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Weed Biocontrol articles

  1. Autumn Activities 2024

    Gall-forming agents 
    Check broom gall mite (Aceria genistae) sites for signs of galling. Very heavy galling, leading to the death of bushes, has been observed at many sites. Harvesting of galls is best undertaken from late spring to early summer, when predatory mites are less abundant. 
    Check hiera...

  2. Weed Biocontrol in the Cook Islands Shows the Way for Others

    MWLR is assisting eight developing countries in the Pacific to develop biocontrol programmes for their most problematic invasive weeds as part of the Pacific Regional Invasive Species Management Support Service.

  3. The Highs and Lows of Cost–Benefit Analyses

    Since the 1920’s New Zealand has released 69 biocontrol agents against 28 weed species. Notable successes that have been analysed economically include the suppression of pasture weeds such as ragwort (Jacobaeae vulgaris) and St. John’s wort (Hypericum perforatum).

  4. The Economic Benefits of Two Beetles

    Does anyone remember St John’s wort (Hypericum perforatum)? This nasty plant was one of the four worst weeds in New Zealand in the 1930s. St. John’s wort infestations were particularly serious in hill-country grazing land, reducing productivity and poisoning livestock due to a toxin known as hyperic...

  5. Summer Activities

    Summer is a busy time for many biocontrol agents, so you might need to schedule the following activities. 

  6. Who's Who in the Biological Control of Weeds

    Comprehensive list of weed biocontrol agents under investigation at Manaaki Whenua.

  7. Spring Activities

    Most biocontrol agents become active during spring, making it a busy time of year to check release sites and move agents around.

  8. Further Reading & Biocontrol Agents Released in 2022/23

    Den Breeyen A, Lange C, Fowler SV 2022. Plant pathogens as introduced weed biological control agents: could antagonistic fungi be important factors determining agent success or failure? Frontiers in Fungal Biology 3: 959753. DOI: 10.3389/ffunb.2022.959753

    Falla C, Minor M, Harrington K, Paynter Q, ...

  9. Mutualism, Malaysia and Molecular Biology

    In 2019, Manaaki Whenua’s weed biocontrol team decided to take a page from the biologist’s textbook when looking for collaborators to assist with developing weed biocontrol agents for novel targets in Vanuatu. Mutualism refers to a situation when two entities form a relationship that is mutually ben...

  10. Shedding Light on Herbivore Preference

    Despite its warm and fuzzy name, woolly nightshade is anything but! Introduced as a garden plant in the 1800s, woolly nightshade has spread insidiously across our landscapes to become one of New Zealand’s worst weeds.