Seasonal activity and habitat associations ofMecodema howittiandMegadromus guerinii,two endemic New Zealand ground beetles (Coleoptera: Carabidae)

Abstract

Seasonal activity and habitat associations of the threatened endemic forest carabid Mecodema howitti Castelnau, and the sympatric but common endemic Megadromus guerinii (Chaudoir), were studied by pitfall trapping in a montane podocarp/hardwood forest remnant on Banks Peninsula, Canterbury, New Zealand. The main surface activity period for adult M. howitti and Mg. guerinii was the austral spring and summer. Megadromus guerinii was active across a wider temperature range than M. howitti, and was less inhibited by rain during the night. Both species were reproductively active in spring and summer, and a teneral Mg. guerinii was recorded in autumn. Mecodema howitti appeared to be randomly distributed and associated with logs. Megadromus guerinii showed spatial clustering, partly due to associations with topography and the proportion of stones in the substrate.

Seasonality and life histories of two endemic New Zealand carabid beetles (Coleoptera: Carabidae):Mecodema oconnoriBroun andMegadromus capito(White)

“…oconnori from pitfall traps in winter appears to be because beetles are inactive during colder weather. Anderson et al (2004) observed a similar pattern for carabids on Banks Peninsula.…”

“…In contrast, New Zealand has a relatively mild, maritime climate with a lack of distinct seasonality (Hurnard 1978), and New Zealand carabids were thought to display "little or no seasonality" (Watt 1978). Manual searches under surface refuges on Banks Peninsula confirmed that adult beetles were present throughout the year (Anderson et al 2004).…”

“…In contrast, very little is known about the life cycles of New Zealand carabids, and basic information about their developmental stages and reproductive biology is completely lacking. Only four published studies have considered the seasonal dynamics and reproductive phenology of native carabids in New Zealand (Butcher & Emberson 1981;Cartellieri & Lövei 2000, 2003Anderson et al 2004). This lack of knowledge is a major impediment for conservation of carabids, and many other native insects, as it hinders appropriate management decisions (McGuinness 2001).…”

Native forest generalists dominate carabid assemblages along a stand age chronosequence in an exotic Pinus radiata plantation

“…Three replicate 50 ha stands of 1-year-old P. radiata were sampled monthly from November 2002 to February 2003 and again in their 2nd year postharvest (mid-December to February 2004). The sampling period covered the known maximum activity periods for New Zealand carabids (Pawson and Emberson, 2001;Cartellieri and Lö vei, 2003;Anderson et al, 2004).…”

Time-lapse cameras improve our understanding of invertebrate activity in the alpine zone

“…Within the late spring to summer period, activity peaks at different times for different invertebrates. For example, some beetles can be more active in spring (Anderson et al 2004), while wētā can be more active in early summer (Van Wyngaarden 1995). There is little information on how invertebrates in New Zealand respond to precipitation beyond observations of wētā activity in wet and dry conditions (Watts & Thornburrow 2009).…”