Researchers at Swansea University have found a strain of fungi that could replace harmful pesticides in the control of the European crane fly (Tipula paludosa). The effects of 17 strains of entomopathogenic fungi, chlorpyrifos-based pesticides and a nematode worm were compared. The pesticides and fungal strain V1005 Metarhizium robertsii were both found to be 100% effective at controlling crane fly larvae, which are pests to many crop and tree species. The larvae, known as ‘leatherjackets’, feed on cereals, cabbages and lettuces, as well as young tree saplings, resulting in millions of pounds of damage every year in Europe and North America.
The fungal strain V1005 M. robertsii was 100% effective at causing larval death within 4 weeks. It is proposed that this could be used in combination with a nematode that is effective at all stages of development. The nematode species Heterorhabditis bacteriophora is around 60% effective at causing death to T. paludosa within 8 weeks. Professor Tariq Butt, who headed the research, hopes that using the combined fungi and nematode control will reduce the need for pesticides, reducing harmful impacts on the environment.
This research comes at a time when there is a lot of interest in biocontrol. The EU has released legislation urging farmers to reduce harmful chemicals and switch to environmentally friendly pest control practices. According to the International Biocontrol Manufacturers’ Association, biocontrol makes up just 3% of the $44 billion crop control market, and research into this has been highlighting viable biological options for years. In 2003, researchers at Newcastle University were able to confirm the age-old theory of using garlic to control slugs and snails. It is the pungency of this common ingredient which causes death to the gastropods, providing good news for farmers of lettuces, cabbages, brussels sprouts, winter wheat, oil seed rape and potatoes.
Due to the increased demand in organic food and concern for harmful chemicals, the biocontrol market is gathering pace, increasing by 10% each year and ensuring continuing funding for research projects. The Agricultural Research Service has recently found that combining the use of parasitoid wasps Habrobracon hebetor and Trichogramma deion could reduce Indian meal moth populations by as much as 97%. This would reduce the need for pesticides, without increasing losses of stored maize and groundnut. It remains to be seen how popular these measures will be amongst farmers, and whether there may be any undesired effects of releasing these biological control species.
Science for Environment Policy-Fungi show strong potential to control crane fly pests
Laboratory equipment – Keeping wasps cold bolsters biocontrol possibility