Te Arai Kete

A B S T R A C T
The katipo (Latrodectus katipo Powell, 1871) is one of two endemic widow
spiders in New Zealand. It is a coastal sand-dune specialist and national
invertebrate icon that has suffered a dramatic decline in numbers, contraction
in geographical range and population fragmentation. This nationwide survey of
the katipo located 26 populations in 90 dune systems sampled of a total of 127
sites visited where it could potentially be found. Details of the 90 dune systems
are presented, including the number of adult female spiders found within a
standard search time, degree of naturalness of the dunes and location. A survey
of sites where katipo had been collected previously, based on specimens in
collections, showed that they were present at only 46% of these sites. On the
basis of this study, 19 key sites for katipo conservation are proposed.
The katipo is threatened with extinction for a myriad of reasons: the main
factors appear to be loss of habitat and declining quality of the remaining
habitat. The dramatic changes to its sand-dune habitat following European
settlement were due to stock grazing, disturbance and burning, and continue to
this day with commercial forestry, recreational use of dune systems and other
activities. The subsequent destabilisation of the dunes led to the introduction of
marram grass (Ammophila arenaria), which continues to displace native sandbinding
species. Marram grass can now become so dense that katipo web
construction may no longer be possible.
Based on this research, recommendations for the conservation of the katipo are
presented. Using the accepted New Zealand invertebrate classification criteria,
the katipo is assessed as a Category B threatened species, i.e. a second-priority
threatened species.
Keywords: black katipo, distribution, widow spiders, sand-dune