How to Control a Borer Infestation?

Borer beetles are destructive pests that are a significant concern for homeowners in New Zealand. These wood-destroying insects can silently cause significant damage to furniture as well as the integrity of your house if left unchecked. Identifying and addressing these infestations early is crucial to prevent extensive damage and costly repairs. This comprehensive guide will help you understand, prevent, and control borer beetles from your property.

How Do You Know You Have Borer?

Recognising the signs of borer activity is the first step in addressing the problem. Here are some telltale signs:

• Flight holes: Adult borers leave small, round or oval exit holes in wooden furniture or structures. These holes are typically 2-7mm in diameter.
• Wood dust (frass): Borer larvae push fine wood dust out of the holes as they tunnel through wood, creating small piles of dust around affected areas.
• Structural damage: Over time, borer infestations can weaken timber, leading to sagging floors, weakened beams or crumbling wood.
• Dead beetles: You may find dead adult beetles around windowsills or near the infested timber as they try to escape the wood.

Sounds in the wood: Audible ticking or rustling sounds within wood can also be a sign of borer.

Types of Borer

• Common House Borer (Anobium punctatum) is, as the name suggests, the most common borer species in New Zealand, infesting both hardwoods and softwood such as untreated pine. It typically targets older buildings and furniture. Adult common house borer are 3-4mm in length and their flight holes are 2-4mm in size.
• The Two-toothed Longhorn Borer (Ambeodontus tristis) is a native species with larger, dark brown adult beetles, measuring 20-25mm in length. They leaves larger, more oval, flight holes that can be as big as 7mm. These borer are less often found in building since they prefer decaying wood but they can infest living trees as well.
• There are other types of borer in New Zealand, like Huhu beetles (Prionoplus reticularis), but these are even less commonly found in buildings. Huhu beetles can usually be found in the bush, where their larvae feed on the rotting wood of fallen logs or dead tree branches. 
• Termites that cause problems to buildings or furniture are not generally common in New Zealand. It takes some skill to detect insect pest presence and identify which pest is causing the problem – this is where JAE comes in! If you think you have a borer, termite or insect problem that’s out of control, be sure to give us a call and we’ll take care of it for you!

‍Can Borer compromise the structure of my home?

Common House Borer larvae typically hatch before they cause severe structural damage to timber since they primarily eat the softer sapwood. The timber may then be more susceptible to rot now that water can enter through the flight holes. 

Two-Tooth Borer infection is much more serious as it can attack both sapwood and heartwood, which can sometimes cause structural failure before its presence has even been noticed.

The Borer Lifecycle

The lifecycle of the common house borer in New Zealand typically involves the following stages:

1. Egg: Female borers lay small, white eggs in cracks or crevices of timber.   
2. Larva: After about 4-5 weeks, the eggs hatch, and the larvae begin to bore into the wood. They spend 3-4 years feeding on the wood, creating tunnels as they grow.   
3. Pupa: Once fully grown, the larvae create a pupal chamber near the surface of the wood.   
4. Adult: After 4-8 weeks, the adult borer emerges from the wood, creating a small, round exit hole. The adult lives for about a month, during which it mates and lays eggs, starting the cycle anew.   

It's important to note that the entire lifecycle can take 3-5 years, depending on factors like temperature and humidity.

While the Two-Tooth Borer shares the same life stages, its lifecycle can extend up to 10 years.

How to Prevent Borer

When it comes to wood-destroying insects prevention is always better than a cure. So leep in mind that borer like moisture, untreated timber, damaged and old timber, poor ventilation and humid conditions. Here’s what you can do to try to mitigate your risk of a borer infestation:

Regular Inspections: Conduct regular inspections of your home, particularly timber structures like beams, joists, and floorboards. Since the south side of your home is usually the coolest and dampest, this is the best place to start looking for signs of borer. Check for signs of borer activity such as small holes, sawdust, or weakened timber.

Maintain Good Ventilation: Ensure proper ventilation in your home, especially in crawl spaces and sub-floor areas. This helps to reduce moisture levels, which can attract borer.

Treat Timber Before Use: Treat timber with boric acid or other effective insecticides before using it in construction or repairs as this can help prevent borer infestations from starting.

Avoid Untreated Timber: For new construction or replacements, use kiln-dried radiata pine, naturally resistant woods like macrocarpa, or timber treated to appropriate levels (e.g. H5 for piles). 

Seal cracks and crevices: Seal any cracks or crevices in timber to prevent borer entry.

Monitor moisture levels: Use moisture meters to check for excessive moisture in timber. Also check for plumbing leaks, unblock air vents, and ensure proper roof sealing

Store firewood properly: Store firewood away from your home to prevent borer from entering.

Eliminate wood-to-soil contact: Maintain a gap between wooden structures and the ground.

Mulch management: Maintain a minimum 15cm gap between mulch and the house foundations.

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How to Control Borer: Common Treatments

‍If you suspect a borer infestation, immediate action is crucial. Here are some common DIY treatment methods you can consider, but it’s worth noting that professional treatment is usually the most effective for borer.

• Surface treatments: Boron-based insecticides can be applied to the surface of infested wood to kill larvae.
• Injecting insecticides: For deeper infestations, insecticides can be injected directly into the flight holes created by adult beetles.
• Fumigation: Fumigation can be used to kill borer larvae inside wooden structures.

If you do try some DIY borer control methods, always remember that safety comes first and unsure you follow the products instructions correctly.

Professional vs. DIY Treatment

While some minor infestations can be addressed with DIY methods, professional pest control, like we offer at JAE, is often necessary for comprehensive and long-lasting results.

‍Benefits of Professional Treatment:

• Access to more potent and effective chemicals
• Qualified technicians with expertise in identifying and treating different species
• Ability to detect hidden infestations
• Can address the root cause of the infestation

Dealing with borer in New Zealand can be challenging, but early detection and swift action can save your home from extensive damage. Regular inspections, preventive treatments, and professional pest control services are essential to keep these wood-destroying pests at bay. If you suspect an infestation, contact your local JAE pest control expert to assess the situation and recommend the most effective treatment options.