Scale Insect

A mostly sedentary pest found on the undersides of leaves and on stems of many ornamental plant species, especially foliage plants in permanent displays. Damage may be due to copious amounts of honeydew that many species of soft scale produce and the associated sooty moulds that grow on honeydew. Armoured or hard scale insects do not produce sticky honeydew and can be more difficult to control. Dead scale insects can remain on plants for several months and may require physical removal to clean up an infection.

Fightascale H (Hard Scale) (Chilocorus nigritus)
Type: Small predatory ladybird beetle.

How it works: Eggs are laid singly, close to hard scale insect colonies. The larvae and adult of Chilocorus are predatory on most hard scale insect species. 

Species controlled: Most hard scale insects. 

When to use: Late spring to early autumn unless lights and 18°C+ temperature can be provided. 

Rates of use: 2 beetles per 1 m2 of infested plants, repeat at least twice at fortnightly intervals. They should establish from season to season. 

Type: Parasitic wasps. 

How it works: Adults lay eggs in soft scale. Parasite larvae develop within the scale insect and emerge as an adult after 3-4 weeks at 25°C. Additional adult feeding on the scale may occur. The scale insect darkens as the parasite develops inside. 

Species controlled: Most common soft scale insects on ornamental plants in protected cultivation. Metaphycus prefers young stages. 

When to use: Recommended only for use in warm conditions. Requires a minimum temperature of 18°C. Some overwintering and establishment may occur. 

Rates of use: 2 wasps per 1 m2 of infested plants.

Type: Nematode parasite. 

How it works: Minute nematode worm swims through a film of water on the plant to attack the scale insects. 

Species controlled: Most species of scale insect where nematodes can be directly targeted. (These products have no label recommendation for this use but from our own trials have been found to be effective) 

When to use: Spray onto foliage when above 14°C and less than 27°C. For best results maintain a wet leaf for several hours after application. Activity ceases when leaves dry. 

Rates of use (for foliar application): Consult Fargro.

 Soft Scale