Preventing Sticky Cotton Caused by Whitefly & Aphid

Peter B Goodell Cooperative Extension Advisor Overview

• On January 23rd, 2014, the cotton industry met to discuss the increasing threat of sticky cotton on SJV cotton. • One outcome of that meeting of PCAs, growers, ginners & processors was – that early populations of whitefly are being missed – Surrounding areas are putting more whitefly population pressure on neighboring cotton fields • OUR GOAL TODAY IS TO ADDRESS THESE ISSUES Program

• Sticky Cotton – What is and Why we Should Care – Pete Goodell, UCCE IPM • Whitefly & aphid biology – Pete Goodell UCCE – IPM • Monitoring and Managing Whitefly – Dr. Larry Godfrey, Dept Entomology, UCD Sugar, The Sticky Source • What’s the problem? • What’s the source • Are all sugars the same? What’s the Problem?

• Producing Quality Cotton in the SJV is everything, • Quality in the lint characteristics but just as important, free from all contamination. • This is NOT an individual problem. One bad apple…… • Mills will blacklist: gins, states, regions, if they have had bad stickiness experience How Can We Think About Sticky Cotton?

Like Cotton Candy in the Hands of a Small Child! Remember trying to clean all the sticky spots off your child And everything with which they came in contact ? That is how this boll with sticky honeydew will interact with the precise machinery in the spinning mills Sticky Cotton Affects Spinning Mills!

Sugars Found on Cotton Lint

Hequet et al Plant Sugar • Always present and evenly distributed on fiber • Mainly glucose based, an be detected with titration • Tends to cause “Chronic” spinning problems, resulting in lower efficiency • Normal cleaning would be at end of shift, plant sugar issues require cleaning several times throughout shift • Will breakdown with storage over time but can result in yellowing • If detected – “aging” and mixing is best solution Insect Sugar

• Not always present • Not evenly distributed on fiber • Not glucose based • Cannot be detected with “Sugar Tests” • Sugars can be detected HPLC • Causes “Immediate” spinning problems • Will shut a mill down as 1 or 2 bales is enough to create massive problem Insect Sugar

Whitefly Aphid

Trehalulose & Melezitose Mainly Melezitose Melting Point of Sugars

250

200 C ° 150

100 Temperature Temperature 50

0 Temperature of Machines

60

50 C ° 40

30 Highest T Lowest T 20 Temperature Temperature

10

0 Card Drawing Roving Ring Rotor Front Roll Spinning Spinning Whiteflies and Aphids Can Create Sticky Cotton • To ensure our reputation for high quality cottons, whiteflies and aphids must be managed • Dr. Godfrey’s will focus on whitefly management while this presentation will focus on the biology of whitefly and aphid • Details of the sampling, treatment decisions and control approaches are incorporated in UC Pest Management Guidelines • www.ipm.ucanr.edu Management Begins with IPM IDEAS

• Identification • Determining population through scouting • Evaluating risk using established thresholds • Acting to manage using multiple approaches • Studying the results Sweet Potato Whitefly Bemisia tabaci Biotype B • Once known as Silverleaf (B. argentifolii) Greenhouse Whitefly

• Trialeurodes vaporariorum Banded Winged Whitefly

• Trialeurodes abutilonia Whitefly Life Cycle Whitefly Population Dynamics Whitefly Population Development

• Developmental thresholds established 1985 – Lower Development: 50° F – Upper Development: 90° F – Number DD required for generation: 569 • Average number of generations in:

16 – El Centro: 13.7 No. WF Generations 14 – Five Points: 8.8 12 Five Pts 10 El Centro

8

6

4

2

0 1-Jan 1-Feb1-Mar 1-Apr 1- 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec May 2000 Accumulated WF DD (50,90) Number of accumulated degree days 1800 between January and June 8th. 1600

1400 2009 1200 2010 1000 2011 Note 2012,2013, & 2014 have 800 2012 been the warmest 2013 600 2014 in the past 6 years 400 200 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun

3.50 Number of WF Generations 1/1 - 6/8 3.00

Number of possible generations 2.50 between January and June 8th. 2.00

1.50

1.00

0.50

0.00 2009 2010 2011 2012 2013 2014 Estimated Number of Generations Bemisia, 1/1 to 9/1, WSREC

No. Gen by Sept 1 8

7.5

7

6.5

6

5.5

5 Whitefly Damage • Direct damage to plants – Phloem feeder –Extract proteins from plant sap • Honeydew formation – Excess sugars passed –Accumulate on plant tissue –Sooty mold • Virus transmission SJV Management Scenarios

• Initial buildup – selective insecticides – July in most years – Low population but building – Control nymphs and adults with selective materials • Gradual Invasion by adults – Partially selective insecticides aimed at adults – August – No or few bolls open – Adults fly from melons, tomatoes, other sources? – Employ partially selective insecticides • Lint exposed – Managing with broad spectrum insecticides – September/October – Heavy migration pressure from other cotton fields, tomatoes, melons – Use synergized pyrethroid combinations • Consult UC Pest Management Guidelines for details – ipm.ucanr.edu Management Approaches

• Cultural Control – Limited to managing crops nearby to prevent movement and – Strive to defoliate ASAP – Manage water and nitrogen to avoid excess late season growth – No specific WF host plant resistance available Management Approaches

• Biological Control – Conserve natural enemies – Use selective insecticides in early phase of invasion – No single enemy is the answer, use them all – Main threat late adult migration which can overwhelm existing natural enemies Encarsia formosa

Eretmocerus sp

Chrysopa spp., Hippodamia convergens Geocoris spp. Chrysoperla spp Cotton Aphid Aphis gossypii • Can be present throughout the season • Wide host range • Two forms (morphs) – Light (yellow, green) – population builds more slowly – Dark (dark green, larger) – population can expand quickly • Asexual reproduction • Telescopic generations Biological Control

• Parasitic wasp , Lysiphlebus testaceipes, is a key population control agent • Lacewing, lady beetles and syrphid flies are more specific predators • Damsel, big eyed and minute pirate bugs will attack but are generalist predators attacking a wide variety of prey. Cultural Control • Strive to produce as early a crop as possible • Manage water and nitrogen to avoid excessive late season growth • No specific host plant resistance available, aphids tend to prefer hairy leaf varieties • Time and manage defoliation to maximize leaf drop using Nodes Above Crack Boll as your guide. • Avoid “regreening” or regrowth in top of plant Chemical Control

• Scout regularly • Examine the 5th leaf from • Use UC IPM Guidelines top of plant, same as WF • Watch for boll • Count and record number maturation and split and color (yellow or black). • Action threshold shifts • Before open bolls, 50/leaf quickly after boll opens • After boll opening, 5/leaf and lint becomes exposed • Use selective materials early Chemical Control

• Use selective insecticides during early in the season to conserve natural enemies • Rotate insecticide mode of actions to prevent development of insecticide resistance • Consult UC Pest Management Guidelines for details – ipm.ucanr.edu Concluding Remarks • Protect the lint from ALL contamination including honeydew • Once a region develops a poor reputation for quality, it “sticks” with you • Look early and look frequently for insect sources of contamination Thanks for Your Interest