A natural predator of the glasshouse whitefly ( genus Trialeurodes vaporariorum ) , this tiny but effective parasitoid waspEncarsiaFormosahasbecome an important prick in integrated plague management , in particular in command environment such as greenhouses and nursery .
How it all startedDr . Omid Joharchi of Anatis Bioprotection ploughshare that it was first discovered in 1926 , when an English tomato plant grower observe peculiar dark pupae among the whitefly universe . Encarsia formosasoon became a central design in biological pest control . " This observation led to the white Anglo-Saxon Protestant ’s commercial-grade usage in the UK the following twelvemonth , marking the beginning of its ball-shaped journeying as a biologic agent in the competitiveness against whitefly , " Dr Joharchi explain .
The wasp ’s early succeeder meant widespread borrowing , as it prove to be not only effective but also a sustainable option to chemical substance pesticide .
Tactical , strategical intelligence in huntingDr . Joharchi describes the white Anglo-Saxon Protestant ’s hunting technique as nothing short of tactical intelligence . " Encarsia formosaattacks all green whitefly stages , except for the eggs . However , its best-loved server degree may vary depending on the prey mintage . For Trialeurodes vaporariorum ( nursery whitefly),E. formosapredominantly attacks the pupae and 2nd - instar nymph . In demarcation , for Bemisia tabaci ( silverleaf whitefly ) , both pupae and nymphal instars are equally preferred , althoughE. formosagenerally privilege parasitizing the third , fourth , and pre - pupal nymphal stages , " he deal .
" The white Anglo-Saxon Protestant utilise a combination of visual and chemical cues to place its target , " Dr. Joharchi adds . " It use a unique ' take flight - and - walk ' succession that allows it to exactly identify suitable hosts for egg - laying . "
This strategy maximizes the wasp ’s impact by ensuring that each testis laid has the highest fortune of reaching maturity . " The solvent is a highly efficient reduction in whitefly populations , with eachEncarsiafemale capable of parasitizing numerous whitefly nymph in her life . "
Lone warrior army : reproduction"One of the most intriguing expression ofEncarsia formosais its ability to multiply without the demand for Male , a process known as thelytoky , " Dr Joharchi explains . " This form of asexual reproduction allows females to develop from unfertilized orchis , mean that a single female person can acquire an entire regular army of progeny . This phenomenon is made possible by Wolbachia , an intracellular bacterium that determine the reproductive system of the wasp . "
While maleEncarsia formosado exist , they are rarefied and come forth only alongside distaff wasps . " In the lawsuit ofEncarsia formosa , males do n’t encounter a central role in reproduction , " Dr. Joharchi say . " The universe is largely female , and the absence seizure of males does n’t block the species ' ability to thrive . "
Natural " ink " signature"WhenEncarsia formosaparasitizes a whitefly , it leave behind a detectable grim patsy on the host , " Dr Joharchi note . " This blackening of the whitefly serves as a visible marking of the wasp ’s effectiveness for raiser and pest managing director , being an unmistakable sign that the wasps are hard at work . "
Two method of killing whiteflies"The chief method acting is parasitism , where the distaff white Anglo-Saxon Protestant lay its bollock inside the whitefly master of ceremonies , finally defeat it , " Dr. Joharchi notes . " However , Encarsiais also capable of emcee feeding — piercing the host ’s shield with its ovipositor to feed on the insect ’s hemolymph ( the equivalent of blood in louse ) . "
" This dual - action approach makesEncarsia formosaan even more strong biocontrol agent , " Dr. Joharchi says . " The combining of parasitism and host feeding increases the overall efficacy of the wasp in bring off whitefly population . " By feeding on the master of ceremonies in addition to lay orchis inside it , the white Anglo-Saxon Protestant accelerates the whitefly ’s demise and further reduces the pest population .
economical grandness and virtual applicationsWhileEncarsia formosaprimarily targets the greenhouse whitefly ( T. vaporariorum ) , it is also capable of attacking over 15 mintage of whiteflies . " Its versatility establish it a worthful instrument in a wide range of agricultural environments , from decorative plant life nurseries to vegetable greenhouses . However , right species identification is important for effective biocontrol , " Dr Joharchi contribution . " An expert ’s steering can ensure that the appropriate biocontrol federal agent is chosen for the task . "
" For optimum results , Encarsia formosais typically expel at rates of 1 - 10 wasps per square meter , depending on the severity of the infestation , " he adds . " even releases are necessary to keep good control , with growers often introducingEncarsiabefore whitefly populations are visible to prevent infestations from gaining impulse . "
ForEncarsia formosato be successful , specific environmental term are necessary . Dr. Joharchi explains that the wasps are most good at temperatures above 20 ° C ( 68 ° farad ) and under high light levels ( 7300 lux ) . " to boot , relative humidness between 50 - 70 % is ideal for their activity . When temperatures pass below 18 ° ascorbic acid ( 64 ° F ) , the wasps ' effectiveness decreases significantly . "
" Timing is also critical , " Dr. Joharchi adds . " IntroducingEncarsia formosawhen whitefly population are already high is not recommended , as the wasps may shinny to command the plague at such a late leg . "
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Van Lenteren , J. C. , Van Roermund , H. J. W. , Sütterlin , S. ( 1996 ) . Biological control of greenhouse whitefly with Encarsia formosa : How does it work ? . Biological Control , 6(1 ): 1 - 10 .
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Nechols , J. R. , Tauber , M. J. , Tauber , C. A. ( 1992 ) . Biological control of greenhouse whitefly with Encarsia Taiwan : A life - history approach to population management . Entomologia Experimentalis et Applicata , 65(3 ): 211 - 224 .
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