Insect Scouting and Diagnosis. Frank A. Hale, Ph.D. Professor Entomology & Plant Pathology

Transcription

1 Insect Scouting and Diagnosis Frank A. Hale, Ph.D. Professor Entomology & Plant Pathology

2 Understanding the Pests to Manage the Pest Life cycle (what life stages are susceptible to control measures?) What control options are less disruptive to natural enemies of the pest and the total environment? Control timing (Control pests when populations are growing but still relatively low)

3 Fall Pest Control Late summer and fall is the time when pests prepare for overwintering Control actions can be made for some type pests so they do not build up to high numbers prior to overwintering Tuliptree and magnolia scale crawlers emerge in September and they molt to second instars later in the fall to overwinter

4 Tuliptree Scale (A Soft Scale)

5 Tuliptree Scale and Magnolia Scale Treat crawlers in September to early October with Sevin, Carbaryl, Orthene, horticultural oil, insecticidal soap, TriStar, Merit, Safari, Allectus SC, or Meridian 25WG Magnolia scale on saucer magnolia

6 Fourlined Plant Bug They overwinter as eggs inserted into tissues of favored host plants Cut off old stalks at ground level and remove and destroy residue

7 Caterpillar Defoliators (Lepidoptera) Canna leafroller

8 Fall Pest Control Azalea lace bugs lay eggs in the underside of the leaves by the fall that will not hatch until spring Hawthorn lace bugs overwinter as adults on the plant under bark and in cracks and crevices

9 Azalea Lace Bug

10 Hawthorn Lace Bugs

11 Hawthorn Lace Bug on Serviceberry

12 Lace Bug Control in the Landscape One time management tool is to drench in March with the systemic Merit, Allectus SC, Meridian 25 WG, Meridian 0.33 G, Acelepryn or in April with Safari 20 SG Azalea lace bug Spray active stages starting in spring with Orthene T,T & O WSP, Safari 20 SG, Merit WG, Allectus SC, Meridian 25WG, or a labeled pyrethroid Basswood lace bug

13 Overwintering Insects and Mites The use of horticultural oil as a dormant application in the late winter or early spring is much underutilized Horticultural oil is easy on beneficial insects which are usually not on the plants at that time of year Oil also has little if any insecticide residual, thus conserving beneficials

14 Winter Pest Control Horticultural oil sprays as a dormant application for control of: Scale insects Aphid adult females or eggs Adelgid adult females and eggs Oak phylloxera eggs Spruce mite and southern red mite eggs Rust mites on conifers

15 Euonymus Scale (Armored Scale) in February Image courtesy of A. Windham, UT Extension

16 Overwintering Adult Female Cottony Camellia Scale This soft scale is common on holly and yew

17 Cottony Camellia Scale Overwintering adults Common on holly and yew Adult laying eggs in ovisac Crawlers Eggs in ovisac starting to hatch

18 Cotton Camellia Scale Control Apply horticultural oil to adults as a dormant application in February-March White egg masses (ovisacs) are laid by adult females in mid-to-late May Drench soil with imidacloprid (Merit and other brands), thiamethoxam (Meridian 25WG), or apply clothianidin (Arena 0.25G) in April-May to control crawlers that emerge in late May to early June. Target adults and ovisacs with horticultural oil in May or wait until crawlers emerge for foliar insecticide applications

19 Spiny Witch-Hazel Leaf Gall Aphid

20 Spiny Witch-Hazel Leaf Gall Aphid Control Horticultural oil spray in February-March to control the overwintering female. Also kills the eggs of other types of aphids. Additional control may be needed using systemic soil drenches of Merit, Marathon, Meridian in Feb.-March or Safari in April Or in April-May spray of Orthene, Merit, TriStar, or Safari

21 Southern Red Mite Control A horticultural oil dormant application for overwintering eggs

22 Spruce Spider Mite Overwintering Eggs Control with horticultural oil as a dormant spray

23 Rust Mite Control on Conifers Best controlled with a horticultural oil spray in February-March Can also be controlled in the fall or spring with horticultural oil, Sevin, Avid, and Forbid

24 Crape Myrtle Bark Scale Eriococcus lagerostroemia Images courtesy of M. Merchant, Texas A&M AgriLife Extension

25 CMBS in February

26 S overwintering nymphs without white waxy ds cover and adults with cover in February

27 July 30, 2014

28 Adult Female

29 Crape Myrtle Bark Scale New fact sheets at: And Image courtesy of M. Merchant, Texas A&M AgriLife Extension

30 Crape Myrtle Bark Scale (July 30, 2014, Germantown, TN) Top or dorsal view Underside or ventral view with eggs

31 Crape Myrtle Bark Scale Eggs

32 Crape Myrtle Bark Scale Peeled back to show eggs on July 30

33 Crape Myrtle Bark Scale

34 Stress Induced By the Scale Natchez crape myrtle on left treated with dinotefuran on May 28, blooms better, appears more thrifty and lacks honeydew and black sooty mold compared to untreated one on right (Courtesy of J. Robbins, University of Arkansas)

35 Insecticide Used Earlier July 30, 2014 Not Treated

36 Crape Myrtle Bark Scale Populations - USA Germantown, TN (2013) Collierville, TN (2014) Ardmore, OK (2012) Little Rock, AR (2014) Newnan, GA (2013) Richardson McKinney Plano Dallas (2004, 2005, 2006, 2007) Longview Tyler (2011, 2012) Shreveport Bossier City (2011) Minden Alexandria (2014) Monroe (2014) College Station (2013) Houma (2012)

37 Crape Myrtle Bark Scale Control in the Landscape As needed, use a JD9-C spray gun at psi with dishwashing soap or insecticidal soap solution as a pressure wash to physically remove scale Apply a dormant application of horticultural oil

38 Crape Myrtle Bark Scale Control in the Landscape Drench with imidacloprid (Merit and other brands), thiamethoxam (Meridian 25 WG) or dinotefuran (Safari 20 SG) in the spring prior to scale crawler emergence

39 Crape Myrtle Bark Scale Control in the Landscape Target crawlers with sprays of acetamiprid (TriStar) when they emerge, probably around mid-may and again for second generation crawlers in early August

40 Scale Monitoring Sticky traps can be made to catch the emerging scale crawlers Use double sided Scotch tape, black electrical tape, or even white tape coated with a thin layer of petroleum jelly (Tape color depends on crawler color) Flag the branch and check at least once per week starting days before expected emergence

41 Crape Myrtle Bark Scale Control in the Landscape Insect growth regulators such as pyriproxyfen (Distance) and buprofezin (Talus 40 SC) targeting crawlers have not been evaluated on this pest but have been very effective on many species of scale

42 Granulate Ambrosia Beetle (GAB) Attacks trees in late winter to early spring

43 Image by M. Windham

44 Granulate Ambrosia Beetle Control In the landscape, treat with bifenthrin (Onyx) or permethrin (Astro) preventatively Or treat at first sign of attack (mid-march to May)

45 Questions?