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Insects | Diseases | Credits

Volume 7, No. 25                                                 August 17, 1998


                                                    43°F      50°F
Current DD accumulations (Geneva 1/1-9/8):          3466      2402
                    (Geneva 1997 1/1-9/8):          2887      1939
                (Geneva "Normal" 1/1-9/8):          3092      2232

Coming Events:                              Ranges:
American plum borer 2nd flight subsides         2841-3698  1907-2640
Apple maggot flight subsides                    2764-3656  1904-2573
Codling moth 2nd flight subsides                2782-3693  1796-2635                  
Lesser appleworm 2nd flight subsides            2775-3466  2002-2460
Lesser peachtree borer flight subsides          2782-3474  1796-2513
Obliquebanded leafroller 2nd flight subsides    2809-3656  1930-2573
Oriental fruit moth 3rd flight subsides         2987-3522  2018-2377
San Jose scale 2nd flight subsides              2494-3257  1662-2302
Spotted tentiform leafminer 3rd flight subsides 3235-3471  2228-2472

TRAP CATCHES (Number/trap/day)
                                  8/17   8/20   8/24  8/31    9/8
Spotted Tentiform Leafminer        428    352    107  73.3    7.9
Redbanded Leafroller               0.3    0.5    0.1   0.3      0
Oriental Fruit Moth (apple)        2.3    5.5    2.8   4.3    4.6
Lesser Appleworm                   1.7    3.0    1.5   0.7    4.3
Codling Moth                       5.2    2.2    1.4   6.4    0.7
San Jose Scale                     7.8    1.3    0.6   2.9    0.4
American Plum Borer                1.0    0.3    0.9   0.4   0.06
Lesser Peachtree Borer             0.8    0.3    0.4   0.9   0.06
Obliquebanded Leafroller           0.3    0.3      0     0    0.1
Apple Maggot                         0    0.1      0     0   0.04

Highland (Dick Straub, Peter Jentsch):
                                   8/3   8/10   8/25   8/31
Spotted Tentiform Leafminer       25.9   19.6   11.3   15.3
Redbanded Leafroller                 0    0.4    3.6    4.3
Oriental Fruit Moth                0.4    0.4      0    0.1
Lesser Appleworm                   0.4    0.5    0.9    0.4
Codling Moth                       8.3    0.9    1.0    0.1
Obliquebanded Leafroller           0.1    0.1      0      0
Variegated Leafroller              0.7    1.1    1.0    0.5
Tufted apple budmoth               0.1    1.2    1.1    0.7
Fruittree Leafroller                 0      0      0      0
Sparganothis Fruitworm             0.4    0.5    1.6    1.7
Apple Maggot                      0.09    0.2    0.3   0.14

European red mite adult female



by Art Agnello
Entomology, Geneva

In light of the Labor Day hail and wind storm that bulldozed its way through much of the state's fruit belt as harvest was just gearing up, it's difficult to know exactly when the final word will be written on the 1998 season. Next, for all we know, the lake level could rise three feet and flood out everything north of the ridge. We can, at least, pause at this time to try summarizing the events involving the insect and mite competitors for this year's fruit crop, and just preface our remarks by noting that most of what transpired in this category that was worthy of any mention, was generally attributable to the early season/ warm season/ long season/ dry season (pick your favorite).

Although the record early bloom in NY apples was preceded by a patch of fairly good weather for early season mite sprays, it didn't last long enough for many growers to actually take advantage of it. The result was a European red mite population that got off to a good early start, and the perennial problem blocks were in trouble by mid-June if they hadn't been attended to during the petal fall period. As it became clear that this would be a summer without plentiful rainfall, we had visions of some serious tree stress/mite damage combinations taking place. However, most of the early summer miticide treatments seemed to do what they were supposed to, and there were remarkably few reports of runaway mite populations during July and August. As often occurs during hot, dry seasons, twospotted mites were more numerous than usual in apples and stone fruits (we didn't hear of very many in pears), and phytoseiid predator mites became relatively scarce as the summer wore on, even in blocks with normally healthy numbers.

The generally favorable conditions during the die-is-cast period (April and May) had both positive and negative effects on the region's insect populations. Pollination weather was good enough to give an acceptable fruit set in most cases, and the warm temperatures assured a fairly swift progression through plum curculio emergence, so few orchards seem to have been caught unprotected by a protracted period of curc egg-laying. However, the good weather was also a boon to several other species that are better able to get an early foothold if the conditions at this time of the year are favorable for mating.

Codling moth and oriental fruit moth were reported to be particularly plentiful in certain areas; trap catches of adults were quite high, and fruit damage was greater than normal in some peach and apple plantings. Pear psylla was likely also a beneficiary of the good spring conditions, but many pear growers stopped paying attention after the mid-May frost wiped out much of the Bartlett crop. There was notable development of spotted tentiform leafminers this year, although with an interesting twist. The trees' phenological stage was sufficiently advanced during the first STLM flight that eggs were laid fairly late into the bloom period; when the first brood mines showed up, most of us didn't notice the large size of the population. This made it even more surprising when the second brood turned out to be very substantial, and generally earlier than expected (more high temperature effects). Some blocks ended up with high mine numbers in July, and several growers considered the need for a relatively a rare treatment against the third brood. Comstock mealybug continued to make unwelcome appearances in Niagara peach orchards.

Obliquebanded leafroller is one pest that just seems to maintain a steady course from one year to the next, regardless of the weather conditions. The first flight started early, of course, and the uniformly warm temperatures resulted in a larval emergence pattern that was a bit more synchronized than usual. We have yet to finish all of our plot evaluations, but the magnitude of this year's fruit damage appears to be at least as great as in past years. The newer chemistries in use against OBLR seem to be holding their own; a few growers who had access to SpinTor reported generally acceptable control, and our Confirm applications may have performed comparably to most standard programs, but all the details are not in yet.

Apple maggot once again suffered from the late summer lack of rain; adult catches were down overall, but the effect was localized some areas saw a normal flush in early August, but in many others, it was simply too dry. This was another instance in which it definitely paid off to hang traps in individual blocks to determine the need for sprays. A few other insects that didn't make much of a mark in the region included tarnished plant bug, aphids (green, rosy, even woolly), and leafhoppers, although the the last brood could be lying in wait for a September ambush, as it did last year.



by Dave Rosenberger
Plant Pathology, Highland

CLARIFICATION: In last week's article on controlling postharvest decays on apples, I stated that "Captan provides good control of postharvest decays when used at the full label rate of 2.5 lb per 100 gallons of drench solution." That sentence should have read, "*Captan 50W* provides good control of postharvest decays when used at the full label rate of 2.5 lb per 100 gallons of drench solution." Postharvest rates for other captan formulations are Captan 80W at 1.6 lb per 100 gallons or Captec 4L at 1.25 quarts per 100 gallons.

THE REST OF THE STORY: The end of the article on postharvest decays was accidentally omitted from the hard copy version of last week's issue. Following are the last two of the six suggestions for controlling postharvest decays of apples that should have been included in last week's article.
5. Use the cleanest bins available for fruit that is most at-risk for decay. Thus, where possible, use new or sanitized bins for Empire fruit that will be held in long-term storage and be especially careful of drench-water sanitation when these fruit are being treated.
6. Rapid cooling can significantly reduce the incidence of decay that develops in storage. If CA rooms are being filled rapidly, fruit should be pre-cooled in separate rooms before it is loaded in the CA room so as to reduce the total cooling time.

Scaffolds is published weekly from March to September by Cornell University - NYS Agricultural Experiment Station (Geneva), and Ithaca - with the assistance of Cornell Cooperative Extension. New York field reports welcomed. Send submissions by 3 p.m. Monday to:

Scaffolds Fruit Journal

NOTE: Every effort has been made to provide correct, complete and up-to-date pesticide recommendations. Nevertheless, changes in pesticide regulations occur constantly, and human errors are possible. These recommendations are not a substitute for pesticide labelling. Please read the label before applying any pesticide.

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Photographs courtesy of New York State Integrated Pest Management Program