Scaffolds 00 index

(Art Agnelloama4@nyseas.cornell.edu & Dave Kain dpk1@nysaes.cornell.edu, Entomology, Geneva)

It hasn't actually begun to feel like fall yet to some of us, and to others it seems like summer had a rough time making its presence felt at all this year. However, if only on the basis of photoperiod alone, it is certain that the fruit insect and mite populations have begun to pack it in for the season, so my natural response as a compulsive summarizer is to attempt to tie it all up in a form that makes it recognizable in (backwards) perspective.

Best Leading Actor. It surprised many of us with its tenacity, but I'm sure that after all the reviews are in, a majority of people will regard plum curculio as the worst insect problem of the year in most of the area's tree fruits. The developmental model we've been using to estimate the length of the oviposition period is a fairly accurate tool under most situations, but we've rarely seen a spring with such a pronounced, stretched out and delayed warming curve as occurred this year. Even the extra spray or two applied by most growers to protect against that last tail of curculio activity seems not to have been enough in many cases, and the tail was so long that it took quite a while for all the curcs to finish up their egg laying, so many orchards now bear a higher incidence of scarred fruit than normally would have been expected, given the relatively late spray cutoff dates. It appears that you can't always put a lot of faith in past performances.

Plum curculio oviposition scars on apple

The Perfect Storm. Most of us had the benefit of waterproof footwear for navigating the sodden orchards during April and May; a numbr of early season regulars didn't fare so well, however, and in some cases it looked like they decided to take the year off. Particularly notable were European red mites, which, between the poor weather and the effective miticides currently in use around the region, failed to make themselves known in many spots until late August.

Pear psylla adult

Rainy conditions similarly thwarted pear psylla and Comstock mealybug from becoming well established, and spotted tentiform leafminer continued its long-running trend of failing to appear until the second or even third generation. One particularly interesting newcomer to the category this year may be obliquebanded leafroller, which generally warrants a paragraph all to itself. To paraphrase one local OBLR expert, if you didn't control your oblique populations this year, you never will; it's assumed that the weather was a big factor in this scenario, but many growers were also helped by some new-chemistry products that were working at their peak efficiencies this season.

The Usual Suspects. The rain clouds giveth and taketh away, of course, so not all of the insect/weather interactions were necessarily benign. Ample moisture translates into lush foliage, which nicely supports flush feeders like green aphids and leafhoppers (several varieties). Potato leafhopper particularly seemed to hang around for a longer period than normal, with attendant foliar damage on trees of all ages.

Green apple aphid terminal infestation

Potato leafhopper foliar damage

Similarly, there were no expectations that apple maggot adults would have another difficult time this year emerging from the water-charged soil. Still, the regional populations appear to have taken some major hits recently, so the increased catches did show up, but still in local hotspots, and rather later than normal in the season. The clearwing moth pests didn't have any trouble either, posing their normal challenges to trunk health; dogwood borer and both peachtree borer species were predictably numerous in sites where they've traditionally been a problem. Catches of oriental fruit moth were particularly high in the western stone fruit plantings, as they have been in recent years, but we won't know until the end of harvest evaluation whether our current research efforts were measurably more successful in controlling their fruit damage.

Oriental fruit moth internal injury to peach.

The Up-and-Comers. Complaints of borers in apple trunks are increasing, with a couple of notable hotspots coming to our attention this year. This is apparently related to the increase in dwarf plantings, which almost invariably express burrknot growth through which borers invade. We are beginning to realize that, in addition to stone fruits, American plum borer is one of the important borers in dwarf apple. Proximity to tart cherry orchards, in which plum borer numbers have been building for some years, is an important factor. Mullein plant bug damage was more widespread this season. Explanations are little more than a guess at this point because this bug remains such a mystery. The most we can say is that weather at bloom plays a role, and that damaged orchards received either no insecticide treatment, or an insecticide with too short a residual effect, at the pink stage.

Damage by mirid bug nymphs to early fruit

Jaws Meets The Blob. Many growers count this as among the most challenging of seasons for growing fruit that they've experienced. Even if the market were in better shape, the debilitating combination of crippling hail storms together with some serious disease-generating conditions will probably make whatever next year brings seem like a walk in the park. But we'll leave that discussion for the folks on the other side of the aisle.

end of this issue

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