How to monitor for mites in peach and nectarine: video and transcript
In this video, Area IPM Advisor Emily Symmes demonstrates how to monitor for webspinning spider mites in peach and nectarine orchards.
(Emily Symmes speaking)
Hi. I’m Emily Symmes, area IPM advisor with UC Cooperative Extension in the Sacramento Valley. I’m here to show you how to monitor for webspinning spider mites in peaches and nectarine.
Use this technique to decide if a treatment is needed and again after treatments are made, through mid-August, to let you know if your application was successful. Webspinning spider mite females are greenish or pale yellow with large dark spots on each side of the body.
Evidence of spider mite infestation includes stippling caused by feeding and build up of webbing with higher numbers. When monitoring, you’ll also look for predators.
The western predatory mite is about the same size as a webspinning spider mite, somewhat transparent, and moves quickly across the leaf. Adult spider mite destroyers are tiny and jet-black. Their silver hairs can be seen with a hand lens. The larvae are dull black, elongated, and covered with many hairs. Adult sixspotted thrips are tiny, brownish, slender insects with three dark spots on each forewing. Their larvae are yellow.
For monitoring, you’ll need a hand lens, monitoring form, a timer, and a counter for recording the trees. Pockets, or an apron with pockets, can be helpful to keep track of your samples before recording the data at the end of your 5-minute search.
Set your timer for 5 minutes and examine 10 trees. Look at 2 to 3 leaves per tree, alternating from the inside of the canopy to the outside of the canopy. Focus on trees in known hot spots or dusty areas.
On each leaf, check for the presence or absence of spider mites and predators. After your 5 minutes are up, record your observations on the mite monitoring form.
Each 5 minutes of monitoring constitutes one search. Complete two 5-minute searches in separate areas of the orchard up to 40 acres. Do at least 1 additional 5-minute search for additional acreage up to 20 acres. Once mites are found, monitor the same trees weekly to track mite and predator numbers.
Use the ratings on the mite monitoring form found in the peach or nectarine pest management guidelines to decide whether or not to apply a miticide.