- Author: Ben Faber
We have had resurgence of broad mite damage on coastal lemons this year. We haven't seen damage like this in a long time. Chlorpyriphos should care of it, but with small orchards, spray drift can be an issue. We looked at releasing the predatoiry mite Neoseiulus californicus. In the lab we challenged broad mite successfully so we took it out to the field. This is not the best time to release, because of the cold weather. Also it's best to release into a rising pest pressure. When there are too many pest mites, it's difficult to get good control. We released at an economic level of about 100 per tree, whihch would cost about $150 per acre. We've counted for 5 weeks and there is little apparent control in the field. ikt's just been too cold to build the population of beneficials. We'll try again next spring if the broad miter is there.
Curlling leaves from mite damage and the small mites hiding in fruit depressions
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- Author: Ben Faber
We have recently had an outbreak of citrus broad mite (Polyphagotarsonemus latus) in lemons. Broad mites feed on fruit and leaves, preferring young fruit up to about 1 inch (2.5 cm) in diameter that are located on the inside of the canopy or on the inward facing side of outer fruit. Feeding results in scarred tissue that cracks as fruit grows, leaving a characteristic pattern of scars and new tissue. Although most feeding occurs on fruit, broad mites may also feed on young expanding leaves causing them to curl. This cupping and curling of leaves can appear similar to mild damage caused by glyphosate-Roundup applications. Several PCAs have claimed that a variety of pesticides have had a very limited control of the pest
To see if predatory mites could help control the pest, Anna Howell in our office did a laboratory trial to see if the two mites, Amblyseius andersoni and Neoseiulus californicus, would feed on the mite. These are both generalist predators and it was not clear that they would take to the broad mite. Well, they both did, and especially the N. californicus dined on the pest. This is a confined feeding trial where the only thing the predators could feed on was the pest. So the next step is to go out in the field and see if they will knock the pest population down. That’s what we intend to do next week. With a group of PCAs, we’ll be out counting broad mite on lemons for the next several weeks to see if a predatory mite treatment can control the pest.