Stink Bugs: A Widespread Orchard Pest

Posted on Categories Blog, Home, Orchard Care, Orchard PestsTags , , , , , , , , , , , , ,
Photo Credit: Lynn Bunting / Getty

Most of us have seen a stink bug (Halyomorpha halys), whether it’s crawling in your house or on your crops. These mottled grayish-brown bugs are ¾’’ in length, six-legged, and have a triangular or shield-shaped body and are probably most perceptibly known for the nauseating stench they release from their thorax when disturbed or crushed. But, have you ever wondered about the story of these beautiful, pervasive, yet destructive creatures?

One of the most versatile pests found in Pennsylvania, these bugs can overwinter beneath brush, under tree bark, in wood piles, or even in your warm wintertime home. When the weather warms, they migrate outside to breed, feed, and devastate your harvest — all in the same year.

The female lays clusters of 150 eggs on plant leaves, trees branches, or on houses,  which can range in color from yellow, brown, white or pink depending on the aging of the nymphs inside. In their nymph stage, the insects are flightless but multiple stages of breeding can happen in the course of the season — meaning their population increases significantly as crops move toward maturity. A field guide to stink-bugs depicting their life cycle, species variety, and feeding habits can be found here

Brown marmorated stink bugs are the most widespread species and are not native to the region. This invasive East Asian species arrived in Pennsylvania in 1996, likely on shipping crates.  Another stink bug species, Harlequin bugs/beetles, are a major pest for cabbage family crops in the region.  

Lacking the natural predators needed to control their spread, stink bugs have flourished until their population growth came to the attention of scientists in Allentown a few years later in 1998.

After the first sighting in Pennsylvania, the stink bug made its way to New Jersey by 1999, Maryland by 2003, West Virginia and Delaware by 2004; now the only states that do not have stink bugs are Louisiana, Oklahoma, South Dakota, Montana, Wyoming, and Alaska. They are also migrating on a global scale due to their ability to cling to different forms of transportation.

Figure 2. U.S. counties where BMSB has been detected as of November 2017. Map via EDDMapS.

Brown marmorated stink bugs feed on a wide variety of fruiting plants we grow in our orchard spaces including apples, raspberries, stone fruits including peaches and apricots, figs, mulberries, citrus fruits and persimmons. They’re fruit lovers (how can we blame them!) but they will also settle on feeding on fleshy stems and leaves. They also consume other plants often grown in North America such as beans, corn, tomatoes, soybeans and many ornamental plants and weeds. For a full list of high, moderate, and low risk crops, see the StopBMSB website.

Besides seeing the stink bugs themselves, you might also notice signs of their feeding, such as a distortion referred to as “cat facing,” the development of spongy areas, or internal tissue damage, as with the images of these affected apples (below), which can lead to more decay, fallen fruit, and spoilage.

Figure 4. Stink Bug Apple Damage – Credit:

Stink Bug Prevention 

There are a number of mechanical, chemical, and biological controls you can use to lessen damage from the stink bug’s piercing-and-sucking mouthparts this season. Keep areas around gardens clear of tall grass, brambles, downed limbs and litter to help minimize spaces for overwintering. By building good soil life and adding regular spring and fall applications of compost to the base of your trees, you can also help to build a vibrant soil ecology to out compete predation from these insects. Row covers, trap crops, pheromone traps, and use of beneficials can also help.

If you have the time and resources, you can grow early crops of stink-bug favorites such as sweet corn, amaranth, and okra which can be destroyed once they’re infested with the pests.

Beneficial insects can also be helpful in controlling stink bug populations. You might consider planting flowers and herbs to help attract parasitic wasps, ladybird beetles, minute pirate bugs, lacewings and other allies that can help control their populations by feeding on stink bugs during stages of their development.  The umbel family of plants (fennel, dill, queen anne’s lace, etc) are particularly effective at attracting some of these beneficials, as are other small-flowered plants like yarrow, coneflowers, and asters.  

Spray applications of kaolin clay on areas of heavy feeding, or neem oil and insecticidal soap (especially earlier in the season) can help provide barriers to stink bugs’ feeding and mating. In the case of severe infestations, you might also consider applying pyrethrin.  Check out the linked POP articles to understand the uses of these organic sprays! 

Set up a simple stink bug trap with an aluminum baking pan, desk light, and a little detergent! Credit:

And, if stink bugs have begun to overwinter in your home, Planet Natural recommends the following fix: “Fill an aluminum turkey pan, preferably recycled, with an inch or so of water and stir in a little dish detergent. Shine a lamp (like a desk lamp) on the surface and leave it on overnight. The light attracts the bugs who land in the water and are held by the detergent. From there, you know what to do.”


EDDMapS. 2017. Early Detection & Distribution Mapping System. The University of Georgia – Center for Invasive Species and Ecosystem Health. Available online; last accessed 30 November 2017.

This POP Blog post was written by POP 2017/18 Repair the World Fellow Megan Brookens. 

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Early Spring Orchard Care Tips

Posted on Categories Blog, Home, Orchard Care, Orchard Pests, POP Orchards, Soil Care, Sprays, Tree Care, Tree DiseasesTags , , , , , , , , , , , , , , ,
Peaches are the only fruit trees commonly pruned in early spring during or immediately following bloom rather than while dormant!

Happy Spring, Fellow Orchardists! With the past few weeks of balmy rain and bud and flower break, we wanted to remind you of some early spring tips for tending to your orchard’s health and managing potential disease and pest woes. For a recap of orchard care through all the seasons, check out our recent POP blog article.

Unwrap Your Figs and Pomegranates

With the danger of hard frosts finally past, it is now safe to unwrap your figs, pomegranates, and other tender plants from their winter protection!

Spring Orchard Sprays 

Apply holistic orchard sprays. Holistic sprays are composed of compost tea, liquid fish/seaweed, neem oil, and/or effective microbes. For best tree health and resistance to disease, apply up to 4 times in the spring (after bud break, at first pink of flowers, after petal fall, and two weeks after petal fall).

Depending on specific pest or disease problems, some orchardists might also consider other organic sprays including the ones listed below.  In particular, plants that have suffered severe crop loss from fungal diseases (like brown rot, mildew, or scab) may be candidates for an early spring sulfur or copper spray.

Check out POP’s guides to orchard applications of:

Compost Tea Sprays for Orchards

Neem Oil Sprays

Kaolin Clay Sprays

Sulfur Sprays and Early Spring Management Techniques

Pyrethrin Orchard Sprays

Bt: Bacillus thuringiensis Orchard Sprays

Phil dilutes compost tea 50-50 before applying one gallon per tree throughout the Awbury orchard.

Soil Cultivation and Compost/Mulch Application

Building healthy soil is key to supporting trees’ health, resilience and yields. Weed around the base of trees, and spread chipped winter prunings, shredded leaves, and or mulch/compost in the early spring. Check out POP’s guide to Ramial Wood Chips and Weeding in Place.  

Early Spring and Emergency Pruning

While optimal dormant pruning season is now behind us, those of you who waited on your peach trees should prune them now (peaches are the only fruit tree typically pruned during or immediately following flowering).  For all other trees, most pruning should be limited to emergency pruning only:

Keep an eye out for any diseased, damaged, or disoriented wood  that should be pruned away no matter the season. Pay special attention to the base of trees – especially of the stone fruit varieties: apricots, peaches, plums, nectarines – and prune away root suckers, the quick upright growth that can be a cover for dreaded borers, which make a home beneath trunk wood.

Remember: use sharp, rust-free hand tools and sanitize between trees at the very least, and between every cut if the tree you’re tending has had previous conditions. For easy disinfecting, we recommend carrying a spray bottle with you of isopropyl alcohol or a bleach solution (1 part bleach: 10 parts water) to wipe down tools.

Remove any mummified fruit, which left hanging on the tree, can become a potential source for disease spores to spread, especially as the humidity rises.

Tent caterpillars are moving in! Remove nests manually to protect trees from defoliation.

Tent Caterpillar Nest Alert!

Spring is the season tent caterpillars hatch! Stopping them in their silky tracks is important to protect trees from becoming a buffet. If you see a silken nest hanging among tree branches, remove and discard as soon as possible. Scrape off and discard overwintering egg masses and tear the protective tents out by hand before the larvae start to feed.  A spiky stick can be used to remove the tents or they can be pruned out depending on their location.  Bacillus thuringiensis or a plant-derived insecticide like neem oil can be used as a spot treatment. Read more about treatment strategies here.  

Please contact us with any questions or concerns!

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POP CORE Recap & Orchard Care Through the Seasons

Posted on Categories Blog, Home, Orchard Care, Orchard Pests, POP Orchards, Soil Care, Sprays, Tree Care, Tree DiseasesTags , , , , , , , , , , , , , , , , ,

POP kicked off its newest training program last Wednesday, March 8th at Bartram’s Garden called POPCORE: Community Orchardist Resilience Education. An endeavor to realize the potential and beauty of fully productive, well cared-for eco-orchards in every neighborhood, POPCORE seeks to encourage the self-sufficiency of our partners and connections between partners in close geographical proximity through group trainings and face-to-face sharing between partners. With increased knowledge, attention, and combined resources, the average community orchard has the potential to produce hundreds of pounds of varied produce per season in addition to being a safe, beautiful outdoor space for gathering and education.

POPCORE combines many elements of orchard stewardship, ecosystem design, and food uses that POP has learned over the past ten years,  synthesized in a 4-part series that can be taken as one-off classes or in pre-season series. Hosted back-to-back over four Wednesdays in March at Bartram’s historic garden, the course covers Pruning and Eco-orchard Seasons (March 8), Pest and Disease Management (March 15); Plants, Fungi, and What To Do With Them (March 22); and Permaculture and The Future of Philadelphia’s Food System (March 29).  Registration info here

The first class taught by POP Executive Director Phil Forsyth and Orchard Director Robyn Mello drew 21 participants, who came from a span of neighborhoods throughout the city to learn about orchard care through the seasons and the specifics of pruning fruit trees, berries & brambles, and fruiting vines, with a pre-class hands-on pruning demo hosted in Bartram’s Community Orchard.

For the health of your orchard, seasonally-appropriate care is important and POP wants you to succeed! Check out POP’s Resource Guide for PDF-downloadable handouts on topics covered during POPCORE’s first session, including orchard care by season (summarized below) a guide to pruning, and relevant POP blog posts linked below. 

Students learn techniques for wintertime pruning of fruiting shrubs in Awbury Arboretum’s food forest.


PRUNING. For best production and tree health, all common fruit trees regardless of age should be pruned during their dormant season every winter, ideally between late January and early March. The basic idea is to open the tree to more air and light.

Check out POP’s guide to Pruning Fruit Trees and  Pruning Bushes, Brambles, and Vines.  

REMOVE MUMMIFIED FRUIT. Any fruit left hanging on the tree is a potential source for disease spores. Pluck and remove any mummified fruit from the orchard during pruning.

SPRAY DORMANT OIL. Apply horticultural oil, neem oil, or vegetable oil at 4% dilution to smother overwintering eggs of insects including aphids and scales.

Check out POP’s guide to Dormant/Horticultural Oil Sprays. 

MAINTAIN ORCHARD EQUIPMENT. Clean and sharpen all orchard tools. Order orchard care supplies. For PHS City Harvest participants, check out a related training on Tool Care on Saturday March 25th from 10am-noon or visit POP Partner The West Philly Tool Library for information on tool rental and care. 

Orchard liaison Tony Dorman spreads compost during a spring workday at Philadelphia Montessori Charter School


APPLY MULCH/COMPOST. Spread chipped winter prunings, shredded leaves and/or compost.

Check out POP’s guide to Ramial Wood Chips and Weeding in Place.  

HOLISTIC ORCHARD SPRAYS. Holistic sprays are composed of compost tea, liquid fish/seaweed, neem oil, and/or effective microbes. For best tree health and resistant to disease, apply up to 4 times in the spring (after bud break, at first pink of flowers, after petal fall, and two weeks after petal fall). Depending on specific pest or disease problems, some orchardists might also consider other organic sprays including the ones listed below. 

Check out POP’s guides to orchard applications of:

TRAINING. New growth can be trained to better angles using clothespins, branch spreaders, or tying to weights.

THINNING. In late May or early June, young fruitlets on peaches, apples, pears and Asian pears, and some plums should be thinned by pinching off with fingers or pruner. Peaches should be thinned to 8” apart, apples and pears to 5”, and heavy-bearing plums to 5” on the tree. Also at this time, all fruit should be removed from any newly planted trees.

Check out POP’s guide on Thinning Fruit Trees. 

BAGGING FRUIT. Place ziplock, paper, or nylon bags around young fruit (especially apples) to protect them from some insect and disease challenges.  

Check out POP’s guide to Bagging Fruit.

Community members pick berries during Strawberry Mansion’s Strawberry Festival


HARVEST. Pick fruit as they ripen, spring through fall according to fruit type. Remove or compost any fallen fruit to reduce potential pests and disease. 

Check out POP’s guide to Summer Harvest Timing and Equipment and Late-Season Fruit Ripeners.

MONITOR. Observe orchard regularly throughout the year for pest and disease problems, identify and respond appropriately with trapping, removal, or possible applications of kaolin clay, neem oil, Bt, pyrethrin, etc.

EMERGENCY PRUNING. Remove diseased or damaged wood, root suckers, and watersprouts any time of year. Be sure to sterilize tools with alcohol or bleach solution between each cut. In some cases, additional structural pruning may be done in early summer to minimize regrowth, but avoid anything but emergency pruning after July.

For more information, check out this POP guide to emergency pruning. 

Executive Director Phil Forsyth brews a batch of compost tea to apply to orchard plantings


APPLY COMPOST. After most leaves have fallen, spread a layer of compost or spray compost tea. An annual soil test can reveal any other specific nutrients or amendments that should be added.

Check out POP’s guide to Autumn Composting. 

We hope this seasonal breakdown provides you with a solid overview to ready yourself for maintaining the health and productivity of your orchard. Hope to see you in a POP CORE class soon!
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Plum Curculio: A Pome and Stone Fruit Pest

Posted on Categories Blog, Home, Orchard Care, Orchard PestsTags , , , ,

When spring weather begins to warm with abundant damp showers, the plum curculio (Conotrachelus nenuphar) sets its sight on plum, apple, peach, apricot, cherry and other pome and orchard stone fruits, under whose skin this true weevil lays its eggs. Causing considerable damage to fruit, the curculio lays eggs under a flap of flesh – leaving bumps or crescent shaped scars visible to the eye. Burrowed-through fruits fall to the ground decayed while scarred fruits show the mark of preliminary laying and feeding.

The plum curculio weevil.

Life Cycle and Laying

Native to North America, plum curculios are snout beetles that overwinter in ground litter, hedgegrows, or the soil and become active again in spring – coinciding with the time of apple tree blossoming. Dark brown or steel gray in color, adults bear four pairs of ridges covering their wings and a rough snout colored with black, gray or brown specks. They emerge as adults during a period of 4-6 weeks in the spring (though 40-60% of emergence occurs in a single day).

After emergence, they feed on tree buds, flowers, and new-set fruit – mate – and then lay tiny oval eggs in crescent-shaped cuts on fruit where they will mature and hatch in 2-12 days. Larvae are 6-9 mm long, grayish-white, legless grub with brown heads that bore into the fruit during a period of 2-3 weeks. After burrowed fruit falls, fully grown larvae pupate in the soil in a period of 12-16 days, where they will hibernate in the soil for overwintering.

The identifiable crescent-shaped scar – the mark of a plum curculio weevil at work.

Controlling Curculio

While plum curculio can seriously affect orchard fruit, organic and home growers have several options for controlling this pest. Successful management requires careful observation of trees and applications of several treatments throughout the year to keep growing trees healthy, along with proper fertilizing, mulching, and watering, so that they may better resist infestation. The Natural Gardener recommends the following protocol:


  • During early spring, when adults emerge from their overwintering stage and begin to feed on newly set fruit and leaves and flowers, lay sheets on the ground beneath trees and shake them vigorously to knock plum curculios to the ground. Submerge the sheets in hot soapy water to kill them. Perform this task twice a day during their 2-3 week spring active season.
  • Apply Kaolin Clay or an organic insecticide such as Pyrethrin or EcoSmart Insect Killer to the tree canopy in the early morning or late evening.
  • Timing is important! DO NOT SPRAY DURING FULL BLOOM or when bees are present!  Choose,  AT PETAL FALL – when 75% of the flowers have fallen (5 days after bloom) and/or AT SHUCK SPLIT: when fruit’s papery covering or calyx has split (14 days after bloom).


  • Gather and destroy all fallen fruit every other day to prevent larvae from tunneling into the ground in their earthen cells 1-3 inches below the soil surface, where they will pupate and form a new generation of adults in 3-4 weeks. Running chickens through your orchard is also a fantastic way to deal with fallen fruit and larvae.
  • A second generation of plum curculios usually emerges in late July through late October. Keep an eye out for crescent shaped scars on fruit and employ the shaking method and/or organic sprays to reduce populations.


  • Spray Beneficial Nematodes to help control larvae in the soil, and clean debris from around the trees (in grass, fallen fruit, leaves) to reduce overwintering sites for the curculio.

For more information:

This edition of POP TIPS prepared with assistance from POP intern Alyssa Schimmel. 

SUPPORT US!  If you found this entry useful, informative, or inspiring, please consider a donation of any size to help POP in planting and supporting community orchards in Philadelphia: