for?

A

Rabbits can be responsible to a huge loss in agricultural and horticultural crops, including herbaceous plants, young trees, shrubs and vegetables.
They will eat the foliage, shoot tips and even bark.
Trees can be ring barked, where the bark is gnawed away the full circumference of the tree.
Young turf and seedlings will also be eaten.
They can chew through fencing and damage planting by digging/burrowing.
They can reach a height of 50cm stood on hind legs.

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29
Q

How can you physically control rabbits?

A

Barriers, wire mesh fencing or brick wall. With 30cm underground so that they can’t tunnel underneath. Ideally 1.2metres in height. Gates need to be rabbit proof too.
Electric fence.
Tree guards 60cm high advised for newly planted trees or shrubs
Surround susceptible plants with netting.

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30
Q

What chemical methods of control are there for rabbits?

A

Repellent chemicals sprayed on bedding /young trees. Aluminium ammonium - has a bitter taste so not suitable for edible crops which are close to harvesting.

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31
Q

What cultural control can be used to deter rabbits?

A

Planting resistant species such as Agapanthus, dahlia, snowdrop, clematis, berberis.

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32
Q

What professional techniques can be used to deter rabbits?

A

Rabbits can be killed by shooting, gassing or trapping.

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33
Q

What host plants does the Peach Potato aphid like?

A

The peach potato eats a wide variety of plants including fruits, flowers and vegetables.
It’s host in winter is lettuce and brassicas in egg form.
In summer it is a particular pest of the potato.
Also helps to transmit the Potato leaf curl virus.

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34
Q

What does the Peach Potato aphid look like?

A

2.6mm long.
Mostly pale green. (sometimes yellow & pink)
Soft pear shaped bodies.
Winged and wingless forms.

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35
Q

What damage does the Peach potato aphid do, and what are the signs?

A

They are sap suckers.
Large colonies will reduce plant vigour.
Aphids can also transfer virus’ from plant to plant.
They have an incomplete metamorphosis, so will shed their exoskeletons leaving white flakes on the leaf below, which looks like dandruff.
They excrete honey dew which ants will farm.

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36
Q

What damage should you look for when checking to see if you have got Peach Potato aphids?

A

Stunted growth.
Shiny leaf surfaces (honeydew)
Cream/white ash like substance of exoskeletons molted
Black leaf mould, which is sooty mould which grows on the sugar rich honeydew and prevents photosynthesis.
Distorted leaves - aphids destroy the balance of plant growth regulators and cause malformation of the growth tips.
Distortion and stunted growth indicating a virus. Aphid transmitted virus can result in plant death.

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37
Q

How can you control Peach Potato Aphids with biological control?

A

Biological -
Outdoors control with natural predators such as ladybirds, lacewing, hoverfly.
Greenhouse biological control - Aphidius - a parasitic wasp.

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38
Q

How can you control Peach Potato Aphids with chemical control?

A

Chemical control of Peach potato aphid.
Plant oil spray which blocks spiracles.
Fatty acids - soap sprays dries out cuticles and can block spiracles.
Deltamethrin - affects nervous system

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39
Q

How can you control Peach Potato Aphids with cultural control?

A

Cultural control of Peach potato aphid
Hand picking/squashing. Strong water jet to wash off.
Remove weeds in Brassica family - Capsella bursa-pastoris.
Use fleece to stop them spreading to susceptible plants.
Fine mesh over vents in greenhouse.

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40
Q

What preventative methods are there to help control spread of Peach potato aphid?

A

Preventative methods of controlling the Peach potato aphid -
Quarantine infected plants
Fleece barrier
Regular checks.
Encourage natural predators.
Do not overfeed as they like sappy growth.

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41
Q

Describe what the black bean aphid looks like?

A

Black 2mm long with pear shaped bodies.
Often referred to as blackfly, though it is not a fly.
They are piercing sap suckers.

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42
Q

What is the Black Bean aphid’s host plants?

A
Broad beans - common early in season.
French beans
Runner beans
Nasturtium
Dahlias
In Winter - Philadelphus, Euonymus and Vibernum.
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43
Q

What damage/symptoms are caused by Black bean aphids?

A

Commonly damage broad beans, but also runner and french beans.
Aphids have a sucking action and excrete honey , which can lead to sooty mould.
Plant growth stunted.
Seed production can be reduced. Broadbean pods do not develop well.
Misshapen leaves and pods form, as aphids disturb the balance of plant growth.
Sooty mould.
Aphids seen in a cluster at the soft growing tips.
Ash like cast skins - exoskeletons.

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44
Q

Describe the lifecycle of the Black bean aphid?

A

Overwinters in egg form on plants like Euonymus or Viburnum species.
All female nymphs emerge and feed on the host shrub, until winged females emerge and fly to the summer host - the broad bean (or french or runner bean).
Female aphids will feed and reproduce A sexually, until food source runs out, then more female winged Aphid’s will emerge and fly to a new host.
In Autumn, male and female winged aphids will fly to winter host where it will lay it’s eggs.

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45
Q

How can you control the Black Bean aphid biologically?

A

Outdoor natural predators - Ladybirds, lacewings and hoverflies.
In greenhouse - parasitic wasp.

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46
Q

How do you control Black bean aphid with chemicals?

A

Plant oil sprays which will block spiracles.
Fatty acids - soap sprays will dry out cuticles and may block spiracles. Particularly affective as they have a soft body.
Deltamethrin attacks nervous system.

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47
Q

What preventative methods can be used for Black bean aphid?

A

Quarantine infected plants to avoid spread.
Fleece barrier.
Regular checks
Encourage natural predators.
Do not overfeed, as they love sappy new growth.

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48
Q

What does the two spotted spider mite look like? (also called red spider mite)

A

Tiny 0.5mm wingless mite.
Turns orange/red when they hibernate over the winter.
Likes warm dry conditions so the heat of a greenhouse speeds up the life cycle.

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49
Q

Give some examples of host plants for the Two Spotted Spider mite?

A

Many greenhouse/ houseplants.
Cucumbers, tomatoes, aubergine, peppers.
Vines, peach, pelargoniums, poinsettias.
Fushcia in the greenhouse.

50
Q

What damage does the Two Spotted spider mite do, and what are the symptoms?

A

Fine pale mottling of upper surface of foliage and leaves lose their colour and fall.
Stunted growth.
Possible plant death.
Rupture leaf cells and cause localised cell death - mottling.
In heavy infestations see a fine silk webbing on the plants.

51
Q

How does the Two Spotted Spider mite feed?

A

The Two Spotted spider mite lack chewing or sucking mouthparts.
Instead they use a pair of needle like stylets to rupture leaf cells and push their mouth into the torn tissue to drink the cell sap.
Both immature and adult mites pierce plant tissues with their mouthparts and feed on cell contents.

52
Q

How does the Two Spotted spider mite (red spider mite) spread?

A

Spread by movement of infected plants or by gardener’s clothing.

53
Q

What time of year is the Two Spotted Spider mite active?

A

Likes warm dry conditions. So March - October.

Can be over longer periods in a heated greenhouse.

54
Q

How quickly can the Two spotted spider mite complete it’s lifecycle?

A

In hot dry conditions it can complete it’s lifecycle in as little as 7 days.

55
Q

When do the female Two spotted spider mite hibernate?

A

Between August and March females hibernate in crevices and leaf litter.

56
Q

What cultural methods of control can be used to deter the Two Spotted spider mite?

A

Remove infected plants from the glasshouse in late summer before lower temperatures and shorter days induce the female to seek sheltered places where they will remain dormant for the winter.
Clear out possible shelters - leaf debris, old canes before the spring.
Once empty, clean glasshouse with disinfectant.
Keep weeds down as they can act as a host.
Do not overcrowd plants, and maintain humidity through damping floors down and misting plants.
Spray water onto the underside of leaves as they dislike humidity and it reduces the breeding rate.

57
Q

What method of biological control can be used on the Two Spotted Spidermite?

A

A predatory mite can be used.

58
Q

What chemical methods of control are there for the Two Spotted Spidermite?

A

A plant oil spray will block spiracles.
A fatty acid spray will dry out the cuticle and may block the spiracles. (Particularly as they have a soft body).
Deltamethrin affects nervous system.

59
Q

Describe what the Cabbage White butterfly larvae look like?

A

The larvae are black with yellow stripes and obvious hairs.

Up to 5-10cm long.

60
Q

What damage does the cabbage white butterfly larvae do to plants?

A

Defoliate plants through feeding on the outer leaves.

Leaves can become skeletonised with just toughened veins remaining and the whole laminar eaten away.

61
Q

What are the host plants for the cabbage white butterfly?

A
Cabbages, broccoli, brussels sprouts, cauliflower, kale.
Shepherds purse (Capsella bursa-pastoris) the weed can also be affected.
62
Q

What symptoms should you look out for Cabbage White butterfly?

A

Holes in leaves.
Only veins left.
Larvae - caterpillars present on leaves.
Caterpillar frass (poo!)

63
Q

How does the cabbage white butterfly larvae (caterpillar) feed?

A

Biting

64
Q

When is the cabbage white butterfly active?

A

May - October

65
Q

How do the cabbage white butterfly larvae spread?

A

The adult butterfly flies and lays eggs on the leaves of the host plants.

66
Q

What is the outline lifecycle of the cabbage white butterfly larvae?

A

April/May - Adults emerge from overwintering pupa.
After mating, female lays batches of yellow eggs (20-100)
In 2 weeks eggs hatch.
Larvae munch and grow!
Instars moult as they grow to reach full size of about 25mm.
June - pupate in a crevice/woody stem.
July - second generation emerge and is more damaging than first.

67
Q

How can knowledge of the lifecycle of the Cabbage white butterfly larvae help in your preventative methods as a gardener?

A

There are batches of eggs laid in stages, so check leaves regularly and rub eggs off.
Do not remove fine mesh after first generation as there is a second generation to come.

68
Q

What physical methods of control are there for controlling cabbage white butterfly larvae?

A

Fine mesh net barriers or horticultural fleece over plants.
Care must be taken to ensure the netting doesn’t touch plants or that there are any gaps / holes the butterfly can fit through and lay its eggs.

69
Q

Biological control of cabbage white butterfly larvae?

A

Blue tits and starlings will eat larvae, but if there is a fine mesh then they can’t get to them or may become tangled in it so be careful.

70
Q

Chemical control of cabbage white butterfly larvae?

A

Deltamethrin affects nervous system.

71
Q

Cultural control of cabbage white butterfly larvae?

A

Inspect plants regularly and pick off the pale yellow eggs from the underside of the leaves. Also hand pick off caterpillars.
Remove weeds such as hedge mustard as this is a brassica, so they can feed on this.

72
Q

What does the Glasshouse white fly look like?

A
Small 1.5-2mm sap feeding insects.
Adult is white and moth like with wings.
Flutter off the plant when disturbed.
Hide on underside of leaves.
The immature stages are flat and oval scale- like nymphs.
73
Q

What lifecycle does a Glasshouse whitefly have?

A

An incomplete lifecycle.

74
Q

Where is glasshouse whitefly found?

A

In a glasshouse!!

Also other types of white fly seen on outdoor crops, such as Outdoor brassica White fly.

75
Q

How does the Glasshouse white fly feed?

A

Sap sucking/piercing.

76
Q

What damage to glasshouse plants does a Glasshouse whitefly do?

A

Stunted growth, weakened plants
Shiny honeydew on lower leaves and then sooty mould
Presence of clouds of small whitefly on underside of leaves when you brush against the plant.
Presence of creamy white scale like nymphs on underside of leaves
Can also transfer viruses

77
Q

When is the Glasshouse white fly active?

A

All year round. But mainly a problem in summer.

78
Q

How is the Glasshouse White fly spread?

A

by introduced plants or chance arrival of adults through vents and doors.

79
Q

Describe the outline lifecycle of the Glasshouse Whitefly?

A

Eggs turn black and hatch in spring - nymphs. (Crawlers)
Crawlers - They move around for a few hours.
Then they become immobile scales for about 3 weeks.
Adult male or female emerges from the final scale stage (like a pupa)
3 days later emerging female lays up to 200 eggs in neat circles

80
Q

What cultural control methods can be used for Glasshouse Whitefly?

A

Remove weeds to prevent overwintering.
Inspect lower leaves.
Quarantine new plants.
Removal of infested leaves (during early stages of development) when whitefly is scale like and immobile.
Hose down plants with fine but strong blast of water.
Monitor with yellow sticky traps to indicate populations.

81
Q

What biological control methods can be used for Glasshouse Whitefly?

A

Parasitic wasp most affective if applied when numbers are relatively low.
Scales turn black and release the next generation of wasps.

82
Q

What chemical control methods can be used for Glasshouse Whitefly?

A

Plant oil sprays will block spiracles.
Fatty acids (soap sprays) dries out cuticles and may block spiracles.
Deltamethrin affects nervous system.

83
Q

What physical control methods can be used for Glasshouse Whitefly?

A

Yellow sticky traps.

84
Q

What does the Vine Weevil look like and what does it do?

A

Adult vine weevil is a pointed nosed crawling and climbing beetle-like insect (9mm long) which lays its eggs at night.
These eggs hatch into vine weevil larvae which are creamy coloured ‘C’ shaped legless grubs with a brown head. These grubs are the major cause of damage of plants in containers.

85
Q

What are the host plants for Vine Weevil?

A

Cyclamen, strawberries, Rhododendron, Euonymus, Camellias, Heuchera, Fuchsia, Primula, Impatiens bedding plants.
Especially if in containers.

86
Q

What damage do Vine Weevil cause?

A

Adults eat crescent shaped notches from margins of leaves on many herbaceous perennials and rhododendrons. But rarely cause damage to affect the vigour of plants, just make evergreens look unsightly.
Larval stage is most damaging, eating roots of container plants such as Heuchera, Sedum, Primula, Cyclamen (in green house), Strawberry and Citrus plants.
Most plant losses occur during September to March, when the grubs are becoming fully grown.

87
Q

What are the symptoms of Vine Weevil?

A

Stunted growth, above ground yellowing and wilting symptoms, similar to water deficiency symptoms.
Notches in leaves. Seeing adults under pots or leaves or seeing larvae in compost.

88
Q

When are Vine Weevil active?

A

Adults are nocturnal and crawl and climb from late Spring to Autumn.
Males are rare.
Larvae feed on plant roots Summer to Spring and can kill plants.

89
Q

How is Vine Weevil spread?

A

By introduced plants or movement of adult females at night.

90
Q

How do Vine Weevil feed?

A

Biting

91
Q

Describe the lifecycle of Vine Weevil?

A

Life Cycle – Adults can over Winter
Larvae can over winter and pupate and hatch in the Spring as adults
Egg laying starts in Spring
There is only one generation but the hatchings are staggered

Most are female, males are rare and reproduction is asexual. Each female lays 500- 600 eggs.

92
Q

What methods of Cultural control can be used to control Vine Weevil?

A

Remove weeds and any plant debris where adults may overwinter.
Pick of adults in spring when weather is mild at night.
In greenhouses look under pots and staging where beetles hide in the day.
Pot toppers or top dressing of pots with 1cm sand, to reduce number of eggs laid.
Check new plants for pests.
Keep an eye on vulnerable plants.
Trap adults with sticky traps around pots.

93
Q

What methods of Biological control can be used to control Vine Weevil?

A

Encourage natural enemies - birds, frogs, toads, shrews, hedgehogs.
Nematode can be watered in - ideally in August /September for maximum effect.

94
Q

What methods of Physical control can be used to control Vine Weevil?

A

Sticky traps around the pots to trap the adults.

95
Q

What methods of Chemical control can be used to control Vine Weevil?

A

Acetamiprid as compost drench.

96
Q

What damage can slugs do and to which kinds of plants?

A

Rasping mouth that damages the stems, foliage, roots and bulbs, tubers of many plants.
Lettuce, marigolds, bedding plants, Dahlias, Hostas, petunias, tomatoes, courgettes, peas. New growth on herbaceous plants - Delphiniums!

97
Q

What are the symptoms of slug damage?

A

Slime trails, adult and eggs present, irregular holes in leaves, defoliation, collapsed stems. No plant! Holes in potatoes.

98
Q

When are slugs active?

A

Slugs are active most of the year. More active in warmer weather, combined with damp conditions greatly increases their activity. Slugs are most active after dark in wet weather.

99
Q

How do Slugs spread?

A

Movement of adults and juveniles. They are in every garden so cannot be irradicated.

100
Q

How do slugs feed?

A

Rasping.

101
Q

What cultural control methods can be used to control slug damage?

A

Copper, transplant stronger plantlets rather than young vulnerable lettuce seedlings, hand pick at night, beer traps,
Grow less susceptible varieties.
Clear slug hiding places.

102
Q

What biological control methods can be used to control slug damage?

A

Natural predators - Centipedes, ground beetles, birds, frogs, hedgehogs.
A nematode can be used - enters slugs’ bodies and infects them with bacteria that cause a fatal disease.

103
Q

What chemical control methods can be used to control slug damage?

A
Ferric phosphate (organically approved)  After ingesting the pest stops feeding and dies 3 days later but usually moves away so no dead slugs are found.  Metaldehyde pellets is being withdrawn in June 2019 so now not available.  
Both blue slug pellets.
104
Q

What physical control methods can be used to control slug damage?

A

Coarse sand, rough surfaces, copper tape, cloches.

A recent RHS study in a garden-realistic scenario however, found no reduction in slug damage from barriers made of copper tape, bark mulch, eggshells, sharp grit or wool pellets

105
Q

When can you find slugs?

A

Slugs are nocturnal and can be found in damp mild weather.

Active most of the year, but especially in damp warm weather.

106
Q

How do slugs reproduce?

A

Slugs are hermaphrodite ie each individual has male and female reproductive organs but they still need to pair up to breed. Some slugs have elaborate courtship rituals.
Most reproduction occurs in Spring and Autumn when the weather is mild and damp. Every individual can lay eggs - up to 300 for each slug. Eggs are laid in batches, usually 10-50, in moist but not waterlogged soil. Staggered generations.

107
Q

How long does the slug lifecycle last?

A

Usually 1 year.

Some slug species can live up to 4 years.

108
Q

Describe the slug lifecycle?

A

Most species found in gardens have an annual lifecycle lasting less than a year.
Can lay eggs in any month provided conditions are suitable.
For example, field slugs hatching from eggs laid in the spring will become adults and lay eggs in the autumn. Eggs laid in the autumn will develop into adults the following summer. Because its generations overlap, all stages of the field slug are present throughout the year.

109
Q

Where do many slugs spend most of their life?

A

Below the soil surface tunnelling like earthworms.

Slugs able to survive dry hot periods, because they can tunnel underground deep in the soil.

110
Q

Describe what the Potato Cyst eelworm looks like?

A

These are microscopic 1-1.5mm worm like organisms and cannot be seen by the naked eye.
There are 2 types - Golden Cyst eelworm and White Cyst eelworm.

111
Q

How does the Potato Cyst eelworm feed?

A

Potato Cyst eelworms (or nematodes) eat with a stylet which is like a modified tooth which helps the nematode to puncture the plant and feed off it.

Piercing and sucking.

112
Q

What damage does the Potato Cyst Eelworm do?

A

Pierce plant root cells and extract liquid. They disrupt the uptake of water and nutrients causing stunted growth and poor leaf colour.

113
Q

What plants are host to the Potato Cyst Eelworm?

A

Potatoes and Tomatoes.

They feed on the roots.

114
Q

What symptoms can be seen on plants infected by Potato Cyst eelworm?

A
Crops show poor growth.
Leaves turn yellow (Chlorosis)
Plants wilt.
Stunted growth.
Low yield.
Plants can be killed in extreme cases.
115
Q

When is the Potato cyst eelworm most active?

A

When soil is at Field Capacity - moist but not saturated.

116
Q

How does the Potato Cyst eelworm spread?

A

As cysts through infected soil.
On boots, tools, tyres.
Can also be blown in by the wind.
Can remain in soil for long periods even if ground is fallow.

117
Q

What is the lifecycle of the Potato Cyst eelworm?

A

Eggs inside cyst can remain viable for 10 years, as they hatch at a slow rate in the absence of host plant.

When tomatoes / potatoes are grown in infested soil, eggs stimulated to hatch in large numbers by chemicals in the roots of plants.

Male & female nematodes.

Spring - Male & female nematodes enter roots, disrupting uptake of water and nutrients.
Then Male & female nematodes burst through root wall to outside of root when almost mature.
Early summer - female nematodes bodies begin to swell, leaving only her head inside root.
Summer - male fertilizes the female and leaves the root. Female changes colour, and becomes a cyst, dropping from the root.

Autumn/Winter - cyst containing the eggs survives in the soil for many years.

118
Q

What methods of cultural control can be used for Potato Cyst eelworm?

A

Crop rotation to starve out the eggs - so there would have to be a long period when no potatoes are grown in the area.
Grow resistant cultivars - Kestrel, Maris Piper.
Remove volunteers.
Sanitise all boots/equipment that comes into contact with infested soil.
Dig out infested roots and weeds, and burn and destroy.
Greenhouses with infested soils, can be completely re-soiled, or grow tomatoes in grow bags or straw bales.

119
Q

What methods of biological control can be used for Potato Cyst eelworm?

A

Growing a mustard crop to the flowering stage as a biofumigant then incorporating as a green manure.
Chemicals contained in mustard reduce Potato Cyst eelworm population.

120
Q

What methods of Chemical control can be used for Potato Cyst eelworm?

A

There are no chemical methods of control.

121
Q

What damage should you look for when checking to see if you have got Peach Potato aphids?

A

Sap suckers.
Stunted growth.
Shiny leaf surface - honeydew
Black leaf surface - sooty mould griws on sugars from honeydew.
Distorted leaves
Distorted leaves and growth - indicating a virus.