🐛✗ Tested and false“Red berry mite from blackberries will spread to raspberries and other cane fruit growing nearby”
Red berry mite is specific to blackberries. It does not affect other cane fruits, and it is not an economic pest of raspberries, despite raspberries growing in the same beds and often trained the same way.
What to do: No need to isolate raspberries or other cane fruit from an infested blackberry patch on this mite's account; watch raspberries for their own separate pests instead of treating red berry mite as a shared risk.
2 sources
- RHSIt does not affect other cane fruits.
- UC IPM (University of California)The redberry mite is a perennial pest of both cultivated and wild blackberries but is not an economic pest of raspberries.
“Spraying an insecticide or miticide will control red berry mite on blackberries”
RHS states there are no suitable controls available to home gardeners for this mite, and the damage has to be tolerated.
What to do: Cut heavily affected canes to ground level as soon as noticed, and use partly-ripened berries for cooking or jam rather than reaching for a spray.
1 source
- RHS: Red berry miteThere are no suitable controls available to home gardeners for the mite and so the damage has to be tolerated
“Blackberries with red berry mite damage are still safe to eat, even though patches stay hard and red”
The mite affects ripening, not toxicity: it feeds inside the drupelets and stops some of them turning black, leaving a patchy, unripe-looking berry rather than a contaminated one. Partly affected fruit is usable rather than something to discard, and can go into cooking, jam or wine instead of being eaten fresh.
What to do: Pick partly affected berries as normal and use them cooked, in jam, or in wine, where the texture of the hard drupelets matters less than eating them raw. Fully green or very hard patches are unpleasant fresh but not unsafe.
1 source
- RHSPartly ripened berries can be used for cooking, making jam or wine.
“Cutting out and destroying badly affected blackberry canes helps control red berry mite”
Red berry mite overwinters under the bud scales of the canes it has colonised, so a heavily affected cane carries next year's population with it. Removing that cane at ground level as soon as damage is spotted, and disposing of it rather than composting it, takes a chunk of the overwintering mites out of the picture before spring.
What to do: Cut heavily affected canes to ground level as soon as you notice the patchy ripening, and bin or burn the material rather than composting it. There is no spray option for home gardeners, so this cane removal is the main lever available.
1 source
- RHSHeavily affected canes can be cut to ground level as soon as the problem is noticed and disposed of as diseased material.
“Late-fruiting blackberry varieties suffer worse red berry mite damage than early varieties”
The mite population builds through the season, so the first fruits on a cane tend to ripen normally while later fruits show increasingly patchy ripening as the season goes on. Late-maturing blackberry cultivars are the most damaged as a result.
What to do: If red berry mite is a recurring problem, weigh that against choosing very late-fruiting blackberry varieties, since they give the mite population longer to build before that fruit ripens. It is not a reason to avoid blackberries altogether, just a factor in variety choice on an already affected plot.
2 sources
- RHSThe first fruits to develop on a cane usually ripen fully; later fruits show increasingly patchy ripening through the season.
- UC IPM (University of California)The pest is most damaging to late-maturing blackberry cultivars.
