Fruit Insect Pest Monitoring and Management Considerations for July

Posted: June 22, 2012

Insect pests to be monitoring at this time include second generation leafrollers, green/spirea aphids, leafhoppers, leafminers, Japanese beetles, wooly apple aphids, mites, apple maggots and brown marmorated stink bugs.
Dr. Greg Krawczyk and Dr. Larry Hull, Penn State Fruit Research and Extension Center Entomologists


Sex Pheromone Traps the Most Reliable Tools to Assess Leafroller Pressure

Although the egg hatch model predicts the start of the second codling moth (CM) generation and the peak of the second Oriental fruit moth (OFM) generation during the week of June 25, the actual situation in each orchard is different and at most locations we are observing the end of the first CM generation and almost no activity from OFM. Tufted apple budmoth (TABM) and oblique banded leafroller (OBLR) populations are also between generations right now. The sex pheromone traps for all four major pest species are the most reliable tools to assess the actual pressure from each pest and the best indicators of “if and when” control measures need to be implemented. The unusual weather pattern not only affected the harvest time for early stone fruit but also influenced the development of our common pests. By now the first generation larvae of OFM, CM, TABM and OBLR should be under control and hopefully no additional treatments will be required until later in the summer. 

Mid-Summer Pests to Begin Monitoring

Green/spirea aphids, leafhoppers (potato, white apple and rose) and leafminers are the pests to watch for during the month of July.  If any or all of these pests are present, they can be controlled with effective application(s) of one of the neonicotinoid insecticides (i.e., Actara, Assail, Belay, Calypso or Provado). 

First Japanese Beetles Detected

In monitoring orchards last week, we observed the first Japanese beetle (JB) adults in orchards located in western and south-central Pennsylvania. All products mentioned above should help with at least partial control of this pest. Carbaryl (Sevin) is also highly effective against JB. In addition, most materials recommended for the control of brown marmorated stink bug should provide good control of JB.

Wooly Apple Aphid Aerial Colonies Detected

Aerial colonies of wooly apple aphids (WAA) have become visible in some orchards. Products such as Diazinon (at 1.5-2.0 lb/acre) or Movento should provide excellent control of WAA (and also scales). 

Managing Mites

Phytophagous mites such as European red mite or twospotted mite can be controlled with a wide assortment of summer acaricides:  Envidor (IRAC Group 23), Kanemite (IRAC Group 20B), Nexter (IRAC Group 21A) Portal (IRAC Group 21A) or Zeal (IRAC Group 10B). When deciding which products to use, please remember the importance of resistance management and do not use products from the same IRAC group during two consecutive seasons.

Intensive Monitoring Required to Prevent Apple Maggot Damage

Although apple maggot is still not one of the dominant pests in our Pennsylvania orchards and in most situations does not require rigorous insecticide treatments, intensive monitoring is required to accurately assess the potential for problems caused by this pest.

Importance of Preparing a Season-Long BMSB Management Plan

Various levels of brown marmorated stink bugs (BMSB) are being observed in and around fruit orchards located mainly in the southern part of Pennsylvania. Although new, young 2nd and 3rd instar nymphs were already observed feeding on stone fruits, no new summer generation adults have been detected so far. All BMSB adults we are finding are still the same individuals that survived the winter and now are reproductively active. We are expecting to see the new summer adults within the next few weeks. As the season progresses, all developmental stages (i.e., eggs, nymphs and adults) will be present in orchards at the same time. Additionally, the ability of this pest to survive and reproduce on almost all green plants in our environment will contribute to a continuous influx of new individuals into orchards from the surrounding vegetation. Based on our observations (as well as those of other researchers working on this pest), it seems that the highest aggregations of BMSB around the edges of orchards can be found on catalpa, tulip poplar, Ailanthus sp.(tree of heaven) and Paulownia sp. (princess tee), however other wild hosts are also capable of supporting high numbers of all BMSB stages. If the last two seasons taught us anything about this pest, we now know that stink bugs migrating from the surrounding vegetation can be the most significant source of infestation, causing injuries to fruit throughout the entire season until mid-October.

Multiple insecticide chemistries are available for the control of BMSB but they cannot control stink bugs that are not present in the orchard at the time of the insecticide application(s). While the residual activity of available insecticides are effective against BMSB nymphal stages, the same residual activity is almost insignificant in protecting fruit from feeding injuries caused by migrating BMSB adults.

As we have learned during the last two seasons, in some locations we will experience incessant pressure from this pest, so it is extremely important to prepare a season-long BMSB management plan. Since pest pressure just before harvest might be as high or higher than earlier in the season, effective insecticides with the shortest pre-harvest interval (PHI) should be preserved for use later in the season. Please note that as of June 24, 2012 the products with the active ingredient dinotefuran (as in Scorpion and Venom) are not registered for use in orchards. As soon as we receive the Section 18 Emergency Registration, we will send a notification.

At the same time, since some products can be used multiple times per season, growers must pay particular attention to the number of allowable applications as specified on the label.  Also, please review the label for the total amount of active ingredient allowed on any particular crop. Another confusing factor to consider is that some products are sold under different names but have the same active ingredient. For all active ingredients, there is only a certain allowable amount that can be applied for the season on any particular crop. For example, thiamethoxam – an active ingredient which is very effective against BMSB – is contained in a number of different products (i.e., Actara®, Voliam Flexi®, Endigo®). The grower is only allowed to use a total of 0.172 lb of active ingredient of thiamethoxam for the entire season on stone fruits regardless of the number of products that contain thiamethoxam.

Please refer to the BMSB management posts at various Penn State web sites for information related to insecticide efficacy and recommended management programs:
a) BMSB management article in the Penn State Fruit Times newsletter
b) 2012-2013 Penn State Tree Fruit Production Guide, which includes updated information on pesticide efficacy and recommended BMSB management options
c) Weekly insect control updates from the Penn State Fruit Research and Extension Center

Seasonal Activity of Fruit Pests

2012 season weekly captures of adult moths in pheromone traps located at Penn State FREC, Biglerville, PA (Adams County)

Species 3-May 10-May 17-May 24-May 31-May 7-Jun 14-Jun 21-Jun
RBLR 1 0 0 0 22 17 43 26
STLM 4 6 2 2 138 65 69 84
OFM 46 51 7 7 4 2 3 0
CM 23 29 21 21 33 6 12 3
TABM 7 6 16 16 9 4 2 1
OBLR - 0 0 0 9 3 1 1
DWB 1 3 15 15 11 4 22 17
PTB - - 0 0 1 0 0 1
LPTB 0 2 1 1 1 0 1 1

Degree-Day Table

Accumulated degree-days base 43°F from Jan 01 for each reported year (courtesy of SkyBit, Inc.). The accumulated degree-days for the last date of the current year (July 01) mentioned in the table are based on the weather forecast.

Site/Date 27-May 3-Jun 10-Jun 17-Jun 24-Jun 1-Jul
Biglerville, 2012 1295 1484 1639 1826 2052 2249
Biglerville, 2011 1023 1247 1458 1642 1866 2082
Biglerville, 2010 1117 1331 1517 1729 1967 2200
Biglerville, 2009 968 1126 1290 1474 1671 1874
Biglerville, 2008 865 1021 1267 1483 1660 1873
Biglerville, 2007 942 1150 1335 1512 1708 1922

Rock Spring, 2012 1120 1282 1422 1596 1802 1967
Rock Spring, 2011 802 1002 1192 1348 1549 1735
Rock Spring, 2010 946 1139 1296 1488 1696 1889
Rock Spring, 2009 789 911 1058 1213 1388 1561
Rock Spring, 2008 665 797 1027 1219 1364 1547
Rock Spring, 2007 788 978 1134 1295 1465 1650

Weekly Insect Bytes Now Available at FREC website

As during previous years, the Penn State Fruit Research and Extension Center web site is providing seasonal insect observations .
The weekly “Insect bytes” are short updates on current events and happenings related to the management of insect fruit pests. Also available are trap data from Penn State FREC orchards and insect developmental models.

Contact Information

Grzegorz (Greg) Krawczyk
  • Extension Tree Fruit Entomologist
Phone: 717-677-6116