Let’s find out how to battle Broad Mites

by Rincon-Vitova Insectary

Broad Mites (Polyphagotarsonemus latus) 

This destructive pest lives on a wide host range. Broad mites secrete and inject a toxic growth regulator into plants as they feed. The toxin causes twisted, hardened and distorted growth and terminal leaves and flower buds become malformed. The reason broad mites are such a problem is they often go unnoticed until they are out of control. Damage can resemble watering deficiency, herbicide damage, a viral disease, micronutrient deficiency or pH imbalance. 

Identification 

Adults are almost microscopic (less than 0.2 mm long), oval, and look swollen in profile  

Light yellow-amber or green (females have a light, median stripe. Males lack the stripe).  

Two hind legs of adult females are reduced to whip-like appendages.  

The male is smaller and faster moving than the female. The male’s hind legs are enlarged for mating  

Eggs are colorless, translucent, elliptical and covered with scattered white tufts on the upper surface  

Life Cycle 

Broad mites reproduce prolifically between 70-80º F.  

Eggs hatch in two-to-three days and each female can produce 40-50 eggs.  

Female broad mites lay 30 to 76 eggs on the leaf surface. 

Un-mated females lay male eggs; mated females usually lay four female eggs for every male egg.  

The larvae hatch in 2 or 3 days, are slow moving and do not disperse far to feed.  

In 2 or 3 days, the larvae develop into a quiescent larval stage.  

Quiescent female larvae become attractive to the males, who pick them up and carry them to the new foliage. 

Females emerge & males immediately mate with them.  

Males live 5 to 9 days; females live 8 to 13 days. 

Monitoring 

Broad mites are so small – virtually invisible on the host plant even with a good hand lens. 

A 60-100x microscope is best to observe broad mites. 

Mites are usually seen on the newest leaves and terminals.  

Mites tend to crowd into crevices and buds and feed on the growing tips. 

Populations of broad mite tend to be most severe in warm, humid conditions. 

Leaf edges tend to cup up or down, become brittle and show signs of scarring. 

Leaves generally curl near the base at the petiole.  

The entire plant will lose its vibrant green color. 

Internodal growth is stunted and overall growth is underdeveloped.  

New growth can blacken and die. 

Cultural Practices 

Broad mites are difficult to control with sprays because they are protected by their habit of feeding in buds or within distorted tissue. 

Hot water treatments can control the mites without injuring the plants: use water at 109.4-120.2°F for 15 minutes. 

Heat treatments: Raise room temp to 115°F for 20 min to 1 hour. 

Take measures to improve overall plant health: compost, compost tea, beneficial microbes to support the plants 

Dust with Diatomaceous Earth: these jagged particles cut the insects and expose to desiccation & disease. It will need to be reapplied as it gets wet. [DE particle size: 10-200 micrometers (μm). Males are 100 μm, females are 200 μm]. 

Plant bean, eggplant, pepper trap crops 

Use Soap & Oil Sprays 

Avoid using pesticides: Triazoles (myclobutanil), spiromesifen, abamectin 

Abamectin: active ingredient occurs naturally, is derived from the soil micro-organism, Streptomyces avermitilis. 

PyGanic is a broad-spectrum insecticide, containing Pyrethrin that is organically compliant. 

Spider mites exposed to carbaryl (Sevin) in the laboratory reproduce faster than untreated populations.  

Carbaryl/some organophosphates/some pyrethroids favor spider mites by increasing levels of Nitrogen in leaves, which stimulates spider mites’ reproduction. These materials are highly toxic to natural enemies and pollinators  

Can cause spider mites to become abundant and damage plants after its application. Insecticides applied during hot weather usually cause dramatic spider mite outbreaks within a few days. 

Cinnamaldahyde, extracted from cinnamon also kills beneficial insects 

Bio-Control 

Predatory mites  

Application Rates: 

A good guideline is that one predator is needed for every 10 spider mites to provide control. 

More than one application may be required if you want to reduce pest populations rapidly.  

Concentrate releases in hot spots where spider mite numbers are highest.  

Once established on perennials, predatory mites may reproduce and provide biological control indefinitely  

Re-augmentation required if nonselective insecticides are applied (which kill the predators). 

Neoseiulus californicus: Persea, Avocado-Brown, Two-spotted spider mite, Pacific, Broad, Cyclamen, Eriophyids 

55°-105°F 40%-80% RH 

*Best in warm/humid conditions   

*Tolerate hot/dry G.H.                            

*Susceptible to pesticides    

*Eats other predatory mite eggs (especially Persimilis)   

Amblyseius fallacis (=Neoseiulus fallacis): Tetranychid mites, European & citrus red, Two-spotted spider mite, Spruce, Broad, Cyclamen, Pacific, Bamboo, Southern red, Bank’s grass mite 

48°-85°F >50% RH 

*OK w Persimilis & Stethorus   

*Can reproduce at cooler temps    

*Can overwinter under snow    

*Best in dense canopy  

*Avoids webbing    

*Can survive at low pest densities   

Scolothrips sexmaculatus: Six-spotted thrips: this is a predatory species of thrips 

Adults and larvae are entirely predaceous, feeding on European Red mite, cyclamen, and Tetranychus species. 

Predaceous adults can be distinguished from phytophagous thrips by three dark spots on each wing cover  

Adults are mostly pale-yellow adult.  

Nymphs are translucent white to yellow and difficult to discern from other thrips species.  

Six spotted thrips can rapidly reduce high populations, but don’t become numerous until after mites have become abundant and damaging. 

Application Rates: 

500-2,000 per acre 

Summary of Strategies 

Diligent monitoring and early detection! 

Sanitation! 

Overall plant health 

Diatomaceous Earth  

Bean, eggplant, pepper trap crops 

Soap & Oil Sprays 

Heat treatments 

Beneficial Insects 

What to expect when your cannabis plant is in the Vegetative (veg) Stage.

by Alex Robles

     Take a moment to pat yourself on the back because that seedling you agonized over is now a plant in the vegetative (veg) stage.  Most new growers usually make mistakes and their plants pay with their lives before they get to veg.  So again, good job on getting your plant this far.  Now that we’re done celebrating we have to plan our work and work our plan because that plant is going to need more of our attention now. 

     I’m going to talk in some broad general terms about the cannabis plants.  The reason for this is because there’s so much variety in cannabis, it’s easy to get tangled up in the small details.  Before we start talking about the veg stage, the importance of pH, nutrient needs and pest control, let’s get to know this amazing plant a little better. 

Continue reading

Get the upper hand on Ants in your garden.

by Rincon-Vitova Insectary

Ants 

There are more than 12,400 species of ants throughout the world. In California, there are about 270 species, but fewer than a dozen are important pests. Ants interfere with biological control.  Honeydew-secreting pests, like aphids, supply sweet food to the ants. In turn, ants protect the pests from beneficial insects that try to eat them. Controlling ants is important when attempting to control these honeydew producing pests. Baiting is a low risk approach that interrupts ants’ interference. Once they have found an adequate food source, they create a pheromone trail, a chemically marked highway, to and from the ant nest. More bait stations are not necessarily the answer, but strategic placement is important. 

Identification 

Ants are close relatives of bees and wasps.  

Common wingless adult forms, known as workers.  

Winged forms, which leave the nest in large numbers in warm weather to mate and establish new colonies, are often mistaken for winged termites. 

Continue reading

IMGS Ep. 130: It’s almost Thanksgiving.

click on the title and link below to listen and watch

A little recap of last weeks IPM question.

Support the show – Go to Patreon.com/inmygrow and donate $1.00 to help keep the show going.   

Show Notes: Welcome to Ep 130.  A word about last week’s episode and the noise.  I will recap the IPM question that I read last week.  Tester pack, Blueberry Muffin.  California doesn’t have employee protection for cannabis patients, how do we change that?  

Strain of the Week:  Gasoline –  The description of this says that It’s a cross of ChemDawg and OG Kush and sativa dominant.  Of course it has a fuel aroma.  There’s also this wet dirt and pine cones and funk smell, with a sweet fruity flavor at the end of exhales.  21% THC wasn’t too heavy, nice day time high.  

Social Media: Social Media:   IPM Spider Mites (SM) during flowering @lonestar_grows.  Same notes as last week.

Report from the cannabis front line: 

More election local results 

Measure G in Ojai increasing cannabis taxhttps://ballotpedia.org/Ojai,_California,_Measure_G,_Marijuana_Business_Tax_(November_2020) 

Ventura County Measure O – https://ballotpedia.org/Ventura_County,_California,_Measure_O,_Marijuana_Permit_Ordinance_(November_2020) 

Ventura City – https://ballotpedia.org/San_Buenaventura,_California,_Measure_I,_Marijuana_Business_Tax_(November_2020

Native owned cannabis company https://www.ganjapreneur.com/michigans-first-tribal-owned-cannabis-business-begins-operations/?mc_cid=c3c77f4910&mc_eid=cdb017092f 

NJ lawmakers trying to change cannabis tax https://www.politico.com/news/2020/11/11/new-jersey-navigates-cannabis-legalization-436232?mc_cid=c3c77f4910&mc_eid=cdb017092f 

Cannabis in Hong Kong https://www.thegrowthop.com/cannabis-news/hong-kong-teens-are-importing-cannabis-products-at-alarming-rates?mc_cid=c3c77f4910&mc_eid=cdb017092f 

New JAMA article https://www.projectcbd.org/cannabis-schizophrenia-conspiracy-causality?mc_cid=c3c77f4910&mc_eid=cdb017092f 

Big thanks to: All the artist for letting me use their music.

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Music:

The High Line

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