An Australian spider species that crushes insects before vomiting into cracks in their exoskeletons is living in southern Christchurch backyards.
Male P. congregabilis, dorsal view (ZMH A0002084)
The spider, Philoponella congregabilis, was recently redescribed in an article in Records of the Canterbury Museum.
Unlike almost all spiders, P. congregabilis does not produce venom to kill its prey. Instead, the prey insect is wrapped so tightly in the spider's silk that its exoskeleton is crushed.
The spider then regurgitates digestive enzymes over its victim and devours the liquefied soft parts of its body.
Female P. congregabilis, dorsal view (ZMH A0002084)
Philoponella congregabilis was first recorded in Christchurch in October 2014 but had likely been present in the area for some time before that.
In recent years it has become widespread in the city’s southern suburbs.
The species was first described in 1916, but that description is not detailed enough to identify specimens with certainty.
Curator Natural History Dr Cor Vink and Lincoln University MSc graduate (and former Canterbury Museum Data Entry Technician) Kate Curtis teamed up to describe P. congregabilis in more detail in their Records article.
Male P. congregabilis, lateral view (ZMH A0002084)
They collected specimens from Christchurch suburbs including Hoon Hay, Cashmere, Westmorland, Somerfield and Huntsbury. Juvenile specimens were raised to adulthood in a laboratory for study.
Philoponella congregabilis is part of the family Uloboridae, commonly known as hackled orb weavers. New Zealand has one endemic spider that belongs to this family, Waitkera waitakerensis.
Philoponella congregabilis is unlikely to compete with this native spider because they occupy different habitats.
Female Philoponella congregabilis, lateral view (ZMH A0002084)
Philoponella congregabilis is common in and around buildings, fences and gardens in Sydney and is found in the same habitats here. It is likely to spread to other parts of New Zealand.
It is one of the 50 introduced Australian spider species that live in New Zealand.
How can you spot it in your backyard? The best way is to look for its distinctive web.
Philoponella congregabilis build untidy-looking horizontal or sloping orbwebs. Debris in the webs often helps to camouflage the spiders and their insects.
You can read the full paper in Records of the Canterbury Museum.