S. Hardwick

The bionomics of an invasive species Sitona lepidus during its establishment in New Zealand

The egg, larval, pupal and adult abundance of the clover root weevil Sitona lepidus Gyllenhal (Coleoptera: Curculionidae) was monitored at three sites for the first ten years following the discovery of this exotic pest in the Waikato region of New Zealand. The species went through an initial boom and bust cycle at two sites, with populations reaching up to 1800 larvae m-2. Thereafter, winter larval populations were relatively stable, ranging between 450-750 m-2. Unlike in the Northern Hemisphere, S. lepidus was found to have two generations a year in the Waikato region of New Zealand. Pasture white clover content at the time of peak adult numbers was positively related to the subsequent peak larval populations for each generation. The factors contributing to the emergence of S. lepidus as one of the most important pasture pests in New Zealand are discussed.

Factors affecting clover root weevil (Sitona lepidus) numbers and clover production

Abstract The impact of a range of simulated pasture management options on damage to white clover resulting from the presence of the clover root weevil was evaluated in a glasshouse experiment. Pasture management options included were irrigation, cutting regime, cultivar, soil fertility (Olsen P) level, and nitrogen application. Two different soil types were used. White clover growth was significantly enhanced by moist soil conditions, as were clover root weevil (CRW) larval numbers recovered per plot. Few (<1%) CRW larvae developed from the eggs (applied at 4000/m2) under dry soil conditions. Dry soil conditions dominated any effect that could be attributed to other treatments. More (c. 10.5%) CRW larvae developed under moist soil conditions, but clover plants tolerated this without significant losses to shoot production, although it did significantly (P = 0.01) affect shoot/ root ratio (on average 50% lower when CRW larvae were present). More clover dry matter was produced on mineral soil (P < 0.05), when nitrogen was applied (P < 0.05) and when the cultivar ‘Challenge’ was used instead of ‘Prop’ (P < 0.001). Cutting regime had a minor influence (P < 0.10) on clover production but the influence of Olsen‐P level was not significant.

Electronic polytomous and dichotomous keys to the genera and species of hard ticks (Acari: Ixodidae) present in New Zealand

Abstract New Zealand has a relatively small tick fauna, with nine described and one undescribed species belonging to the genera Ornithodoros, Amblyomma, Haemaphysalis and Ixodes. Although exotic hard ticks (Ixodidae) are intercepted in New Zealand on a regular basis, the country has largely remained free of these organisms and the significant diseases that they can vector. However, professionals in the biosecurity, health and agricultural industries in New Zealand have little access to user-friendly identification tools that would enable them to accurately identify the ticks that are already established in the country or to allow recognition of newly arrived exotics. The lack of access to these materials has the potential to lead to delays in the identification of exotic tick species. This is of concern as 40–60% of exotic ticks submitted for identification by biosecurity staff in New Zealand are intercepted post border. This article presents dichotomous and polytomous keys to the eight species of hard tick that occur in New Zealand. These keys have been digitised using Lucid® and Phoenix® software and are deployed at http://keys.lucidcentral.org/keys/v3/hard_ticks/Ixodidae genera.html in a form that allows use by non-experts. By enabling non-experts to carry out basic identifications, it is hoped that professionals in the health and agricultural industries in New Zealand can play a greater role in surveillance for exotic ticks.

Quantifying the economic cost of invertebrate pests to New Zealand’s pastoral industry

ABSTRACT The invertebrate pests most commonly affecting New Zealand’s pastoral-based production in ‘average’ years cause losses of between

Using mass-emergence devices to introduce an insect biocontrol agent to a new region and assist its dispersal

1.7B and

If and when successful classical biological control fails

2.3B p.a. of which up to

Evaluation of DNA melting analysis as a tool for species identification

0.9B occur on sheep and beef farms and

Clover root weevil in the South Island: detection, response and current distribution

1.4B on dairy farms. The native scarab grass grub is the most costly pest causing losses of

MANAGING BIOLOGICAL SUCCESSION IN INTENSIVE PASTORAL ECOSYSTEMS FOR IMPROVED PRODUCTION AND SUSTAINABILITY

140–380 M on dairy farms and

Parasitoids of the painted apple moth Teia anartoides Walker (Lepidoptera: Lymantriidae) in Australia.

75–205 M on sheep and beef farms annually. The exotic scarab, black beetle, although only affecting approximately 1 M ha, costs dairy farmers up to