Greenhouse TPM/IPM Report Central Maryland Research and Education Center Ellicott City, Maryland May 26, 2015 From: Stanton Gill, Extension Specialist – IPM for Greenhouse and Nurseries, Central Maryland Research and Education Center, University of Maryland Extension Karen Rane, Extension Specialist, Director of the Plant Diagnostic Clinic, University of Maryland Extension Andrew Ristvey, Extension Specialist, Wye Research and Education Center, University of Maryland Extension Suzanne Klick, Technician, CMREC, University of Maryland Extension Four-Lined Plant Bugs Are Active in May By: Stanton Gill, UME Garden centers might receive questions about several insects active in the landscape this week. Adults and nymphs of four-lined plant bugs are feeding on perennials this week. The four-lined plant bug uses its piercing/sucking mouthparts to feed on chlorphyll. It secretes a toxin in its saliva that causes white, dark, or translucent spots on the leaves. If damage is extensive, these spots coalesce and form large blotches. Heavy damage can cause leaves to turn brown and drop.The damage is sometimes mistaken for disease leaf spots. They feed on a wide range of annual flowers and herbs, mainly in landscapes and nurseries. I have Four-lined bug adults are yellowish green with not seen them damaging plants in greenhouses. There is four black stripes one generation per year so damage only occurs early in the season. The four-lined plant bug nymphs are a bright red to orange color with black dots on the abdomen. Later instars have black wing pads running halfway down the abdomen with a yellow stripe on each wing pad; their wings are not fully developed yet. Adults are usually a greenish-yellow color with four black strips running longitudinally down the wings. Control: Acephate or acetamiprid. You can try neem products if they are still in the nymph stage. Phlox Plant Bug Another question for gardens center might be about phlox plant bugs which are active on phlox in the landscape this week. Look for the yellow stippling and distorted foliage caused by this feeding. The feeding by this plant bug can stunt plants. Control: For control, you can use any systemics (e.g. acephate). These phlox plant bug nymphs are causing distortion on plants and stippling damage on the foliage Insect Update Up to now in the season we have mainly had reports of spider mites and tarsenomeid mites as the major pests in greenhouses. As the weather continues to warm up, thrips pressure is increasing on greenhouse crops are still in the greenhouse at this point, With many plants in bloom now, they are producing plenty of pollen as a food source for thrips. Blue sticky cards are good for detecting adult thrips in a greenhouse. Place at least 3 – 4 cards in a 10,000 sq ft of growing area and check the cards once a week to see if the population is going up or down. Yellow sticky cards also work, but the blue ones are more attractive to the adult thrips. Control options: For low thrips populations, you can use Azadirachtin (Aza-Direct, Azatin XL, Ecozin Plus, Ornazin, Neemix) which will help keep them suppressed. The insect growth regulator, Pedestal (Novaluron), is another good option for immature stages of thrips and works best when populations With the warm temperatures, monitor crops closely for thrips with sticky cards and are relatively low. You can also use Pylon (Chlorfenapyr) tap plants against white paper to dislodge or Spirotetramat (Kontos). Kontos is both foliar and root thrips from flowers and foliage absorbed. Kontos is phloem-active, meaning users can foliar-apply (spray) and be assured that the active ingredient (spirotetramat) will move down in the plant. Growers can also soil drench Kontos, and because it is xylemactive, the active ingredient will move up systemically through the roots to the growing tips. Upcoming Conferences Greenhouse Tour and Picnic June 25, 2015 Location: Greenstreet Growers, Lothian, MD Alternative Crops for Greenhouse Production Conference August 5, 2015 Location: Brookside Gardens, Wheaton, MD The information given herein is supplied with the understanding that no discrimination is intended and no endorsement by University of Maryland Extension is implied. Read labels carefully before applying any pesticides. Photographs are by Suzanne Klick and Stanton Gill unless stated otherwise. The University of Maryland Extension programs are open to any person and will not discriminate against anyone because of race, age, sex, color, sexual orientation, physical or mental disability, religion, ancestry, national origin, marital status, genetic information, political affiliation, and gender identity or expression.
© Copyright 2024