Queensland Longhorn Beetle
NOTE: QLB has NOT been found outside the Hilo-Pahoa-Mountain View area. If you find a suspect beetle anywhere on the island, send a picture to BIISC.
The Queensland Longhorn Beetle (Acalolepta aesthetica) was accidentally introduced to Puna, Hawaiʻi likely through imports from Australia. Larvae tunnel through wood, weakening it and disrupting the plant’s ability to transport nutrients and water.
Larvae develop into adults within the wood and can emerge even from cut trees; chipping wood will prevent emergence. Do not move unchipped wood – including to the green waste collection and landfill sites – to prevent the spread of the beetle.
There is no known treatment for an infestation of A. aesthetica. Adult beetles appear to be attracted to light at night, where they can be collected. HDOA advises that routine IPM insecticidal applications may deter adult beetles from selected areas; however, research is needed to determine how to address a beetle infestation. The best strategy is prevention: be very cautious in moving potential host plant species from the infected area between Keaʻau and Pāhoa. Trees infested with larvae should be destroyed.
Description:
- 0.75 in to 1.8 in. long
- Brown, velvet-like appearance
- Long antennae (1-2x body length)
- No patterns or spots on body
- Two spines on its ‘neck’
What to look for:
- Sawdust-like frass coming out of holes in trunk
- Oozing sap from damaged area
- Perfectly round exit holes
- Girdling on trunk
- Branch die-back and dropping
Update from Hawaiʻi Dept of Agriculture, July 2020
Confirmed host plants:
- Kukui (Aleurites moluccanus)
- Breadfruit (Artocarpus altillis)
- Various citrus (Citrus spp.)
- Queen Sago (Cycas cirinalis)
- Cacao (Theobroma cacao)
- Mulberry (Morus sp.)
- Trumpet tree (Cercropia obtusifolia)
- Kalamungay (Moringa oleifera)
- Norfolk pine cut logs (Araucaria heterophylla)
- Avocado (Persea americana)
- Hibiscus (Hibiscus spp.)
- Croton (Codiaeum variegatum)
- Elder berry (Sambucus nigra)
- Gunpowder tree (Trema orientalis)
Unverified, but possible host plants:
- Loquat (Eriobotrya japonica)
- Tree spinach, Chaya (Cnidoscolus aconitifolius)
- Passion fruit (Passiflora edulis var. flavicarpa)
- Cycads spp. (Encephalartos Horridus, Encephalartos Laurentianus, Dioon Merolae, Microcycas)
- Jade plant (Crassula ovata)
Did you catch a QLB?
Live beetles are being accepted at the USDA-ARS PBARC research center in Hilo. (64 Nowelo St, mauka of Komohana above Imiloa). Researchers are tracking the spread of QLB (Queensland longhorn beetle) in East Hawaiʻi. If you’ve captured a QLB on your property, please fill out this reporter form
Are you sure it’s a Queensland Longhorn Beetle?
Not sure if it’s a QLB? Use this guide to see the most commonly found longhorn beetles on Hawaiʻi island. You can always contact us to ID your beetle (make sure to include pictures!).