Capsicum whitefly

Capsicum whitefly (Aleurothrixus trachoides) is a small flying insect in the Order Hemiptera.

Capsicum whitefly has 6 life stages:

Adults

• Small flying insect 1-2mm long.
• White with wings.
• Covered with a white waxy layer.

Four nymphal stages

• First stage nymphs are:
  • flat, oval and yellow
  • mobile, but usually remain on the leaf where laid.
• Second to fourth stage nymphs are:
  • attached to the leaf and gradually become covered in cottony white filaments
  • 0.8mm long and turn black at the end of their development.

Eggs

• Found on the underside of leaves.
• Newly laid eggs are oblong, tiny and translucent.
• Turn yellow to greyish-brown when mature.

Plant stage and plant parts affected

• Affect plants at any growth stage.
• Adults prefer to feed on new shoots.
• Can infest leaves, fruit, flowers and stems.
• Leaves show large amounts of white, waxy material or sooty mould.

Plant damage

As with other whitefly species, adults and nymphs pierce plants with their mouthparts to feed on sap.

Large amounts of white, sugary honeydew is produced by adults and nymphs, promoting the growth of sooty moulds (fungi). This reduces the plant’s ability to access sunlight to photosynthesise and results in poor plant health.

Depending on the life stage, capsicum whitefly could be confused with other species of whitefly; as adult stages of whitefly all look the same. Common endemic whitefly species that could be confused with capsicum whitefly include:

• Greenhouse whitefly (Trialeurodes vaporariorum)
• Spiralling whitefly (Aleurodicus dispersus)
• Coconut whitefly (Aleuroctarthrus destructor)
• Silverleaf whitefly (Bemisia tabaci).

Some aphids and mealybugs also produce large quantities of honeydew when feeding, which may resemble the cottony and waxy filaments produced by capsicum whitefly.

Capsicum whitefly is the only whitefly known to heavily infest the ornamental plants, geisha girl and golden dewdrop.

• Widely distributed in tropical areas throughout the world, including Central and South America, the Caribbean, the United States of America (California, Florida, Hawaii, Louisiana, Texas), Africa (Mozambique, Nigeria and Reunion), Oceania (Fiji, French Polynesia, Guam and Micronesia) and India.
• Has been observed in the Solomon Islands and on the south coast of Papua New Guinea.
• Occurs in Queensland, on Boigu Island in the Torres Strait.

Capsicum whitefly is polyphagous (feeding on a wide range of plants), and infesting species from at least 33 plant families.

Solanaceous and Convolvulaceous plants are preferred hosts. Crops most affected include:

• avocado
• capsicum
• celery
• chilies
• eggplant
• rose
• sweet potato
• tomato,
• tobacco.

Ornamental plant species can also be infested, for example geisha girl (Duranta repens) and golden dewdrop (Duranta erecta).

Capsicum whitefly has 6 life stages: egg, 4 larval instars and adult.

• Eggs are laid on the underside of the host plant’s leaves in circular masses.
• Development from egg to adult is about 29 days.
  • 8 days after being laid eggs hatch into first instar nymphs, followed by
  • 21 days for the nymphs to grow through the second, third and fourth nymph stages, before emerging as adults.
• Adults are most prevalent overseas in late spring to early summer.
• Numbers decline in cooler months.
• In warm climates, all life stages can be present all year.

Queensland’s horticulture (fruits, nuts, vegetables and production of ornamental plants) industry is highly diverse and was estimated to be worth $4.5 billion in 2018.

Whiteflies are pests of a wide range of host plants. They can cause severe damage to crops, reduce yield and can disrupt domestic and international access to markets.

Backyard growers can also be affected by new whitefly infestations.

Most easily spread by people moving infested plant material, such as cut flowers, whole plants, and fruit and vegetables.

• Adults can fly short distances.
• Adults and nymphs may be blown by the wind.
• Not known to be a vector of plant diseases.

Check common host plants, especially geisha girl and golden dewdrop for:

• small, white, winged adults at rest on host plant leaves or fluttering around like tiny moths when disturbed
• eggs and nymphs on the undersides of leaves
• large amounts of white, waxy material or sooty mould.

If you suspect capsicum whitefly call Biosecurity Queensland on 13 25 23.

Protect your farm from plant pests and diseases:

• Protect your farm from emergency plant pests
• Understand good farm biosecurity
• Visit the farm biosecurity website

Two biosecurity zones have been established by the Australian Government in the Torres Strait under the Australian Biosecurity Act 2015 – the:

• Torres Strait Protected Zone
• Torres Strait Permanent Biosecurity Monitoring Zone.

These zones limit the spread of capsicum whitefly within the region and to the Australian mainland, by restricting the southward movement of fresh fruits and vegetables, soil, live plants, including cuttings, seedlings or plant products between the zones.

You will require a permit from the Australian Government Department of Agriculture, Fisheries and Forestry to transport plant or plant products from any Torres Strait island to mainland Australia.

Your vehicles, machinery and other goods moving between zones or to mainland Australia will be inspected to ensure pests or pest carriers are not moved from the zone.

If you think you have found capsicum whitefly, you must take all reasonable and practical steps under your control to minimise any further spread. This is called a general biosecurity obligation (GBO) under the Queensland Biosecurity Act 2014.

Report suspected capsicum whitefly to Biosecurity Queensland immediately on 13 25 23 or contact the Exotic Plant Pest Hotline on 1800 084 881.