Sound Horticulture Blog

Nematode Notions

Nematode Notions

While beneficial nematodes may be microscopic, they have a big impact on pest control and can achieve very visible results!

Nematodes are safe for pets, animals, biological control agents, and humans! If you are dealing with fungus gnats, thrips, or other soil dwelling pests like grubs or weevils, we recommend adding nematodes as a quick knockdown.

Life Cycle of the Beneficial Nematode

Infective juveniles are inoculated into packaging that is shipped to you!

These infective juveniles set out to find a new host to reproduce in. Preemptively saturating the root zone of plants you are treating can encourage their exploration. They infiltrate the pest through natural orifices and release symbiotic Xenorhabdus bacteria that kills the host within 24-48 hours. Infective juveniles mature into male or female adults and initiate breeding, using the pests’ resources to spawn future generations. These fresh infective juvenile nematodes will leave and scour the root zone for a new host and continue this cycle.

We offer nematode options from two main suppliers, Sierra Biological and BASF

While application rates may differ, we want you to know that these products are equally effective.

Application Rates:

BASF

-50 million per 1,000 Sq ft of soil surface

-250 million per 5,000 Sq ft of soil surface

-1-2 Billion per acre

Sierra Biological

-1 million per 1,000 sq ft of soil surface

-24 million per acre

Application rates will vary based on target pest, reach back to us at Sound Horticulture for specific guidelines based on soil depth of pest, media type, and other growing factors.

Nematodes can be applied as a drench, through spray equipment, or through irrigation systems. Nematodes are also compatible with many fertilizer and soil applied pesticides/fungicides. Compatibility has been tested with over 100 different chemical pesticides such as insecticides, fungicides, and herbicides.

Link To Nematode compatibility (BASF)
Link To Nematode compatibility (BioWorks)

Beneficial nematodes mixed with water and examined under a microscope.

Reasons to choose each:

BASF nematodes are reared in vitro meaning within a culture dish. While this option may have higher application rates, they are still very effective and have extended shelf life when stored in refrigeration. These nematodes can be stored up to 6 weeks! These nematodes are shipped in trays of 50 million, 250 million, or 1,250 million. BASF is one of the largest producers in the world and have been in business for over 150 years! Check out a tour of their industrial facility here!

BASF TOUR on youtube (3 Min)

Sierra Biological uses in vivo production or as they say, “Mother Nature’s very own formula” This can be much more labor intensive but creates a wonderfully active and effective population. Wax worms are the perfect rearing host to produce these nematodes for production and sale. These nematodes are shipped in a sponge that are pre-inoculated with infective juveniles, sizes range from 1 million, 6 million, and 24 million of either single species or blends. We also offer other formulations, please inquire for more details.

Beneficial Nematodes are used to control a variety of soil-dwelling pest. There are several types of nematodes, each specializing in the eradication of various pests.

Pests targeted by species:

Steinernema feltiae:

-Fungus gnats (Bradysia spp.)

-Western Flower Thrips (Frankliniella occidentalis)

Heterorhabditis bacteriophora:

-European chafer grub (Rhizotrogus majalis)

-Japanese beetle grub (Papillia japonica)

-Oriental beetle grub (Exomala orientalis)

Lepidoptera

-Coleoptera

Steinernema carposcapsae:

-Black vine weevil (Otiorhynchus sulcatus)

-Cranberry girdler (Chrysoteuchia topiaria)

-Shore Fly (Scatella stagnalis)

-Cut worms (Agrostis sp.)

-Army worms (Spodeptera frugiperda)

-Wood borers (Buprestidae sp.)

Steinernema krassei:

-Cold tolerant species (Optimal range 41-86ºF)

-Black vine weevil (Otiorhynchus sulcatus)

Application Tips:

Best Practices

Use fresh nematodes, they can be stored in the refrigerator for multiple weeks but have the highest efficacy when fresh. Examine under a microscope and look for wiggly live worms. Dead nematodes will be straight as a pin.

Apply early in the morning or in the evening as nematodes are susceptible to desiccation and UV light. When ready to apply, bring nematodes out of refrigeration and allow them to warm up in room temperature for 20 minutes. Always use room temperature water to mix the nematodes.

Apply to already moist soil and keep the soil moist for several days after application. Soil should be 54-86ºF.

Remove all filters if using sprayer or irrigation and keep pressure below 300 psi.

Once mixed, use within a couple hours and keep agitated as nematodes will sink to the bottom. Try to only make enough solution to hit every plant you are trying to treat. Nematodes left in reservoirs will die as they are soil dwelling creatures, not aquatic. They need the water to reanimate from their packaged state.

Do not oversaturate pots, the nematodes will flow through the pot and exit the drain holes.

Watering By Hand (Home growers)

1. Mix a stock solution. Add 2 gallons of clean, cool water to a five-gallon bucket and mix in nematodes. Allow five minutes to disperse. Continue to stir throughout the application as they will sink to the bottom.

2. Add 1 cup of stock solution to a 2 gallon watering bucket. Water plants to saturate the potting medium 2″ deep. This will fill 32 buckets.

3. Apply approximately 3 oz/4 inch pot and 8 oz/ 1 gallon pot.

-Steinernema feltiae nematode sponge

Steinernema feltiae (SF) is unique in maintaining infectivity in soil temperatures as low as 50ºF (10º C). SF has a foraging strategy in between “ambush” and “cruiser” and is effective against immature dipterous insects including mushroom flies, fungus gnats, thrips, and tipulids as well as some lepidopterous larvae.

-Heterorhabditis bacteriophora (HB) nematode sponge

Heterorhabditis bacteriophora (Hb) is a warm temperature nematode performing best above 70ºF (20ºF) soil. Hb is among the most ecomonically important entomopathogenic nematodes that possess considerable versatility, attacking lepidopterous and coleopterous insect larvae among other insects. This “cruiser” species appears quite useful against root weevils, particularly black vine weevil where it has provided consistently excellent results.

-Steinernema carpocapsae (SC)

Steinernema carpocapsae (Sc) is the most studied of all entomopathogenic nematodes and most effective between 72-82ºF (22-28ºC). They can also survive for several months in room-temperature soil. Sc is particularly effective against lepidopterous larvae, including various armyworms, cutworms, webworms, girdlers, some weevils, and wood-borers. A classic sit-and-wait or “ambush” forager, it stands on its tail in an upright position near the soil surface and attaches to passing hosts. Therefore, Sc is especially effective against highly mobile surface-adapted insects.

-BASF NEMAforce SF tray

Beneficial nematodes attack, invade and kill targeted pests in the easily applied form of NemaForce SF Biosolutions by BASF.

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By |2022-12-02T09:26:10-08:00November 30th, 2022|Uncategorized|0 Comments

Thrip Control and Intraguild Predation

Thrips Control and Intraguild Predation

Are you familiar with different species of Thrips?

 

Have you ever wondered if beneficial bugs are compatible?

 

Will releasing more than one biocontrol agent at a time lead to them eating each other?

 

Orius insidiosus on dianthus kahori

Photo by Alec Blume

This week we are going over various species of thrips, identification, and control.

The most common species of Thrips in North America are Western Flower Thrips (Frankliniella occidentalis) a pest found in both vegetable and ornamental crops, Onion Thrips (Thrips tabaci) usually a problem only in vegetable crops, and Chili Thrips (Scirtothrips dorsalis) which is a significant global pest of ornamental, vegetable, and fruit crops. While these three species of Thrips are pests that damage your crop, it is important to note that there are predatory Thrips, such as the Sixspotted Thrips, Banded Thrips, and Franklinothrips. These species will feed on pests and actually help your crops! Lowering pesticide usage through using biocontrol agents can boost these beneficial populations.

Adult Thrips tabaci female

Thrips Damage, Life Cycle, and Control

Thrips have a feeding damage pattern that typically leaves behind silvery splotches with darker spots which are known as frass (excrement). While this may appear on some plants, their damage can vary depending on plant species. Their eggs are also laid inside leaf tissue which gives their offspring a perfect place to emerge and begin feeding. As populations increase, damage will become more noticeable and will bring on further stress symptoms to the plant. Some of the more economic impacts of this pest include the distortion and stunted growth of fruit and leaves that is a result of the plant being robbed of its precious water and nutrients. This damage will significantly lower your crops value. On tomatoes, thrips feeding can cause “ghost rings” on the fruit. Further, thrips are also known to be viral vectors meaning their feeding can spread viruses from plant to plant. One example of this is Western Flower Thrips transmitting Tomato Spotted Wilt Virus, which is lethal to tomatoes and some ornamentals.

Each of these three species of thrips have similar life cycles. Eggs are laid in leaf tissue and hatch after 5-8 days. Female thrips can lay 6-10 eggs per day over their life span of 4-5 weeks. Just one female can lay upwards of 200 eggs in her lifetime. The nymphs feed on plant tissue for 8-10 days, then drop to the ground to complete development in protected sites in the soil. The prepupa and pupa stages are both non-feeding stages while in their underground development stage. When fully grown adults emerge, they fly to upper parts of plants to continue feeding and laying eggs after a day or two.

As with any pest, a combination of biological and cultural controls, compatible chemicals and preventative measures gives the best results. These biological controls described below are compatible and can be used together.

Amblyseius cucumeris/Amblyseius swirskii – These predatory mites feed on immature stages of thrips. The cheaper, slow release sachets are a great option for long term coverage and are easy to hook on every plant. A. cucumeris will feed on both Western Flower Thrips and Onion Thrips. A. swirskii may be a good option for Chili thrips. If you need help determining the best choice of predator mite for your particular growing environment, please contact us at Sound Horticulture. We would be happy to help!

Orius insidiosus – This tiny pirate bug feeds on pollen and all mobile stages of thrips. When Orius is combined with A. cucumeris, relatively low release rates have given excellent control. One of best feature of this predator is that it will feed on all life stages of thrips, including adults! For complete control it is important to use a predator that can eat immature and adult stages. They also have small wings and can fly short distances, giving them a solid chance at thoroughly exploring your canopy in search of food. Orius will feed on WFT, Onion, or Chili thrips.

Stratiolaelaps scimitus – This soil-dwelling predatory mite feeds on the immature stages of thrips in the soil or growing media. Strats alone cannot control thrips infestations, but it contributes to the effectiveness of biological control when used other predators. This predator will also feed on fungus gnat larvae, which do actively feed on roots.

Monitoring and scouting are also important in controlling this pest. Many growers will be familiar with the yellow sticky trap. Thrips happen to be more attracted specifically to blue sticky traps. In areas where Thrips are the main pest concern, blue sticky traps should be used. Yellow sticky traps may make counting and identifying pests more accurate and will also attract other flying pests such as fungus gnats, winged aphids, as well as thrips. Tracking pest levels stuck to the cards on a regular basis can give you an idea if pest populations are increasing or declining. They can also give you an idea of where these pests are more present in your space. This can help you determine where your biocontrols can be most useful. Here at Sound Horticulture, we offer both of these sticky traps and have plenty available for your growing space!

Western-Flower-Thrip-Life-Cycle-| Pest Control

Life cycle of the Western Flower Thrips

Note the soil inhabiting prepupa and pupa stages. Using soil predators can help eliminate thrips from becoming full grown adults. This can often be overlooked as a method of thrips control.

Thrips Identification

It is imperative to identify the species of thrips that are causing damage to your plants. Certain thrips species can put a halt on plant exportation (Chili thrips) and some methods of control may differ for some species. Onion thrips and chrysanthemum thrips are both susceptible to spinosad containing products while Western Flower Thrips are not. Echinothrips is a species that does not pupate in the soil so Stratiolaelaps will not be as effective for control.

Check out this link for more information on identification. This key was developed by Dr. Sarah Jandricic, currently the Greenhouse Floriculture IPM Specialist for the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA).

Link to Identification Key

What is Intraguild Predation?

Intraguild Predation (IGP) occurs when one biological control agent feeds on another biological control agent.

Predators that feed on the same prey are known as a guild. This occurrence can lead to a negative effect on the impact of the biocontrols. “Through intense intraguild predation, predators can reduce the impact of other guild members such as the parasitoids that are released to control the aphid population, and trigger or worsen prey outbreaks indirectly and potentially allow for an increase in the amount of aphid damage to the plants.” (Rosenheim et al., 1993; Snyder and Ives, 2001, 2003)

Some examples of observed IGP are:

Neoseiulus californius will feed on Phytosieulus persimilis while they both share the same prey of Two Spotted Spider mites

Amblyseius swirskii will prey upon the larvae of the aphid predatory midge Aphidoletes aphidimyza and will also feed on the eggs, larvae and nymphs of P. persimilis

Orius insidiosus will feed on sweet potato whitefly, Bemisia tabaci, nymphs that have been parasitized by the parasitoid Encarsia formosa

We are aware of these intraguild interactions and will cater your orders to meet your company’s needs considering growing environment and achieving comprehensive control while avoiding IGP.

Orius insidiosus

Also known as Minute Pirate Bug, Orius insidiosus are generalist predators that consume pollen and a variety of species of small, soft-bodied insects including mites, aphids, and small caterpillars. They are most effective for pests with life stages that inhabit flowers (such as flower thrips), as adults are attracted to, and often found in flowers. All stages of Orius move very quickly. The adults are good flyers and move efficiently throughout a greenhouse to locate prey.

Application rate: 0.5 – 1 per 10 square feet of canopy

Neoseiulus-cucumeris-50K-

Amblyseius cucumeris or swirskii

A. cucumeris prefers to feed on first instar thrips larvae but will also feed on second instars. Being a generalist, it is also capable of feeding on other mites such as broad mites, the eggs of two-spotted spider mites, and pollen in the absence of prey. It works well on low to moderate infestations of thrips and as a preventative measure but should be used with other thrips predators such as Orius, or A. swirskii for improved control of serious infestations. Apply with Stratiolaelaps scimitus (formerly called Hypoaspis miles) to control thrips pupae in the growth media.

Application rate: 25-40 mites per sq ft depending on pest severity. If dealing with broad or russet mites, 60 per sq ft.

Dalotia-coriaria-500c-bottle-6516

Dalotia coriaria

Atheta coriaria or Rove beetle (Dalotia coriaria), formerly known as Atheta coriaria, is a native species of a soil-dwelling rove beetle which feeds on small insects and mites. Both adults and larvae are active aggressive predators and are attracted to decomposing plant or animal material and algae, where their hosts are found. While they are beetles, they do not necessarily look like beetles. They are light to dark brown in color, with adults being 3-4 mm long. They are slender with short wing covers. Rove beetles have an interesting habit of curving their abdomen upwards like scorpions and can run or fly when disturbed (usually close to the ground). Since they can actively fly, they rapidly colonize the release area. However, too many Atheta in flight may be because of disturbance to their home.

Application rate: 0.1 to 0.5 per sqft

Stratiolaelaps-scimitus-12.5k-Tube-7486

Stratiolaelaps scimitus

Stratiolaelaps scimitus ‘Womersley’ (formerly Hypoaspis miles) is a native species of soil dwelling mite, which feeds on small insects and mites (e.g., springtails, root mealybug crawlers, spider mites). They move rapidly over the soil surface. Stratiolaelaps are used primarily to control young larvae of fungus gnats in the soil or planting media. To control high numbers of fungus gnats, use of Stratiolaelaps can be integrated with insect parasitic nematodes (e.g., Steinernema spp.) or Bacillus thurinigiensis israelensis (BTI), both of which control the larval stage of fungus gnats. They also help control soil stages of thrips and may account for up to 30% of thrips control.

Application rate: Roughly 25,000 per 1000 square feet of soil medium

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By |2022-10-31T12:17:10-07:00October 28th, 2022|Uncategorized|0 Comments

Fall Newsletter : Attack of the Mealybugs

Fall Newsletter : Attack of the Mealybugs

Photo by Maddy Baker

As we move into the fall, we have received a spike of inquiries detailing mealybug outbreaks.

With that in mind, we would like to share some information on the subject, hoping we can shed some light on a fairly common pest.

There are two main species of Mealybug that we see here in the US. Longtailed mealybug (featuring tails that can protrude as long as the main body of the insect) and citrus mealybug(does not feature long tails). There is also a species of mealybug that can reside in soil so checking root balls can be crucial for plant care.

Mealybug Hosts

Longtailed Mealybug hosts: Dracaena, avocado, citrus, grapes, pear, persimmon, pineapple, tropical/subtropical plants, cycads, orchids, jade, oleander, beans, flax, guava, apple, potato, lemon, begonia, sedum, sempervivum and other ornamentals.

Citrus Mealybug hosts: As the name suggests, these are primarily pests of citrus but also enjoy ornamentals, vegetables, and fruits. They seem to prefer grapefruit over other citrus but other hosts include amaryllis, asparagus, begonia, cactus, coconut, coleus, croton, cucurbits, cyclamen, dahlia, yams, ficus, strawberries, gardenia, impatiens, poinsettia, sweet potato, mango, bananas, avocado, guava, pomegranate, pineapple, pear, apple, eggplant, tulips, milkweed, rosemary, and the list goes on!

Needless to say, these pests have a very wide host range and can attack many houseplants. Production growers should be vigilant of these pests and should consistently ship out clean material. It is always a good idea to inspect plants thoroughly, even the soil, before sending them off to customers.

Pictured are 3 different developmental stages of mealybugs right next to each other. Smaller nymphs leading up to a full grown female adult mealybug.

Photo by Brendan Kelly

Mealybug Damage: Signs to Look Out for

Mealybugs and other insects with piercing-sucking mouthparts, like aphids, feed directly from the host plant vascular system. Feeding from this pest can lead to wilted, yellowed chlorotic leaves, premature leaf drop, stunted growth, and even death!! The sugary honeydew secreted from mealybugs as a byproduct of their feeding habit can cause sooty mold to grow on plant surfaces, hindering photosynthetic capability. The honeydew can also attract ants to the situation which can lead to distribution of the mealy pest.

Options for Control:

For small infestations, a light isopropyl alcohol solution spray can help kill some of these pests on contact without damaging your plants. Mechanical removal by washing plants with water can help significantly as well. These pests are great at getting down into plant crevices and hidden points in new growth that will help keep the covered from sprays and washes, not to mention their waxy coating can also act as a barrier to sprays. Another defensive behavior that has been observed is the egg laying, adult female Mealybug covering stage 1 and 2 instars when sprays are being conducted.

Commercially, we can offer an entomopathogenic fungi such as Beauveria bassiana to help with mealybug outbreaks. Some of the products that we offer including this fungi are Velifer, Botanigard MAXX, Mycotrol, and BioCeres. Another successful biopesticide that we offer is the beneficial fungus product NoFly. This contains the fungal organism Isaria fumosorosea and works wonders for mealybug control. Long Shadow does include mealybug on its label but comes with caveat that cinnamon oil can be highly phytotoxic, so use caution and do a test before spraying everything.

Cryptolaemus montrouzieri are the best biocontrol option. These adults and their larvae are both predacious and a single Cryptolaemus can eat up to 250 small mealybugs over its lifetime. Their larvae do look oddly similar to the mealybug, although they appear a bit “harrier”, are much larger, and eventually turn into an adult Ladybird Cryptolaemus. They spend about 2-3 weeks as larvae and can live over a month as an adult. This gives them close to 50 days of life, which is pretty long compared to other beneficial predators. They may be more effective against citrus mealybug because they are known to lay eggs in cottony masses. The long tailed mealybug is still a good prey option for the Cryptolaemus but are not known to lay eggs which is an easy target for the predator. The predators will likely go after younger mealybugs first. The Cryptolaemus is a specialized predator so its’ main focus will be the Mealybug.

Chrysoperla rufilabris, or the Green Lacewing is a generalist predator that will eat just about anything (including its own kind!). These predators have shown success in controlling mealybugs and can be a cheap option for coverage of multiple pest issues.

Mealybugs can reproduce without mating, like aphids and each female can lay up to 350-600 eggs. The mealybugs can each live for around a month and will do damage the entire time. Some mealybugs can also be found colonizing in soil so scouting root masses can be an integral part of monitoring and control.

Sources of this information are:

-New Zealand Landcare Research

-NC State Extension

-University of California IPM

-University of Florida Entomology Department

Cryptolaemus montrouzieri

Cryptolaemus montrouzieri is the most commonly used biological control for mealybugs. Cryptolaemus is used to control mealybugs mainly in interior plantscapes. They can be used outdoors, but will not survive sub-freezing temperatures. To keep mealybug populations down to acceptable levels in greenhouses, several releases of Cryptolaemus may be necessary, particularly during winter months. They are less effective on longtailed mealybug (Pseudococcus longispinus) because this species lacks the cottony masses Cryptolaemus requires for egg laying.

Adults and young larvae prefer to eat mealybug eggs, but older larvae will feed on all stages of mealybugs. The adults can fly and cover large areas to search for food. If food is scarce they will also eat soft scales and aphids.

BioCeres Wettable Powder

BioCeres WP targets common insect pests such as aphids, whiteflies and thrips.

BioCeres WP is a contact biological insecticide that contains the entomopathogenic fungus Beauveria bassiana. This particular strain, ANT-03, was isolated from Lygus bugs in Canada. It works by germinating into the cuticle of insects and releasing toxins while also consuming the hemolymph.

One of the advantages of BioCeres is that it is an i-502 allowable product containing B. bassiana without the pyrethrins. BioCeres WP can also be tank mixed with several other biorational pesticides (check the technical info for specific combinations).

NoFly-8oz-6476

NoFly

NoFly WP is a naturally occurring fungi strain which acts as a natural pesticide. The concentrated spores of Isaria fumosoroseus strain FE 990. Highly effective under humid conditions, this microbial fungal spore germinates and infects a select group of pests, including aphids, whitefly, thrips, mealy bugs and more. Beneficial predator mites that may be in your growing system are not affected. See the link for additional label and important application instructions. NoFly WP is also compatible with many chemicals making it an excellent tool for use in an integrated pest management (IPM) program.

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By |2022-10-03T13:11:56-07:00October 3rd, 2022|Uncategorized|0 Comments