Huntsman spider (Sparassidae family)

In New Zealand, there are two main species of huntsman spiders (introduced from Australia):

• Avondale spider (Delena cancerides)
• Christchurch huntsman (Isopedella victorialis)

The Avondale spider is also called the communal or social huntsman, as they typically live in groups. They became ‘famous’ as the spider used in the film Arachnophobia.

They are sometimes called tarantulas due to their size, but this is incorrect.

Huntsman spiders are not widely distributed in New Zealand, probably due to the climate and lack of suitable environments. 

The Avondale spider is pretty much restricted to Auckland and the Christchurch spider in Christchurch.

Their natural habitat is underneath bark and rocks. Many species have very flattened bodies to allow them to squeeze into the tightest of spaces (think into a car, under the back door, etc!).

The Avondale spider has a mid brown / grey body with brown legs (with back towards the end). The Christchurch huntsman is a mottled grey colour.

The sizes of the different species is also variable – although their bodies rarely exceed 2 cm long, the leg span of the can exceed 15 cm!

Apart from the flattened body in some species, all have a crab-like arrangement to their legs. Their joints are twisted so their legs can spread out laterally and to the front (which also aids squeezing into small spaces).

Huntsman spiders have eight eyes, set in two rows of four.

The Avondale spider is a social huntsman species (Delena cancerides), which lives in groups of up to 200 hundred, with a single dominant female.

Web:

Huntsman spiders do not build webs – they are considered a ground, running or hunting spider.

Mating:

The mating ritual of huntsman involves a lengthy courtship process which includes mutual caressing. Unlike in many other spider species, the male is rarely attacked during the courtship process.

Eggs:

The various huntsman species lay their eggs flat, oval egg sacs, containing up to 200 eggs. In many species the egg case will be placed under bark or rock, which the female will guard until they are ready to hatch. Some species will carry the egg sac under their body.

Huntsman baby spiders:

It will take several weeks for the eggs to hatch (depending on temperature). In some species the female spider will moisten and tear open the egg sac. The young huntsman spiderlings are pale and it takes several moults for their colour to darken. They will stay with the mother for several weeks / moults, before dispersing.

Life-span:

Huntsman spiders can live for 2 years or more.

Huntsman spiders will eat insects, other arthropods, small lizards and frogs.

Huntsman themselves have a number of predators including some predatory wasps, which will paralyse the huntsman and take it back to their nest to use a live food for their larvae when they hatch.

Although huntsman may look scary, they are actually quite timid and will generally run way rather than bite. The exception can be females who are guarding an egg sac, who may get more aggressive.

Symptoms:

The huntsman bite causes localised pain and swelling, and occasionally mild nausea and headaches.

First aid:

• Apply an ice pack to the bite area
• (Capture or take a photo of the spider for identification)
• Seek medical attention if an allergic reaction occurs

Huntsman spiders are generally outdoor spiders only coming indoors ‘by accident’ or to escape rainy or hot weather. Having less vegetation around the perimeter of the building will reduce the chances of a huntsman getting in. Having well fitted doors and windows (they need to be very well fitting), will also help.

Huntsman are generally considered as beneficial, in that they target other pests around the home including cockroaches.

It’s always a good idea to keep clothes off the ground and check the bed sheets in summer – huntsman will often come inside to escape the heat and squeeze under clothes and sheets is just like squeezing under bark… they feel quite at home!