R2103 3.1 – 3.4 Pests COPY Flashcards

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1
Q

Give 3 methods of pest feeding.

A

Biting mouthparts (aphids, vine weevil, rabbit, deer)

Piercing/sucking mouthparts (whitefly)

Rasping mouthparts (molluscs)

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2
Q

Describe the damage done by cabbage white butterfly, and 2 methods to minimise.

A

Leaves of brassicas, nasturtiums etc are gradually eaten away. Skeleton leaves may result. Larvae and excrement on leaves. Cover crops with fine netting. Pick off larvae. Encourage blue tits by building nest boxes. Spray with insecticide containing pyrethrum.

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3
Q

Outline the lifecycle of the cabbage white butterfly.

A

April/May: butterfly emerges from pupa April/May and July/Aug: females lay < 50 yellow/skittle-shaped eggs on underside of brassica leaves + 4–14 days: eggs hatch into caterpillar larvae which feed on the leaves and go through 4 moults (instars) for a month + 2 weeks (June): larvae form a pupa + 10 days (July/August): adult emerges winter: pupa over-winters

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4
Q

Describe the damage done by black-bean aphid, and 2 methods to minimise.

A

Most commonly damaged are broad beans. Dense swarms of aphids on soft new growth and flowers. Shoots weakened by the aphids sucking phloem out of shoots. Aphids secret sugary liquid (honeydew) that can get infected by sooty mould. Growth is affected and seed production dramatically reduced. Control biologically by encouraging ladybirds, lacewings, hoverflies. Physical hand squishing. Spray with insecticide containing Pyrethrum, or natural fatty acids.

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5
Q

Outline the life cycle of black bean aphid.

A

Eggs overwinter on woody host e.g. Euonymous europaeus or Vibernum opulus. Spring: female nymphs emerge, feed on winter host. At maturity they grow wings and fly to summer host such as beans. Females give birth to many live young. In autumn these live young include males and along with females they fly back to winter host to mate and lay eggs.

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6
Q

Describe the damage done by peach-potato aphid. And 2 methods to minimise.

A

Greenfly Glasshouse and hot outdoors Sucking stylet - inject a digestive juice - distorts tissues Secrete honeydew - blocks stomata - attracts sooty mould - slows photosynthesis/growth Transfers viruses such as leaf roll virus, mosaic virus Control by ladybirds, lacewings, hoverflies Insecticide containing Pyrethrum, or fatty acids

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7
Q

Describe the damage done by two-spotted spider mite. And 2 methods to minimise.

A

Piercing and sucking mouth parts inject poison into leaf cells, causing localised death Yellowish mottling of the leaf. Lose green colour, dry up and drop off. Severe infestations – fine silk webbing. Chemical – spray insecticides containing fatty acids. Biological – introduce predatory mite. Cultural – check all new plants. In winter clean and disinfect.

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8
Q

Name the predatory mite used as biological control for red spider mite.

A

Phytoseiulus persimilis Can’t be used in conjunction with any other chemicals other than organic whilst awaiting delivery.

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9
Q

Describe the damage done by glasshouse whitefly. And 2 methods to minimise.

A

Attacks Solanum persicum and other greenhouse plants. When plant disturbed clouds of small white winged insects fly up. Flat oval, scale-like nymphs on underside of leaves. Honeydew on foliage which attracts black sooty mould Biological – Encarsia formosa parasitic wasp Sticky yellow sheets hung above plants to trap whitefly. Quarantine new plants. Chemical – Pyrethrin and fatty acids

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10
Q

Name the parasitic wasp used as a control for greenhouse whitefly.

A

Encarsia formosa

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11
Q

Outline the lifecycle of glasshouse whitefly.

A

Adult lays eggs Eggs – 200 minute white rugby-ball shaped in circular pattern on under side of the leaf. Eggs turn black Hatch into nymphs (crawlers) which then turn into scales 3rd instar Pupa Adult Lays eggs again 3 days later.

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12
Q

Describe the damage done by vine weevil. And 2 methods to minimise.

A

Damage grape vines, and tubers such as cyclamen and begonias Irregular-shaped notches on leaf margins in summer Plants wilt and die during autumn – winter due to white grubs eating roots. Cultural – encourage natural predators such as birds, shrews, frogs etc. Picking/shaking off adult weevils at night in summer. Biological – nematodes Chemical – Bug Clear Ultra vine weevil killer

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13
Q

Outline the life cycle of the vine weevil.

A

Adults feed on leaves and then lay eggs in august in soil or compost next to roots of Cyclamen or Begonia. Larvae emerge white and legless with brown head usually lying in C-shape. Pupate in soil in December and adult emerges.

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14
Q

Describe the damage done by slugs and 2 methods to minimise.

A

Feeds with radula and can scoop out cavities. In moist warm weather damage is done to leaves of hostas etc. Completely eat young seedlings Irregular holes in plants Slime trails Biological - Nemaslug nematodes watered in in spring Place traps such as scooped out citrus halves, jars filled with beer Hand pick with torch. Encourage frogs and birds Copper tape around pots

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15
Q

Outline the lifecycle of a slug.

A

Hermaphrodite slugs mate in spring summer and lay clusters of pearl-like eggs in rotting vegetation or under pots.

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16
Q

Describe the damage done by potato cyst eelworms and methods to minimise.

A

Stunted potato plant, yellow leaves turn brown and hang down Cysts on the roots. (Dead body of females containing up to 600 eggs) Use of resistant cultivars such as Maris Piper and certified seed. Four-year crop rotation or more

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17
Q

Outline the life cycle of potato cyst eelworm (nematode).

A

Eggs hatch in spring and larvae invade roots and suck up cell contents. Once larvae are fully developed they wriggle to outside of root. Female leaves head buried in root and swells. Males leave root and fertilise females. Females change colour and form cyst which then drops from the root into the soil where it can survive many years with eggs inside.

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18
Q

Describe how insects breathe.

A

Insects breathe through holes in their abdomen called spiracles which lead to an internal breathing system of tracheae.

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19
Q

Name 3 entry points for insecticides into insects.

A

Waxy exoskeletons can be penetrated. Spiracles allow fumigant chemicals in or are blocked by sticky pesticides. Digestive systems take in poison to stomach.

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20
Q

Which pests have a winter host?

A

Aphids Black fly /black bean aphid – Euonymus Europaeus Greenfly – peach potato aphid – Prunus

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21
Q

Which weed is a host for clubroot?

A

Capsella bursa pastoris (chickweed)

22
Q

Method of reducing effects of black bean aphid?

A

Pinching out tops of broad beans Spray with organic pesticide – fatty acids

23
Q

Method of reducing effects of two-spotted spider mite

A

Increase relative humidity in greenhouse by damping down floors and misting foliage. Biological control with Phytoseiulus persimilis.

24
Q

Method of reducing effects of glasshouse whitefly?

A

Sticky yellow traps to monitor and control. Biological control with Encarsia formosa.

25
Q

Method of reducing effects of vine weevil?

A

Inspecting container plants for grubs, staging and outdoor plants for beetles, and removing. A compost drench of a systemic pesticide.

26
Q

Method of reducing effects of slugs and snails?

A

Beer traps Attracting predator to the garden such as hedgehogs, by providing suitable habitats

27
Q

Method of reducing effects of potato eelworm?

A

Use early potato crops. Use resistant cultivars.

28
Q

Name i) a glasshouse pest ii) an outdoor pest

A

(i) 2-spotted spider mite Glasshouse whitefly (ii) Rabbits Cabbage white larvae Black bean and peach potato aphid Vine weevil Slug Eelworm

29
Q

What two named beneficial organisms can be encouraged into a garden to help control peach potato aphid?

A

 Blue tits can be encouraged with the provision of food e.g. bird seed and fat balls and hedges and bird boxes for nesting  Parasitic wasps e.g. Ahidus praon can be supplied as parasitised aphids which can be placed on plants in the evening. Rove beetles can also be used  Ladybirds and lacewings can be encouraged by providing overwinter shelter in hollow stems, herbaceous material, crevices in walls etc. or by purchasing products which provide a similar habitat and are called ‘insect hotels’.

30
Q

State a named example for each of the following control methods for black bean aphid: Physical Chemical

A

Physical – squashing/rubbing aphids off between finger and thumb, removal of the bean shoot tips by pinching out by hand before the aphids are able to colonise the plant and using a strong jet of water to wash aphids from an infested plant, without causing damage to the plant. Chemical – The use of fatty acids, pyrethrin or deltamethrin.

31
Q

Describe how slug populations can be controlled using a microscopic biologicalcontrol.

A

 The nematode Phasmarhabditis hermaphrodita which is available in a spore form is used.  The nematode is applied as a drench to moist soil.  The soil temperature must be above 5°C.  The nematode invades the slug, infecting it with bacteria.  The nematodes feed on the slug body, causing death, and also reproduce in it.  A second application may be required if tender seedlings are grown later in the year.

32
Q

State 2 benefits and 2 limitations of using biological control to minimise the population of pests.

A

Benefits:  Reduces the use of chemicals  Reduces operator exposure to harmful chemicals  Reduces the incidence of pest resistance  Does not harm beneficial insects  Maintains pest/predator balance  Targets specific pests Limitations:  Requires a knowledge of the pest life cycle  May require a controlled environment  Must accept some pest damage  Must apply when conditions are right  Each pest requires a different control agent  Effects may not be immediate

33
Q

State biological and cultural control method for slugs

A

Biological: using the nematode Phasmarhabditis hermaphrodita

Cultural: removing any rotting debris where slugs can hide or by surface cultivation to expose slug eggs to predators.

34
Q

State biological and cultural control method for glasshouse whitefly

A

Biological: by using the parasitic wasp Encarsia formosa or the predatory mite. Cultural: new plants can be placed in quarantine and good hygiene should be practiced by frequently cleaning the greenhouse and glass and removing host weeds that harbour the pest.

35
Q

State biological and cultural control method for black bean aphid

A

Biological: by using the parasitic wasp or the predatory midge. Cultural: pinching out the tender growing tips of plants before the aphids appear or sowing an autumn crop of beans which are less susceptible to attack as the growing tips will have matured.

36
Q

Describe a suitable method of chemical and physical control for the large cabbage white butterfly.

A

i) Chemical: e.g. deltamethrin applied as a spray at the larvae stage in the pest’s life cycle. Other suitable chemicals included; Fatty acids, ii) Physical: by covering the crop with fine netting, ‘Enviromesh’ or horticultural fleece before the adult lays eggs. The netting must not touch the crop.It is important to inspect the plants frequently and pick off and squash the eggs or caterpillars to prevent the crop from being damaged.

37
Q

State 2 distinct methods used to minimise the damage caused by the cabbage white butterfly.

A

 A bacterial spray of Bacillus thuringiensis for the larval (caterpillar) stage.  Crops can be covered by fine netting to prevent the adult butterfly from laying eggs.  Use of the chemicals Deltamethrin or Cyhalothrin can be used to kill the larval stage (caterpillar).

38
Q

State 2 ways of limiting the spread of potato cyst eelworm (other than using a resistant cultivar).

A

 The use of early crop potatoes so that the eelworm has less chance to develop.  Ensuring good hygiene to avoid transfer of soil on boots, tools etc.  Reduce possible contamination by growing potatoes in pots with fresh, sterilised soil.  Sowing Solanum sisymbriifolium to trigger the eggs to hatch. The eggs cannot develop in the roots, which helps eliminate the soil of live eggs.

39
Q

Give example of biting pest.

A

Beetles and caterpillars. Consume plants directly.

40
Q

Give example of piercing/sucking pest.

A

Aphids. Thread their mouth parts through intercellular spaces, tap into the plant’s vascular system, and feed by withdrawing sap from the phloem.

41
Q

Give example of raspers.

A

Molluscs. Rasping, scraping or slicing the surface of the plant tissue and sucking out the fluids from the ruptured cells.

42
Q

What growth stage does cabbage white (large) do its damage?

A

Larval (caterpillar). Vast quantities of plant material eaten by the biting mouthparts.

43
Q

Symptoms of black bean aphid damage?

A

Colonies appear on young shoots. Shoots become distorted and plants weakened.

44
Q

What growth stage does peach potato aphid do its damage?

A

Nymph and adult. Directly by piercing the leaf with their feeding tubes and sucking the sap, or indirectly by infecting the plant with a virus.

45
Q

Describe the damage caused to plants by the peach potato aphid.

A

Sap sucking - yellowing, mottled leaves and curled/puckered/distorted young growth. Youngest leaves and shoots, or on the underside of older leaves. Honeydew excreted on the leaf by the aphid which leads to the secondary infection of sooty mould. Reduced psn. The stylets of aphids can also transmit viruses such as severe mosaic virus (on potatoes), and tomato aspermy virus (on chrysanthemums).

46
Q

Describe TWO distinct symptoms of vine weevil damage.

A

‘Notching’ of the leaf edges carried out by adult weevils on evergreen foliage. Root damage carried out by the larvae which causes wilting, total collapse and often death of the plant, especially in ornamental herbaceous plants.

47
Q

Describe how glasshouse whitefly feed, including the damage they cause.

A

Piercing-sucking mouthparts Like aphids they feed on the sap and cause a sticky honeydew residue, often leading to a sooty mould which lowers the rate of psn Growth is stunted and crop yields lowered

48
Q

Name ONE pest that causes damage by biting.

A

vine weevil, deer, rabbit, caterpillars

49
Q

Contact-action synthetic pyrethroid?

A

Provanto Ultimate Fruit (has deltamethrin)

Westland Resolva Bug Killer (has lambda-cyhalothrin)

50
Q

Plants for whitefly/aphid predators?

A

calendula, buckwheat (Fagopyrum esculentum), thistles, oregano, fennel, parsley, poached egg plant (Limnanthes douglasii)

51
Q

Cultural control for cabbage white?

A

Flowers and blooming herbs - nectar for beneficial insects, such as garden wasps, parasitic wasps and insect-eating birds. Check plants regularly, especially for the appearance of holes in the leaves and caterpillar excrement. Remove caterpillars by hand or use a hose daily to knock them off the plants and expose them to ground-dwelling predatory beetles and insectivorous birds. Nasturtiums will attract cabbage butterflies away from the crop.