Zeal (etoxazole) is now registered for control of phytophagous mites in caneberries.  Zeal is a very welcome addition to our limited suite of miticides in caneberries.  Link to the label is here:

http://www.cdms.net/LDat/ld7DK007.pdf 

Had lunch at the Nickel with Tom Dewitt from Valent to get some clarification on the use of this material.  Our conversation was as follows:

Breadth of Control: Zeal controls phytophagous mites in the Tetranychid family very well, so this includes both twospotted spider mites and Lewis mites.  It does not kill eriophyid mites such as redberry mite nor tarsonemid mites such as cyclamen mite.  As a translaminar material, it doesn't matter that the residue doesn't stick around that long on the leaf surface, since plant feeding mites will still pick it up when they penetrate the leaves to feed.  It is important then also to not apply Zeal with surfactants that are stickers because they will impede the translaminar activity and instead to go with a good nonionic surfactant.

Activity on Predatory Mites: Zeal should not be applied on top of a population of predatory P. persimilis mites since it renders the males sterile and the population will cease to grow.  It is recommended to hold off on releasing predatory mites until 30 days after an application of Zeal so as not to impede with their activity.

MRL's: Growers and shippers please take note that while Zeal now has a MRL (maximum residue limit) for Canada in strawberries, it does not have an MRL yet in caneberries. 

I discuss the use of a miticide in this article.  As always, before using this of product, check with your local Agricultural Commissioner's Office and absolutely consult the product label for product registration, restrictions, and use information.

A thread I have been participating on with the North American Raspberry and Blackberry Association (NARBA) email discussion group regards the heavy fruiting of the blackberry variety 'Natchez' and the subsequent repercussions on fruit ripening and to some extent flavor.  This is a fairly common problem here on the Central Coast with growers of this variety and I have been asked on several occasions what to do about it.

As one can see from the picture below, the ability of 'Natchez' to produce fruit is tremendous, but unfortunately the leaf area to fruit ratio is rather low here, resulting in the ripening problems mentioned above.

This past week we were fortunate enough to have plant breeder John Clark, who among other blackberry varieties bred 'Natchez', weigh in on managing overcropping of this variety. 

He writes that 'Natchez' plants without any lateral shortening, ie pruning of the laterals, overcrop (load up with too much fruit), especially on plants which are fruiting in the first year after planting. He suggests that laterals be shortened to 15-25 inches long (prior to flowering obviously) to limit the crop down to what the plant can ripen with the available leaf surface area and carbohydrate reserves in the plant itself.

Simply put, the key to getting 'Natchez' to ripen and flavor up properly is maintaining an adequate ratio of leaves to fruit by pruning the laterals back to 15-25 inches.

Interesting case here of calyx browning caused by spider mites.  Most strawberry industry people normally will correctly associate calyx browning with a lack of water or plant physiological issues, but this case of calyx browning is clearly being caused by spider mites.

As one can see from the series of pictures below, brown and spotted patches are all associated with mites and webbing.

The grower reports that the rest of the plant is fine and very few leaves are affected anywhere.  It does beg the question why the mites would be specifically infesting the fruit calyces only, but control will be the same as for foliar infesting mites.

The following is regarding a sample of raspberry sawfly submitted to this office this afternoon.  This sawfly, very likely Monophadnoides geniculatus, is not that common on the Central Coast but the infestation described to me was sort of acute.
As one can see from the photos below, the larvae of the raspberry sawfly are rather bristly and run around 10 to 13 millimeters in length.  The damage is distinctive, consisting of a patchwork of holes on infested leaves.  The literature describes leaves being skeletonized by raspberry sawfly feeding, but I have yet to see anything as severe here.
The important part for growers and consultants to know is that raspberry sawfly is a wasp, not a moth or fly.  It belongs to the family Tenthredinidae in the insect order Hymenoptera, which derive the common name of sawflies from the ovipositor of the females which is adapted for sawing.  The female raspberry sawfly inserts her eggs into the leaves in May, and the larvae emerge obviously right around now.  They feed for two to three weeks after which they drop to the ground to form a cocoon, from which the adult emerges the following year in the spring.  There is only one generation per year.
From a pest management point of view on the Central Coast, the incidental damage we see on the leaves will not harm the plant and by any measure the damage is short lived and limited to the two to three week feeding period.  However, growers who are concerned about incidental contamination of the harvested fruit from a medium to heavy raspberry sawfly infestation may want to treat. 

Thanks to the PCA and his apprentice for bringing these samples by the office this afternoon.  It really helps me keep current on what is going on out there.