Time to treat borer is now

Northern Outlook - - LOCAL -

Borer is a com­mon prob­lem in New Zealand and spring and sum­mer, when the tiny wood­eat­ing in­sects emerge from their tim­ber bur­rows to breed, is the ideal time to take ac­tion against in­fes­ta­tions.

The most com­mon form of DIY borer treat­ment is usu­ally only ef­fec­tive a few mil­lime­tres from the sur­face of the wood and when in­gested by the bee­tle.

Given that for much of the three or four years the borer spends inside the wood it is far from the sur­face and not eat­ing but clear­ing room for its lar­vae to grow, now is the best op­por­tu­nity for the home handy­man to act.

The process should start with a care­ful in­spec­tion, be­cause while borer holes with fresh piles of saw­dust in­di­cate ac­tion within, in many cases the holes found will be his­toric.

The most pop­u­lar treat­ment able to be ap­plied with­out a li­cence is what is of­ten re­ferred to as a ‘‘wood pre­server’’, which typ­i­cally has boric acid and boron as its ac­tive in­gre­di­ents. Sold as a pow­der, it can be wet­ted and painted onto tim­ber.

The prod­uct is safe to use, how­ever it must be eaten by the borer to be ef­fec­tive. Be­cause it can’t be mixed with sol­vents, it doesn’t pen­e­trate deeply into the tim­ber, and it also tends to break down rel­a­tively quickly with mois­ture and sun­light. As such, it is mainly a warm­sea­son treat­ment, tar­get­ing borer as they emerge to breed and re­turn to lay eggs.

Most pro­fes­sional pest con­trol busi­nesses will use a wa­ter-ap­plied in­sec­ti­cide. Th­ese re­quire a li­cence. A very lim­ited amount of sol­vent is added to the mix, which means there is lit­tle fire risk. How­ever, it also means pen­e­tra­tion into the tim­ber is lim­ited.

Such in­sec­ti­cides do have the ad­van­tage of killing borer on con­tact, though, and are usu­ally for­ti­fied against the dele­te­ri­ous ef­fects of sun­light and mois­ture.

The most ef­fec­tive – but rarely used – treat­ment is a sol­vent-sus­pended in­sec­ti­cide. This will pen­e­trate deep into the wood in a mat­ter of hours, killing on con­tact and putting a quick end to in­fes­ta­tions.

The down­side is higher ma­te­rial costs and the need for spe­cial equip­ment to mit­i­gate the fire risk of work­ing with the sol­vents, which can make this an ex­pen­sive ap­proach for many.

Borer are of­ten found in a home where mois­ture con­tent is high and where tim­ber is un­treated, such as in the sub­floor and ceil­ing spa­ces of older homes.

Pro­fes­sional ad­vice is rec­om­mended in the first in­stance. Given New Zealand’s large num­ber of older tim­ber homes, this is usu­ally easy to find.

Borer leav­ing their bur­rows to breed, as in­di­cated by small piles of saw­dust out­side their holes, are the eas­i­est to erad­i­cate with DIY treat­ments, which are usu­ally only ef­fec­tive when borer con­sume wood at the sur­face.

Newspapers in English

Newspapers from New Zealand

© PressReader. All rights reserved.