A Texas A&M AgriLife Extension Service entomologist is canvas how a compounding of beneficial insects can help control the pests in nursery .
Erfan Vafaie , AgriLife Extension program specialist in Integrated Pest Management , Overton , just twine up the 2d year of a three - twelvemonth field looking at the use of vulturous good insect – mites and wasps – to control sweet potato whitefly in commercial-grade preferences .
Vafaie ’s study is for his doctor’s degree dissertation under the supervision of Kevin Heinz , Ph.D. , a senior professor in Texas A&M University ’s Department of Entomology at College Station .
Whiteflies are sucking dirt ball pesterer , interchangeable to aphids , and can feed on century of different ornamental , field and veg crop . Adults are wing while young whiteflies lie flat against foliage and can be hard to see with the naked eye .
Erfan Vafaie , Texas A&M AgriLife Extension Service bugologist , Overton , holds a vile filled with whiteflies captured during a trial focus on the enjoyment of good insects to operate whitefly populations . ( Texas A&M AgriLife Extension Service exposure by Adam Russell )
They reduce works growing by consuming plant food , he said . whitefly also excrete honeydew melon , which can direct to jet-black mold . Sooty mold will not directly hurt the plant but can trim down plant life esthetic ; the most authoritative characteristic for retailing cosmetic plant . Left unchecked , whitefly populations can overwhelm and have mortality to many flora , include poinsettias .
Vafaie said decorative crop , like poinsettias , are especially vulnerable to decreased marketability and finally loss in value from appearing of whiteflies and their eating . grower are often sharply proactive with chemical substance spray treatments to ascertain their poinsettias will meet market place demands .
“ They ’re protective of their harvest , ” he said . “ But the potential for using a combination of biologic control to address a suite of harmful insects instead of conventional chemical controls is something grower are concerned in and want to larn more about . I think there are a number of possible benefits to using good insects in commercial background . ”
Fighting pests with predatorsVafaie say there are many question about pesticide efficacy , pest resistivity to sure chemicals , increased pesticide applier regulation and the overall cost of using pesticides . Consumer trends also show they want ornamentals to have define - to - no exposure to pesticides .
An grownup mellisonant potato whitefly on the underside of a poinsettia foliage with her late produced chemical group of eggs . ( Texas A&M AgriLife Extension photo by Erfan Vafaie )
Using beneficial louse to control cuss and downplay harm to crops could be an important aspect of sustainable production , he say . There are numerous study showing the effectiveness of using beneficial insects in commercial configurations in more temperate climates , especially in yield and veggie production , but very little information about how they handle blighter of ornamentals in red-hot , humid field like East Texas .
Previous bailiwick have tended to focus on the consumption of a single good insect , such as a bloodsucking wasp , he suppose .
“ The finish is to determine whether the compounding of two beneficial worm species to manage whiteflies can play considerably than just one for Mexican flameleaf in a greenhouse environment , ” he said . “ I require to know how the wasp and mite work together to suppress whiteflies . ”
Vafaie is looking to determine how introducing beneficial predatory mites and parasitic wasps affect the need for pesticide spray treatments . His study started with determine initial whitefly populations on painted leaf cutting at the agriculturalist facilities over two years , whitefly retail merchant thresholds for two years , and small - scale discipline to find out if the combination of the two good insects works better than either one alone .
parasitical wasps are distributed by hanging posting containing more than 60 wasp pupa per card , and lento emerge and disperse within the greenhouse . The predatory touch are disperse using a custom - made blower that distributes the mites on carrier material ( wood chip - comparable material seen on the leaves ) . ( Texas A&M AgriLife Extension photo by Erfan Vafaie )
In the most recent year , Vafaie has focalize on commercial-grade trials to handle whitefly populations using beneficial insects in three fix where poinsettias are being grown – two local commercial-grade growers ’ nursery and Texas A&M AgriLife Research greenhouses hold poinsettia trials in Overton .
The mites , which are tiny wanderer , and wasps , which are modest than yield flies and do not sting humans , are natural whitefly predators . The mites feed on humble soft - bodied insect houri and eggs , include eggs and young nymphs of whiteflies and thrips . The WASP lie eggs under halfway - aged nymph , and the young WASP ultimately fertilize on the whitefly nymphs .
wasp have a dependable power to move around and often find dense populations of whiteflies , whereas mites ’ dispersal is much more limited , Vafaie said .
Vafaie and his assistant scout for whiteflies in both greenhouses make out under conventional insecticide rotation and greenhouses that bank mainly on the wasps and tinge for whitefly control .
So far , so goodAt Location 1 , Vafaie say smear sprays were required in addition to the beneficial insect in section of the greenhouses after whitefly populations move in . At Location 2 , no pesticide diligence for whiteflies were necessary in the good louse - wield greenhouse , but fire ant bait was needed to manage the fire ants , which were consuming the beneficial insects .
In Overton , two program applications were postulate to lend whitefly populations back down to manageable levels for the beneficial insects .
A predatory hint run on a whitefly houri on the undersurface of a poinsettia leaf . ( Texas A&M AgriLife Extension photograph by Erfan Vafaie )
In modest - shell trials , Vafaie say the compounding of wasps and mites work out as well as either predator alone . reconnoitre for whitefly and spot - crop-dusting alone help decrease the use of pesticides during the study .
Pesticides that do not vote out the wasps and mites are typically used , or a nebuliser that will not leave residual that will harm the good insect following a intervention , he said .
“ Throughout the small - scale study , the combination of mites and wasps were more reliable in handle simulated whitefly migrations into the greenhouses , ” he say . “ hint are retrieve to wait and stop incoming whiteflies , while wasps actively move around and find Modern populations of whiteflies . ”
WASP were released every week while mite were resign every four hebdomad , Vafaie say .
Vafaie said software of good insects direct less clock time and labor than spray lotion . Although the price of good insects was some tantamount to the distinctive price of pesticide inputs , a full price comparing between formal insecticide rotations and the good insect scheme is still pending .
“ The key to this strategy is to use the beneficial insect to hold whitefly below the retailer limen , ” he say . “ Unlike pesticide applications , biological dominance is a numbers game ; each good insect can only use up or lay eggs under so many whitefly for a afford period of time . If whiteflies are reproducing at a faster charge per unit than the good worm can eat up , then it ’s time to knock down whitefly population with some selective pesticides to layer achievable by the beneficial insects again . ”
Vafaie hopes to carry the report further and incorporate an economic expert to analyze the toll benefits of using beneficial insect liken to formal preventative insecticide rotations for commercial poinsettia production .
germ : AgriLife Today ( Adam Russell )
