CABI PEST AND DISEASE PHOTOGUIDE TO
Cacao disorders
KNOWLEDGE FOR LIFE Introduction
This photo booklet has been produced by the CABI-led Plantwise programme (www.plantwise.org) in collaboration with The International Permanent Working Group for Cocoa Pests and Diseases (INCOPED) and funded by Mondelēz International to aid extension officers and other plant health advisors in diagnosing the most common pests, diseases and abiotic problems of cacao around the world. The symptoms presented on a real plant sample can be compared with the photos in this guide to identify possible causes. The booklet is organized into two broad sections, one showing the common insect pests that attack the crop and the other showing the various symptoms of poor health. In the symptoms section, the images are arranged by plant part, with similar-looking symptoms displayed together. Some biotic and abiotic factors cause more than one type of symptom, so there may be multiple images in different parts of the photo booklet for a specific problem. The photos for a particular problem are cross-referenced to make it easy to find all the relevant photos. Contents
Sign or symptom Box #
Insects 1–29
Leaf 30–50
Pod 51–84
Stems 85–109
Root 110–113
Whole Plant 114–127 Conopomorpha cramerella Cocoa Pod Borer • • • Photo: CABI Active atnight resting position Antennae are verylongandsweptbackwards intheir at thetipofforewings Adult isasmall(7mm)brown mothwithyellowpatches INSECT 2 3 52 53 54 55 Asia, Oceania 56
BACK TO CONTENTS 1 Conopomorpha cramerella Cocoa Pod Borer • • • Photo: CABI Feeding causesdamageandsticking togetherofthebeans Late-instar larvaeare cream (10mmlong) First-instar larvaeare translucentwhite(1mmlong) INSECT 1 3 52 53 54 55 Asia, Oceania 56
BACK TO CONTENTS 2 Conopomorpha cramerella Cocoa Pod Borer • Photo: CABI 6-9 mmwide)thatcanbeseenin leaf litter Larvae pupateinpaleyellow,ovalcocoons(13-18mm longand INSECT 1 2 52 53 54 55 Asia, Oceania 56
BACK TO CONTENTS 3 Sahlbergella singularis Cocoa Mirid • • • • • • Photo: RBabin,CIRAD Adults can fly1-2km,this isthemainmechanism ofdispersal Legs (L) are long andthin Pronotum (P)is broader thanlong Eyes are prominent (E) Antennae (A)are longandthin with smallprotuberances onthebody Adults (left)are approx. 1cmlong,roughly oval, INSECT 5 58 59 98 Africa
BACK TO CONTENTS 4 Sahlbergella singularis Cocoa Mirid • • Photo: RBabin,CIRAD Nymphs are rounder andmore reddish incolourthantheadult There are 5nymphalstages INSECT 4 58 59 98 Africa
BACK TO CONTENTS 5 Distantiella theobroma Cocoa Mirid • • • • • • Photo: RBabin,CIRAD Adults can fly1-2km,which isthemaindispersal mechanism Legs (L) are andthick short Pronotum (P)is as broad aslong Antennae (A)are short Eyes (E)are small with smallprotuberances onthebody Adults (right)are approx. 1cmlong,roughly oval, INSECT 7 58 59 98 Africa
BACK TO CONTENTS 6 Distantiella theobroma Cocoa Mirid • • Photo: RBabin,CIRAD Nymphs are rounder andmore reddish incolourthantheadult There are 5nymphalstages(plusadult ontheright) INSECT 6 58 59 98 Africa
BACK TO CONTENTS 7 Monalonion spp. Cocoa Mirid • • Photo: DGopaulchan,CRC Reddish brown ororange Adults are activeduringtheday INSECT Central, America,SAmerica
BACK TO CONTENTS 8 Helopeltis antonii Cocoa MosquitoBug • Photo: ESulistyowati,ICCRI • • Helopeltis antonii Active duringtheday Adults are darkred orgreen tobrown-black INSECT andfeedinglesionsonacocoapod 10 60 Africa, Asia,Oceania 99 100
BACK TO CONTENTS 9 Helopeltis antonii Cocoa MosquitoBug • • Photo: ESulistyowati,ICCRI Pear-shaped withyellow-orange tobrown Five nymphalinstars INSECT 9 60 Africa, Asia,Oceania 99 100 10 BACK TO CONTENTS Various Mealybugs • • • • • Photo: Anon. Bottom right Planococcus kenyae Bottom leftPlanococcuscitri Top right Planococcuslilacinus Top leftFerrisia virgata mealybugs oncacao Morphology offourcommontypes offoliarfeeding INSECT 12 13 14 15 79 Worldwide 11 BACK TO CONTENTS Planococcus citri Citrus Mealybug • • • • • Photo: COlsen,USDAAPHISPPQ,Bugwood.org Short waxyfilaments canbeseenaroundShort theedges ofthebody P. citrihasacharacteristic faintgrey stripedowntheir backs white wax The bodyissegmented,yellowincolour andcoatedwith Approx. 1-3mm inlength Females are wingless,ovalandflattened INSECT 11
79 Worldwide 12 BACK TO CONTENTS Planococcus lilacinus Cocoa Mealybug • • Photo: POoi,CABI mealybugs Wider bodyshapeandmore rounded thanothersimilar (purple) coating Small, segmented,slowmovinginsects withadustywhite-lilac INSECT 11 79 Worldwide 13 BACK TO CONTENTS Ferrisia virgata Striped Mealybug • • • • Photo: GGoergen/IITA InsectMuseum Narrower bodyshapethan othersimilarmealybugs longitudinal stripes, longglassywaxthreads, a‘tail’ Unlike othermealybugs adultfemalehasapairofdark Live incoloniesusuallyonyoungtissue leaves, youngshootsandberries Small, segmented,slowmovingdusty whiteinsectsvisibleon INSECT 11 79 Worldwide 14 BACK TO CONTENTS Planococcus kenyae Kenyan Mealybug • • Photo: RReeder, CABI of theunderlying insect iseasiertosee They havelesswaxthanthecitrus mealybug andthecolour back oftheadultcompared toothersimilarmealybugs This mealybughasamore prominent central linedownthe INSECT 11 79 Africa 15 BACK TO CONTENTS Pseudococcus longispinus Long-tailed Mealybug • • Photo: JWLotz/Florida ofAgriculture Department andConsumerServices/Bugwood.org segment ofadult females Two long,waxyfilamentsprotruding from thelastabdominal stems, fruitsandalongtheveinson theundersideofleaves P. longispinusappearaswhite,waxymassesofmealybugs on INSECT 11 79 Worldwide 16 BACK TO CONTENTS Planococcoides njalensis West Africancocoamealybug • • • • • • Photo: FOro, UniversitéPéléforo-Gbon-Coulibaly An important mealybugvectorofcocoa swollenshootvirus(CSSV) inWestAn important Africa They occur increvices onleaves, shoots,barkandpods ground level Majority ofP. njalensiscanbefoundinthecanopy 3–4metres above from lightchocolate orreddish brown to lightyellow Body colourbeneaththewaxcoveringis generally pinkbutcanvary Broad andovalinshapeshowsdistinct segmentation Adult femalesare softbodiedandwingless INSECT 11
79 Africa 17 BACK TO CONTENTS Bathycoelia thalassina Stinkbug • • Photo: BOppong-Mensah,CABI Yellow togreen incolour Young stinkbugnymph INSECT 19 82 Africa 18 BACK TO CONTENTS Bathycoelia thalassina Stinkbug • Photo: RBateman,www.dropdata.org penetrate the pod cortex and causefeedinglesions penetrate thepodcortex Adult stinkbugshavelongfeeding stylets (2.2cm)thatcan INSECT 18 82 Africa 19 BACK TO CONTENTS Ephestia cautella Tropical Warehouse Moth • • • Photo: CSIRO, WikimediaCommons The wingspanis11-20mm Adults havegrey-brown wingswithvaguedarkermarkings Postharvest pestcasingdamagetocacaobeans INSECT 21 Worldwide 20 BACK TO CONTENTS Ephestia cautella Tropical Warehouse Moth • • • Photo: CSIRO, WikimediaCommons base ofeachhair There are smallbrown-black spotsdownthebodyat Larvae are 1.5-15 mminlength Postharvest pestcasingdamagetocacaobeans INSECT 20 Worldwide 21 BACK TO CONTENTS Araecerus fasciculatus Cocoa Weevil • • • • • Photo: GGoergen/IITA Benin particularly ifpreviouslyparticularly damaged bylarvae Adult feedingcauses irregular raggedpatterns ofdamage, Adults bore circular holeswhenthey emerge from thebeans Adult ismottleddark-brown (3-5mmlong) Cacao beansmaybehollowedout or tunnelledbythelarvae Postharvest pestcasingdamagetocacaobeans INSECT Worldwide 22 BACK TO CONTENTS Xyleborus spp. Ambrosia Beetles • • • • Photo: GJLenhard, Louisiana StateUniversity, Bugwood.org galleries inthe trunkand branches amounts of finewoodshavings (frass)when makingbreeding Beetles are attractedtodiseased plantsandproduce large of thebeetlesand cansurvivepassingthrough the gut Spores of C.cacaofunesta Vector ofCeratocystisWilt Female ambrosia beetles2.0-2.7mm,Males1.7-2.0mm INSECT maybecarrieduponthebodies Caribbean, CentralAmerica,SAmerica 101 115 23 BACK TO CONTENTS Termites • • • Photo: SBauer, USDAAgriculturalResearch Service,Bugwood.org reddish brown head They havewhite(translucent)bodies withawhiteto Similar insizeandgeneralappearance toants Small, soil-inhabiting,socialinsects INSECT 96 Worldwide 24 BACK TO CONTENTS Eulophonotus myrmeleon Stem Borer • • Photos: KFN’Guessanetal.(2014) larva exitingbore hole(inset) and darkwings Female mothhasared andblackbodywithabrown head INSECT Africa 25 BACK TO CONTENTS Zeuzera coffeae Stem Borer • • • Photo: DrAYakovlev, Flickr.com The wingsandabdomenalsohave darkspots Thorax colouriswhitewithfourblue-black spots Adult mothhasawingspan30-50 mm INSECT 27 26 Asia BACK TO CONTENTS Zeuzera spp. Stem Borer • • • • Photo: RBateman,www.dropdata.org Larvae bore intobranchesandthe trunk Younger larvaeare darkerincolour Orange tored incolour Larvae cangrow to50 mm INSECT 26 27 Asia BACK TO CONTENTS Glenea celia Shoot Borer • • Photo: BSale,Wikimedia.org and longantenna Easily recognisable from the bluecolourwithblackspots Adult femaleis10mmlong INSECT 29 28 Asia BACK TO CONTENTS Glenea spp. Shoot Borer • • Photo: RBateman,www.dropdata.org makes themeasilyrecognisable Larvae haveanenlarged flatsectionbehindthehead which Larvae bore into shootsandbranches INSECT Asia, Oceania 28 29 BACK TO CONTENTS Ceratobasidium theobromae Vascular StreakDie-Back (VSD) • • • • Photo: ADaymond,UniversityofReading Once the leaffallssymptoms developinadjacent leaves The leafisusually onthe2ndor3rd flushbehindthetip green approximately 2–5 mm indiameter“green islands” Chlorosis isnot completebutcontainsscattered patchesof single leaf Most characteristicearlysymptom isyellowing(chlorosis) ofa FUNGUS 31 32 94 95 Asia, Oceania 123 30 BACK TO CONTENTS Ceratobasidium theobromae Vascular StreakDie-Back (VSD) • • Photo: PKeane for severalweeks These infectedleavesremain attachedtothebranch necrosis (death)developsongreen leaves In Indonesiaothersymptomshave been seenwhere leaf FUNGUS 30 32 94 95 Asia, Oceania 123 31 BACK TO CONTENTS Ceratobasidium theobromae Vascular StreakDie-Back (VSD) • • Photo: PKeane Sporulation tendstooccurduringwet weather veins andpetioles(leafstalks) White fungalgrowth andspores produced oncracksintheleaf FUNGUS 30 31 94 95 Asia, Oceania 123 32 BACK TO CONTENTS Badnavirus Cacao SwollenShootVirusDisease(CSSVD) • • Photo: ODomfeh,CRIG Vectored bymealybugs ‘fernlike’ patternonsomecacaovarieties Vein clearing/yellowbandinginmature leaves,producing a VIRUS 11 16 17 34 35 51 92 Africa, SriLanka 116 33 BACK TO CONTENTS Badnavirus Cacao SwollenShootVirusDisease(CSSVD) • • • Photo: AWhetten,UWE Vectored bymealybugs Swelling ofthestemnodescanalso beseen Yellowing (chlorosis) orflecking/mottlingofmature leaves VIRUS 11 16 17 33 35 51 92 Africa, SriLanka 116 34 BACK TO CONTENTS Badnavirus Cacao SwollenShootVirusDisease(CSSVD) • • • Photo: Dzahini-Obiatey, CRIG,Ghana Vectored bymealybugs The red colourcandisappearastheleafmatures CSSV causingred veinbandinginyoung‘flush’leaves VIRUS 11 16 17 34 36 51 92 Africa, SriLanka 116 35 BACK TO CONTENTS Colletotrichum gloeosporioides Anthracnose • • • Photo: WPhillipsMora,CATIE leaving thebranches bare Eventually theleavesare completelydamagedandfalloff, Spots spread from theedgetocentre oftheleaves Dry, brown spotswith yellow edges FUNGUS 84 121 Worldwide 36 BACK TO CONTENTS Boron Deficiency • • Photo: IllustrationCWatts inEvansandMurray(1952) DEFICIENCY spiral twisting(b) Leaves become thickandbrittlewithcurlingand/or Young leavesare paleandreduced insize(a) Worldwide 37 BACK TO CONTENTS Calcium Deficiency • • • • Photo: IllustrationCWatts inEvansandMurray(1952) DEFICIENCY The unaffected area shows an oak-leavedpattern (b) necrosis ofolderleaves(b) he leaf. Necrotic areas merge intocontinuousmarginal Necrotic areas spread betweentheveinsfrom the edge oft growing point(a) Tip andmargins becomenecrotic anddie-backspreads from the Young leavesshowsmallwhitespots Worldwide 38 BACK TO CONTENTS Copper Deficiency • • • • Photo: IllustrationCWatts inEvansandMurray(1952) DEFICIENCY wedge shape from theapex towards themidrib (c) Collapsed tissues laterturnsbrown andformsa time (a,b) Tissue atthetipcollapsesandremains green forsome Young shootsfrequently lookwilted Young flushleavesare anormalshapebutsmallerinsize Worldwide 39 BACK TO CONTENTS Iron Deficiency • • • • Photo: IllustrationCWatts inEvansandMurray(1952) DEFICIENCY Older leaves oftenshowdrying around the edge (b) Symptoms lessprominent inleavesoftheprevious flush Drying ofthetip(b) leaf tissue(b) leaf tissue(a),orgreen veinswithpaleyellow/white Younger leaveshavedarkgreen veinsonpalegreen Worldwide 40 BACK TO CONTENTS Magnesium Deficiency • • • • Photo: IllustrationCWatts inEvansandMurray(1952) DEFICIENCY Unaffected areas are palergreen andforman oak-leavedpattern (b) necrotic margin (b) and islandsofnecrotic tissueoftenappearinadvance ofmain A brightyellowzone occursatthefront ofthenecrotic area necrosis onolderleaves(b) Areas of necrosis combineintoacontinuous marginal Necrotic areas occurbetween theveinsnearleafmargin (a) Worldwide 41 BACK TO CONTENTS Manganese Deficiency • • Photo: IllustrationCWatts inEvansandMurray(1952) DEFICIENCY necrosis occurs at thetipandmargins (b) The mainveinsare darkgreen againstpalebackground and chlorotic pattern around themidrib(a) Young leavesare paleyelloworyellow/green anddevelopa Worldwide 42 BACK TO CONTENTS Molybdenum Deficiency • • • Photo: IllustrationCWatts inEvansandMurray(1952) DEFICIENCY Later developingscorch/necrosis around theleafmargin (c) Developing mildchlorotic mottling(a,b) Young leavesare thinandtranslucent(a) Worldwide 43 BACK TO CONTENTS Nitrogen Deficiency • • • Photo: IllustrationCWatts inEvansandMurray(1952) DEFICIENCY Older leavesatthe basemayshowtipscorch (b,c) and petioleshaveanacuteanglewith stem Younger leaveshavelittleornogreen associatedwiththeveins Leaves pale/yellowish incolourandreduced insize(a) Worldwide 44 BACK TO CONTENTS Phosphorus Deficiency • • • Photo: IllustrationCWatts inEvansandMurray(1952) DEFICIENCY margin follows Mature leavesare paletowards tip andmargin, scorch ofthetip between theveins Young leavessmallerinsize,oftenwithpalegreen colouration Plants canbestunted Worldwide 45 BACK TO CONTENTS Potassium Deficiency • • • Photo: IllustrationCWatts inEvansandMurray(1952) DEFICIENCY Yellow zone ontheinneredgeofnecrotic zone joining togetheraround themargin (b) Leaves quickly becoming necrotic (a)withnecrotic areas Pale yellowareas formedbetweentheveinsnearleafmargin (a) Worldwide 46 BACK TO CONTENTS Sulphur Deficiency • • Photo: IllustrationCWatts inEvansandMurray(1952) DEFICIENCY with theveins,later becomingpaleyellow/green Leaves brightyellow atfirstwithnogreen associated but withnoreduction insize Leaves ofwhole plantare paleyellowishoryellow/green Worldwide 47 BACK TO CONTENTS Zinc Deficiency • • • • Photo: IllustrationCWatts inEvansandMurray(1952) DEFICIENCY of midrib and/oronthemain lateralveins(d) Larger leavesshowchlorotic patches inrows either side Small chlorotic patches canoccurbetweentheveins (b) wavy (a,b,c) Leaves are narrow inproportion tolengthandmargins are often Very youngleaveshavedarkveinletsandare inshape(a,b) distorted Worldwide 48 BACK TO CONTENTS Boron Toxicity • • Photo: IllustrationCWatts inEvansandMurray(1952) where wounds occur(b) Older leaveshavenecrotic margins andnecrotic areas green veins(a)laterdevelopingnecrotic tipsandmargins Younger leavesyellowandare cuppeddownwards with TOXICITY Worldwide 49 BACK TO CONTENTS Chloride Toxicity • • Photo: IllustrationCWatts inEvansandMurray(1952) of darkgreen andgrey (b) Tissues inadvanceofnecrotic areas are variousshades margin (a)quicklymerging to formanecrotic area Pale yellowareas developbetweentheveinsaround the TOXICITY Worldwide 50 BACK TO CONTENTS VIRUS 11 16 17 33 34 35 92 116 51 Cacao Swollen Shoot Virus Disease (CSSVD) Badnavirus Africa, Sri Lanka
Photo: K Kouakou, CNRA
• Abnormally shaped pod (right) from an infected tree compared to a pod from a healthy tree (left) • Vectored by mealybugs BACK TO CONTENTS INSECT 1 2 3 53 54 55 56 52 Cocoa Pod Borer Conopomorpha cramerella Asia, Oceania
Photo: M Rutherford, CABI
• Beans are seen clumped together and are difficult to remove from the pods after harvest • Beans may be discoloured (black), smaller, lighter in weight and have a flat shape BACK TO CONTENTS INSECT 1 2 3 52 54 55 56 53 Cocoa Pod Borer Conopomorpha cramerella Asia, Oceania
Photo: M Rutherford, CABI
• Larva of cocoa pod borer under silk membrane can be seen attached to pods (often in pod ridges) BACK TO CONTENTS INSECT 1 2 3 52 53 55 56 54 Cocoa Pod Borer Conopomorpha cramerella Asia, Oceania
Photo: CABI
• Pods ripen prematurely and unevenly BACK TO CONTENTS INSECT 1 2 3 52 53 54 56 55 Cocoa Pod Borer Conopomorpha cramerella Asia, Oceania
Photo: M Rutherford, CABI
• Larval entry (A) and exit holes (B) on pod BACK TO CONTENTS INSECT 1 2 3 52 53 54 55 56 Cocoa Pod Borer Conopomorpha cramerella Asia, Oceania
Photo: R Bateman, www.dropdata.org
• Internal pod damage by larva BACK TO CONTENTS INSECT 57 Cocoa Husk Borer Various Worldwide
Photo: E Cartier-Bresson
• Pod husk borer larvae feed on the husk of the pod • Damage to the pod allow entry of secondary fungal infection • Heavy infestation can cause severe damage to the pod and losses in bean yields BACK TO CONTENTS INSECT 4 5 6 7 59 58 Cocoa Mirids Sahlbergella singularis and Distantiella theobroma Africa
Photo: CRIG
• Feeding lesions on the pods appear as round black spots usually around the peduncle • When the pod lies against the stem mirids hide in the sheltered area and the feeding lesions are grouped on the area closest to the stem BACK TO CONTENTS INSECT 4 5 6 7 58 59 Cocoa Mirids Sahlbergella singularis and Distantiella theobroma Africa
Photo: R Babin, CIRAD
• Heavy infestations and feeding can cause malformation of pods BACK TO CONTENTS INSECT 9 10 99 100 60 Cocoa Mosquito Bug Helopeltis spp. Africa, Asia, Oceania
Photo: R Babin, CIRAD
• Typical damage of Helopeltis spp. on mature pods • Feeding lesions are small black spots scattered over the whole pod surface BACK TO CONTENTS FUNGUS 62 63 64 65 66 67 68 69 70 61 Frosty Pod Rot Moniliophthora roreri Central America, S America, Jamaica
Photo: J Crozier, CABI
• A young pod showing deformations (bumpy swellings) on the surface • This is an early symptom to recognise the disease BACK TO CONTENTS FUNGUS 61 63 64 65 66 67 68 69 70 62 Frosty Pod Rot Moniliophthora roreri Central America, S America, Jamaica
Photo: H Morales, CABI
• Young pod showing necrosis of the inner surface of the pod and infection spreading to the beans BACK TO CONTENTS FUNGUS 61 62 64 65 66 67 68 69 70 63 Frosty Pod Rot Moniliophthora roreri Central America, S America, Jamaica
Photo: H Morales, CABI
• Young pod with swellings and irregular brown necrotic lesions on the surface BACK TO CONTENTS FUNGUS 61 62 63 65 66 67 68 69 70 64 Frosty Pod Rot Moniliophthora roreri Central America, S America, Jamaica
Photo: H Morales, CABI
• Premature ripening can be an indication of infection BACK TO CONTENTS FUNGUS 61 62 63 64 66 67 68 69 70 65 Frosty Pod Rot Moniliophthora roreri Central America, S America, Jamaica
Photo: H Morales, CABI
• An indication of infection is the appearance of brown “oily” on the pod surface • Premature ripening of the pod around the “oily” spot BACK TO CONTENTS FUNGUS 61 62 63 64 65 67 68 69 70 66 Frosty Pod Rot Moniliophthora roreri Central America, S America, Jamaica
Photo: J Crozier, CABI
• Irregular brown necrotic lesion appearing on pod • These lesions spread rapidly across the pod • This symptom is similar to those produced by Witches’ Broom and Black Pod BACK TO CONTENTS FUNGUS 61 62 63 64 65 66 68 69 70 67 Frosty Pod Rot Moniliophthora roreri Central America, S America, Jamaica
Photo: H Morales, CABI
• White fungal mycelium develops within the brown lesion on the pod surface BACK TO CONTENTS FUNGUS 61 62 63 64 65 66 67 69 70 68 Frosty Pod Rot Moniliophthora roreri Central America, S America, Jamaica
Photo: J Crozier, CABI
• Later stage of the disease on more mature pods • A thick layer of powdery cream/light brown coloured spores is produced on the mycelial mat as it develops on the necrotic area • This is the most distinctive symptom to recognise the disease BACK TO CONTENTS FUNGUS 61 62 63 64 65 66 67 68 70 69 Frosty Pod Rot Moniliophthora roreri Central America, S America, Jamaica
Photo: H Morales, CABI
• Internal rot of the pod • Extensive internal breakdown of the pod and destruction of the beans • Beans become a soft, watery mass attached to the pod wall • Similar to symptoms caused by Witches’ Broom BACK TO CONTENTS FUNGUS 61 62 63 64 65 66 67 68 69 70 Frosty Pod Rot Moniliophthora roreri Central America, S America, Jamaica
Photo: H Morales, CABI
• Pods gradually shrink and dry becoming hard and mummified • The hard cream/brown covering on the pod is the remains of the fungus • Infected mummified pods stay attached to the tree BACK TO CONTENTS FUNGUS 72 73 85 86 87 88 89 117 71 Witches’ Broom Moniliophthora perniciosa Caribbean, S America, Panama
Photo: J Crozier, CABI
• Irregular brown necrotic lesion on the pod • These lesions spread rapidly across the pod • This symptom is similar to those produced by Frosty Pod Rot and Black Pod BACK TO CONTENTS FUNGUS 71 73 85 86 87 88 89 117 72 Witches’ Broom Moniliophthora perniciosa Caribbean, S America, Panama
Photo: J Crozier, CABI
• Internal pod damage, watery rot of beans and internal pod tissue • Beans become a soft, watery mass attached to the pod wall • Similar to symptoms caused by Frosty Pod Rot BACK TO CONTENTS FUNGUS 71 72 85 86 87 88 89 117 73 Witches’ Broom Moniliophthora perniciosa Caribbean, S America, Panama
Photo: J Crozier, CABI
• “Strawberry” shaped pods also known as chirimoyas are often produced on infected cushions • These deformed pods contain no beans BACK TO CONTENTS WATER MOULD 75 76 77 93 74 Black Pod Disease Phytophthora megakarya Africa
Photo: CABI
• Brown lesion on pod surface • Brown lesions usually appear on the top or bottom of the pod • They expand rapidly over the pod in a week or two • A sparse covering of white spores appear on the brown lesion
• A “fishy” odour can be detected BACK TO CONTENTS • Can be difficult to distinguish between different Phytophthora species WATER MOULD 74 76 77 93 75 Black Pod Disease Phytophthora palmivora Worldwide
Photo: S Thomas, CABI
• Brown lesion on pod surface • Brown lesions usually appear on the top or bottom of the pod • They expand rapidly and sometimes a sparse covering of white spores appear on the brown lesion • A “fishy” odour can be detected BACK TO CONTENTS • Can be difficult to distinguish between different Phytophthora species WATER MOULD 74 75 77 93 76 Black Pod Disease Phytophthora spp. Worldwide
Photo: S Thomas, CABI
• Mummified pod in the late stages of Phytophthora spp. infection • The lesion covers the pod and is covered in spores • The pod dries but remains attached to the tree BACK TO CONTENTS WATER MOULD 74 75 76 93 77 Black Pod Disease Phytophthora spp. Worldwide
Photo: W Phillips-Mora, CATIE
• The infection spreads from the outside of the pod into the internal tissues • The beans eventually become infected and rot • Depending on the age of the pod when infected the beans can remain healthy until harvest BACK TO CONTENTS UNKNOWN 78 Warty Pod Unknown Africa
Photo: B Oppong-Mensah, CABI
• Brown lesions and protrusions/swellings (warts) on the pod surface • Damage occurs only to the pod and the beans remain healthy BACK TO CONTENTS INSECT 11 12 13 14 15 16 17 79 Mealybugs Worldwide
Photo: E Hidalgo, CABI
• Cacao pod with mealybug infestation • Mealybugs cluster between the ridges of the cacao pod BACK TO CONTENTS FUNGUS 80 Lasiodiplodia Pod Rot Lasiodiplodia theobromae Africa
Photo: B Oppong-Mensah, CABI
• Infection appears as dark brown to black spots which spreads rapidly to cover the pod creating a “charcoal pod” • Infection occurs on wounded or stressed pod • Cacao pod covered in sooty black fungal conidia BACK TO CONTENTS MAMMAL 81 Mammal Damage Rattus spp. Worldwide
Photo: PR Brown, ACIAR
• Pods damaged by rats BACK TO CONTENTS INSECT 18 19 82 Stinkbug Bathycoelia thalassina Africa
Photo: J Crozier, CABI
• Pod deformation caused by Stinkbugs feeding on a young pod BACK TO CONTENTS FUNGUS 83 Mealy Pod Rot Trachyspaera fructigena Africa
Photo: AY Akrofi, CRIG
• Cacao pod showing dense white spore mass later becoming pinkish/brown BACK TO CONTENTS FUNGUS 36 121 84 Anthracnose Colletotrichum gloeosporioides Worldwide
Photo: W Phillips-Mora, CATIE
• Diseased pods develop brown lesions • White mycelia appear on the lesions, which turn pink when the fungus produces spores • The diseased fruits eventually turn black BACK TO CONTENTS FUNGUS 71 72 73 86 87 88 89 117 85 Witches’ Broom Moniliophthora perniciosa Caribbean, S America, Panama
Photo: H Evans, CABI
• Terminal broom, with swollen stem BACK TO CONTENTS FUNGUS 71 72 73 85 87 88 89 117 86 Witches’ Broom Moniliophthora perniciosa Caribbean, S America, Panama
Photo: H Evans, CABI
• Infected flower cushion with flower showing swollen stems BACK TO CONTENTS FUNGUS 71 72 73 85 86 88 89 117 87 Witches’ Broom Moniliophthora perniciosa Caribbean, S America, Panama
Photo: T Peters, Ministry of Agriculture, Grenada
• Cushion broom growing from a flower cushion BACK TO CONTENTS FUNGUS 71 72 73 85 86 87 89 117 88 Witches’ Broom Moniliophthora perniciosa Caribbean, S America, Panama
Photos: J Crozier, CABI (main), R Reeder, CABI (inset)
• Dried brooms with small pink fruiting bodies • Close-up of a fruiting body (inset) BACK TO CONTENTS FUNGUS 71 72 73 85 86 87 88 117 89 Witches’ Broom Moniliophthora perniciosa Caribbean, S America, Panama
Photo: H Evans, CABI
• Proliferation of shoots on a branch producing a characteristic witches’ broom with many swollen stems growing from a single point BACK TO CONTENTS FUNGUS 120 90 White Thread Blight Marasmiellus scandens Worldwide
Photo: AY Akrofi, CRIG
• Strands of white thread fungus on cacao branch BACK TO CONTENTS FUNGUS 120 91 Horse Hair Blight Marasmius crinis-equi Africa, Asia, Caribbean, Oceania
Photo: CABI
• Strands of black thread fungus growing over a cacao branches and leaves BACK TO CONTENTS VIRUS 11 16 17 33 34 35 51 116 92 Cacao Swollen Shoot Virus Disease (CSSVD) Badnavirus Africa, Sri Lanka
Photo: E Muller, CIRAD
• Characteristic swollen choupons growing from the stem of an infected plant • Vectored by mealybugs BACK TO CONTENTS WATER MOULD 74 75 76 77 93 Stem Canker Phytophthora spp. Worldwide
Photos: CABI (top), W Phillips-Mora, CATIE (bottom)
• The canker appears as a rusty-brown area on the bark of the stem, often with a sticky red gum (exudate) (top) • When the bark is scraped away a reddish lesion can be seen on the tissue below (bottom) BACK TO CONTENTS FUNGUS 30 31 32 95 123 94 Vascular Streak Die-Back (VSD) Ceratobasidium theobromae Asia, Oceania
Photos: CABI
• Rusty red staining seen inside the infected stem with comparison of healthy stem • When a leaf is removed and the surface of the leaf scars (where leaves were joined to the stem) is scraped away with a fingernail, three black spots are visible (inset) BACK TO CONTENTS FUNGUS 30 31 32 94 123 95 Vascular Streak Die-Back (VSD) Ceratobasidium theobromae Asia, Oceania
Photo: P Keane
• The most characteristic initial symptom is yellowing (chlorosis) of a single leaf, usually on the second or third flush behind the tip • The Branch continues to grow normally beyond point of infection BACK TO CONTENTS INSECT 24 96 Termites Worldwide
Photo: J Vos, CABI
• Typical damage to cacao tree caused by termites • Termites can form colonies within the trunk or large branches of the tree • Damage to the living wood can cause the death of the tree BACK TO CONTENTS INSECT 4 5 6 7 97 Cocoa Mirids Sahlbergella singularis and Distantiella theobroma Africa
Photo: R Babin, CIRAD
• Black elongated feeding lesions on a young shoot BACK TO CONTENTS INSECT 4 5 6 7 98 Cocoa Mirids Sahlbergella singularis and Distantiella theobroma Africa
Photo: R Babin, CIRAD
• A canker on the bark of a young branch caused by mirid feeding BACK TO CONTENTS INSECT 9 10 60 100 99 Cocoa Mosquito Bug Helopeltis spp. Africa, Asia, Oceania
Photo: E Sulistyowati, ICCRI
• Small black elongated feeding lesions on a young shoot • Necrosis of the tissue causes drying of the shoot tip and dieback BACK TO CONTENTS INSECT 9 10 60 99 100 Cocoa Mosquito Bug Helopeltis spp. Africa, Asia, Oceania
Photo: R Babin, CIRAD
• Feeding lesions develop into cankers (arrow) and can result in death of the bud BACK TO CONTENTS FUNGUS 23 115 101 Ceratocystis Wilt Disease of Cacao Ceratocystis cacaofunesta Caribbean, Central America, S America
Photos: TC Harrington, Iowa State University (main), C. Suárez-Capello, UTEQ (inset)
• Characteristic discoloration of internal tissues of stem • Close up of the fungal fruiting bodies (perithecia) on cacao xylem tissue (inset) • Can be vectored by ambrosia beetles (Xyleborus spp.) which burrow into the cacao stem and spread the fungus BACK TO CONTENTS FUNGUS 118 102 Verticillium Wilt Verticillium dahliae Worldwide
Photo: E Boa, University of Aberdeen
• Internal symptoms showing blackening of the infected vessels in the wood of the stem BACK TO CONTENTS INSECT 25 103 Stem Borer Eulophonotus myrmeleon Africa
Photo: J Crozier, CABI
• Borehole in the cacao trunk created by the larva BACK TO CONTENTS FUNGUS 104 Pink Disease Erythricium salmonicolor Worldwide
Photo: AY Akrofi, CRIG
• Dieback of the infected branches with leaves turning brown • The branches are covered in pink to salmon coloured (pale orange) fungal growth BACK TO CONTENTS UNKNOWN 105 Lobular Gall Central America, S America
Photo: D Parra, Milagro State University
• Lobular gall has rounded appearance • No buds or flowers BACK TO CONTENTS UNKNOWN 106 Knob Gall Central America, S America
Photo: S Pérez-Martínez, Milagro State University
• Hard woody smooth swelling approx. 2cm in diameter BACK TO CONTENTS UNKNOWN 107 Fan Gall Central America, S America
Photo: R Rumbos, Milagro State University
• Stem-like growths develop in the shape of a fan BACK TO CONTENTS UNKNOWN 108 Flowery Gall Central America, S America
Photo: D Sosa, Milagro State University
• Many closely packed flowers are produced throughout the season BACK TO CONTENTS FUNGUS 109 Green Point Gall Albonectria rigidiuscula Central America, S America
Photo: S Pérez-Martínez, Milagro State University
• Swollen flower cushions • Numerous tiny shoots are produced that do not develop into normal flowers • Buds remain green and unopened, giving the appearance of “green points” BACK TO CONTENTS FUNGUS 110 Black Root Rot Rosellinia pepo Worldwide
Photo: GM ten Hoopen, CIRAD
• Rosellinia pepo attacks cacao roots • White mycelial fans can be seen under the root bark BACK TO CONTENTS FUNGUS 111 Armillaria Root Rot Armillaria mellea Worldwide
Photo: JJ Guillaumin, CABI Plantwise (left), R Reeder, CABI (right)
• Fruiting bodies of A. mellea at the base of the trunk is a sign of the later stages of the disease (a) • White fungal mycelium can be seen growing under the dark (b) • If this is seen the tree will be heavily infected and will die BACK TO CONTENTS FUNGUS 112 White Root Disease (on rubber tree) Rigidoporus lignosus Worldwide
Photo: J Crozier, CABI
• Minor disease of cacao • White fungal mycelia have a string like appearance and age to an orange-red colour • Fruiting bodies (large brackets fungi) can be seen after death BACK TO CONTENTS FUNGUS 119 113 Brown Root Disease Phellinus noxius Africa, Asia, Caribbean, Central America
Photo: B Ritchie, CABI
• Cacao trunk showing brown encrustation at the collar/base of the tree BACK TO CONTENTS INSECT 4 5 6 7 114 Cocoa Mirids Sahlbergella singularis and Distantiella theobromaAfrica
Photo: R Babin, CIRAD
• Extensive feeding can cause the leaves to dry, turn brown and fall • Where this has occurred the trees are sometimes described as ‘stag-headed’ trees BACK TO CONTENTS FUNGUS 23 101 115 Ceratocystis Wilt Disease of Cacao Ceratocystis cacaofunesta Caribbean, Central America, S America
Photo: TC Harrington, Iowa State University
• The leaves become limp and eventually dry and turn brown • These symptoms may be seen initially on only one side or part of the tree • Eventually the entire tree will be affected and die, although brown leaves may remain attached to the branches • Can be vectored by ambrosia beetles (Xyleborus spp.) BACK TO CONTENTS VIRUS 11 16 17 33 34 35 51 92 116 Cacao Swollen Shoot Virus Disease (CSSVD) Badnavirus Africa, Sri Lanka
Photo: E Muller, CIRAD
• Leaves gradually turn yellow and fall • The branches dry and turn brown from the tip (dieback) • The tree can eventually die BACK TO CONTENTS FUNGUS 71 72 73 85 86 87 88 89 117 Witches’ Broom Moniliophthora perniciosa Caribbean, S America, Panama
Photo: J Crozier, CABI
• Terminal broom on a cacao seedling • The stem and side shoots are abnormally swollen BACK TO CONTENTS FUNGUS 102 118 Verticillium Wilt Verticillium dahliae Worldwide
Photo: E Boa, University of Aberdeen
• Aerial symptoms showing chlorosis and drying of the leaves BACK TO CONTENTS FUNGUS 113 119 Brown Root Disease Phellinus noxius Africa, Asia, Caribbean, Central America
Photo: Anon., CABI CPC
• Wilting and drying of the leaves caused by damage to the root system BACK TO CONTENTS FUNGUS 90 91 120 Thread Blight Marasmius scandens Worldwide
Photo: AY Akrofi, CRIG
• Dead leaves held in position by the thread fungus BACK TO CONTENTS FUNGUS 34 84 121 Anthracnose Colletotrichum gloeosporioides Worldwide
Photo: W Phillips-Mora, CATIE
• The affected leaves dry and fall from the tree leaving only the bare branches BACK TO CONTENTS PARASITE 122 Mistletoe Tapinanthus sp. Worldwide
Photo: M. Schmidt, Wikimedia Commons
• Mistletoe with red/pink tubular flowers BACK TO CONTENTS FUNGUS 30 31 32 94 95 123 Vascular Streak Die-Back (VSD) Ceratobasidium theobromae Asia
Photo: P Keane
• Necrotic leaves develop on infected trees BACK TO CONTENTS EPIPHYTE 124 Monarch Fern, Wart Fern Phymatosorus scolopendria Africa
Photo: Aka Aka Romain, CNRA
• Rhizomatous fern with pinnately lobed leaves • Deeply sunken sori (structures producing the spores) on the lower surface of the fronds that result in wart-like bumps on the upper surface BACK TO CONTENTS EPIPHYTE 125 Orchid Angraecum bracteosum Africa
Photo: Aka Aka Romain, CNRA
• Leaves are leathery, bright green, 10 to 30 cm long and 2 to 4 cm wide • Flower stalks are shorter than leaves are born at the base of the plant • 5 to 10 white flowers BACK TO CONTENTS EPIPHYTE 126 Fishtail Fern Microsorium punctatum Africa
Photo: Aka Aka Romain, CNRA
• Large simple fronds with minute sori (structures producing the spores) that are scattered over the lower surface BACK TO CONTENTS EPIPHYTE 127 Wax Orchid Diaphananthe bidens Africa
Photo: Aka Aka Romain, CNRA
• Elongated hanging stems often up to 1m long with numerous aerial roots • Numerous pendulous salmon-coloured flowers with an unpleasant smell BACK TO CONTENTS Contact us
Africa Ghana CABI, CSIR Campus, No. 6 Agostino Neto Road Airport Residential Area, P. O. Box CT 8630, Cantonments Accra, Ghana T: +233 (0)302 797 202 E: [email protected]
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