B. I. P. Barratt

Do new Access and Benefit Sharing procedures under the Convention on Biological Diversity threaten the future of biological control

Under the Convention on Biological Diversity (CBD) countries have sovereign rights over their genetic resources. Agreements governing the access to these resources and the sharing of the benefits arising from their use need to be established between involved parties [i.e. Access and Benefit Sharing (ABS)]. This also applies to species collected for potential use in biological control. Recent applications of CBD principles have already made it difficult or impossible to collect and export natural enemies for biological control research in several countries. If such an approach is widely applied it would impede this very successful and environmentally safe pest management method based on the use of biological diversity. The CBD is required to agree a comprehensive Access and Benefit Sharing process in 2010, in preparation for which the IOBC (International Organization for Biological Control of Noxious Animals and Plants) Global Commission on Biological Control and Access and Benefit Sharing has prepared this position paper. Here, we first describe the practice of biological control in relation to the principles of ABS, illustrated extensively by case studies and successes obtained with biological control. Next, we emphasise the very limited monetary benefits generated in biological control when compared to other fields of ABS such as the collection of germplasm for development of human drugs, chemical pesticides or crop cultivars. Subsequently, we inform the biological control community of good ABS practice and challenges, and we hope to make clear to the community involved in ABS under the CBD the special situation with regard to biological control. Finally, based on the non-commercial academic research model, we make recommendations which would facilitate the practice of collection and exchange of biological control agents, propose a workable framework to assist policy makers and biological control practitioners, and urge biological control leaders in each country to get involved in the discussions with their national ABS contact point to take their needs into consideration.

Sitona lepidus Gyllenhal (Coleoptera: Curculionidae), a potential clover pest new to New Zealand

Sitona lepidus Gyllenhal (syn. S. flavescens (Marsham)) (Coleoptera: Curculionidae), a potential legume pest species new to New Zealand, is reported from near Hamilton. A key is provided to distinguish S. lepidus from S. discoideus Gyllenhal, a lucerne pest already established in New Zealand. Information is given on the distribution of S. lepidus in New Zealand and overseas, the biology and life cycle, mostly derived from the literature, and potential pest status and control.

Beyond Bt: Alternative Strategies for Insect-Resistant Genetically Modified Crops

Bacillus thuringiensis (Bt) plants dominate today’s commercial market for insect-resistant transgenic crops. However, not all pests are susceptible to Bt Cry toxins and there are concerns that even susceptible species may evolve to become resistant to these crops. The search for alternatives is well under way, with significant progress already made towards producing transgenic crops expressing insecticidal compounds from plants, such as protease inhibitors, lectins and alpha-amylase inhibitors. New types of proteins from B. thuringiensis, such as the vegetative insecticidal proteins, are also being exploited. At an earlier stage of development but attracting much research interest are other insecticidal compounds, such as chitinases, defensins, enhancins, biotin-binding proteins, proteases and toxins, sourced from bacteria, viruses, plants and arthropods. Fusion proteins, combining the features of different insecticidal proteins, have significant potential for extending the range of insect species which could be controlled via transgenic plants. In the future, metabolic engineering of plants could allow us to alter with great precision the ways in which plants and insects interact. The compatibility of these novel insect control strategies with biological control and integrated pest management is discussed.

Insect-Resistant Transgenic Crops and Biological Control

Natural enemies such as predators and parasitoids fulfil an important ecological and economic function by helping to keep herbivore populations below the economic injury level. Thus, they contribute to sustainable integrated pest management (IPM) systems. It is well established that plant resistance factors that affect herbivores also interact with natural enemies and consequently with the biological control function they provide. Similarly, host plant resistance derived from genetic engineering will have an impact on biological control. There is evidence today that the currently available transgenic crops that express Cry proteins derived from Bacillus thuringiensis (Bt) have no direct effects on natural enemies due to their narrow spectrum of activity. However, the fact that the target pests are efficiently controlled by the deployed Bt crops has inevitable consequences for natural enemies that specialize on these species as hosts or prey. On the other hand, it has become clear that in crop systems where the deployment of Bt varieties has lead to a decline in insecticide use, biological control organisms have benefited significantly. Consequently, this technology can contribute to natural enemy conservation and thus be a useful tool in IPM.

Predicting the Risk from Biological Control Agent Introductions: A New Zealand Approach

Since the publication of Silent Spring (Carson 1963) there has been increasing demand to reduce the amount of agricultural pesticides used. This need has been further supported by the development of increasing levels of pesticide resistance, and the market advantages for products from “sustainable” agricultural systems. Classical biological control, where a predator, parasite, or pathogen is imported to control a weed or pest, is one obvious alternative to pesticides and has often been promoted as environmentally safe (e.g., DeBach and Rosen 1991).

Biodiversity of indigenous tussock grassland sites in Otago, Canterbury and the central North Island of New Zealand II. Nematodes

Abstract Soil samples were taken from around the base of tussock plants and paired areas of inter‐tussock vegetation at four native tussock grassland sites across New Zealand, in three consecutive summers. Seventy nematode taxa were identified with the plant associated nematode trophic group being the most abundant at three of the four sites. Of the plant parasitic nematodes, Criconema, Pratylenchus, and Helicotylenchus spp. were found at all sites, with Hemicycliophora, Longidorus, a putative Punctodera, and Rotylenchus found at only one site each. The observation of mermithid nematodes at three of the four sites, coupled with absence of insect parasitic Steinernema or Heterorhabditis sp. from microscopic observations and soil baiting suggests that the insect parasitism niche is occupied largely by mermithids in the tussock grassland habitats studied. A range of community indices were calculated, with Shannon‐Weiner (2.10–2.39), Simpson dominance (0.129–0.205), Maturity Index (2.67–2.92), and Structure Index (67.7–87.5) being significantly different among sites. Total nematode abundance was significantly greater beneath tussock than inter‐tussock vegetation, but the number of nematode taxa and species richness were significantly greater from inter‐tussock samples. This suggests that tussocks may provide a more productive habitat but that the increased diversity of the vegetation in inter‐tussock areas is reflected in some measures of nematode diversity. Comparisons are made and discussed with other studies of native grassland nematodes in New Zealand and worldwide.

Effect of Fire on Microarthropods in New Zealand Indigenous Grassland

Abstract Indigenous tussock grassland in New Zealand has a history of extensive pastoralism, and burning has been used to remove litter to improve establishment of aerially oversown pasture species and to promote palatable tussock growth for livestock. In recent years, considerable areas of tussock grassland have been retired from grazing and formally protected. Conservation land managers, as well as farmers, require information on the impacts of both managed burns carried out in spring and accidental fires that usually occur in warmer, drier conditions in summer. This study investigated the impact of spring and summer tussock grassland burning on the predominant soil microarthropods, Collembola and Acari, at 2 sites in Otago, in the South Island of New Zealand. Quantitative sampling was carried out before and for up to 26 months after burning replicated 1-ha plots. Total density of microarthropods in unburnt plots covered a similar range at both sites with an average over 3 years of about 18 000–20 000·m−2 at each site. Both sites shared a dominance of Mesostigmata and Oribatida (Acari) and Isotomidae (Collembola). Burning in spring reduced densities of Oribatida after treatment at both sites for the duration of the study. However, after initial postburn reductions in density, populations of Isotomidae and Poduroidea (Collembola) recovered in the second year after burning. Prostigmata (Acari) appeared to be unaffected by fire. The effects of spring and summer grassland fires on microarthropod densities were rarely different. It was concluded that longer-term sampling would be required to observe the full recovery period for microarthropod populations after fire but that results from this study indicate rapid recovery of some microfaunal populations after fire, which is not strongly influenced by seasonal effects.

Host specificity testing and suitability of a European biotype of the braconid parasitoid Microctonus aethiopoides as a biological control agent against Sitona lepidus (Coleoptera: Curculionidae) in New Zealand

Abstract The European biotype of the parasitoid Microctonus aethiopoides Loan (Hymenoptera: Braconidae) is being considered for release against Sitona lepidus Gyllenhal (Coleoptera: Curculionidae) in New Zealand. Host specificity was evaluated in the laboratory using both endemic and introduced weed biological control curculionid species, with 12 no-choice and three choice experiments carried out comparing the S. lepidus and test weevils. Two further no-choice tests used the Moroccan M. aethiopoides biotype to compare attack rate between European and Moroccan M. aethiopoides, the latter released in 1982 to control the lucerne pest S. discoideus. Across all experiments, total parasitism of S. lepidus was 69% compared with 15% for the test weevils. European M. aethiopoides was able to develop in the native weevils Irenimus aequalis, Nicaeana cervina, Catoptes cuspidatus, Protolobus porculus and Steriphus variabilis with parasitism rates of 13, 28, 2, 7 and 8%, respectively. These levels were significantly less than those in the corresponding S. lepidus control. Total parasitism of I. aequalis and C. cuspidatus increased significantly in the presence of S. lepidus than recorded under no-choice conditions. The presence of European M. aethiopoides caused minor, if any, test weevil mortality prior to the onset of prepupal emergence and there was no significant reproductive suppression in parasitoid-exposed test weevils. Parasitism of the introduced weed control agent R. conicus by European M. aethiopoides was significantly lower (1.1%) compared to the Moroccan biotype (47.5%). Based on these and other experiments, should the European M. aethiopoides be released as a biological control agent of S. lepidus, its ecological impacts are likely to be less severe than those already exhibited by the Moroccan M. aethiopoides.

Morphospecies as a substitute for Coleoptera species identification, and the value of experience in improving accuracy

Abstract Biodiversity studies are often limited by unavailability or inaccessibility of taxonomic expertise; in New Zealand, taxonomic revisions and keys to many invertebrate groups are far from complete. To make progress with ecological and biodiversity studies, the separation of organisms into recognisable taxonomic units or morphospecies has sometimes been adopted. Coleoptera are speciose, trophically diverse, and taxonomically well known compared with other large trophically diverse groups and so they are useful to include in biodiversity studies. This study opportunistically examined the accuracy of Coleoptera species separation using morphologically recognisable features of specimens collected from three different vegetation communities, by three student researchers with different levels of training and previous expertise. Their morphospecies were examined by a single researcher with experience in taxonomy of Coleoptera. In total, 155 morphospecies were separated by the three students, compared with 151 determined by the specialist, which included representatives from 23 families of Coleoptera. All three students identified a total number of morphospecies within about 10% of the actual number, irrespective of previous training. However, the proportion of correct species separation increased from 63 to 87% in accordance with the level of previous experience. Common errors in species separation made by parataxonomists in relation to coleopteran families are discussed.

Biodiversity of indigenous tussock grassland sites in Otago, Canterbury and the central North Island of New Zealand I. The macro‐invertebrate fauna

Abstract This contribution introduces a short series of papers on biodiversity of indigenous tussock grassland at four sites in New Zealand. A survey of invertebrates of tussock grassland sites was carried out in summer of 3 successive years, 2001–03. The sites included two in Otago in snow tussock grassland at Deep Stream and Mt Benger, a site at Cass in inland Canterbury, and one at Tukino in the central North Island. Sampling was carried out by taking turf samples from each site, and extracting the invertebrates with heat extractors. The invertebrates were divided into 30 major groups. This quantitative sampling method allowed the densities of invertebrate groups to be calculated. Total macro‐invertebrate density for all sites ranged between c. 1600 and 5600 m–2. Total invertebrate abundance was highest at the central North Island site, but this was very much dominated by Formicidae. Across all sites, Formicidae, Coleoptera, and Pseudococcidae were consistently the most abundant groups represented.