Christchurch, New Zealand Integrated Pest Management Policy
Status: In effect
Integrated pest management
Outlined below is a summary of methods used for integrated pest management at the Christchurch Botanic Gardens. Included here are some practical ways which can be adapted for use in a home garden situation
Until recently the Christchurch Botanic Gardens have used a range of spray programmes to prevent and control pest and disease infestations. A variety of chemicals were used from relatively safe synthetic pyrethroides through to toxic organophosphates. Because of increased chemical costs, pest and disease resistance to pesticides plus staff and public safety concerns, the Christchurch Botanic Gardens have adopted other methods of pest and disease prevention and control.
The new approach being adopted is termed Integrated Pest Management (IPM). This management programme is one in which cultural practices are integrated with biological control and plant derivative sprays. The three types of control can be broadly categorised under the following headings.
This involves using a pest's naturally found enemies (predators and parasites) to control the pest at an acceptable level. The predators and parasites feed specifically on the insects they are released to control. They are harmless to all other beneficial insects. Therefore, when there are no further insects left to feed on the predators and parasites die. Biological control is often used in conjunction with an appropriate spray programme which avoids killing the predators or parasites.
Plant derivative sprays
These sprays are derived from plants and used to control a variety of pests and diseases. They can be divided into two categories, pesticides and anti-feedants. The pesticide kills the pest while the anti-feedant acts as a preventative to pest infestations. Protective measures are still necessary when mixing and applying these sprays as some are toxic to humans, predators and parasites.
This involves the manipulation of cultural practices to the disadvantage of plant pests and for the encouragement of beneficial predators and parasites. The micro-climate that predators and parasites live in needs to be monitored and adjusted to suit their particular needs. This may involve appropriate climatical changes, the provision of mulches for pupating insects or the growing of plants with shallow nectaries as many adult predators and parasites are small and need small flowers to feed on the nectar which supplements their diet.
Identification, control and monitoring pests
As pest populations are part of a comprehensive biological community it is important to accurately identify the pest and obtain information on its life cycle, plant host range, natural controlling factors, mobility and capacity for reinfestation. A decision can then be made about selecting the appropriate control measures available.
Consideration should be given to the controls effectiveness, toxicity, method of application, compatibility, timing of application, stage of development of pest and plant, repeat applications and cost.
Effective control does not generally suggest complete eradication of the pest. Frequent monitoring and assessment of the pest numbers and plants affected mean that problems can be controlled appropriately and effectively when necessary.