MAJOR COCONUT PESTS Rhinoceros Beetle (Oryctes rhinoceros L.)

Transcription

1 BREAKTHROUGH S

2 MAJOR COCONUT PESTS Rhinoceros Beetle (Oryctes rhinoceros L.) Coconut log was found to support generations of beetles from 5 to 7 years starting on the 10 th month after felling with peak population of 141 individuals per linear meter of decaying log. Thickness of sawdust was found directly proportional to the beetle population. Trap boxes containing sawdust prevented beetle outbreak in newly felled coconut situation by trapping the initial wild beetle population. Laboratory and field trials showed that the larva, pupa and adult of the beetle are highly susceptible to baculovirus and fungus infections.

3 Metarhizium anisopliae or the green muscardine fungus (GMF) was found effective in controlling beetle population by: a) incorporating the granular form of fungus into trap boxes, b) injecting or pouring spore suspension using a spray gun (sumpit) into the breeding places, and c) introducing GMF-inoculated larvae of the beetle into trap boxes and breeding areas. Application of granular insecticides (gamma BHC, carbosulfan, carbofuran, pirimiphos-ethyl, and diazinon) into the leaf axil of young palms was found to repel beetle attacks.

4 Slug Caterpillar Identified five (5) predominant species namely: Thosea philippina (green), Parasa philepida (white), Darna mindanensis (brown), Penthocrates spp. (small limacodid), and Setora `longifurca (orange), attacking coconut and found widespread in Mindanao. Long dry spell generally caused outbreaks of the pest. Ultra-violet light traps installed in the field at night resulted to more catches of adult moth and proved as one of the effective control measures against the pest. Peak period of catches of the different species are 11:00pm-2:00am (white); 9:00pm-11:00pm (green); 5:00pm-8:00pm (brown); and 6:00pm- 7:00PM (small limacodids). A predatory pentatomid bug, Eocanthecona furcellata was successfully mass reared and effective release techniques against the caterpillar was formulated. Several species of parasitoids were identified, but only few are considered potential biocontrol agents.

5 Observed infections of bacteria, virus and fungus on larvae and pupae of the pest. Crude extracts of suspected virus was found to infect healthy larvae of the limacodids Tractor/carabao driven roller proved to minimize slug caterpillar infestation as it crushes/destroys the mature larvae and pupae on the vegetation under coconut

6 The Greater Coconut Spike Moth (Tirathaba rufivena) Determined the lifespan of the moth (from egg laying to death) which ranged from days. Incubation of eggs is 4-7 days, larval period of 15 days with 4-6 larval instars, 2-4 days prepupa and 5-8 days pupa period. Observed three parasitoids namely : Telenomus tirathabae (eggs); Apanteles tirathabae (larvae), Ventura palmaris (larval-pupal) as potential biocontrol agents against the moth. Developed rearing techniques of an imported tachinid fly Argyrophylax basifulva Bezzi, a biocon agent of T. rufivena. Simulated Tirathaba damage experiment showed that 40-60% button thinning does not affect yield of coconut. Laboratory bioassay test of the fungus, Beauveria bassiana, showed infections on larval, pupal, and adult stages of the moth. Application of diazinon, triazophos, pirimiphosmethyl, and azinphos-ethyl significantly lowered infestation on buttons or young nuts.

7 Leafminer (Promecotheca cumingii) Survey showed this pest is widely distributed in the country. Six hymenopterous parasitoids belonging to family Eulophidae (Sympiesis sp., Cirrospilus sp., and Pedobius anomalus), family Aphelinidae (Centrodora sp.) and family Proctotrupidae were observed parasitizing the pest. The most promising of which is Sympiesis sp.

8 Two-Colored Hispid Beetle (Plesispa reichie) Biological studies showed developmental period (egglaying to emergence) from days. Egg incubation is 5-9 days, larval period of 22 to 32 days with 4 larval instars, pre-pupal of 2-8 days and pupal stages of 5-12 days. Adult longevity is 101 to 202 days. An Encyrtid, Ooencyrtus sp. was observed parasitizing field collected eggs of the beetle. Bioassay test of fungus, Beauveria bassiana showed infections on beetle larvae, pupae and adults.

9 Scale Insect (Aspidiotus destructor) Observed coccinellid predators preying on immature scale insects namely : Scymnus sp. and Pseudoscymnus sp. Application of dimethoate, methyl parathion, methomyl, pirimiphos-methyl insecticides effectively controlled scale insect population after 4 consecutive weekly sprayings. Asiatic Palm Weevil (Rhynchophorus schach) Application of diazinon, dimethoate, and malathion through Drill-Pour-Plug (DPP) method was found most effective in controlling the pest.

10 Mites Identified new mite pest, Rarosiella cocosae Rimando, heavily infesting all stages of coconut in the entire island of Camiguin, Misamis Oriental. Predatory mites (Amblyseius largoensis and Armacirus taurus) and a coccinellid beetle (Telsimia ephippiger) were found voraciously feeding on eggs, nymphs and adults of the mites. Telsimia ephippiger Amblyseius largoensis Armacirus taurus

11 Rodents Identified Rattus tanezumi (formerly R. r. mindanensis) as the most predominant species attacking coconut causing as much as 23.4% nutfall of the annual nut yield on infested farms. Trunk banding and 5% coumatetralyl-prepared baits were found effective in reducing rat damage as shown in field experiments. Lesser rat damage on nuts was observed on intercropped and covercropped areas due to increase food source of the pest. Four (4)-gram brodifacoum wax blocks containing 0.005% a.i. basally applied at 1 block per palm showed significant reduction of 70% nutfall due to rats with corresponding increase of 82 nuts/ha/mo.

12 MAJOR COCONUT DISEASES Bud and Fruit Rots Caused by Phytophthora palmivora Butl. Nationwide survey showed that MAWA (Malayan Yellow Dwarf x West African Tall) hybrids is highly susceptible to the disease while the local talls showed marked tolerance. Established apparent susceptibility of hybrids were MYD and MRD as parent materials Field surveys and artificial inoculation in-vitro showed that colored populations are generally highly susceptible to Phytophthora infection than the green populations. Trichoderma sp. and Chaetomium sp. were found as potential biocontrol agents against the disease as indicated in in-vitro bioassays.

13 Practice farm sanitation, cutting & burning of infected palms/nuts and other host e.g. durian stem canker & cacao pod rot to prevent further spread. Application of cupric hydroxide at 25 g/l/palm every 6 mo. significantly lowered disease incidence. Treatment application is done through canopy spray and solution directed to axils of leaves/fruits. Leaf Spot Caused by Pestalozzia palmarum Cke. & Grev. and Helminthosporium sp. Uncovered the role of potassium chloride (KCl) fertilizer in inducing resistance of palms to the disease. Practice cultural management to prevent leaf spot Tacunan, Yellow Dwarf, and Orange Dwarf populations showed marked susceptibility to infection while Catigan consistently showed tolerance.

14 Socorro Wilt Disease occurrence was found in 12 barangays of Socorro, Oriental Mindoro and exhibited a jumpspread pattern of incidence. Geographical range of disease spread is 12 km radius from coconut farm where it first occurred.

15 Stem Bleeding Caused by Thielaviopsis paradoxa (de Seynes) Von Hohnel Observed to be a common disease on introduced and local varieties. both Too much damage of internal tissues create hollow stem Avoid unnecessary wounding of palms In-vitro bioassay showed that Aliette and Benlate are effective fungicides in inhibiting the growth of T. paradoxa

16 WEED MANAGEMENT IN COCONUT Establishment of leguminous covercrops after glyphosate application proved to be a satisfactory way of suppressing cogon, (Imperata cylindrica L.) infesting coconut plantations. Demonstrated the adaptability of winged bean (Psophocarpus tetragonolobus) as a profitable weed suppressant doubling as covercrops in coconut farms. Discovered an arctiid moth, Pareuchaetes pseudoinsulata, a voracious foliage feeder, as a biocontrol agent of Chromolaena odorata (hagonoy), a noxious weed infesting coconut plantations. Imported and successfully mass reared Procecidochares conexa (Diptera: Tephritidae), a specific stem galling fly against hagonoy. Found P.connexa safe on other weeds, fruits and fruit seedlings and has been cleared for field release.