Put A Stop To Whitefly Attacks In Your Greenhouse Simply By Adding These Easy-to-apply Cards Containing Parasitic Wasp Encarsia Formosa, The Effective Biological Pest Control.when Temperatures In Your Greenhouse Rise In Spring To 12°c (54°f) Small Female Parasitic Wasps Become Active & Search Out Pesky Whitefly Larvae Into Which They Lay Eggs. This Mummifies & Renders The Whiteflies Inactive, As The Wasp Eggs Hatch & The Young Wasps Emerge.whiteflies Damage A Number Of Flowers Including Fuchsias & Pelargoniums (tender Geraniums) & A Range Of Other Houseplants As Well As Indoor Vegetable Crops Like Cucumbers & Tomatoes.encarsia Formosa Parasitic Wasp Also Attacks The Greenhouse Pest The Cotton/ Sweet Potato whitefly bemisia Tabaci Which Harms Tender Greenhouse Crops. separate Cards Along Perforated Strip & Aviod Handling The Black Scales In The Centre Of The Cards.simply Hang Cards Around Your Greenhouse Out Of Direct Sunlight, When The Spring Arrives & Temperatures Rise To Above 12°c (54°f).where Possible Attach Card To Plant Stem, Out Of Direct Sunlight Concentrating Cards In Areas Where Whitefly Is Present.regular Fortnightly Introductions From Spring Until Autumn Provide Best Results.this Product Can Be Applied In Conjunction With Physically Acting Sprays Such As Sb Plant Invigorator To Provide enhanced Levels Of Control.please Note – This Is A Live Product So We Are Keen To Get It To You When The Conditions Are Best For The Product & Will Prove Most Effective. To This End Your Product Will Be With You At Any Point Within A Three Week Period So We Can Ensure We Deliver You This Quality Product At The Most Appropriate Time.