Tropical Grass Webworm monitoring
Latest results
No TGW moths were caught in any of the 6 pheromone traps on the Aupouri Peninsula 17-31 March.
Some moths were seen in rank kikuyu at Harrington and Blucher properties. No larvae or pupae were found in the 25 kikuyu quadrats sampled.
Rainfall 17-31 March – nil . No rainfall since 6 March.
This concludes monitoring for this season – pheromone traps have been removed and the temperature recorder removed and data downloaded. Final report to follow.
With few moths about and no damage seen or reported it is expected that there will insufficient moth numbers or enough warmth for kikuyu damage to occur in April.
Previous results
There has been welcome rain in the Far North - from 9- 17 February - 43ml at Motutangi. This has freshened up pasture and there is new kikuyu growth.
Trap catches for 3 -17 February 2009
Motutangi
- Harrington East trap – 0 moths
- Harrington west trap – 1 moth
- Blucher roadway trap – 0 moths
- Blucher gully trap – 0 moths
Ngataki
- Kuhtz property 20 Jan – 17 Feb
- Yards trap – 0 moths
- Macrocarpa hedge trap – 0 moths
Very few moths trapped since 20 January – a result of very dry conditions in January. Only one moth seen in rank kikuyu pasture at Harrington property next to west trap. However, mid-late instar larvae were recorded today feeding on kikuyu pasture on the Blucher property – three larvae/square metre of pasture. These represent the first TGW generation which are always seen in mid- February.
Weather conditions in the next couple of weeks will determine how many of these survive and how large the second generation in March will be. If weather continues to be moist, humid and overcast there will be ample fresh kikuyu growth for TGW populations to build-up. Recently cut pasture opposite the Billot property in Motutangi is especially vulnerable at the moment as new growth kikuyu is very attractive to TGW at the moment.