Scale Insect Predatory Beetles - Rhyzobius lophanthae


*Please be advised there is a 2 week lead time for this product. Your order will be shipped sooner if possible.

What are Scale Insects and how do I identify them?

Scale insects are small insects that feed on leaves and plants. They are often a pest spotted on house plants, tropical plants, and plants grown in warm, humid conditions. Scale insects can be spilt into two groups: the Armoured Scale and Soft Scale. The Armoured Scales inject substances into leaves that turns them yellow, or brown and are a serious plant pest for many types of plants, especially those grown in plant collections in greenhouses and conservatories. The Armoured Scale appear frequently on Palm Trees and Orchids. Soft Scales extract sap from plants and leave honeydew on leaves, which black moulds can grow on. 

What are Rhyzobius lophanthae beetles and how can they help?

Biological control of Hard Scale insect or Armoured Scale insects can be achieved with the predatory Ladybird; Rhyzobius lophanthae. The larvae and adult Rhyzobius will chew holes in scale insects, killing them, before feeding on the bodies. They will feed on Armoured Scale insects that include the:

  • Boisduval Scale (Diaspis boisduvalii)
  • Oleander Scale (Aspidiotus neriiI)
  • Cactus Scale (Diaspis echinocacti)
  • Rose Scale (Aulacaspis rosae)

When should I use the Rhyzobius beetles?

Use these predators as soon as Armoured Scale Insect infestations are observed. We recommend use of the Rhyzobius from March to September.

Where should I use the Rhyzobius?

Rhyzobius should be used indoors only. They are best suited for use in greenhouses, conservatories or in other heated areas.

How do I apply the Rhyzobius?

It is recommended that you release the Rhyzobius in the evening, with windows and vents closed so they cannot fly away. Leave these closed for a period of at least 8 hours.

Simply open the container and lodge it in foliage for the beetles to emerge naturally. If, after a few hours, some adults are left inside, gently tip them out onto the infested plants. For best results apply the beetles directly to areas where Scale Insects are present.

Full instructions will be provided on delivery.

What conditions do they require?

The Rhyzobius can be used at slightly lower temperatures and in a lower humidity than our other Scale Insect predatory beetle; Chilocorus nigritis. The Rhyzobius require temperatures averaging around 18. The beetles also still prefer release in areas of higher humidity. 

How many Rhyzobius lophanthae beetles do I need?

We advise applying Rhyzobius at the following rate:

In treating light infestations on small / medium sized plants: apply 3 - 5 predators per plant

In treating heavier infestations on larger sized plants: apply 10 predators per plant

Repeat applications may be required for the heavy infestations. Add more Rhyzobius every 2 weeks until clear populations of Rhyzobius can be observed, and have established on the plant. 2-3 weeks after application, given adequate levels of prey, Rhyzobius larvae should be observed on the plants too.

Chemical Pesticides

Rhyzobius lophanthaeis a living creature and can be affected by any chemical pesticides used within the previous few weeks. As a general guide, refrain from using Pyrethrum or SB Plant Invigorator 2 days prior to use. Other chemicals insecticides can have long lasting residues that could harm Rhyzobius and other predators for much longer periods. Refrain from using these products or check with Dragonfli for information on the effect of these products on our predators.