The Rhinoceros Beetle Oryctes agamemnon arabicus in ... - Iresa

Review ArticleThe Rhinoceros Beetle Oryctes agamemnon arabicus inTunisia: Current Challenge and Future ManagementPerspectivesRasmi Soltani, Institut Supérieur Agronomique de Chott-Mariem, 4042 Sousse,Tunisia__________________________________________________________________________ABSTRACTSoltani R. 2010. The rhinoceros beetle Oryctes agamemnon arabicus in Tunisia: Currentchallenge and future management perspectives. Tunisian Journal of Plant Protection 5: 179-193.Oryctes agamemnon arabicus was signaled in the oases of Southwest Tunisia in 1995, its only hostplantis date palm tree (Phoenix dactylifera). Favorable development sites are the standing alive palmtree with its different parts. Female laid about 27 eggs. Adults fly at night and during day they shelterin their development sites. They feed occasionally on the juice extracted from respiratory roots. Theirroles are limited to reproduction and dispersion of the species on short distances. Larvae stand as theharmful stages of the species and none the adults. Larvae damages affect different levels of the tree:respiratory roots, superficial part of stem (fibrilium, stem bark and midrib) and the lower part of thecrown, which are the breeding sites of the immature stages. The most severe damage is related torespiratory roots, basal support of the palm tree, and secondary to crown periphery. Management of thespecies is above all preventive targeting mainly the breeding sites to reduce population. Quarantinemeasures by the restriction of offshoots movement impede the spread of the pest to new zones, culturaltechniques target the control and the destruction of development sites and traps of different type attractadults. All these methods reduce enormously the population inside plantations.Keywords: Damages, date palm, distribution, life cycle, management, Oryctes agamemnon arabicus,Tunisia.__________________________________________________________________________INTRODUCTIONDate palms, Phoenix dactylifera, areconsidered as one of the mosteconomically important fruit trees in Arabworld. These trees and their fruits aresubject to depredation by several seriousinsect pests (17). Among these insects,the genus Oryctes (Coleoptera:Sacarabaeidae) was represented byseveral species in date palm orchards ofmany Arabian countries as O. elegans, O.Corresponding author: Rasmi SoltaniEmail: soltani_rasmi@yahoo.comAccepted for publication 19 October 2010agamemnon and O. rhinoceros (1); all ofthem known as rhinoceros beetle. InArabian Peninsula, O. agamemnon iswidespread in Gulf countries as Kingdomof Saudi Arabia, United Arab Emirates,Sultanate of Oman (1), and recently inTunisia (6) where its mainly registeredhost is date palm tree.Historically, O. agmemnon arabicuswas accidentally introduced in Tunisia forthe first time at the end of 70’s decadefrom the oasis of United Arab Emirates(13) into the oases of Mrah Lahouarbelonging to the governorate of Tozeur(6), and this as part of varietal exchangeTunisian Journal of Plant Protection 179 Vol. 5, No. 2, 2010

etween both countries. Closely linked topalm tree, it stands as the only registeredspecies of the genus Oryctes in someplantations of Southwest Tunisia (14).However, from its introduction tothe first report of its severe damage,expressed by the sudden collapse of manyproductive palm trees in 1995, O.agamemnon arabicus populations haveconsiderably grown up and this specieshas become a major pest of date palm treein this region. Few research studies arefocused in this species which threatincreases each year in infested oases:despite this danger; no serious controlprograms were set up against this beetle(14).The aim of this paper is to develop amanagement strategy based on fieldstudies conducted during the last fifteenyears, to fight O. agamemnon arabicus indate palm plantations of SouthwestTunisia.INSECT DESCRIPTIONAdult of O. agamemnon arabicus arestocky, stout, black or reddish black incolor with shining aspect. They measure30-57 mm in length and 14-21 mm inbreadth. The male is characterized by acurved cephalic horn and a largedepression on the pronotum (Fig. 1), bothcharacters are rudimentary and sometimesabsent on female. The pygidium isclothed by reddish brown hairs which aremore densely in female than male (13).Fig. 1. Holometabolous life cycle of Oryctes agamemnon arabicus and anexample of damage on the respiratory root parts of date palm tree (13).After eggs hatching, life cyclecompleted through three distinguishlarval stages and a pupal period. At fulldevelopment, length of larva of thirdstage, which is the most destructive in thefield, can exceed 90 mm (13).Current distributionDelimiting surveys performed in2006 indicated that the infestation wasrestricted to some oases of extremeTunisian Journal of Plant Protection 180 Vol. 5, No. 2, 2010

Southwest, from Tozeur and Kebiligovernorates (Fig. 2), and permitted alsoto mark out the historical spread of thespecies in this zone. Based on thecollected data, the historical spread of O.agamemnon arabicus was characterizedby two distinguished periods (14).Fig. 2. Geographical localization of the date palm oases in Southwest Tunisia (Djerid and Nefzaoua) (satellite photo,Google Earth).Before 1987, the spread of thisspecies was limited to Mrah Lahouaroases (387 ha) situated 5 Km in the Westof Tozeur town just on the North edge ofChott El Djerid (F1 in Fig. 3). However,initially introduced in little numbers (15larvae of third stage maximum), adultbeetles of first generations secured bytheir reproductive activity, the growth ofthe population and then its continuity andperpetuation in this new environment. Inaddition, adults, the only mobile andobserved stage out of the palm tree,assure the local and progressive spread ofthe pest between adjacent or borderedoases. Infestation reached the oasis ofDhraa El Janoubi located at 100 m in theWest of Mrah Lahouar and which cover200 ha. So, preliminary and based on thisinformation, it is important to mentionthat flight activity can be considered asthe most likely method of spread on shortdistance both within and betweenadjacent date palm plantations (14).Tunisian Journal of Plant Protection 181 Vol. 5, No. 2, 2010

Fig. 3. Distribution of O. agamemnon arabicus in the oases of Djerid zone (Tozeur): F 1: Mrah Lahouarand Dhraa El Janoubi, F 2: Ibn Chabbat, F 3: Dhafria, F 4: El Oudia I et II (satellite photo, Google Earth).After 1987, the lack of necessaryprimary plant material to achieve theplantation of Ibn Chabbat oases (F 2 inFig. 3), located 5 Km in the North ofMrah Lahouar and in South of Chott ElGharsa, leaded to use offshoots originatedfrom infested oases of Mrah Lahouar.This action permitted the spread of O.agamemnon arabicus between distantoases both in intra- and inter- regionallevel. In early 90’s, the same caseoccurred in the five localities of RjimMaatoug zone (1434.5 ha) located in theextreme Southwest of Kebili governorateand approximately 8 Km on the Southedges of Chott El Djerid (F in Fig. 4), thelack of offshoots in Kebili oases imposedthe use of offshoots originated from IbnChabbat oases (800 ha), both to continuethe plantation process and to replace thelacks which favored more pest spread.During the 90’s decade and from IbnChabbat oases, the major site of thespread, O. agamemnon arabicus reachedthe oases of El Oudia (40 ha) and ElDhafria (250 ha) both situated in theNorth of Tozeur governorate (F 3 and F 4 inFig. 3). Thus, the most likely mode ofspread between regions and distantplantations is with offshoots removedfrom infested plantations (14).Tunisian Journal of Plant Protection 182 Vol. 5, No. 2, 2010

Fig. 4. Distribution of O. agamemnon arabicus in the oases of Nefzaoua (Kebili): Rjim Maatoug zone (F)constitute the only infested zone (satellite photo, Google Earth).Many biotic and abiotic factors havecontributed to the spread of O.agamemnon arabicus. In fact, during the15 years elapsed between its introductionand its first report, favorable conditionsexpressed by adequate regional climate,abundance of food resources, absence ofnatural organisms (predators, parasitoidsand micro-organisms) that regulate thepopulation and time (years) allowing pestacclimatization to local conditions.Therefore, the pest reproduces rapidlyand outbreaks of its populations occurred.The biotic potential of O. agamemnonarabicus may be considered as one of themajor factors involved in its populationexplosion (14).All these conditions were enforced by theignorance of the species usually confusedwith other white grubs and thiscontributed mainly to its establishmentand spread. As a result, it became a realthreat to date palm trees. Actually,surveys estimated that the beetles affectedabout 3113.5 ha (Table 1) i.e., almost10%, of the total area of palm trees inTunisia (14).Table 1. Distribution of O. agamemnon arabicus in the oases of Southwest TunisiaGovernorate of Tozeur Governorate of Kebili (Rjim Maatoug zone)Locality Area (ha) Locality Area (ha)Mrah Lahouar 389 Rjim Maatoug 1 300Edhraa El Janoubi 200 Ferdaous 1 360Ibn Chabbat 800 Ferdaous 2 349Ed Hafria 250 Nasr 1 281.5El Oudia 40 Nasr 2 144 TotalTotal 1679 - 1434.53113.5haTunisian Journal of Plant Protection 183 Vol. 5, No. 2, 2010

DEVELOPMENT SITESThe availability of development orbreeding sites and the knowledge of theirnature and quality are determinant in theexistence of any insect population in agiven area. Indifferently of the infestedoasis in Southwest Tunisia, it has beenfound that the breeding sites of O.agamemnon arabicus are the same both inthe Djerid and Rjim Maatoug zones. Allthe stages develop in live standing palmtrees. The large number of beetles, eggsand larvae were collected from respiratoryroots both on the ground and in the aerialpart, on the external dead wood throughthe stem as the matrixes of fibrilium, thebark of stem and basal part of dry petioles(13, 14, 15).In Oman, O. agamemnon arabicus isconsidered as a fruit stalk borer whichlarvae are usually found inside the deadand weaken offshoots. In Saudi Arabia,larvae of O. elegans were found betweenthe frond bases and trunks (1). However,the most favored breeding sites for O.rhinoceros in Pacific area are deadstanding palms which die from old age,dead coconut trunks and stumps, anddecaying cocoa pod humus (2, 16).As with all beetles, larvae of O.agamemnon arabicus hatch from eggs anddevelop into nymphae, and theseultimately develop into adult beetles. Eggsare deposited directly on the area of futuretarget. However, female burrows to lay theeggs singly 5 to 10 cm below the surfacebetween fibrous of respiratory roots,through the stem eggs are laid betweentough layers. In both cases and in newtargeted place, female chewed and reducethe fibrous roots or the matrixes offibrilium on small granules used to preparechipboard of firm material where eggs arelaid. However, when firm material exists,eggs are laid at intervals along the tunnelmade in it. Each female lays at mean 27eggs in single or several clutches (14).Favored breeding sites are standingalive date palm trees in the goodentertained oases, weakened palms areless attacked than vigorous ones. In thezone of Tozeur, where the species firstlyappeared, targeted parts of standingvigorous palm trees are preferred tounhealthy and dead standing ones (13).DAMAGES, THREAT ANDECONOMIC IMPORTANCEIn Southwest Tunisia, O.agamemnon arabicus was localizedinside plantations of less than 30 yearsold and damage caused by this pest, areirreversible, particularly in respiratoryroots part, and may result in one of thefollowing symptoms, perceived throughsight, depending upon the stage ofinfestation (14):i) Occurrence of chewed planttissues on the ground beside the attackedside and on the upper surface of toughlayers,ii) Weakened bases of fibriliummatrixes and dry petioles made them easyto pull up,iii) Heavily attacks on offshootslinked to mother plant let them partiallydry with wrinkled aspects of palms.Damages are localized from thebottom to the top of the plant on therespiratory roots, external components ofthe stem and the basal levels of old greenpalms. Larvae of O. agamemnon arabicusconstitute the mainly harmful stages (14)and not the adult beetle like for O.rhinoceros (2, 3, 12, 16) and O. elegans (1,11). The concealed nature of the pestmakes detection of infested palms adifficult task.In respiratory roots, larvae move bycutting into fibrous roots. Through thestem, matrixes of fibrilium, frond midribsand stem bark are the interested part ofattack and larvae are never seen inside thestem. Basal part of crown, represented byTunisian Journal of Plant Protection 184 Vol. 5, No. 2, 2010

the fourth oldest floor of green palms,was also infested by this pest but, greenpalms are not attacked and concernedparts are mainly matrixes of fibrilium andstem barks. Larvae move by feeding onthe attacked tissues where they cut anddig tunnels. It is important to mention thatindifferently from the level of attackseach larva dig its own tunnel (14).The most important danger ofdamage appears on the attack ofrespiratory roots which represent thebasal support of the palm. In this part andin late stage of infestation, after severalsubsequent years of attacks, larvalgalleries can overlap and interpenetrate.This leads to most severe damages: theformation of a hole of importantdimensions in roots. Thus, the plant basebecomes unbalanced by the weakening ofits support, and, consequently, the risk ofits sudden collapse increases even undermoderate wind. Happily, palms cansupport pest attacks for several years yetfor more than two decades depending onthe two next linked parameters: therepetitive attacks and the yearly registeredpopulation of larvae. This slow damageexpression constitutes a positive point infavor of palms which can be exploited tosave/cure infested trees using severalcontrol methods if infestation wasdetected at early stage (14).Attacks were also registeredlaterally between fibrous roots at 40 cmfrom the stem. However, risks from thespecies were increased when offshootstufts developed at the base of the tree; thisplace constitutes the most preferential siteto females’ beetle for eggs deposition (13,14, 15).Stem is covered for several yearswith the bases of the old dry fronds(matrixes of fibrilium and midrib),making it rough, but with age these basesweather and the trunk becomes smootherwith visible scars of the bases (17).Attacks through different parts of stemare not harmful to palm trees becauselarvae bore into dead parts withoutaffecting the tree vital function. Eggs arelaid between reduced parts of thematrixes of fibrilium located between theinterior face of midrib and stem bark.Their number can not exceed five inmaximum. After eggs hatching, larvaebegan their attack as follows: theydestruct the tissues of fibrilium matrixes;after they attack superficially the stembark and can penetrate inside midrib onlyin third larval instars where they continuetheir development until pupation. A frondmidrib assures the development of onlyone larva of third stage (14, 15).Crown attack interests the basalfourth oldest floor of green palms. Newemerged adults, pupae and particularlylarvae of third stage are collected fromthis part and never eggs and larvae of firstand second stages. Invaded parts aremainly the matrixes of fibrilium and thebark of stem. Green palms petioles aresuperficially injured by mouthparts oflarvae but never interiorly attackedbecause of the hardness of the woodwhich still alive and overloaded water(15, 14). However, existence of larvae oncrown periphery level can be at the originof indirect damage represented byharmful fungal diseases that are alwaysrelated to stem invasion (6, 13, 14).The pest does not affect the yearlyharvest of date because attacks werenever registered on the base of fruitbunches (14). Thus, this species wasconsidered as secondary pest resulting inits late identification and lacking inrelated research studies.Offshoots developed in tuftslaterally on respiratory roots and allaround the date palm tree (17). Theseunclean places are the best suited sites foradult beetles for egg deposition. Itcontributes to enhance the risks related toTunisian Journal of Plant Protection 185 Vol. 5, No. 2, 2010

strict pre-departure period (3 months) andpost-entry period (9 months) as aquarantine protocol. In fact, during thefirst period selected and pulled offshoots,originating from infested areas, must beset in nursery where they undergo asevere control by the continuous surveyof the presence of any form of the pest(eggs, larva, pupa or adult) in conjunctionwith insecticides spraying untilplantation. This method might be held asan efficient way to prevent the spread ofOryctes through planting material andmust be considered as an importantcomponent of the Oryctes-managementprogram that offers the much neededquarantine security against these pests.However, the second period interestedautonomous offshoots during the firstyear after plantation. A simple methodcan be mentioned and which would avoidand restrict the spread of adults and theidentification of suspicious materialundetected by quarantine service. Itstands in caging offshoots with a meshnet within plantations. This method couldserve as a useful post-entry or postplantationprotocol. This, if done undersupervision and proper certification,would play a major role in preventingspread of the pest to new plantations,regions and countries.AGRONOMIC MEASURESAgronomic methods which may beapplied against O. agamemnon arabicusin the oasis of Southwest Tunisia are easyand not expensive but meticulous.Universally, major recommendationshave been made for cautiousphytosanitary steps inside and aroundplantations to destroy any life historystages found in all breeding sites. Forfarmers, sanitation constitutes the mostsimple and effective way of controllingthe species. Its principle, based on severalmethods and techniques, is to unbalancethe middle of life of the pest bymaintaining the growing area in a cleancondition. It mainly targeted breedingsites (13).In the first part, the control targetsoviposition and breeding sites at differentlevels of palm trees. It is important tomention that this control method has to beapplied out of the season of reproduction,between November and late April. Majoroperations are (14):• Eradication of suitable ovipositionand breeding sites of the pest by theelimination of destroyed vegetal materialpreviously transformed by larvae to smallgranules (firm material) where femaleslaid their eggs and young larvae live anddevelop until new adult emergence.Moreover, this operation allows on onehand to expose these parts to ambient airand sun radiations making them dry, hardand unattractive to beetle, and on theother hand the handpicking (manualextraction) using a metallic wire of allencountered life history stages of the pestfrom feeding tunnels and theirdestruction.• Throughout stem, farmers have touse a saw to prune on scale the drypetioles levels. This action destructs theoviposition sites of beetles by eliminatingthe matrixes of fibrilium with larvae andadults. However, it is far better to keepthe last 4 to 6 levels of dry petioleslocated just under the crown as a trap tobeetles in the goal to avoid the passage ofinvasion to the basal levels of the crown.The second part is related to uncleanpalm trees which display too manyoffshoots at their base. These palms offerto beetles suitable sites for reproductionand eggs oviposition. Therefore, to breakthe pest cycle in this place, it is necessaryto make it clean, exposed to sun light andair. Accordingly, farmers are encouragedto eliminate the excessive number ofoffshoots which can be either used toTunisian Journal of Plant Protection 187 Vol. 5, No. 2, 2010

eplace lacks inside the same plantationafter being treated with insecticides to killlarvae, developing in its basal part, ormust be automatically eradicated.However, sanitation is a carefulwork and a slow methodical processwhich can be hindered by the ability todetect infested material and the necessarytime to execute this work. Approximatelyevery five years, the Ministry ofAgriculture launches a campaign oferadication of this pest by collecting andburning the various stages of the pest ininfested oases. Despite the granting offinancial incentives to make this work,the low involvement of the farmers in thecampaign follow up has translated into asignificant growth of the O. agamemnonarabicus population. Consequently, thelack of consciousness rising about therisks of this pest induce few farmers toapply these techniques within theirplantations (14).TRAINING AND EXTENSIONExtension constitutes a veryimportant method to diffuse informationbetween farmers. In Southwest Tunisia,few meeting and studies are organized onthe subject of this pest. Thus, the solutionconsists in the organization of meetingconferences, field days, and workshops incollaboration between researchinstitutions (researchers), agriculturalorganisms (engineers, technicians) andfarmers are indispensable to the diffusionof important information about therelative pest danger. In addition, the pestis free of control by natural enemies ondate palm oases of Tunisia which makeworse this problem. Consequently, thegoals of these meetings and training are totake farmers informed concerning meanof control of this pest. Farmers can alsohelp to the diffusion of these techniquesto other farmers.CHEMICAL CONTROLPresently, chemical controlperfected against O. agamemnon arabicusis quiet ineffective. Subsequently, thispest management of both in oldproductive and young date palm oasesscarcely relies on insecticide use that isalmost absent. This is due in part tospecific factors in relation with thebiology and ecology of the species, and inother part to the morphology of the plant(problems of access to the crown ofmature palms). However, insecticides canbe used for both as preventive andcurative applications as listed below(unpublished data).Preventive treatment. Preventivetreatments have to be applied during thewhole period of adults’ activities to besure about their effectiveness in killingadults making possible the prevention oftheir entry in the reproduction andoviposition sites situated on differentlevels of the palm tree. Next applicationscan be useful: Stem and crownspraying/soaking. Protecting wounds and entryholes localized on the aerial part of therespiratory roots with insecticides. Use of repellent products onthe crown of productive palms and in newplantations to drive away adults from thepalm tree.Curative treatment. Curativespraying intended for the immature stageslocated on the respiratory roots areineffective, the pesticide emulsion can notreach the location of these stages wellprotected inside their shelter. However, ifthe spraying focus on the higher parts ofmature palm trees, in this case and to beeffective, specific treatment must beapplied by spraying or soaking the wholestem and crown. The application of suchTunisian Journal of Plant Protection 188 Vol. 5, No. 2, 2010

type of treatment, which requires higherdosages of chemical products, constitutesthe only way to make possible the contactof pesticide with different developmentalstages and then its effectiveness.However, although the efficiencyapplication of this method, it isconsidered to be too expensive forgeneral use within plantations comparedto the low value per hectare of dateproduction which severely limitsexpenditure on control measures.Moreover, other serious hazards involvedin spraying tall palms by this way, due tothe loss of products at the time of itsapplication to higher palms make farmershighly exposed to the risks of toxicantspillage and inhalation. Thus,disadvantages of this application resideon the use of important quantities ofchemicals per treatment endangered byrepetitive treatments to ensure theremanence of the product and itsefficiency and this was not safe both toenvironment and human.However, chemical control wasrecommended and constitutes the widelyadvocated method of control(unpublished work): To sweep out the existingstages of the pest within offshoots, beforebeing replanted offshoots bases aredipped within a barrel containing asolution of insecticide for 5 min,necessary time to penetration of thepesticide inside larval galleries. By thisway, larvae were killed by the product ina short period. This method can ensurethe safety of offshoots during the residualperiod, after that they constitute a newtarget to other invasion by adult beetles. To protect young palmreplanting (< 5 years old), by soaking allthe plant with pesticide during the periodof adults’ activity. Use of repellent products asnaphthalene balls into the frond axils canbe very effective in protecting youngpalms (17) and also in old palms bydriving away adults before they causedamage.ATTRACTANTSCompost heaps. Traps of varioustypes can be used. The simplest are on theform of breeding sites and play the role ofa trap or attractant for adults such ascompost of sheep manure and sawdust orheaps of decaying vegetable matter buriedinside a pit on the ground within invadedplantations. Traps of compost must be putin place on the late spring early summer(late April to May) before the starting ofthe reproduction and oviposition periods(14).These organic heaps operate as trapsby attracting a large number of beetles, inparticularly females, which lay downtheir eggs and subsequently largelycontribute in the decline of the pest’spopulations inside plantations and of theirimpact on the palm trees (14).Consequently, compost heaps standsas very favorable breeding sites for theOryctes species and then can receive andproduce large populations in one cycle. Inthis case, compost piles within plantationsshould be maintained properly. Its upkeepincludes the destruction of all life stagesof the pest and its treatment usinginsecticide or inoculums of the parasiticfungus like Metarhizium anisopliaewhich contaminated and killed thebeetles’ larvae of the similar species O.rhinoceros in the Pacific region (8, 9, 10).Also, before its application as soilfertilizer, compost must be sieved toeliminate the remainder of larvae andadults (14).Light traps. Adults are nocturnaland attracted to any source of light. Earlyexperiences at trapping Oryctes in Mrahlahouar zone include the use of one lightTunisian Journal of Plant Protection 189 Vol. 5, No. 2, 2010

trap by the Regional Research Center ofOasis Agriculture at Deguech (6). The useof only one light trap in the pilot station(3.5 ha) of Rjim Maatoug permitted toexperiment the effectiveness of light trapfor three years. However, more than 550adults are trapped per season of activity,from June to mid-October. These goodresults and by the availability of severaltraps inside oasis and their exploitationfor successive years during the period ofactivity of beetles can ensure importantreduction of the pest population (14).BIOLOGICAL CONTROLO. agamemnon arabicus is an exoticspecies in Tunisia. Therefore, naturalfactors that keep the beetle under controlin its native range are not present whenintroduced and this factor facilitates andmakes easy its reproduction and localspread. Biological control via parasitoids,predators and entomo-pathogenic fungiare not yet identified and availableagainst this pest in Tunisia due to itsrecent introduction and to the lack ofdeeper relative studies (14).RECOMMENDATIONSFor raising awareness and capacitybuilding, it is necessary to make farmersof the Southwest region understandingthat O. agamemnon arabicus is not somuch a national responsibility, but rathera regional responsibility. If it was alreadyestablished in some oases of the region, itis highly likely that it will eventuallyspread to others (14). Next steps areneeded both to limit its spread and itspopulation increase within infested oases:■ Adoption and serious applicationof strict quarantine measures on themovement of offshoots from infested tohealthy areas,■ Need of more attention to the pestfrom the authority and scientists due to itsthreat to palm trees,■ Distribution of the pest should beassessed by exploratory surveys inhealthy regions,■ Adoption and application ofphytosanitary steps in infested oases,■ Need to organize programs on O.agamemnon arabicus to get farmersinformed about the real danger of thespecies and its threat on this economicallyimportant crop,■ Making available information onthis pest in the regions concerned withdate palm trees cultivation and includinggood photos of larvae, adults, symptomsand damages,■ Extension of information oncontrol measures to concerned farmers,■ Extension of compost use withinplantation to a significantly decrease bothof the pest’s impact on palm trees and oftheir populations.■ Support and implementation ofIPM program■ Development of mass trappingusing light traps and compost technique■ Establishment of researchprograms to tackle and develop masstrapping with aggregation pheromone■ Introduction of biological controlrelying on the use of the fungusMetharizium anisopliae and theantagonist Oryctes virus showingeffective results in the Pacific coconuts’plantation (4, 5, 11).CONCLUSIONIn conclusion, O. agamemnonarabicus has became a major pest and aworrying threat to palm trees in infestedoases of Southwest Tunisia where it hasthriven unnoticed. Economically, it isconsidered as secondary pest withouteffect on production. This point madefarmers and administration in charges ofagriculture unaware of the hazard for tworeasons: the unperceived damage and theTunisian Journal of Plant Protection 190 Vol. 5, No. 2, 2010

small number of yearly collapsed palmtrees.All means of its management stillrudimentary and traditional relyingmainly on hand collection of differentstages. Then, farmers are encouraged toachieve a careful and intensive workevery year to cleanse their plantations but,this repeated work is very hard and timeconsuming and farmers are unable tocontrol all their palm trees. Consequently,they give up collecting the pest whichpopulation explode and becameuncontrollable.Facing to this situation and due tothe ineffectiveness of chemical controland the lack of biological control, severequarantine measures are the only way toprevent the spread of the pest out ofunhealthy zones. Obviously, it is time toconsider this species as a serious pest ofpalm trees in Tunisia. So, first steps haveto target the control and to limit itspopulations; this can be possible by: i)informing farmers how to use thecompost technique to bait adults, ii)studying the possibility of biologicalcontrol by the introduction of naturalenemies inside infested oases.ACKNOWLEDGEMENTSOur thanks go specifically to Dr. IkbelChaieb, from the Institut National de RechercheAgronomique de Tunisie (INRAT) for his help in therevision and amelioration of the manuscript content.__________________________________________________________________________RESUMESoltani R. 2010. Le scarabée rhinocéros Oryctes agamemnon arabicus en Tunisie: situationactuelle et les futures perspectives de lutte. Tunisian Journal of Plant Protection 5: 179-193.Oryctes agamemnon arabicus a été signalé dans certains oasis du sud ouest Tunisien en 1995. Les sitesfavorables à son développement sont les différentes parties du palmier dattier vivant. La femelle déposeenviron 27 œufs. Les adultes sont nocturnes et passent le jour cachés dans leur abri, ils s’alimententoccasionnellement sur le jus extrait à partir des racines respiratoires. Leur rôle est limité à lareproduction et à la dispersion de l’espèce sur de courtes distances. Cependant, les larves représententles stades nuisibles de l’espèce et non les adultes. Elles s’attaquent à différentes parties du palmierdattier, racines respiratoires, parties superficielles du stipe (fibrilium, écorce du stipe et pétiole sec) etla base de la couronne. Ces derniers représentent les sites de développement d’Oryctes. Le danger réelde cette espèce réside dans l’attaque de la zone respiratoire de la racine, support de base de la plante etsecondairement à la périphérie de la couronne. La lutte contre cette espèce est avant tout préventiveciblant les sites d’élevage afin de réduire les populations. Les mesures de quarantaine par l’interdictiondes mouvements des rejets bloquent la dispersion de l’espèce vers de nouvelles zones, les techniquesculturales ciblent le contrôle et la destruction des sites de développement et les pièges de différentstypes attirent les adultes. Toutes ces méthodes contribuent à réduire considérablement les populations àl’intérieur des plantations.Mots clés: Cycle de vie, dégâts, lutte, Oryctes agamemnon arabicus, palmier dattier, Tunisie.___________________________________________________________________________Oryctes agamemnon arabicus.2010Tunisian Journal of Plant Protection 5: 179-193ملخصسلطاني،‏ رسمي.‏المستقبلية لإدارتها.‏الخنفساء وحيدة القرنفي تونس:‏ الوضع الراهن والآفاقفي واحات الجنوب الغربيتمت الإشارة إلى وجود حشرة الخنفساء وحيدة القرنالتونسي في نخيل التمر المضيف الوحيد للحشرة.‏ وتتمرآز مواقع نمو آل أطوار هذه الآفة على مختلف(Oryctes agamemnon arabicus)1995، يعدّ‏Tunisian Journal of Plant Protection 191 Vol. 5, No. 2, 2010

أجزاء النخيل الحي،‏ حيث تضع الأنثى ما يقارب بيضة.‏ تع ‏ّد هذه الآفة من الحشرات الليلية حيث تختبئ أثناء النهار فيمواقع تطورها على النخلة وتنشط خلال الليل.‏ وهي تتغذى عَرَضيًا على العصارة المستخرجة من الجذور التنفسية للنخلة .ويقتصر دور البالغات على التزاوج والمساهمة في انتشار النوع لمسافات قصيرة.‏ ولا يمكن اعتبار الحشرة الكاملة ضارةبالنخلة مقارنة بالأطوار اليرقية التي تلحق أضرارا بأجزاء مختلفة من النخلة:‏ منطقة الجذور التنفسية والأجزاء الخارجيةللساق والمنطقة السفلية من الجريد الأخضر حيث تمثل هذه الأهداف أهم مواقع نمو مختلف أطوار الحشرة.‏ وتع ‏ّد الأضرارالمحدثة في منطقة الجذور،‏ التي تمثل قاعدة ارتكاز النخلة،‏ الأخطر على الإطلاق بينما تعتبر الأضرار الموجودة علىمحيط التاج ثانوية ودون خطر يذآر.‏ أما فيما يخص طرق مكافحة هذه الحشرة فتعد وقائية قبل آل شيء وتستهدف أساسامواقع تزاوج الحشرة للحد من آثافة أعدادها.‏ أما تدابير الحجر الزراعي المتمثلة في تقييد تبادل الفسائل بين المناطقفتعتبر من أهم التدابير لمنع الحشرة إلى مناطق جديدة زيادة؛ بالإضافة إلى التقنيات الزراعية المتاحة التي تهدف أساساإلى تدمير مواقع تطور الحشرة للحد من أعدادها وآذلك استعمال المصائد بمختلف أنواعها لجذب بالغات الحشرة.‏ تسهمآل هذه الطرائق مساهمة آبيرة في الحد من أعداد الحشرة داخل الواحات.‏نخيل التمر،‏ Oryctes agamemnon arabicus__________________________________________________________________________27آلمات مفتاحية:‏ انتشار،‏ أضرار،‏ تونس،‏ دورة حياة،‏ مكافحة،‏LITERATURE CITED1. Al-Sayed, A.E. and Al-Tamiemi, S.S. 1999.Seasonal activity of the fruit stalk-borer,Oryctes agamemnon (Burm.) (Coleoptera-Scarabaeidae) in Sultanate of Oman. Egypt. J.Agric. Res. 77: 1597-1605.2. Bedford, G.O. 1976. Observations on the biologyand ecology of Oryctes rhinoceros andScapanes australis (Coleoptera: Scarabaeidae:Dynastinae): Pests. J. Aust. Entomol. Soc. 15:241-251.3. Hammes, C. and Monsarrat, P. 1974. Recherchessur Oryctes rhinoceros L. Source CahiersORSTOM. Série Biologie 22: 43-91.4. Huger, A.M. 1966. A virus disease of the Indianrhinoceros beetle, Oryctes rhinoceros(Linnaeus), caused by a new type of insectvirus, Rhabdionvirus oryctes. J. Invert. Pathol.(Special issue) 8: 38-52.5. Huger, A.M. 2005. The Oryctes virus: Itsdetection, identification, and implementation inbiological control of the coconut palmrhinoceros beetle, Oryctes rhinoceros(Coleoptera: Scarabaeidae). J. Invert. Pathol.89: 78-84.6. Khoualdia, O. and Rhouma, A. 1997. Premièresobservations sur Oryctes agamemnon, ravageurdu palmier dattier en Tunisie. Fruits 52: 111-115.7. Lepesme, P. 1947. Les insectes des palmiers. PaulLechevalier Editions, France, 799 pp.8. Ohler, J.G. 1999. Modern Coconut Management.Palm Cultivation and Products. FAO andintermediate technology publications Ltd,London, UK, 458 pp.9. Ramle, M., Mohd, B.W., Norman, K., Mukesh,S., and Siti Ramlah, A.A. 1999. Impact ofMetarhizium anisopliae (Deuteromycotina:Hyphomycetes) applied by wet and dryinoculum on oil palm rhinoceros beetles,Oryctes rhinoceros (Coleoptera: Scarabaeidae).J. Oil Palm Res. 2: 25-40.10. Ramle, M., Wahid, M.B., Norman, K., Glare,T.R., and Jackson, T.A. 2005. The incidenceand use of Oryctes virus for control ofrhinoceros beetle in oil palm plantations inMalaysia. J. Invert. Pathol. 89: 85-90.11. Rochat, D., Mohammadpoor, K., Maloose, C.,Avand-Faghih, A., Lettere, M., Beauhaire, J.,Morin, J.P., Pezier, A., Renou, M., andAbdollahi, G.A. 2004. Male aggregationpheromone of date palm fruit stalks borerOryctes elegans. J. Chem. Ecol. 30: 378-407.12. Sivapragasam, A. 1988. The Rhinoceros Beetle,Oryctes rhinoceros (Linn.): An appraisal of itsproblem and control in young Coconutreplantings in Malaysia. Workshop on coconutreplanting, UNDP/FAO Projet RAS/80/032.November 23-27, 1988, Mardi, Malaysia.13. Soltani, R. 2004. Oryctes agamemnonBurmeister (Coleoptera, Scarabaeidae):contribution à l’étude de sa biologie et de sesdégâts dans les Oasis du Djérid au Sudtunisien. Diplôme d’Etudes Approfondies.Ecole Supérieure d’Horticulture et d’Elevagede Chott-Mariem, Tunisie, 81 pp.14. Soltani, R. 2009. Oryctes agamemnon arabicusFairmaire, 1896: Etude bio-écologique etéthologique dans les oasis de Rjim Maâtoug auSud Ouest Tunisien. Thèse de Doctorat, InstitutSupérieur Agronomique de Chott-Mariem,Tunisie, 152 pp.15. Soltani, R.,Chaieb, I., and Ben Hamouda, M.H.2008. Descriptive study of damage caused bythe rhinoceros beetle, Oryctes agamemnon, andits influence on date palm oases of RjimMaatoug, Tunisia. J. Insect Sci. 8: 53. Availableonline: insectscience.org/8.53.Tunisian Journal of Plant Protection 192 Vol. 5, No. 2, 2010

16. Waterhouse, D.F. and Norris, K.R. 1987.Oryctes rhinoceros (Linnaeus). Pages 101-117.In: Biological control: Pacific prospects. D.F.Waterhouse, and K.R. Norris, ACIAR,Melbourne: Inkata Press.17. Zaid, A. and De Wet, P.F. 2002. Botanical andsystematic description of the date palm. In:Date palm cultivation. FAO Plant Productionand Protection Paper 156, Rev.1.-----------------Tunisian Journal of Plant Protection 193 Vol. 5, No. 2, 2010

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