|Field scout Jenna Horine holds a navel 0rangeworm trap,|
- Check twice weekly to determine the bio fix – this is the first of two dates in which egg laying increases in 75 percent of the traps in a given location.
- Record the biofix date.
- Continue monitoring traps, counting and recording egg numbers of a monitoring form. Remove eggs as you monitor.
- Change bait – a mixture of almond meal and almond oil – about every four weeks.
|NOW trap should be 6 to 7 feet above ground.|
- Look for flat eggs that are laid mostly on the ridges of the trap or on the raised lettering on the top and bottom of the trap. Eggs will be white when first laid but turn orange-red before hatching.
- Graph numbers of eggs laid at each trap reading on the monitoring form. This will give you an idea of when new generations of navel orangeworm are laying eggs.
- Use this information to verify degree-day calculations. If you wish to use this information for timing a hullsplit spray, continue monitoring for the entire season.
- Use the biofix determined by egg trap monitoring to start accumulating degree days for following navel orangeworm development and to time hullsplit treatments.
- Egg laying by the second flight of moths is predicted to begin 1056 DD after the biofix.
- Shake trees before third generation egg laying takes place.
- If treatments are planned and hullsplit begins before egg laying predicted, apply the hull split spray at the beginning of egg laying. If hull split begins after egg laying is predicted, apply the spray at the beginning of hull split. Back up degree-day predictions by checking egg traps.
|Early stage of NOW development.|
- Whether there was significant loss the previous three years.
- The prospects of infestation from nearby orchards, including pistachios.
- Orchard sanitation, meaning trees had two or less mummy nuts.