This document summarizes biological control possibilities for common white grub pests in Belgium and the Netherlands. It describes the life cycles of key species like the garden chafer and Welsh chafer. Nematodes like Heterorhabditis and Steinernema are effective biological controls. Application involves spraying nematodes onto moist soil in the evenings at dosages of 0.5-1 million per square meter. Proper watering after application is important for nematode effectiveness.

1. Biological control of white grubs

2. Content
• Enemy species
• Most occurring white grubs in Belgium and the
Netherlands
• Biological control possibilities
• Chemical control possibilities
• Working of nematodes
• Life cycle:
– Garden Chafer
– Welsh Chafer
– Black vine weevil
– others
• Determination
12 May 2011

3. Enemy species
Lawns and sports fields
– Emelts = larvae of crane flies (Tipula)
– Click beetles = larvae of wireworms
– White grubs = larvae of beetles
(Coleoptera: Scarabaeidae = scarab beetles)
Perennials and shrubs
– Othiorynchus sulcatus = Black vine weevil
12 May 2011

4. 17 oktober 2012
Emelts

5. 17 oktober 2012
Click beetles Bron:www.zin.ru

6. 17 oktober 2012
White grub

7. 17 oktober 2012
Larva Black vine weevil

8. Most occurring white grubs
in Belgium and the Netherlands
• Hoplia philanthus = Welsh Chafer
(lawns, moist until drier sandy soils)
• Phyllopertha horticola = Garden Chafer (lawns)
• Amphimallon solstitiale = Summer Chafer
(lawns, dry sandy soils)
• Melolontha melolontha = Cockchafer (very local)
12 May 2011

9. Most occurring white grubs in Belgium
and the Netherlands (continued)
• Melolontha hippocastani = Chestnut Cockchafer (very
local)
• Serica brunnea = Brown Chafer
• Polyphylla fullo = Pine Chafer
• Aphodius sp. = Dung Beetle
• Anomala sp.
12 May 2011

10. Biological control possibilities
• Emelts (Tipula)
 nematode Steinernema feltiae (bad to moderate action)
• Bacteria preparation
based on Bacillus thuringiensis var. israelensis
(no homologation in Belgium and the Netherlands)
12 May 2011

11. Biological control possibilities
• White grubs
 B-Green (Heterorhabditis bacteriophora) as from 12 – 15°C
+++ Phyllopertha horticola
++ Aphodius contaminatus
+ Anomala dubia
+ Hoplia philanthus
+ Serica brunnea
- Amphimallon solstitiale
--- Melolontha melolontha
12 May 2011

12. Biological control possibilities
• White grubs (continued)
 Steinernema scarabaei most effective also against
Aphimallon and Melolontha
(not native in Europe and cannot be produced for the
moment)
• Black vine weevil
 Heterorhabditis-System (Heterorhabditis megidis) as from
12°C
12 May 2011

13. Chemical control possibilities
• Results are disappointing, better results when injected
• Chlorinated hydrocarbons (e.g. Lindaan), Temik
(aldicarb) and Confidor (imidacloprid) are forbidden, with
a Confidor injection the larvae stop feeding.
• Other carbofuran, chloorpyrifos, …..
12 May 2011

14. Working of nematodes
1. Nematode searches actively for a prey
– excrements
– cuticula
– respiration (CO2)
– temperature
1. Penetration through natural openings: mouth and anus
2. Movement to the intestinal canal and penetration
12 May 2011

15. Working of nematodes
4. Release of symbiotic bacterium
Steinernema: Xenorhabdus
Heterorhabditis: Photorhabdus
5. Bacterium releases toxin  blood poisoning within 48h
6. Reproduction of the nematode in the cadaver
7. Thousands of new nematodes leave the cadaver to
search for new prey
12 May 2011

16. Life cycle of Garden Chafer
(Phyllopertha horticola)
12 May 2011

17. Life cycle of Garden Chafer
(Phyllopertha horticola) (continued)
• Beetles (adults) copulate during the first night of their life and
then lay 85 % of the eggs in the neighbourhood of pupation.
During the next 3 weeks in May and June during the ripening
gluttony they fly in late morning (10 – 12h) and feed with
leaves.
Then they swarm out 3 to 4 km from the birth place to lay the
other 15 % of the eggs.
The larvae eat the roots of the grasses.
• Treatment period August-September before the larvae drain
deeper.
12 May 2011

18. Life cycle of Welsh Chafer
(Hoplia philanthus)
Fecundity before the end of June Year 1
Year 2: L3 as from April Year 1
L1 August
Year 3: L3 until April L2 September
Source: PCS
Pupation May Year 3
12 May 2011

19. Life cycle of Welsh Chafer
(Hoplia philanthus) (continued)
• The life cycle is spread over 3 years and the total development
takes about 24 months
• Year 1
– Adults (beetles) lay eggs
(25 to 40 per female end of June, flight radius ± 10 meters)
– Eggs hatch end of July, L1 white grubs in August
– As from September L2 white grubs
(These white grubs hide in the winter months deeper in the
soil)
12 May 2011

20. Life cycle of Welsh Chafer
(Hoplia philanthus) (continued)
• Year 2
As from April, May L3-larvae, year with the most damage
• Year 3
L3 white grubs colour in April and May completely white and
pupate in May
• Treatment period in April and May on L3-larvae when the soil
temperature contains 15°C.
12 May 2011

21. Control of Welsh Chafer
(Hoplia philanthus)
12 May 2011

22. Black vine weevil
(Othiorynchus sulcatus)
Fecundity before the end of May
Larvae as from June
Pupation around May
Source:
PCS
12 May 2011

23. Black vine weevil
(Othiorynchus sulcatus) (continued)
• Adults around the end of May damage leaves and lay
eggs. Eggs come out and become larvae (white grubs),
which eat the roots. Pupation occurs around the month
of May.
• In protected crops the development stages overlap.
• Treatment period at soil temperatures above 12 – 15°C
– April-May: against pupating larvae
– August-September: against larvae which have just come
out
12 May 2011

24. Others
• Summer Chafer: 2-year life cycle, fly in the evening
• Cockchafer: 3- or 4-year life cycle
• Brown Chafer: 2-year life cycle, treatment period
April-July
• Pine Chafer: 3 to 4 years
12 May 2011

25. Determination
• Adults are often not detected which is the reason why
identification is done with white grubs
• Running white grubs
– Phyllopertha horticola
– Anomala dubia
• Twisting white grubs
– Hoplia philanthus (reddish dorsel hair = )
– Melolontha melolontha
– Amphimallon solstitiale
– etc.
12 May 2011

26. Determination
Garden Chafer larva (Phyllopertha horticola)
12 May 2011

27. Determination
Garden Chafer larva
12 May 2011

28. Determination
Adult Garden Chafer
Bron:www.zin.ru
Source: Paul Parey
12 May 2011

29. Determination
Black vine weevil larva
12 May 2011

30. Determination
Black vine weevil adult
12 May 2011

31. Determination
Welsh Chafer larva (Hoplia philanthus)
12 May 2011

32. Determination
Welsh Chafer larve
12 May 2011

33. Determination
Adult Welsh Chafer
Source: Ingrid Altmann
Source: Paul Parey
12 May 2011

34. Determination
Summer Chafer (Amphimallon solstiale)
12 May 2011

35. Determination
Summer Chafer larve
12 May 2011

36. Determination
Adult Summer Chafer
Source: entomart
Source: Paul Parey
12 May 2011

37. Determination
Cockchafer (Melolontha melolontha)
12 May 2011

38. Determination
Cockchafer larve
12 May 2011

39. Determination
Adult Cockchafer
Source: Paul Parey
12 May 2011

40. Application
• Always use an entire packing
• Remove all filters from the spray equipment
• Use spray caps with a diameter of min. 0.8 mm
• Use a good stir installation or return
• Apply in the evening or on a cloudy day
• Sprinkle the soil before application
• Sprinkle after application with 2 to 5 liters per m²
(depending on the tatch)
• Keep the soil moist during 4 weeks
12 May 2011

41. Dosage
• Heterorhabditis-System (Heterorhabditis megidis)
– Preventive: 0.5 million nematodes/m²
– Curative: 1 million nematodes/m²
• B-Green (Heterorhabditis bacteriophora)
– Curative: 0.5 million nematodes/m²
12 May 2011

42. Packing
• Heterorhabditis-System:
– 50 million
– 200 million
• B-Green:
– 50 million
– 500 million
12 May 2011