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Pests in public gardens
 
Aphid
Horse chestnut leafminer
Vine weevil
Garden chafer
Caterpillars
Slugs
General remarks on biological control in Public gardens
 
Before introducing beneficials, the greenhouse and plants should be free of harmful pesticide residues.
In case of doubt about the side effects of pesticides, contact your advisor or consult the Side Effects Manual.
Biological control of aphid
  More than 600 aphid species are present in Belgium. The most common is the Peach Potato Aphid.
  Adalia-System (ladybird - Adalia bipunctata)
 
Introduce 50 to 100 Adalia larvae per m² in hot spots.
  Adalia-System-Plus (ladybird - Adalia bipunctata)
 
The jute sachets with larvae of Adalia bipunctata are suspended in trees, shrubs or bushes. The number of sachets needed will depend on factors such as severity of pest infestation, density of the crown or bush, trunk circumference, etc.
  Spruzit
 
This product acts by contact and is based on a natural pyrethrum. It is effective against all biting and sucking insects. The recommended application rate is 3 ml per liter. The product is packed in 100 ml plastic bottles.
This product is only available in Belgium.
Monitoring of chestnut leafminer
  The horse chestnut leafminer, Cameraria ohridella, has become a major problem in the last few years. Larvae of this moth cause a lot of damage in mainly Aesculus hippocastanum.
  Pheromone Cameraria ohridella
 
The pheromone for the horse chestnut leafminer can be used in combination with a Funnel trap. The pheromone attracts males, which are then captured in the trap. This makes it possible to follow the evolution of the pest population and to take action if necessary.
This product is only available in Belgium.
Biological control of vine weevil
  Vine weevils, Otiorhynchus sulcatus, occur mainly in crops such as taxus, rhododendron, azalea, etc. Weevil larvae cause a lot of damage by eating the roots of these plants.
  Heterorhabditis-System (H. megidis)
 

There are two critical periods of application. The first period is April-May when larvae start pupating; the second around the end of August and beginning of September.
The most important factors for application of this product are:

  1. A minimum soil temperature of 12°C
  2. The soil has to be kept moist during minimum 2 weeks.
  3. Active larvae must also be present.
Application rate: 1 million nematodes per m².
Biological control of the garden chafer
  Garden chafers, Phylloperta horticola, can cause a lot of damage in grass fields and sport fields. Chafer larvae eat the roots of the grass, causing the turf to turn brown.
  B-Green (H. bacteriophora)
 

The optimal period when to use this product starts around mid-July and lasts until the end of September. Sometimes, it is possible to apply B-Green earlier or later, depending on the climate.
The most important factors for application of this product are:

  1. A minimum soil temperature of 12°C
  2. The soil has to be kept moist during minimum 2 weeks.
  3. Active larvae must also be present.
Application rate: 1 million nematodes per m².
Biological control of caterpillars
  Caterpillars of butterflies and moths cause damage to trees (damaged trees loose their leaves prematurely). Some caterpillar species can even represent a danger for the public health if they are present in large numbers (e.g. Oak Procession Moth Thaumetopoea processionea).
  Scutello 2x and Scutello (only avialable in Belgium)
 

This is a biological preparation based on spores of the bacterium Bacillus thuringiensis. After eating plant parts that were sprayed with the preparation, caterpillars become infected with the bacterium. Infected caterpillars move slowly, discolour and die.

 

Biological control of slugs
 

Slugs cause the most damage, but snails also eat ornamental plants. The characteristics of slug damage are small to large holes in the leaves, together with typical mucus spores. Slugs are especially active during the night at moist and warm weather.
  1. Control of snails
Ferramol
 

Ferramol is a new snail bait based on ferri-phosphate. This product attracts the snails; after eating Ferramol, the snails stop feeding and eventually die. This product is safe for humans and animals; birds are not attracted by this product.
This product is only available in Belgium.
  2. Control of slugs
  Phasmarhabditis-System
 

Phasmarhabditis-System provides an effective biological control of slugs. The activity of this product is based on a specific strain of the insect-parasitic nematode Phasmarhabditis hermaphrodita. After application, these nematodes actively search for slugs to destroy them.
  Ferramol
 

Ferramol guarantees an efficient slug control.
This product is only available in Belgium.
 

 

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