Beetles help track success of pest control work

Environment Waikato is using beetles to help track the success of pest control work being carried out under its Hamilton Halo project.



The Halo project aims to bring tui and other New Zealand birds back to Hamilton’s urban area, where there are very few iconic native bird species left. It involves intensive control of rats and possums at key forested sites within a 20km radius of the city.



“By getting rid of predators and creating safe areas where native birds can breed, we hope to see more tui flying to Hamilton to feed,” Environment Waikato biosecurity officer Ben Paris said.



As well as preying on native birds and their eggs, the rats targeted under the Halo project eat insects.



This week, Environment Waikato will begin trapping scarab beetles at its Halo site at Old Mountain Rd, Whatawhata so it can benchmark population numbers prior to pest control.



A number of native beetles live their larval stage underground until they have developed into adults, when they emerge in the spring to spend the remaining 2-3 weeks of their lives eating and mating.



“Scarab beetles are a good insect to monitor because they’re one of the insect species rats eat, they’re only around for a short period of time and there are lots of them,” Mr Paris said.



“The idea is that the diversity and number of the scarabs will give a general indication of what’s happening with other insect populations.”



‘Pitfall traps’, which are small cups buried in the ground, and ‘Malaise traps’‘, which look like tents covered in mosquito netting, will be used to capture the beetles. The traps will be set up this week.



“We will be hoping to see an increase in the beetle population next year once our pest control programmes have taken full effect,” Mr Paris said.



The beetle traps will remain in the bush for two months and be checked and cleared regularly.