Katipo

Abstract: New Zealand has two endemic widow spiders, Latrodectus katipo Powell, 1871 and L. atritus Urquhart, 1890. Both species face many conservation threats and are actively managed. The species status of the Latrodectus spiders of New Zealand was assessed using molecular (COI, ITS1, ITS2) and morphological methods and with cross-breeding experiments. Latrodectus katipo and L. atritus were not found to be reciprocally monophyletic for any of the gene regions or morphological traits. Other than colour, which is variable, there were no morphological characters that separated the two species, which cross-bred in the laboratory and produced fertile eggsacs. Colour variation is clinal over latitude and correlates significantly with mean annual temperature. We conclude that L. atritus is a junior synonym of L. katipo. An example of introgression from the Australian species L. hasseltii Thorell, 1870 was also detected and its conservation implications are discussed.

Abstract: Introduction Katipo are endemic widow spiders belonging to the genus Latrodectus (Theridiidae), a genus notorious for the dangerous bites of adult females. Latrodectus has a global distribution and is represented in New Zealand by two species; L. atritus Urquhart 1890 and L. katipo Powell 1871. Recently, it was recommended that these be referred to as ‘black’ and ‘red’ katipo, respectively (Patrick 2002). Both species of katipo have declined throughout their respective coastal duneland habitats and ranges. A recent nationwide survey for red katipo revealed they were present at only 46% of sites where they had been recorded previously (Patrick 2002). Threats to red katipo are degradation and loss of habitat due to historical and on-going processes, including replacement of the native sand-binder pingao (Desmoschoenus spiralis) with introduced marram grass (Ammophila arenaria), deliberate and accidental spread of exotic species such as Monterey pine (Pinus radiata), and damage caused by stock and recreational vehicles (Griffiths 2001). Although red katipo appear to have declined in number and distribution, the scarcity of detailed historical records and lack of a nationallyimplemented standard survey methodology mean that current rates of population declines and range reductions are difficult to determine. Monitoring is sporadic and consists of repeated sampling of some known populations over time in combination with surveys at sites were red katipo are scarce and/or have been recorded previously. Such surveys rely on hand-searching of suitable habitat, ideally by experienced observers. The probability of detecting katipo may vary according to the complexity and structure of the habitat being searched (Patrick 2002), observer experience, time-of-year, and the developmental stage, with spiderlings and males being more difficult to detect than adult females (Troup 2004). This variability can remain despite efforts to standardise survey conditions in-so-far as this is possible. For instance, two successive 30 min searches conducted by experienced observers at the exact same site yielded 33 and seven red katipo, respectively (Patrick 2002). Collectively, these difficulties highlight the need for practical and robust monitoring methods. New Zealand Entomologist 29: 99-102 (2006)

Abstract: New Zealand's endemic sand dune Latrodectus widow spider species, L. katipo and L. atritus, possess behavioral and physiological attributes likely to promote dispersal over large distances. Morphological, physiological and behavioral similarities between L. katipo and L. hasselti, an Australian endemic, suggest gene flow may occur across the Tasman Sea. In this study we examine intraspecific and interspecific genetic relationships within the ND1 gene region between L. katipo, L. atritus, L. hasselti and L. hesperus to assess whether the genetic evidence supports current taxonomic species designations. We found low interspecific pairwise distances among L. katipo and L. atritus populations, suggesting either introgression, incomplete lineage sorting, or that the current taxonomic distinction between the two species may be invalid. Parsimony and maximum likelihood analyses were inconclusive as to the rela- tionships between the New Zealand Latrodectus species and the Australian L. hasselti. Low pairwise distances between L. hasselti and the New Zealand widow fauna indicated that L. katipo and L. atritus were not present in New Zealand before the fragmentation of Gondwana.

Abstract: SUMMARY In May 1969 the distribution of the Katipo spider Latrodectus katipo (Araneae : Theridiidae) at South Brighton Beach, Christchurch, was investigated The spiders were most abundant in a narrow zone about 10-30 metres from the most seaward clumps of marram grass Habitat characteristics were examined and a preference for sparse to medium densities of marram on sloping ground facing north-west, was found An analysis of the contents of 32 webs indicated that a weevil, Cecyropa modesta, is probably the most important prey