This article will detail whitefly growth cycle, explain why they are such a hard pest to control and then list treatment options which work.
Related articles: APHIDS APPLE MAGGOTS BAGWORMS BUDWORMS THRIPS TWIG GIRDLERS
WHAT ARE WHITEFLIES?
Whiteflies are small winged insects which look more like moths than flies. They have a powdery wax on their body and wings which both protects them and is key to identification. They are active in all parts of the world and can thrive year round in the south but go dormant during the winter further north. Though whiteflies can be a tough and persistent pest, the right combination of chemicals combined with the right timing of treatment can solve any infestation.
Whiteflies have two main species which are active in the United States. The Citrus and the Greenhouse are tje most common found but others exist. Citrus whiteflies are found on just about any plant – not just fruit. Citrus whiteflies are hardy and most likely to be active year round. This especially true in the south.
Greenhouse whiteflies are easier to control and will go dormant as winter sets in around the country. Greenhouse whiteflies are more prevalent in greenhouses though plants which move to homes and gardens carrying active populations will surely enable them to get established.
WHITEFLY LIFE CYCLE
Both species develop from eggs and grow through a series of instars. The last instar is the pupa stage during which young change to adults.
Adult whiteflies will lay eggs in less than a week once emerged. Eggs are very small; almost invisible. Eggs will be laid on the underside of leaves, in hard to see locations, in generally well protected parts of the plant.
Once the young emerge, they will immediately begin to feed. Young are round and almost “clear” so they are easy to miss. Though their development can occur in less than a month, a much longer development time frame is not uncommon. Cycles can take as long as a year if conditions are not so favorable. However, regardless of how long it takes them to develop in your yard, damage will certainly happen to any host plant where they reside.
PLANT DAMAGE WHITEFLIES WILL DO
Whiteflies are a problem because they have piercing mouth parts which allow them to suck plant sap. This behavior is what will lead to a range of problems for host plants prone to attack. The short list of related issues from feeding whiteflies includes:
- Leaf damage. Feeding whiteflies will cause leaves to turn up and brown, disabling them to perform their responsibilities. Damaged leaves look bad and promote decay fungus and bacteria to form.
- Sap drainage. Whiteflies have an insatiable hunger for plant sap and will suck as much of it as they can from the host plant. Young host plants will not be able to meet these demands and don’t stand much of a chance to survive; adult plants which loose vital sap are more prone to disease, heat stress and less likely to rebound from any environmental shock.
- Whiteflies excrete honeydew which lures other nuisance insects onto the host plant. These secondary insects will feed off the honeydew and effectively farm it for it’s nutritional value but invariably they will become established on the property or in nearby structures. This secondary insect infestation is usually some type of ant, wasp or beetle. Regardless, feeding whiteflies allow such populations to thrive. Furthermore, the honeydew goes bad and grows a mold known as Black Sooty. This mold damages host plants preventing them from processing food properly further contributing to the host plants demise.
- Whiteflies are unsightly when they populate any plant and if prized landscaping gets infested it really looks bad. Active whiteflies will buzz around host plants throughout the day and are very noticeable. They are annoying when active on fruit or flower producing stock and can easily be brought into the home with anything harvested off infested plants.
- Lastly, whiteflies are extremely prolific. Once they get established on any plant around the home or garden they will readily migrate and look to infest any other nearby vegetation. Whiteflies don’t discriminate; they will move onto any plant that has healthy and abundant sap. It is not uncommon to have local populations thrive on some field of weeds only to start migrating into someone’s prized roses.
HOW TO CONTROL WHITEFLIES
To control an active problem or prevent whiteflies from getting established in your yard or garden, we have a range of liquid concentrates. This range of options include products for the organic gardener as well as the traditional tomato grower. We even have systemics for fruits and vegetables as well as any type of shrub or tree. Systemics offer long term protection and only need be applied 1-2 a year.
INSTALL WHITEFLY TRAPS
WHITEFLY TRAPS can first identify a whitefly problem before it gets bad. Finding just a few whiteflies means more will soon be active so take this as a warning and treat.
Our traps are bright yellow which whiteflies will see easily and be drawn to them. Traps can help slow a problem by catching foraging reproductives. Traps can also be your first line of defense serving as an alarm. Once a trap catches a whitefly, you’ll know its time to treat.
Effective on on garden pests like APHIDS too, set them out every 1000 sq/ft or every 10 feet along a garden row.
If you already have whiteflies active in your garden or house plants, using traps alone probably won’t solve the problem so consider one of the treatment options below.
ORGANIC WHITEFLY SPRAY
For the organic gardener, we have two concentrates safe enough for fruits and vegetables yet strong enough to control even stubborn whiteflies.
The “best” is the MULTI PURPOSE INSECT KILLER. This product works immediately will be mixed with water to be sprayed as needed.
Multipurpose Insect Killer will provide a fast knockdown of all garden pests including whiteflies. Expect to see dead bugs a few minutes after being sprayed. But since nothing can kill the developing eggs and instars, plan on spraying once a week for at least 2 weeks (3 treatments total) to get rid of them food good.
Add 6.4 oz per gallon of water and plan on getting 500-750 sq/ft of plant foliage treated per mixed gallon. Multipurpose Insect Killer has a “one day to harvest” which means its safe enough to use right up to the day before you harvest your fruits or vegetables. It comes in both quarts and gallons.
Our 3 IN 1 CONCENTRATE is similar to Multipurpose Insect Killer but it includes a fungicide making it a “dual action” product. So if your plants have been suffering with a fungus or mold related to the whitefly activity, use this option.
Add 4-8 oz to a gallon of water to cover up to 500 sq/ft of plant foliage. Like the Multipurpose Insect Killer, you should plan on spraying weekly for the first 2 weeks (3 times total) to get rid of the current whiteflies and control the fungus. Treatments will work immediately on the whiteflies but it will take a week or so for the fungus to wither away.
GARDEN SAFE WHITEFLY SPRAY
If you want a more “traditional” (aka: stronger) product for your garden, go with VEG PLUS PERMETHRIN. This active can be safely used on plants yielding fruits and vegetables although the “days to harvest” will be 7-14 days compared to organic products which are gone in day. This is true since these products provide residual.
Veg Plus Permethrin is odorless, labeled for use on garden plants and will work when applied. Whiteflies will immediately die of being sprayed and treatments can last up to 2 weeks. But if you notice the whiteflies returning before two weeks, spray again.
Mix 1/2 oz per gallon of water and plan on getting 500-750 sq/ft of coverage per mixed gallon.
If you have a large garden to treat, CYONARA RTS might be more efficient to use. It too is a concentrate but it comes in a handy “ready to spray” jug. This jug hooks to your garden hose and using the power of your water pressure, will automatically mix the concentrate with water creating a total of 20 gallons of mixed material.
Each jug can cover up to 16,000 sq/ft and treatments will last up to 2 weeks. Expect a fast kill but if whiteflies come back in less than 2 weeks, spray again.
The longest lasting treatment for whiteflies are products know as systemics. When fed to the plant as a soil drench, these actives will be absorbed by the roots of the plant and effectively become part of the foliage. This process will take 2-6 weeks to occur but once the active makes it’s way to the foliage, any insect trying to eat the plant will die.
LAWN TREE AND SHRUB SYSTEMICS
So if you have whiteflies in the lawn or trees and want season long control, use PROTHOR.
Prothor can last up to a whole year so in general, if you spray in the spring, you shouldn’t get insects on the treated tree for the year. Prothor is a great “one spray” protection for most any plant in the yard for a range of insects including whiteflies.
Now if you treat mid or late season, Prothor will take care of the current activity but it could take several weeks to reach the foliage. So to get the active insects immediately, mix some up for spraying affected areas.
For mixing up a spray-able solution for surface treatments, add .5 oz of Prothor per gallon of water and use the mixture over 1,000 sq/ft of surface area.
For systemic treatments, add .1 oz per inch of tree or hedge trunk thickness. So if you have a holly with 3 main trunks coming up from the base and each trunk is about 3″ wide, add 1 oz of Prothor in a 5 gallon plastic pail with 3-4 gallons water. Next, make 5-8 holes in the ground within 1-2 feet of the hedge. Use a piece of rebar or a pick axe to make the holes. Next, pour out the mixture of Prothor into the holes being sure to pour it slow enough so the material doesn’t run away from the plant. If done properly, the treatment will remain in the ground around the shrub where it will be absorbed in the coming weeks following the application.
SPRAY EQUIPMENT NEEDED
When spraying plant foliage, you’ll need a sprayer. We have several options all of which have advantages and disadvantages.
For small jobs, our standard PUMP SPRAYER is adequate. It requires pressure so you have to manually pump it but once pressurized, expect to reach 15 feet out or up.
A good HOSE END SPRAYER can also be used. The advantage of using this design is that it will use the power of your garden hose which means it can sometimes spray 25 feet or more. Also, you only have to add small amounts of chemical to the tank when using it to spray any of the concentrates above. If you decide to get one and a concentrate above, email us for specific directions on how to prepare the sprayer before hooking it to your hose to treat.
Lastly, the TROMBONE SPRAYER is a totally portable option that is handy when you need to treat high locations like an whitefly infested tree. Using the power of the “slide” mechanism much like a sliding trombone, one can reach 30 feet or more.
The sprayer comes with an 8 foot long hose you drop into a pail of mixed insecticide. Your “sliding” action will in turn pump out the chemical targeting the area you direct your spray.
GREENHOUSE FOGGERS and FOGGING MACHINES
If you have a greenhouse or small confined area with whitefly activity, you might consider a misting machines.
If you’d like a more “controlled” application done over time, install METERED AEROSOL MACHINES. These discreet machines are easy to deploy and go off every 15 minutes releasing a small amount of pyrethrin. This naturally occurring insecticide is active on whiteflies and will take out active insects around the clock. Because the machine is going off all the time, you don’t have to worry about a new population getting established. After 1-2 weeks of keeping the machine on, the active problem should be cured.
This machine comes in three basic designs. The AERO 1000 is a fixed machine meaning it will only go off every 15 minutes. The AERO 2000 has a photo cell to sense light so you can program it to go off during the day or night only and the AERO 3000 has a range of timer option so you can increase the frequency to more than every 15 minutes meaning it can go off every 5 minutes, every 10 minutes, every 30 minutes, etc.
Each machine will need a charged can of CLEAR ZONE INSECTICIDE. The can will last up to 30 days when set to release product every 15 minutes and will control a range of flying pests like whiteflies.
WHITEFLY FOGGING MACHINE
For large greenhouses, a good FOGGING MACHINE can cut costs and do a great job controlling whiteflies. These devices convert water to a “fog” so you can effectively blanket all the foliage of your plants without having to worry about whiteflies hiding.
This machine features a 1/2 gallon tank and pumps about 3 oz per minute. For covering 10,000 sq/ft or less, its plenty powerful. Just plug it in and direct the mist over the plants you want to protect. Its well suited for the yard too where it can be used to control a range of pests like mosquitoes and gnats.
There are several chemicals you can use in the fogging machine but in most cases, ESSENTRIA IC is a good choice. Made with food grade actives, Essentria can be used safely most anywhere and it can be applied as needed. With pests like whiteflies, treatments can be needed more than once a week. And having a product you can apply without having to worry about over applying it is nice.
Add 3 oz of Essentria to the tank and plan on using the 1/2 gallon mixed solution for every 5,000 sq/ft. Essentria will control any pest active in the treated area and since treatments will be easy to do as needed, there is not much prep work required. Just let the treatments settle for at least 1 hour after fogging before entering the treated zone.
THINK LONG TERM FOR ONGOING WHITEFLY PREVENTION
Once you get your whitefly problem under contro, plan on being ready to treat again.
- If you are in a region with a lot of local whitefly problems, don’t think your plants will be overlooked or “missed” by migrating flies. Inspect for whitefly activity throughout the growing season and use traps to help spot colonizing adults.
- Start treatments as soon as you identify activity and don’t rely on one or two sprayings to solve an active problem. Once you think you have it solved be sure to check for new flies every week.
- For any stubborn infestations, treat more frequently for the first two weeks. This will ensure you break their cycle.
- Remember that removing infested plants will generally only do just that; remove a plant which had whitefly activity but it will not get rid of the problem. Whiteflies are here to stay!
- All your other plants are just as likely to one day soon develop a problem if you don’t protect them with a little bit of preventive maintenance.
Whiteflies can be a persistent pest which seems to always be around and never go away. Use traps to monitor local activity and once you’re sure you have activity, begin a management program using our products listed above. Remember, treating early is always best as it will save time, money and effort. Once you have the outbreak under control, be sure to watch for their return and be particularly careful the following year since this is when most growers seem to forget the previous years happenstance.
Give us a call if you need further help. Our toll free is 1-800-877-7290 and we’re open Monday through Friday, 9:00 AM to 4:00 PM. On Saturday, 9:00 AM to 2:00 PM (Eastern Standard Time).
Email questions here: https://bugspray.com/about-us/contact-us
Order online and get a 5% discount! We ship fast with 99.9% of all orders shipping within 1 business day!!
Learn more about BUGSPRAY.COM and why it’s never been easier or safer to do your own pest control.
Please show your support for our business by purchasing the items we recommend from the links provided. Remember, this is the only way we can stay around to answer your questions and keep this valuable web site up and running. Thanks for your business!