Broad Mites(Polyphagotarsonemus latus ) seem to be a regular occurrence nowadays in bound harvest , especiallyReiger begonia and New Guinea impatiens . Other crops that are commonly affected include torenia , exacum , ipomea and gerbera .
Broad mite are often hard to detect and mastery . learn on for point on monitoring andthelatest management strategiesfor this gadfly .
Monitoring
regrettably , liberal mite ’s small size ( 0.2 mm ) means thatspotting the mite is near unsufferable using just a handwriting lens . Damage is normally the first sign a grower see , so susceptible crops should be walked and inspected on a regular basis . equipment casualty can come about at very low soupcon densities , and oftendoesn’t occur for a good 20 to 30 days after the harvest has already been infested .
Here ’s what distinctive damage can search like :
blanket mitesfeed on raw growing , so that ’s where you require to look . The mite ’s toxic saliva results incopper or purplish - colored damage on growing points . Leaves often turn downwards .
Broad mite,Polyphagotarsonemus latus. Photo credit: USDA BARC
Unfortunately , “ newfangled development ” also mean buds , which canbecome discolor and malformed . Flowersoften areprevented from fully originate . leafstalk and internodes can also become shortened , so look for stunt plant growth , as well .
Is it Broad Mite? Or Something Else?
If equipment casualty from full mite is suspected , it ’s important toconfirm the diagnosisby in reality see the mites using a microscope ( or havingthem confirmed by OMAFRA staff or an experient pathfinder ) .
Broad mite legal injury can easily be confused with thing like :
You may not see the grownup mite themselves , but spotting even 1 egg(see depiction below),along with characteristic hurt , is usually enough to confirm that broadmite is the culprit .
Broad mite damage on torenia. Photo by S. Jandricic, OMAFRA.
However , if you uprise a lot of susceptible crops(refer to this leaning of“magnet ” crops ) , or you ’ve regularly had all-encompassing mite topic in the past tense , you may want to consider a more rigorous monitoring regime specific to this gadfly . This involves taking random sample of meristems , wash them in alcohol , and inspecting the contents under a microscope on a regular basis . Details of this technique can be foundhere .
I’ve Confirmed broad Mite: Now what?
Biological control can be an selection , if it is well time . Neoseiulus cucumeris , N. californicusandA. swirskiican all suppress this plague . Beneficial touch should beintroduced early on in the crop cycleof susceptible crop to prevent unspecific mites from establishing , andhigh rates of release will be demand over the life of the crop .
But are predatory mites as effective for broad pinch as pesticide ? The response is yes ! A study in Belgium showed thatA. swirskiiwas actually more effective than Avid on Rhododendron plants , if released 2x / calendar month , along with supplemental food ( Artemia cyst ) . you may take more about that tryout in the following papers , on page 125 :
If the crop in question can brook it , biocontrol of spacious jot is base by some consultants to be more effectual if the pest is first suppressed with an practical program of Suffoil Xor another type of mineral rock oil . ( Reminder : always do phytotoxicity examination first before murder untried plants with oil ! ) .
Broad mite damage on unopened buds. Photo by S. Jandricic, OMAFRA.
For more details onbiocontrol of broad mites , take a look at these article fromMichigan State ExtensionandDr . Rose Buitenhuis ( Vineland Research )
Miticides are often your good selection , particularly in crops that are mostly only susceptible to mite pests , where a “ one and done ” spray approach can be takenwhen the crops are young . However , it can often unclearwhichmiticides are good against mite pests besides wanderer mites . For broad mite , here are the effectual products * :
observe : many growers have been finding Avid has n’t been work as well as it used to , and are plow to a combining of Avid / Pylon or another chemistry . Also remember that all of the chemistries listed are also operose on predatory speck , so theyshould only be used on plant species where large-minded touch ( and not thripid ! ) are your primary and only pest of concern .
Adult and eggs of broad mite.Photo by S. Jandricic, OMAFRA.
Whether you choose pesticide or biocontrol as your management scheme , plant with damage , as well as those plant instantly surrounding them , should be treated . This is because , by the time you notice damage , the speck have plausibly spread to side by side plants .
