August 14

July 15

July 3

Insects: To my knowledge (and to my sweepnet), since the middle of June, caterpillar pests have not been an issue for anyone. Numbers have been very low. Tipworm populations have been extremely variable from site to site, though consistently lower than in previous years for growers who have added Assail to their insecticide regiment this season.  For growers who haven't used Assail*, tipworm numbers have been all over the board (zero, remarkably, at one site with no insecticide use at all other than B.t., but at other non-Assail sites the levels are generally in the 60%+ range for infestation and damage levels). Callisto is performing extremely well against weeds.  Even cinquefoil, which is reported to be one of the harder ones to knock out with Callisto, did not fair very well after only a single application.  Yellow loosestrife is growing now at sites with a history of it, and most of them are now above the cranberry canopy.  None of the sites where I know yellow loosestrife is abundant have used Callisto, so I cannot report on Callisto's effectiveness against that weed at this time.

Next insect to be watching for: Blackheaded Fireworm (2nd generation larvae) (watch for uprights that are pulled together at the tips, with webbing holding them together)

Umbrella Bloom - As was the case last year, there is a large amount of umbrella bloom to be found again this year.  I believe it is due to tipworm injury in our (i.e. Maine's) case.  Many uprights with the umbrella bloom have the beginnings of small side shoots, near the tips, that I suspect will yet grow out and therefore rectify the abnormality.  That is precisely what took place in at least one bed in 2007, and the yield from that bed was a record-setting yield for that particular grower.

* Note: Tipworm is not on the Assail label for a target pest. Cranberry fruitworm and fireworm are. Keep in mind that blackheaded fireworm goes through two generations each season, with the 2nd generation of caterpillars beginning in mid to late July.

June 12

Where Assail has been sprayed against fireworm, tipworm numbers have also been very low, though it is proving difficult to know if the low tipworm counts are due to the Assail when tipworm numbers have been so low everywhere else as well.  As the season progresses, this uncertainty should evaporate. 

Numbers of false armyworm and blackheaded fireworm caterpillars have been below threshold at most locations.  Fireworm larvae were still being caught in the Augusta area as of June 10th, with counts of 4 per 25 sweeps at one site (threshold is 1-2).

Callisto: Callisto has worked very well at each of two locations I have seen it used on to date.  In Washington State, growers have learned that a second application is needed to control most perennials. They usually apply the 2nd dose once re-growth occurs, but on some weed species, control is best when the second application is applied 2-3 weeks after the first.  The timing of that 2nd application depends heavily on the sensitivity and vigor of the specific weeds being targeted. Yellow loosestrife needs to be hit early, often and hard. For other weeds, the general strategy is to let them die back, and wait for regrowth before putting on the 2nd application. 
 

May 29 (Spring caterpillars, and tipworm)

Make sure you sweep your bed(s) each week, and don't throw away the contents of your net too quickly.  The green, active, false armyworms are easy to see and count right away, but with the blackheaded fireworm, you have to be extremely patient and thorough, and paw through the leaf litter/debris frequently, in order to scare the tiny caterpillars out of hiding.  I highly recommend using something with a white background (in full sunlight if possible) when spreading out your net contents.

Tipworm Update: I found my first 2008 tipworm egg and larva yesterday, in southern Waldo County.  So I would expect them to be showing up in Washington County by June 4th. 

May 21

May 16

Degree Days: Unfortunately, the number of degree days that accumulated--to mark the start of tipworm and blackheaded fireworm--ended up being considerably less than the number that was derived last year.  I was hoping last year's numbers and this year's numbers would match up better.  What that says to me is that we just need additional years of measurements, before we can pinpoint what the true number of degree days might be, for either the tipworm or the fireworm.  Visit the Degree Days page in order to see the final values.  It could be that the best we can hope for is a 'range' of degree days as a model for these pests.  Even the best degree day models are not perfect.  You still cannot beat your own two eyes!
 

May 15

May 13 (Degree Day Update)

May 2 (Degree Day Update)

May 1

There is a new and improved version of SpinTor available for use (for caterpillars), called Delegate (Delegate WG).  It is also higher than SpinTor in its toxicity to bees (considered "highly toxic"), so do not apply it during bloom and be alert to potential drift to any hives or to flowering weeds where a lot of bees might be present.  It is also mildly toxic to aquatic organisms. Delegate contains spinetoram, which is derived from a naturally occurring soil organism, and--together with spinosad materials--is classified as a Group 5 insecticide. Since spinosad and spinetoram fall into the same class, you are not supposed to rotate between these two products, as that would foster the onset of resistance in the target pests.

United Phosphorus, Inc. is no longer making the Devrinol 10G formulation, but it is still legal to use any that you may have or may be able to obtain.

The 2008 Maine Cranberry Pest Management Guide is nearly finished, and I have begun work on a Cranberry Management Calendar for Maine that you can find a link for on the home page. 

April 17