2000 – Current Pest Report – Visual Observations

Tree Stage for McIntosh trees:

3/27/2000 – green tip
4/7/2000 – half inch green
4/14/2000 – tight cluster
5/1/2000 – pink
5/4/2000 – early bloom
5/8/2000 – early petal fall
5/10/2000 – petal fall

Visual Observations

8/25/2000 – Sorry I haven’t written any observations lately!

We are still catching apple maggot flies, though I removed most of the traps this week. I don’t think an insecticide is needed for apple maggot fly after the middle of August. Trap captures did peak the first week of August as they usually do.

I found a little bit of fly speck in a commercial orchard this week. This is the first time this year I found fly speck on trees which received fungicides. I expect most growers included Topsin M or Benlate in the final pesticide application.

Leafhoppers are present now as small nymphs, large nymphs and adults. We do not have a good handle on how many leafhoppers can be tolerated in an orchard. The biggest problem with leafhoppers is that they are a nuisance to pickers. This may be very important to you if your pick-your-own customers are bothered by the leafhoppers flying around. Leafhoppers also deposit brown “tar spots” on the fruit. So, it is really up to you how much you can tolerate. For a rough threshold we use 25 nymphs per 100 leaves. (If you have one nymph per leaf I really think you want to spray for them.) Pesticide options include a low rate of Provado (1 oz/100 gal) or Sevin, though Sevin is harsh on mite predators.

8/10/2000 – Found even more apple maggot flies at orchards this week. This surely seems like peak apple maggot time. I found 60 AMF on one trap set up in an early variety – Redfree.

Found fly speck in a commercial orchard yesterday. Only found a few lesions – but it’s out there. Be sure to include Benlate or Topsin M in your final spray cover to protect against fly speck and sooty blotch diseases.

European red mites and two spotted mites are present in some orchards. Some orchards have a high number of mite predators too. The threshold for this time of year is 7.5 mites per leaf. If this threshold is exceeded apply Pyramite or Vendex plus Tactic. Pyramite has a 25 day preharvest interval and Vendex has a 14 day PHI.

Rose leafhoppers may be present now as adults or nymphs. I’m primarily finding young nymphs but, there are also a few old adults flying around.

8/8/2000 – Found quite a few apple maggot flies at two out of three orchards today.

Many growers have applied insecticides and fungicides in the last few days. May be that will be their last spray, or perhaps they’ll apply one more cover.

8/4/2000 – See Fly Speck and Sooty blotch on apples that have received not fungicide this year.

8/2/2000 – I caught 38 AMF in 5 traps in one orchard. This orchard had not been sprayed in more than 14 days. Trap captures in other orchards are about one AMF per trap. In 3 orchards I have caught zero AMF all season.

Rose leafhoppers are primarily adults now and too difficult to control. It is better to wait until the next generation nymphs hatch before trying to control rose leafhopper – probably in 1-2 weeks. Use Provado, Sevin, or Thiodan – watch the days to harvest interval (Thiodan is 21 days).

7/19/2000 – I caught apple maggot flies in 2 out of 4 orchards checked today. Both of these orchards are now above the threshold of 1-2 apple maggot flies per trap. Most growers have applied Imidan or Guthion this week.

Two spotted mites are building in several orchards. I think some orchards will require a miticide application for two spotted mites. Vendex at 1 lb./ 100 gal. plus 6 oz. Tactic or Silwet per 100 gal of finished tank mix will probably give the best control against two spotted mites. Use a magnifying glass and look on the underside of paler leaves for two spotted mites. Leaves damaged by two spotted mites do not look bronzed like those damaged by European red mites.

Rose leafhoppers are large nymphs now and easier to see. Sevin, Thiodan, or a half rate of Provado should still control most rose leafhoppers now. Remember, Thiodan has a 21 day pre-harvest interval.

More second generation leafminer mines are showing up. If you sprayed Provado in early July for second generation leafminer, you may need to make a second application now. No orchards I monitor need to spray for second generation leafminer.

7/18/2000 – I only checked one orchard today and caught a total of 5 apple maggot flies on 5 traps. I thought I would catch more at this orchard because it usually has a large population. Also, I thought the rain of 7/15 would bring out the apple maggot flies. 5 AMF/ 5 traps is within the threshold of 1-2 AMF per trap. I recommended the grower apply Imidan some time soon.

7/13/2000 – I finally caught some apple maggot flies yesterday. In one orchard I caught 6 AMF on 5 traps. I caught flies in two other orchards, both low numbers. For actual trap captures in each orchard see AMF trap capture web page.

European red mites above threshold in several blocks. The majority of orchard blocks are well below threshold. Two spotted mites are building in several orchards. Vendex at 1 lb/ 100 plus Silwet or Tactic at 6 oz. per 100 gal finished tank mix controlled two spotted mites and European red mites well last year. Pyramite is effective against red mites but not very effective against two spotted mites.

Rose leafhoppers are present as small, white nymphs in many orchards. A true threshold for rose leafhoppers does not exist, but we use the ball park threshold of 25 nymphs per 100 leaves. Nymphs may continue to hatch, so, check now and check again in a week to see if you have too many rose leafhoppers. Guthion or Imidan will not control rose leafhoppers. Thiodan, Sevin, or Provado (1 oz/100 gal) should be effective.

Leafminer second generation mines are starting to be visible from the upper leaf surface, called the tissue feeding stage. Once mines have advanced to this stage they are not controlled by insecticides. If you intend to spray for second generation mines, now is your last chance. I do not see any orchards that have high numbers of second generation mines that need to be controlled.

Green apple aphid populations have been destroyed by natural predators in all blocks I monitor.

7/11/2000 – I only checked one orchard today, but this orchard usually has a good population of apple maggot flies. I did not find any apple maggot flies there. I still have not seen any this year.

7/7/2000 – Sorry for the big break in messages!

I have not captured any apple maggot flies on red sticky spheres yet this season. I checked traps in 6 orchards – all zeros.

Europe red mite populations are building. Some blocks are above the threshold of 65% of leaves with motile mites. Best miticide choices include Pyramite or Vendex. Last year two growers got excellent control of two spotted mites and European red mites using Vendex at 1 lb./100 gal. plus Silwet or Tactic at 6 oz./100 gal. of finished spray mixture.

Potato leaf hopper populations are at an all time high, I think. Potato leafhopper feeding stunt shoots and causes terminal leaves to cup and turn pale green. I especially see many water sprouts with this damage. This is only a problem to very young trees where you want maximum shoot growth. It is not a problem in mature trees. To control in young trees apply Thiodan or Sevin.

Leafminer adults and parasites have been emerging over the last couple of weeks. I haven’t seen any new, second generation mines but I haven’t looked very hard. I also don’t seen many leafminers – no orchard I visit needs to control the second generation sap feeding mines. If you find 13 old mines out of 100 fruit cluster leaves, consider applying Provado within the next few days.
The only problem with using this monitoring strategy is it doesn’t take into account any leafminer parasitism. Often, many leafminer are parasitized – so rather than a leafminer adult emerging, a parasite emerges. You may be able to still tell which emerged by looking at the underside of the mine. When a leafminer adult emerges it leaves its brown pupal case sticking out of the mine. When a parasite emerges it makes a small exit hole on the underside of the mine. If many of the mines were parasitized than an insecticide treatment may not be needed.

San Jose Scale crawlers were still active on July 5. I also found red marks on fruit where crawlers had settled down on fruit. You may want to apply another insecticide against the crawlers if it has been more than 10 days since your last insecticide for San Jose Crawlers. Use a hand lens and look for the tiny lemon-yellow crawlers on twigs and fruit.

Green apple aphids are present but so are aphid predators. I don’t see any aphid populations requiring insecticides at this time. Usually the predators can adequately control aphids.

6/23/2000 – White apple leafhopper nymphs and adults causing damage in one orchard. Damage looks like white stippling on interior leaves as well as brown/black “tar spots” on apples. Hopefully Sevin will control these large nymphs and adults.

Found too many European red mites in block that received no prebloom oil or miticide. Perhaps will need to apply Pyramite in this block.

Found what looks like fire blight strikes on one ‘Gala’ and one ‘Paulared’ tree. This is the first time I’ve seen fire blight on apples in RI.

Planning on setting up apple maggot fly traps

6/19/2000 – Scab slightly worse this week than last week. Many growers are aggressively trying to control scab by applying Sovran. Other growers are using combinations of Captan and Benlate or Topsin M. Some growers are applying Syllit.

Potato leafhoppers found in many orchards. This small, pale green hopper feeds on terminal leaves and causes the leaves to cup and turn yellow on the edges. Feeding also causes shoots to stop growing. This is only a problem with young trees where you want maximum shoot growth. are not a problem on mature trees. To control potato leafhoppers on young trees, use Sevin or Thiodan; Imidan or Guthion may also work.

San Jose Scale crawlers have probably emerged by now. We sprayed the trees I was checking at East Farm on June 16th. Crawlers had not emerged by then, but we needed to spray a fungicide and we figured the crawlers would emerge during the heat of June 16 & 17. We will apply Imidan again in 10-14 days.

I found my first empty leafminer pupal case on June 15. This means the next generation of leafminers has begun. If you find more than 13 mines out of 100 fruit cluster leaves now, consider applying Provado for second generation mines. Apply the Provado when most of the second generation mines are the small, sap feeding stage. This will probably occur in the first week of July.

6/12/2000 – Scab still the number one problem! Seeing more scab in more orchards!

San Jose Scale crawlers still have not emerged at URI’s orchard. Expecting them any day. To control San Jose Scale apply Imidan or Guthion when crawlers begin emerging and again 10 days later.

See adult leaf hoppers in two orchards. I believe they are rose leafhoppers migrating into apple orchards from wild rose. No treatment needed for control at this time.

6/9/2000 – Looked at East Farm in Kingston for San Jose Scale crawlers. I did not find any crawlers today. At least in Kingston, they have not emerged yet. I’m expecting them any day.

6/7/2000 – Apple scab continues to spread in some orchards. If you are battling scab I recommend 2 sprays of Captan at the full rate, 7 days apart. Hopefully this will keep the fruit protected.

I believe plum curculio season is over for most Rhode Island growers. No additional insecticides should be needed against plum curculio.

European red mites are primarily in the egg stage right now. No miticide is needed at this time.

I’ve been looking for San Jose Scale crawlers in 2 SJS infested orchards. I have not found any crawlers yet. Crawlers usually begin emerging around June 10th. If you have a scale infestation, it is recommended that you apply an insecticide at first crawler emergence and again about 10 days later. Lorsban, Imidan, or Guthion all control SJS crawlers.

6/2/2000 – We have had perfect plum curculio weather but I see very little plum curculio activity. I did a thorough check at our East Farm orchard at URI today and found only one tree with fresh plum curculio scars. So, some plum curculio may still migrate into orchards but I don’t think we will get any large flush. If you sprayed an insecticide within the last 10 days you are probably well protected against plum curculio for this season.

5/31/2000 – Oh, all the scab I have seen! I can think of only one orchard that is free from scab – and some orchards are in real trouble. Scab is showing up on fruit in commercial orchards now and I’m afraid it could be very bad in some orchards! Scout your trees now! Especially McIntosh trees! A full rate of Captan will hopefully protect the fruit.

No other troubles in the orchards. Red mites haven’t been very active in this cool weather. Leafminer control stategies have been successful. Leafhoppers have not been present or are controlled with Sevin used for thinning.

See 5/30 for my comments on plum curculio. Forcasted warm weather should tell us once and for all what is up with plum curculio. Check this visual observation page on Friday (6/2) for the latest update.

5/30/2000 – At our East Farm orchard I have decided not to apply another insecticide against plum curculio. We only applied a petal fall spray of Imidan on 5/12/2000. I see a few old scars here but nothing very fresh. I wouldn’t expect a commercial grower to follow my example.

5/27/2000 – I found fresh plum curculio scars in an orchard sprayed 5/15/2000 with Imidan. This sort of throws out the window the theory of a petal fall insecticide totally controlling plum curculio this year. On the other hand, this orchard where I found fresh PC is notoriously bad for plum curculio and often needs to be sprayed 4 times to control plum curculio. I guess the message is, keep looking for fresh plum curculio scars and spray accordingly.

5/26/2000 – I’ve looked several times this week on unsprayed apple trees and trees that received their last insecticides sprays on 5/12/2000. On the unsprayed trees I find lots of fresh plum curculio scars. On trees sprayed at petal fall with Imidan I do not find any damage. Perhaps a petal fall insecticide application is really all that is needed this year to control plum curculio!

Scab in sprayed orchards has not infected many fruit. Hopefully it will stay this way! In unsprayed orchards, the fruit is loaded with scab.

Leafminers were well controlled by petal fall applications of Provado or AgriMek.

European apple sawflies were well controlled by petal fall insecticide applications.

European red mites coming to the end of their first generation. I know of one instance where AgriMek at petal fall controlled mites well.

5/22/2000 – Primary apple scab season should be over but, our problems with scab are not over. I see more orchards with scab this year than ever before! See lesions on fruit too!

Leafminer have begun to advance to the tissue feeding stage. Too late to apple Provado. If you are using AgriMek it should be applied within the next day or two.

I found a few more plum curculio scars today but they certainly have not been very active.

European red mite situation has not changed much; there are a few more summer eggs. If you are going to apply AgriMek against red mites it should be done very soon.

5/20/2000 – See apple scab lesions in another orchard!

5/18/2000 – See apple scab lesions in many orchards. Some orchards have serious problems! Scout your orchard now. Apply Captan, Sovran or Flint to orchards with more than a little bit of scab.
Apple scab infection period today and tomorrow.

5/15/2000 – See 2 plum curculio scars on unsprayed Lodi! First of the season. I don’t expect much plum curculio activity until temperatures return to 80’s.

European red mites starting to lay summer eggs on leaves.

Leafminer have not advanced to the tissue feeding stage yet. Still time to apply Provado or AgriMek.

5/13/2000 – Apple scab infection period. Nearing the end of primary scab season. 90% of ascospores should be mature by now.

5/11/2000 – Leafminer eggs hatching and forming sap feeding mines; rather difficult to see. I think the hot weather of last week will concentrate the time when leafminers hatch. This should make controlling leafminers easier – as long as you don’t miss when insecticides should be applied. Use Provado at petal fall or AgriMek plus a surfactant at first cover.

Apple scab lesions found in 3 orchards! New York recommends spraying a strobilurin fungicide (Sovran or Flint) or Captan if scab is found on 2 or more clusters when you examine 50 clusters on each of 5 trees.

See cedar apple rust lesions found on leaves. Galls in cedars still releasing spores for infections in apples.

See European apple sawfly egg laying scar on fruit.

Ron Prokopy from UMASS reports plum curculio have moved into orchards but have not begun feeding and laying eggs yet. Do not delay your petal fall insecticide application of Imidan or Guthion.

5/10/2000 – Apple scab infection period

5/8/2000 – See Apple Scab lesion in commercial orchard!

European apple sawfly trap capture above the threshold in one orchard. I won’t have data from many orchards because I didn’t set up many traps. European apple sawflies usually above threshold in all monitored blocks; this indicates a need for a petal fall application of insecticide.

Apple scab infection periods have occurred in some locations between 5/5 – 5/8. Late day scattered showers wet leaves that remain wet into the night causing infection periods. This is especially true on 5/8/2000.

Many growers did not apply a prebloom insecticide this year. Need to scout at petal fall for leafminer mines and European red mite nymphs.

5/4/2000 – Catch first European apple sawfly on white sticky trap.

5/1/2000 – See many more European red mites hatched in orchard that did not receive oil.

Find many leafminer eggs in 4 orchards where not many leafminers were caught on red sticky traps.

4/25/2000 – European red mites starting to hatch. I saw small nymphs in two orchards today. Most eggs have not hatched but don’t delay your oil application.

Buds starting to separate

Finding leafminer eggs easily in two orchards where we haven’t caught many leafminer adults on red sticky traps. This concerns me. In one orchard I set up 4 traps on 4/6/2000 and have only caught a cumulative average of 6.5 per trap. On leaves in this orchard I found about one egg per cluster. Maybe I set up the trap too late or maybe I simply don’t have enough traps set up. UMASS does recommend 10 traps per site.

4/24/2000 – Three days of wet weather add up to a major apple scab infection period!

Apple blotch leafminer above threshold of 8 per trap by tight cluster in 2 orchards. I easily found eggs on underside of leaves in one orchard where I did not catch many adults on red sticky traps. This worries me! Maybe the best monitoring tool will be looking for new sap feeding mines at petal fall. The problem with this strategy is that the mines are small and difficult to see at petal fall.

See many pear thrips in one orchard – more than 1 per cluster. Some clusters with 5 pear thrips per cluster.

4/20/2000 – On again, off again wet weather causing infection periods. The cool weather doesn’t allow many additional spores to mature so infection may not be so severe.

Leafminers still only above threshold in one orchard.

4/18/2000 – Apple blotch leafminer way above threshold in one orchard: 110/trap by tight cluster. See Apple blotch leafminer eggs on the underside of cluster leaves.

4/16/2000 – Apple blotch leafminer trap captures low in all blocks so far. No blocks close to the threshold of 8 leafminers per trap by tight cluster.

One rosy apple aphid in one orchard.

No hatched European red mites found yet.

Syrphid fly eggs found on leaves. Eggs are small, whitish, and oblong.

4/15/2000 – First apple scab infection period. Started 4/15, ending????

4/13/2000 – Catch first apple blotch leafminer on red sticky trap

 Catch first tarnished plant bug on white sticky trap

– Found one green pug moth larva feeding on apple cluster leaves. Tiny green larva making small holes. Larva moves like an inch worm. Green pug moth not a problem unless found in great numbers.

– See Harmonia lady bug on apple tree, probably feeding on aphids

– Don’t see any rosy apple aphids

4/11/2000 – Pear thrips in one orchard. Finding about 1 thrips per cluster. Tentative threshold is 5 per cluster but one per cluster makes me nervous.

4/8/2000 – Early evening rain could be considered an apple scab infection period in high inoculum orchard. Most growers don’t need to worry about this infection period.

4/6/2000 – See more deer damage this year than ever before