Sugarcane weevil and Cane-Phorus: an IPM approach

Does adding a pheromone lure make weevil traps more effective?

Yes, on the published trial evidence. In a sugarcane plantation trial on the West Indian sugarcane weevil (Metamasius hemipterus), bamboo traps baited with insecticide-treated sugarcane plus pheromone lures, set at 5 traps per hectare, caught an average of 66 weevils per trap per week, against 6 weevils per trap per week for traps baited with insecticide-treated sugarcane alone, set at 30 traps per hectare (Oehlschlager et al., 2002). This article explains how weevil mass trapping works and how Cane-Phorus fits into an integrated pest management (IPM) programme for cane.

Why are weevils so hard to control with spraying alone?

The damaging weevils bore into the stem or rhizome, so the larvae develop inside the plant where contact insecticide cannot reach them. Adults are cryptic, active at the base of the crop and in crop residue, and they move between stools. Spraying reaches only the small, exposed fraction of the population present at any moment. The cost and resistance pressure of repeated spraying add to the case for trapping as a core tool.

How does pheromone mass trapping work?

Many of these weevils aggregate in response to a pheromone. A lure releasing that pheromone, paired with a trap baited with cut cane or similar plant material, draws adults in and removes them from the breeding population. In the published sugarcane trial, traps with pheromone and cane bait caught more weevils than cane-only traps throughout the six-month trapping period, with the largest difference in the first two months after planting. The same study found that adding ethyl acetate to the lure improved attraction, and that traps at ground level caught more than traps raised on a stick (Oehlschlager et al., 2002). Mass trapping works directly on the adult population that spraying mostly misses.

Cane-Phorus is the pheromone lure component of this system. Deployed in cane-baited traps at ground level across the field, it draws adult weevils into the traps as the main trapping layer of the programme.

How do you build an IPM programme around the lure?

Trapping is the backbone, but it performs best inside a few supporting practices:

• Sanitation: remove and manage crop residue and old stools that harbour adults and larvae, lowering the population the traps have to work against.
• Trap density and servicing: distribute traps across the field, keep the cane bait fresh, and replace lures on schedule so release does not fade. In the published trial, total catches rose roughly in proportion to trap density between 5 and 15 traps per hectare (Oehlschlager et al., 2002).
• Monitoring: weekly catch counts double as a monitoring signal, telling you where pressure is building and whether the programme is keeping up.
• Targeted intervention: where a hotspot persists, a focused treatment can supplement trapping rather than replace it, keeping overall chemical load low.

The aim is to make trapping and sanitation do the heavy lifting, with any chemical use targeted and occasional rather than routine.

What are the practical benefits?

• Higher catches of adult weevils when a pheromone lure is added to cane-baited traps, on the published trial evidence.
• Less reliance on routine spraying, which can reduce residue and resistance pressure.
• Built-in monitoring from trap counts, so management decisions are data-led.

Frequently asked questions

Does trapping replace insecticide completely? Trapping can become the primary tool and reduce routine spraying, but a targeted treatment may still be needed for persistent hotspots. Note that the traps in the published trial were baited with insecticide-treated cane. The goal is to minimise, not necessarily eliminate, chemical use.

How many weevils can a trap catch? In the published sugarcane trial, pheromone traps with insecticide-treated cane at 5 traps per hectare averaged about 66 weevils per trap per week, against about 6 per trap per week for cane-only traps at 30 traps per hectare (Oehlschlager et al., 2002). Catches depend on weevil pressure, crop age, trap density and servicing.

What makes the trap effective? The combination of the pheromone lure and a cane bait that mimics the breeding and feeding substrate draws adults in and holds them. Keeping the bait fresh, the lure active and the trap at ground level is essential.

Request a quote

Pheromone mass trapping is a well-studied core for weevil management in sugarcane and, for the related banana weevils, in banana (Alpizar et al., 2012). To set up a Cane-Phorus trapping and sanitation programme for your fields, request a quote or talk to a Chemiseed agronomist on WhatsApp at +62 877 7837 4714.

Sources

• Oehlschlager, A.C., Gonzalez, L., Gomez, M., Rodriguez, C. and Andrade, R. (2002). Pheromone-based trapping of West Indian sugarcane weevil in a sugarcane plantation. Journal of Chemical Ecology 28(8): 1653-1664. https://doi.org/10.1023/A:1019936831696
• Alpizar, D., Fallas, M., Oehlschlager, A.C. and Gonzalez, L.M. (2012). Management of Cosmopolites sordidus and Metamasius hemipterus in banana by pheromone-based mass trapping. Journal of Chemical Ecology 38(3): 245-252. https://doi.org/10.1007/s10886-012-0091-0