The life histories, behaviour, diet, habitat, and diurnal activity patterns of two species of Snares Island weta, Zealandrosandrus subantaraticus and Insulanovlectron spinosum, are presented. The males and females of Z. subantarcticus had 12 instars. The males of I. spinosum had 9 instars while the females had 10 instars. Eclosion, moulting, inter- and intraspecific interactions, oviposition, and cannabalism are described. The diet of both species included arthropods, plant material, and dead seabirds. Descriptions of abdomina-femoral stridulatory apparatus for both species are presented. Reproductive parameters and sex ratio of both species were examined. Diurnal activity patterns showed an increase in activity half an hour after sunset and a decrease half an hour before sunrise for both species. These species of weta from the Snares Island showed similarities in aspects of their biologies to those of mainland species

The abundance and size classes of ground weta, cave weta, carabid beetles and prowling spiders were monitored in the La Trobe Forest Ecosystem Restoration Project, Karekare, West Auckland, where rodent populations had been reduced. These were compared with those in control sites, where the rodent populations had not been manipulated. The arthropods were sampled using pitfall traps set in young podocarp-broadleaf, mature kanuka and mature taraire forested sites, and each treatment site was matched with two control sites. Data was collected monthly from all nine sites from December to May, 2005-06. In kanuka forest, data collected during December to May, 2004-05 has also been used.Rodent populations and possum populations were monitored during the course of the study. Tracking tunnel indices indicated that rat numbers were lower in the treatment sites than the control sites during 2005-06, and that rats were low in abundance at the treatment sites, apart from the occasional spike in numbers, in the three years prior to the start of this research. Mice tracking indices were relatively high at some specific sites, mainly in spring and autumn. Evidence indicated that possum abundance was low in both the treatment and the control sites.Ground weta were more abundant at the kanuka treatment site than the control sites in 2005-06, but were rarely found in the podocarp-broadleaf and taraire forest types. Carabid beetles were trapped in greater numbers in podocarp-broadleaf and kanuka forest treatment sites in 2005-06, than in their respective control sites, and an increase in carabid beetle abundance was recorded between the 2004-05 and 2005-06 sampling seasons at the kanuka treatment site. Prowling spiders were more abundant at the podocarp-broadleaf treatment than at the control sites. Cave weta abundance at the podocarp-broadleaf and kanuka treatment sites was similar to their respective control sites. The arthropod abundance data from the taraire forest sites was confounded by many differences between the treatment and the control sites, which may have masked any effects caused by the suppression of rodent numbers at the treatment site.Ground weta and cave weta in the larger size classes appeared to be selectively preyed upon by predators, however, it was unclear whether rodents were entirely responsible because stoats and cats are also known to target larger arthropod prey, and their presence was not monitored.Ground weta in kanuka forest, carabid beetles in kanuka and podocarp-broadleaf forest and prowling spiders in podocarp-broadleaf forest are identified as potential indicators for monitoring the effects of rodent control in the Waitakere Ranges.This study was limited by a lack of knowledge of life histories and basic ecology of the arthropods. Further research at these sites is required to establish the long term population patterns of the arthropods.

The abundance and size classes of ground weta, cave weta, carabid beetles and prowling spiders were monitored in the La Trobe Forest Ecosystem Restoration Project, Karekare, West Auckland, where rodent populations had been reduced. These were compared with those in control sites, where the rodent populations had not been manipulated. The arthropods were sampled using pitfall traps set in young podocarp-broadleaf, mature kanuka and mature taraire forested sites, and each treatment site was matched with two control sites. Data was collected monthly from all nine sites from December to May, 2005-06. In kanuka forest, data collected during December to May, 2004-05 has also been used.Rodent populations and possum populations were monitored during the course of the study. Tracking tunnel indices indicated that rat numbers were lower in the treatment sites than the control sites during 2005-06, and that rats were low in abundance at the treatment sites, apart from the occasional spike in numbers, in the three years prior to the start of this research. Mice tracking indices were relatively high at some specific sites, mainly in spring and autumn. Evidence indicated that possum abundance was low in both the treatment and the control sites.Ground weta were more abundant at the kanuka treatment site than the control sites in 2005-06, but were rarely found in the podocarp-broadleaf and taraire forest types. Carabid beetles were trapped in greater numbers in podocarp-broadleaf and kanuka forest treatment sites in 2005-06, than in their respective control sites, and an increase in carabid beetle abundance was recorded between the 2004-05 and 2005-06 sampling seasons at the kanuka treatment site. Prowling spiders were more abundant at the podocarp-broadleaf treatment than at the control sites. Cave weta abundance at the podocarp-broadleaf and kanuka treatment sites was similar to their respective control sites. The arthropod abundance data from the taraire forest sites was confounded by many differences between the treatment and the control sites, which may have masked any effects caused by the suppression of rodent numbers at the treatment site.Ground weta and cave weta in the larger size classes appeared to be selectively preyed upon by predators, however, it was unclear whether rodents were entirely responsible because stoats and cats are also known to target larger arthropod prey, and their presence was not monitored.Ground weta in kanuka forest, carabid beetles in kanuka and podocarp-broadleaf forest and prowling spiders in podocarp-broadleaf forest are identified as potential indicators for monitoring the effects of rodent control in the Waitakere Ranges.This study was limited by a lack of knowledge of life histories and basic ecology of the arthropods. Further research at these sites is required to establish the long term population patterns of the arthropods.

Three methods of communication were examined in the Middle Island tusked weta, Motuweta isolata (Orthoptera: Anostostomatidae); defence behaviour, acoustic and chemosensory signalling. Previous studies had been limited to basic autecology and anecdotal evidence. This study was undertaken to understand the behaviours of this species to assist in conservation efforts. Defensive behaviours were elicited through repeated stimulation while aggressive behaviours were acquired through male-male battles. Femoro-abdominal stridulation was induced within both situations. Defensive stridulation functioned as alarm behaviour and was often accompanied by a visual display. Agonistic stridulation was executed by the eventual winner of combat. Aggressive battles were a progression of behavioural units of increasing risk on injury until an individual was determined the winner. Acoustic analysis was preformed on stridulations observed in aggressive and defensive behaviours. Stridulation was a broad band signal covering a range well above 16 kHz and possibly into the ultrasound range (>20 kHz). Two different forms of stridulation were identified; click train sound and hiss sound. High speed frame-by-frame analysis of stridulation and scanning electron micrographs of the abdomen and medial femur deciphered the mechanism and found the interaction of the cuticle to be unique among weta. Strikingly, micrographs also revealed two morphologies of abdominal projections; truncated ridges and columnar pegs. Both these points were not previously observed. Y-maze and partition tests were utilized for evidence of chemosensory signalling, while gas chromatography-mass spectrometry identified faecal volatiles in M. iisolata and 4 other weta species in a parallel study. Through partition experiments, evidence exists for a species-specific volatile pheromone and a sex-specific chemo-tactile pheromone. Dimethylsulphide, (CH3)2S, was present in the faeces of all 5 weta species, and may be produced by the individual.

Recently, hybridisation has been increasingly recognised as contributing to the extinction of species; with the risk especially high for rare species hybridising with more common species. Such risks have raised concerns for the Banks Peninsula tree weta, Hemideina ricta, which is restricted to the eastern half of Banks Peninsula and in some areas lives in sympatry with the more widespread Canterbury species, H. femorata. A previous genetics study found evidence of hybridisation between these two species. However, conclusions made by this study were likely limited by its small sample size. To further assess the risk hybridisation poses to the conservation of these species, a larger genetic study was undertaken. With hybridisation between H. ricta and H. femorata previously hypothesized to be a rare event, modelling of likely sympatric zones was undertaken to optimize the sampling effort. The results of genetic analysis on the resulting samples were consistent with the previous study, in that they suggest hybridisation does occur but is fairly rare. To help determine what processes are maintaining the distinction between the two species, the current study has expanded to incorporate observations of mating behaviour and egg hatching experiments. As well as potential risks from hybridisation, H. ricta and H. femorata have also suffered habitat loss. The Canterbury region has been transformed by the introduction of exotic plant species, fire and logging, with only small patches of native bush remaining. The loss and fragmentation of the native forest is likely to impact the forest fauna such as the tree weta. A previous study of a closely related species H. maori, in a naturally fragmented habitat, determined that dispersal between suitable habitat patches was fairly limited. Therefore, similar to their habitat, H. ricta populations may be small and isolated. Such populations are prone to the fixation of deleterious alleles as well as a loss of genetic diversity. Deleterious traits not only have a short term negative impact but a lack of genetic variation can prevent adaptation in the long term. In the past, studies of population structure have included the influence of intrinsic factors, such as dispersal capabilities but neglected extrinsic factors, such as the environment. The current study uses microsatellite markers to determine the population structure of both species and where possible, maps of land-cover are analyzed for a correlation with genetic structure.

Three methods of communication were examined in the Middle Island tusked weta, Motuweta isolata (Orthoptera: Anostostomatidae); defence behaviour, acoustic and chemosensory signalling. Previous studies had been limited to basic autecology and anecdotal evidence. This study was undertaken to understand the behaviours of this species to assist in conservation efforts. Defensive behaviours were elicited through repeated stimulation while aggressive behaviours were acquired through male-male battles. Femoro-abdominal stridulation was induced within both situations. Defensive stridulation functioned as alarm behaviour and was often accompanied by a visual display. Agonistic stridulation was executed by the eventual winner of combat. Aggressive battles were a progression of behavioural units of increasing risk on injury until an individual was determined the winner. Acoustic analysis was preformed on stridulations observed in aggressive and defensive behaviours. Stridulation was a broad band signal covering a range well above 16 kHz and possibly into the ultrasound range (>20 kHz). Two different forms of stridulation were identified; click train sound and hiss sound. High speed frame-by-frame analysis of stridulation and scanning electron micrographs of the abdomen and medial femur deciphered the mechanism and found the interaction of the cuticle to be unique among weta. Strikingly, micrographs also revealed two morphologies of abdominal projections; truncated ridges and columnar pegs. Both these points were not previously observed. Y-maze and partition tests were utilized for evidence of chemosensory signalling, while gas chromatography-mass spectrometry identified faecal volatiles in M. iisolata and 4 other weta species in a parallel study. Through partition experiments, evidence exists for a species-specific volatile pheromone and a sex-specific chemo-tactile pheromone. Dimethylsulphide, (CH3)2S, was present in the faeces of all 5 weta species, and may be produced by the individual.