Insect Pests

1. Insect Pests

2. Cabbage White Butterflies
Pieris Brassicae
Day 1
Day 2-11
Day 11-18
Day
18-26
Day
26-55

3. Cabbage White Butterflies Pieris Brassicae
Caterpillars damage cabbage, [white & coloured]
swede, turnip, radish, horse-radish, garden radish,
rape & other crucifers.
They occur also on nasturtium, capers, onions, & hedge garlic
Crop rotation, removal of plant debris from fields, insecticides in the period of
caterpillars hatching & biological control
e.g. Apanteles glomeratus & Hyposoter vulgaris
Control Measures

4. Very long life cycle, with individual larvae often living 2-3 years in the soil
Adults emerge and fly in the spring
Potato crops following grain crops or weedy fallow are especially at risk
Damage can occur in spring to seed pieces, to tubers during bulking,
and after vine kill (avoid in-field storage to prevent the latter type of
damage)
Holes these pests make are then exploited by slugs, which enlarge the
hole & devour the tuber from the inside
Wireworms Elateridae

5. Control Measures
Nemasys Chafer Grub Killer
Nematode - heterorhabditis megidis
Most commonly used for the control of chafer grubs
Not been specifically tested for control of wireworms
but the producers of this nematode are confident a
good degree of control can be obtained.
Soil insecticides applied at planting e.g. Mocap, Nemathroin,

6. Yellowing of the grass in a similar way
as Leatherjackets
Also the turf can be damaged by birds
Starlings, Magpies & Crows
as they dig for the grubs
+ badgers can be very destructive,
leaving a trail of small craters
Cockchafer Grubs
Melolontha melolontha
Quite destructive to cereal &
other grass plant roots.
Live in the soil for 3 or 4 years
Adult beetles
35mm long & can fly, usually at dusk in May
Also destructive, feeding on flowers & foliage
Control Measures
Nematode - heterorhabditis megidis

7. Over winter in the soil near the host plant
Eggs hatch from March to May and larvae feed on the foliage during the daytime
Larvae then return to the soil to pupate and emerge as adults
Turnip Flea Beetle
Leaves, flowers, stems & seed pods
Young seedlings & transplanted plants are most
susceptible to injury during heavy infestations
Larvae have a long segmented body
Pupae are bright orange
Control Measures
Seed dressings - benzene hexachloride
Dried quickly, was not dusty & was ready for drilling in about ±1/2 h
Did not impair germination
Under extremely heavy attack, a single subsequent surface dusting would still be necessary

8. Control - Non-chemical control
Regularly check the plants from mid-April onwards for sawfly larvae and pick them off by hand
A pathogenic nematode, enter the bodies of the sawfly larvae & infect them with a bacterial disease
Chemical control
Spray when young larvae are seen, with an insecticide approved for use on
gooseberry and red currants - lambda cyhalothrin
Severe defoliation of the bushes
can be caused by the caterpillar-like larvae,
which are up to 20mm (almost ¾in) long
Adult females are 5-7mm (up to ¼in) long
Gooseberry Sawfly Nematus ribesii
Red/White Currant Bushes

9. Codling Moth Cydia pomonella
The most important pest of Apples & Pears
Adult moths first emerge in May followed by a second
generation and occasionally a third as the summer
progresses. After mating, the female moth lays eggs on the
developing fruit.
Eggs hatch in one to two weeks and tiny larvae burrow into
the apple immediately, usually around the calyx end.
The larva feeds as it bores into the apple + feeds on the
seeds and core. As it matures, it tunnels back out to
develop to the adult stage.
Steinernema
Carpocapsae
[Nematode]
or
Deltamethrin
Control

10. Apple Sawfly Hoplocampa testudinea
Maggot holes with the larva’s blackish-brown
excrement pellets
Affected fruitlets drop off
Fruits are misshapen and have a long ribbon-like scar
about 4mm wide
Chemical Control
Pick off damaged fruitlets
Spray within seven days of petal fall with deltamethrin

12. Vine Weevil Otiorhynchus sulcatus

13. Vine Weevil Otiorhynchus sulcatus
March and April indoor pots &
May and June from outdoor pots and borders.
Female lays between 500 to 1, 500
eggs into the soil.
Eggs hatch 10-15 days later into white C-shaped
larvae with brown heads, which begin feeding on
roots, tubers, corms and the lower stems of
susceptible plants.
They grow to around 1.5cm in length.

14. The larvae remain in the soil until they emerge as adults.
Most adults will die in late autumn when cold weather sets in.
Although those in houses can often survive into the next year.
Overwintering larvae will feed on the deep roots in the soil &
pupate around late April to early May.
Vine Weevil Otiorhynchus sulcatus
Chemical Control Non-chemical Control
Systemic insecticide
Thiacloprid (in liquid form as a soil drench) Nematodes (Steinernema kraussei)

15. Biological control –
Naturally-occurring soil fungus - Metarhizium anisopliae.
Commercial non-food use, including application on ornamentals, shrubs,
forest & shade-tree seedlings. Met 52
• Extensively researched in
Britain, Europe & North America
• Trials have demonstrated long term
control for up to 2 years
• Viable over a wide temperature range
• Resistance unlikely
• No problems with chemical residues

16. Brown-tail Moth Euproctis chrysorrhoea Linnaeus
The caterpillars are well-known for their
urticating hairs; they cause extreme
irritation if in contact with human skin.
They feed in a communal web on the
leaves of hawthorn (Crataegus) &
blackthorn (Prunus spinosa).
Control - Larvicide

17. European Pine Sawfly Neodiprion sertifer
Female sawfly deposits larvae
eggs in current year’s needles
near branch ends.
The eggs over winter in the
pine needles,
(looks like white spots on needles),
and hatch in late April to mid-May.
The larvae feed in groups and eat only pervious year’s needle growth,
feeding on one branch completely before moving to the next.
Feeding season is short, 2 weeks – but multiple generations
Susceptible Species: Mugo, Scotch, Jack and Red Pine.
White and Austrian Pine are less preferred by the host.
Control
Strong liquid dish soap with the water or
spray infested trees or Pyrethrin

18. 280 Million Years

19. Aphids
Sap-sucking insect pests, 1-7mm long.
Aphids are also known as greenfly & blackfly,
but other types may be yellow, pink, white or mottled.
Woolly beech aphid & woolly aphid on apple,
cover themselves with a fluffy white waxy secretion.
Feed on foliage, stems & flowers
Ornamental plants, vegetables & fruits,
greenhouse plants & houseplants.
500+ aphid species in Britain.

20. Symptoms
Some aphids transmit viruses, this is a particular problem on
strawberries, raspberries, tomatoes, cucumbers, dahlias, tulips and sweet peas.
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22. Excreting a sticky substance (honeydew) on foliage, which attracts the growth of sooty moulds.
Symptoms
Sticky Traps

23. Lacewings Ladybird/ Larva
Non-chemical Control

24. Aphidius spp
Parasitized
Aphid
Mummies

25. Aphid Midges Aphidoletes aphidimyza
Midge larva paralyses each aphid by
attacking its leg joints and then sucks it dry,
leaving a blackened, collapsed aphid
attached to the leaf.

26. Whitefly Trialeurodes vaporariorum
Whiteflies actually are not flies -
related to aphids 1200 species
Cucumber, Melon, Tomato, Peppers,
Chrysanthemum, Gerbera,
Pelargonium, Fuchsia, Lantana,
Poinsettia & Verbena
Brassicas, Viburnum tinus, Rhododendron,
Pesticide-resistant strains, biological
control often gives better results

27. Whitefly Biological Control - Encarsia Formosa
Eretmocerous californicus - "blood feeding"

28. Scales or shell-like bumps on plant stems &
underside of leaves.
Heavy infestations may result in poor
growth.
Some species of scale insect excrete
honeydew
A wide range of ornamental plants,
fruit trees & shrubs
25 different species
Soft Scale Coccus hesperidum
Systemic Insecticides - thiamethoxam
Control

29. Slugs Gastropod Mollusc
Mucus is hygroscopic
Hermaphrodites, having both female & male reproductive organs
Important ecosystem – dead leaves, fungus, decaying vegetable material, worms
Frogs, toads, snakes, hedgehogs, rats,
birds, some beetles
When attacked - contract their body, making
themselves harder & more compact, +
more slippery mucus

30. Snails Cornu aspersa
Most active after dark
or in wet weather
Eating roots, leaves, stems,
fruits, seedlings, soft growth,
plant crowns,
Irregular holes in plant tissues
with their rasping mouthparts

31. Pneumostome
Control
Iron Phosphate

32. Spider Mites

33. Mite family Tetranychidae, which includes about 1,200 species
Generally live on the under sides of leaves of plants.
May spin protective silk webs.
Damage by puncturing the plant cells to feed.
Known to feed on several hundred species of plant.
1mm & vary in colour.
They lay small, spherical, initially transparent eggs.

34. Hot, dry conditions.
Spider mite can hatch in 3 days, &
become sexually mature in 5 days.
1 female can lay up to 20 eggs per day &
can live for 2 to 4 weeks.
Accelerated reproductive rate - adapt quickly &
resist pesticides/miticides
1000,000
mites in a month or less

35. Horticulture Week 30/03/12

36. Hungry Beasties,
3rd November 2010
By Anon
Very effective spider mite treatment –
all signs of mite infestation had disappeared
after less than three weeks.
A simple, easy to use product.
Phytoseiulus or Amblyseius sp
Release early when mite populations are low and spider mites are first noticed.
Voracious, specialist predatory mite needs to have spider mite prey
or it will disperse or starve.
Adults & nymphs actively search for prey and suck them dry.
Spider mite colonies should be reduced in 2 to 3 weeks.

37. Root Knot Eelworm

38. Attack tomatoes, cucumbers, carrots,
parsnips,
Nematode feeding & egg laying on
roots = swellings
Should not be confused with nitrogen
fixation nodules on legumes
Severe infestation results in stunted
growth, yellowing of leaves,
wilting, poor yield,

39. Control
Clear up infected plant debris & weed out unwanted plants.
Crop rotation – nematode lives 2 years without host species.
Resistant varieties.
Growing French & African marigolds (Tagetes) &
ploughing them in the soil keeps this pest at bay.

40. Asparagus Beetle Crioceris duodecimpunctata

41. Pest adult & larval stages
Heavy infestations weaken the plants
& poor crop in the following spring
Eat foliage & gnaw bark from the
stems - point of damage dries up
Adult beetles 6-8mm (1/4in), black in
colour with six yellow blotches on
their wing cases & a reddish thorax

42. Non-chemical control
Burn old stems at the end of the year
to destroy overwintering beetles.
Hand pick the beetles and larvae from plants
when seen from late spring onwards.
Biological control
Steinernema feltiae
Highly effective
No resistance issues
High quality, easy to apply and almost no residue
Compatible with natural enemies
& many pesticides
Chemical control
Pyrethrum
If the plants are in flower,
spray at dusk to avoid harming bees.

43. Correct PPE for Spraying –
Herbicides, Pesticides, Insecticides, Fungicides

44. Spraying Safety
I have
been
spraying
today!

45. Health and Safety at Work Act 1974
Also referred to as HASAW or HSW,
is the primary piece of legislation covering
occupational health and safety
in the United Kingdom.
The Poisons Act 1972
Control of Pesticide Regulations 1986

46. www.linkedin.com/in/fenwickrichard

47. By
Richard
Fenwick