Chemical fertility control of rice-field rats

Project Leader: Dr Lyn Hinds, CSIRO

Aim: To deliver an orally active chemical fertility control agent for use in rodent management

Project: 3.t.3e

Project summary

Current management of rodents in cropping systems mainly involves the use of rodenticides. These poisons require repeated application and can have effects on non-target species. Additional tools for rodent management are needed to add to, or replace, existing practices. Fertility control techniques are under development by various groups around the world. Efforts continue in the development of immunocontraceptive vaccines, and in the identification of chemical agents which can efficiently disrupt reproductive capacity. In the field, these agents will need to be delivered orally in bait. The overall objective of this project is to deliver an orally active chemical fertility control agent for use in rodent management.

A new chemical fertility control technology that could substantially reduce rodent impacts on rice production in developing countries is being formulated by SenesTech, based in Flagstaff, Arizona. Studies are being conducted in parallel in the USA, Australia and Indonesia.

The project aims to:

  • achieve a lab-based demonstration of the induction of ovarian follicle depletion by 4-vinylcylohexene diepoxide (VCD) delivered by oral gavage in Rattus norvegicus and Rattus argentiventer
  • achieve a lab-based demonstration of the long term effects on fertility of Rattus norvegicus and Rattus argentiventer after oral dosing with VCD
  • if (1) and (2) are demonstrated move to field enclosure studies to demonstrate efficacy at a population level
  • if (3) is successful move to farm-scale field experiments to assess efficacy in a wild population.

Key achievements

  • Designed and tested food pellets palatable to captive rice field rats.
  • Establish in vitro ovarian cultures for Rattus argentiventer to allow preliminary assessments of effects of VCD isomers and other chemicals.
  • Assess effects of other chemicals in the presence and absence of VCD isomer, once a palatable pellet type has been identified.

Key deliverables

  • Design and test food pellets palatable to captive rice field rats.
  • Establish in vitro ovarian cultures for Rattus argentiventer to allow preliminary assessments of effects of VCD isomers and other chemicals.
  • Assess effects of other chemicals in the presence and absence of VCD isomer, once a palatable pellet type has been identified.

Project team

Dr Lyn Hinds, IA CRC and CSIRO is working collaboratively with
Dr Loretta Mayer and Dr Cheryl Dyer of Northern Arizona University to assess the contraceptive and sterilising effects of the chemical, 4-Vinylcyclohexene Diepoxide, (VCD) in rodent species.

Project partners

IA CRC, CSIRO, Northern Arizona University (under contract to SenesTech).

Further information

Humphrys S and Lapidge SJ (2008) A review of delivering and registering species-tailored oral anti-fertility products. Wildlife Research 35: 578-585.

http://www.senestech.com
(select ‘scientific journal publications’)