Longhorn beetles · import & nursery
Citrus longhorned beetle: nursery and import inspection
Citrus longhorned beetle arrives in plants, not in timber. Surveillance therefore belongs in nurseries, importers’ holding areas and bonsai collections — places where a trap grid designed for a forest would never be placed.
Anoplophora chinensis has been moved around the world in the root zone and stems of live plants: nursery stock, bonsai, and the potted ornamentals trade. Its larvae develop inside the base and roots, which means an infested plant can pass a visual inspection and still be carrying a beetle.
Where the risk sits
Three settings account for most detections: nurseries importing or holding host material, post-entry quarantine and holding areas, and mature amenity plantings near those sites. A surveillance programme that traps forests but not importers’ yards is looking in the wrong place.
- Holding areas and dispatch yards: traps on the perimeter host trees, canopy height.
- Nursery blocks: traps among the oldest host stock, where larvae have had time to complete development.
- Bonsai and specimen collections: individual traps near high-value hosts, checked closely.
- Adjacent amenity trees: the population that establishes outside the fence is the one that spreads.
Trapping the same signal, in a different geometry
The lure is the same aggregation pheromone used for ALB — an ether plus its aldehyde precursor. What changes is the geometry: in a nursery, traps go on the host stock itself rather than in a forest canopy, and closer together, because the beetles do not travel far from the plant they emerged from.
Trap numbers can be modest. Ten to twenty traps across a nursery holding susceptible stock will detect an established population; a hundred traps over the same area adds little unless the site is a known incursion zone.
The detection problem
By the time an adult is caught, the larvae are already in the stock. That is the uncomfortable logic of CLB surveillance, and it is why the trap is treated as a trigger for destructive sampling rather than as a control measure. A confirmed catch should be followed by examination of the root collar and lower stem of nearby hosts, not by more traps.
For importers, the operational value is in the record rather than in the catch: a documented trapping programme around a holding area is evidence of due diligence when a consignment is questioned.
Documentation for regulatory and commercial use
Lot-level certificates of analysis, GC traces and SDS are supplied with every consignment, and the same lot numbers appear on the trap record. For a nursery operating under a plant passport or phytosanitary scheme, that traceability is usually the first thing an inspector asks for.
Compounds used in this programme
The materials below cover the blend this programme is usually built from. Where a specification names a different ratio, the components are the same — the ratio is what we quote against.
| Compound | CAS | Class | Recorded targets |
|---|---|---|---|
| 4-(n-Heptyloxy)butan-1-ol | 318256-94-9 | Ether | Asian longhorned beetle, Citrus longhorned beetle |
| 4-heptyloxy-butyraldehyde | 65885-35-0 | Aldehyde | Asian longhorned beetle, Citrus longhorned beetle |
Assay and isomeric composition are stated per lot. Packing starts at 1kg / 25kg / 100kg with development quantities below that.
Questions this programme usually raises
Is CLB surveillance legally required?
It depends on the jurisdiction and on what you import. Many schemes require a documented monitoring programme for host material; the trap record is what makes it documented.
Can traps protect a nursery?
No. They detect. Protection comes from sourcing, isolation and inspection of incoming stock; traps tell you whether those measures are working.
What should happen after a positive catch?
Destroy the adjacent host material and survey the root collar of surrounding plants. More traps in the same place will confirm the population but will not remove it.