Upcoming Pest Events | Trap Catches | Pest Focus | Insects

Return to top

Upcoming Pest Events | Trap Catches | Pest Focus | Insects

Return to top

Upcoming Pest Events | Trap Catches | Pest Focus | Insects

Geneva: 
Degree days (base 45F) since first Obliquebanded Leafroller
trap catch = 384. Degree days (base 45F) since Spotted
tentiform leafminer 2nd flight began (6/23) = 140

Highland:
Brown stinkbug and Japanese beetle observed on pple.
Degree days (base 50F) since first Codling Moth trap catch = 655
Degree days (base 45F) since first Oriental Fruit Moth trap catch = 927
Degree days (base 50F) since first San Jose Scale trap catch = 577
Degree days (base 45F) since first Obliquebanded Leafroller trap catch = 628

Return to top

Upcoming Pest Events | Trap Catches | Pest Focus | Insects

Geneva Predictions:
Roundheaded Appletree Borer
Peak egglaying period roughly: June 24 to July 6.
First RAB eggs hatch roughly: June 23.

Dogwood Borer
First Dogwood borer egg hatch roughly: June 27.

Codling Moth
Codling moth development as of June 27: 1st generation adult emergence at 98% and 1st generation egg hatch at 80%.

Obliquebanded Leafroller
Where waiting to sample late instar OBLR larvae is not an option (OBLR is known to be a problem, and will be managed with early application of an insecticide only effective against young larvae): The optimum date to begin 2 to 4 weekly low-rate Bt applications for small OBLR larvae is: June 20.
The optimum date for application of Intrepid, SpinTor or other insecticide with comparable efficacy against OBLR (with possible follow-up at 10-14 days) is: June 25.
Where waiting to sample late instar OBLR larvae to determine need for treatment is an option, or to check on results from earlier sprays: Optimum sample date for late instar summer generation OBLR larvae: July 2.

Oriental Fruit Moth
2nd generation OFM flight begins around: June 28.
Optimum 2nd generation - first treatment date, if needed: July 4.

Redbanded Leafroller
2nd RBLR flight begins around: June 29.

San Jose Scale
1st generation SJS crawlers appear: June 18.

Spotted Tentiform Leafminer
Rough guess when 2nd generation sap-feeding mines begin showing: July 4.

Highland Predictions:
Roundheaded Appletree Borer
RAB peak egglaying period roughly: June 23 to July 5.
First RAB eggs hatch roughly: June 23.

Dogwood Borer
First Dogwood borer egg hatch roughly: June 26.

Codling Moth
Codling moth development as of June 27: 1st generation adult emergence at 99% and 1st generation egg hatch at 87%.

Lesser Appleworm
2nd LAW flight begins around: July 5.

Obliquebanded Leafroller
Where waiting to sample late instar OBLR larvae is not an option (OBLR is known to be a problem, and will be managed with early application of an insecticide only effective against young larvae): The optimum date to begin 2 to 4 weekly low-rate Bt applications for small OBLR larvae is: June 16.
The optimum date for application of Intrepid, SpinTor or other insecticide with comparable efficacy against OBLR (with possible follow-up at 10-14 days) is: June 23.
Where waiting to sample late instar OBLR larvae to determine need for treatment is an option, or to check on results from earlier sprays: Optimum sample date for late instar summer generation OBLR larvae: June 30.

Oriental Fruit Moth
2nd generation OFM flight begins around: June 27.
Optimum 2nd generation - first treatment date, if needed: July 1.

San Jose Scale
1st generation SJS crawlers appear: June 15.

Spotted Tentiform Leafminer
Rough guess of when 2nd generation sap-feeding mines begin showing: June 30.

Return to top

 Mites
   Mite numbers generally have not been too high yet in most places, but the current and ongoing trend of very hot weather is perfect for explosions of not only European red mite, but also twospotted spider mite.  This is still the early part of the season, and trees are quite sensitive to big mite buildups right now (the threshold in apples is 2.5/leaf in June and 5.0/leaf in July), so please do not pass up this opportunity to examine the foliage of all your tree fruits for emerging populations of either of these species.  Two-spots, especially, respond quite rapidly to high temperatures.  [Note: For those growers opting for a summer program of horticultural mineral oil, recall that the June 6 issue of Scaffolds stated that Sunspray Ultra-Fine is no longer registered in NY; however, Whitmire Micro-Gen has taken over marketing and just calls it Ultra-Fine Oil (their label says 'Prescription Treatment Ultra-Fine'; EPA# 862-23-499), and it has pretty much the same label as the original.]

Obliquebanded Leafroller
   Although early season populations of OBLR were not has high as they have been traditionally, this pest can always fool you by roaring back when least expected.  We caught the first moths June 12 in most WNY sites, which means that the 360 DD (base 43F) timing for expected first hatch should occur early this week.  In problem blocks, this would be a prudent time for an initial B.t. or Intrepid application; low- or variable-pressure blocks can wait until 600 DD, when a visual sample for infested terminals can provide information on the need for a treatment.

San Jose Scale
   The first crawlers of the season should be showing up any day now, so this would be an advisable time for the first application of an effective insecticide against the most susceptible stage of this recently rejuvenated pest.  Materials recommended include OP's such as Guthion and Imidan, as well as Provado and Esteem.

Comstock Mealybug
   It also shouldn't be long before we start seeing some adult Comstock mealybugs in pear foliage, followed by their invasive crawler offspring.  The crawlers are the most susceptible stage for chemical control, which we expect sometime during the next couple of weeks, especially in the Hudson Valley.

   The overwintered eggs hatch from mid-April through May and the nymphs (crawlers) migrate from the oviposition sites to their feeding sites on terminal growth and leaf undersides of trees and shrubs.  This hatch is completed by the petal fall stage of pears.  Nymphs that hatch from these overwintered eggs are active from roughly early May to early July.  As the nymphs approach the adult stage, they tend to congregate on older branches at a pruning scar, a node, or at a branch base, as well as inside the calyx of pears.  Second- (summer) generation nymphs are present from about mid-July to mid-September.

   The Comstock mealybug poses two major concerns for the pear processing industry of New York:  First, the emergence of crawlers and adult females from the calyx of pears  at the packinghouse creates a nuisance to workers.  Second, pears to be made into puree typically are not peeled or cored by New York processors, so infestations can potentially result in unacceptable contamination of the product.

   Another problem, of concern to apple growers in the 1930s and 1940s, and again in the Hudson and Champlain Valleys in the early 1980s, is that the honeydew secreted by the crawlers is a substrate for sooty molds growing on the fruit surface.  This type of damage has also been noted on peaches in Niagara Co. and in Ontario, Canada.  These molds result in a downgrading of the fruit, and are therefore an additional cause of economic loss. 

   To date, the Comstock mealybug has been a problem to growers of processing pears because of the contamination and aesthetic reasons noted.  An infestation generally requires one or more insecticide sprays during the growing season, directed against the migrating crawlers.  Examine the terminal growth for crawler activity periodically throughout the summer.  Crawler and adult female activity can also be monitored by wrapping double-sided tape such as white carpet tape around low scaffold branches and inspecting for crawlers that have been caught by the tape.  They can be recognized with a hand lens or, with some experience, by the unaided eye.

   Sometime in early August, we'll advise an application of a material such as Provado, Diazinon, Actara, or Assail to control this insect.

Dogwood Borers
   Adults should be laying eggs in susceptible apple orchards now (those with succulent burrknot tissue or suckers).  The larva of this clearwing moth feeds on apple trees, primarily on burrknot tissue on clonal rootstocks.  Burrknots are aggregations of root initials that can develop on the above-ground portion of the rootstock; all commercial dwarfing and semi-dwarfing rootstocks have a tendency to develop burrknots.  Some chemicals with hormone effects, such as NAA, can increase the expression of burrknots, as will failure to keep the area around the trunk weed-free and open to sunlight.  White latex paint brushed on the exposed portion of the rootstock will prevent new infestations of the borers, and also protect against southwest injury to the bark. 

   Dilute trunk applications of an insecticide with good residual activity can provide control of established infestations.  Lorsban 4E or 50W may now be used postbloom as a directed trunk spray in N.Y. for borer control in apples.  We feel that Lorsban is the best tool we presently have for this use, and early to mid-July would be a good time to take advantage of this welcome opportunity to use it on apples to control both dogwood borer and the second generation of American plum borer.  Another option at this point in the season is an application of Thiodan 50WP applied once during this first week of July, and again one month later at the beginning of August.  We would also note that, in case you didn't follow the strategy of using Lorsban as a prebloom trunk spray for American plum borer, these treatments will also serve as the last opportunity for a control measure against this pest.

Peachtree Borers
   If you're not using pheromone disruption ties against peachtree and lesser peachtree borers, this is the time of the season when a second trunk application of a pesticide should be made against these pests in cherries and peaches.  A coarse spray directed at the trunk and scaffold branches gives the best protection against ovipositing adults; shutting off all but the bottom nozzles on a speed sprayer won't do an effective job.  Use Lorsban 4EC, Thiodan, or a pyrethroid (Ambush, Asana, Pounce, or Warrior; Danitol is NOT registered in stone fruits).  Do not spray the fruit.

Woolly apple aphid (WAA), Eriosoma lanigerum (Hausmann)
   WAA colonizes both aboveground parts of the apple tree and the roots and commonly overwinters on the roots.  In late spring, nymphs crawl up on apple trees from the roots to initiate aerial colonies.  WAA also migrate in from other hosts (such as American elm, hawthorne and mountain ash) and congregate at the base of root suckers during this time.  Most nymphs are born alive to unmated females on apple trees during the summer.  Colonies initially build up on the inside of the canopy on sites such as wounds or pruning scars and later become numerous in the outer portion of the tree canopy; although these are not always noticed until later in the summer, we have already seen healthy populations in a number of plantings around the state.

   Aerial colonies occur most frequently on succulent tissue such as the current season's growth, water sprouts, unhealed pruning wounds, or cankers.  Heavy infestations cause honeydew and sooty mold on the fruit and galls on the plant parts.  Severe root infestations can stunt or kill young trees but usually do not damage mature trees.  Large numbers of colonies on trees may leave sooty mold on the fruit, which annoys pickers because red sticky residues from crushed WAA colonies may accumulate on their hands and clothing.

   Root suckers, pruning wounds, and scars on the inside of the tree canopy should be examined for WAA nymphs.  Any new growth around the outside of the canopy should be examined for WAA colonies.  No economic threshold has been determined for treatment of WAA.

   Aphelinus mali, a tiny wasp, frequently parasitizes WAA but is very susceptible to insecticides and thus does not provide adequate control in regularly sprayed commercial orchards.  Different rootstocks vary in their susceptibility to WAA.  The following resistant rootstocks are the only means of controlling underground infestations of WAA on apple roots: MM.106, MM.111, and Robusta.

   WAA is difficult to control with insecticides because of its waxy outer covering and tendency to form dense colonies that are impenetrable to sprays.  WAA is resistant to the commonly used organophosphates, but other insecticides are effective against WAA, including Diazinon and Thiodan.  Also Note: If you are considering a trunk spray of Lorsban against borers at this time, you will achieve excellent control of any newly forming WAA colonies as a side benefit of this application.

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
Editors: A. Agnello, D. Kain
Dept. of Entomology, NYSAES
P.O. Box 462
Geneva, NY 14456-0462
Phone: 315-787-2341 FAX: 315-787-2326
E-mail: ama4@cornell.edu

Online at <http://www.nysaes.cornell.edu/ent/scaffolds/>