Journal of Oil Palm ResearchBIOLOGICAL Vol. 29 AGENTS (3) September AND INSECTICIDES 2017 p. TO 323 CONTROL – 332 BUNCH MOTH, Tirathaba rufvena IN OIL PALM ESTATES IN SARAWAK, MALAYSIA DOI:Journal https://doi.org/10.21894/jopr.2017.2903.04 of Oil Palm ResearchBIOLOGICAL Vol. 29 AGENTS (3) September AND INSECTICIDES 2017 p. TO 323 CONTROL – 332 BUNCH MOTH, Tirathaba rufvena IN OIL PALM ESTATES IN SARAWAK, MALAYSIA
BIOLOGICAL AGENTS AND INSECTICIDES TO CONTROL BUNCH MOTH, Tirathaba rufvena IN OIL PALM ESTATES IN SARAWAK, MALAYSIA
SAHARUL ABILLAH MOHAMAD*; ZULKEFLI MASIJAN*; RAMLE MOSLIM*; MOHAMAD ROSMAN SAHARULSULAIMAN*; ABILLAH SU CHONG MOHAMAD*; MING**; ZULKEFLI SIAW TING MASIJAN*; CHUAN‡; NORMANRAMLE MOSLIM*; KAMARUDIN*; MOHAMAD SITI RAMLAH ROSMAN ‡ SULAIMAN*; SU CHONGAHMAD MING**; ALI* SIAW and TING SITI NURULHIDAYAHCHUAN ; NORMAN AHMAD* KAMARUDIN*; SITI RAMLAH AHMAD ALI* and SITI NURULHIDAYAH AHMAD*
ABSTRACT ABSTRACT The effectiveness of biological products and insecticides in controlling the infestation of Tirathaba The effectiveness of biological products and insecticides in controlling the infestation of Tirathaba rufivena in oil palm estates in Sarawak, Malaysia was evaluated. The study was conducted in two sites rufivena in oil palm estates in Sarawak, Malaysia was evaluated. The study was conducted in two sites from November 2014 to May 2015 on oil palm aged 4 and 5 years. The treatments tested in both sites were from November 2014 to May 2015 on oil palm aged 4 and 5 years. The treatments tested in both sites were commercially available and MPOB-produced Bacillus thuringiensis product, Metarhizium anisopliae, commercially available and MPOB-produced Bacillus thuringiensis product, Metarhizium anisopliae, chlorantraniliprole and cypermethrin. The study showed that the first and second instar larvae of bunch chlorantraniliprole and cypermethrin. The study showed that the first and second instar larvae of bunch moth were found mostly on male inflorescences, and the third and fourth instar larvae were found on female moth were found mostly on male inflorescences, and the third and fourth instar larvae were found on female inflorescences and developing bunches. All treatments were effective in reducing the larval population inflorescences and developing bunches. All treatments were effective in reducing the larval population of bunch moth as early as seven days after the first treatment (DAFT). However, the larval population of bunch moth as early as seven days after the first treatment (DAFT). However, the larval population at plots treated with B. thuringiensis recorded inconsistent results. In Site 1, it was observed that only at plots treated with B. thuringiensis recorded inconsistent results. In Site 1, it was observed that only the commercial B. thuringiensis was able to control the larval population of bunch moth up to 34 DAFT. the commercial B. thuringiensis was able to control the larval population of bunch moth up to 34 DAFT. Whereas in Site 2, both B. thuringiensis and Metarhizium anisopliae products gave control as good as Whereas in Site 2, both B. thuringiensis and Metarhizium anisopliae products gave control as good as chemicals up to 49 DAFT. Chlorantraniliprole application gave rapid reduction and was able to reduce and chemicals up to 49 DAFT. Chlorantraniliprole application gave rapid reduction and was able to reduce and maintain low population of bunch moth up to 59 days after the last spraying. A more comprehensive study maintain low population of bunch moth up to 59 days after the last spraying. A more comprehensive study is needed to be carried out by incorporating other control measures such as mass trapping of adults and is needed to be carried out by incorporating other control measures such as mass trapping of adults and spraying of larvae using biological and chemical products in the coastal peat areas. spraying of larvae using biological and chemical products in the coastal peat areas.
Keywords: oil palm, bunch moth, Tirathaba rufivena, cypermethrin, chlorantraniliprole, Bacillus thuringiensis, Metarhizium anisopliae, peat. Keywords: oil palm, bunch moth, Tirathaba rufivena, cypermethrin, chlorantraniliprole, Bacillus thuringiensis, Metarhizium anisopliae, peat. Date received: 29 December 2016; Sent for revision: 3 January 2017; Received in final form: 27 February 2017; Accepted: 4 July 2017. Date received: 29 December 2016; Sent for revision: 3 January 2017; Received in final form: 27 February 2017; Accepted: 4 July 2017.
INTRODUCTION and Indonesia (Khoo et al., 1991; Susanto et al., INTRODUCTION 2011).and Indonesia This species (Khoo is eteasily al., 1991;recognised Susanto based et alon., Bunch moth is also known as ‘inflorescence moth’ the2011). forewing This colourationspecies is easily of the recognised adult moth, based which on orBunch ‘fruit moth moth’ is ofalso palm known (Basri as and‘inflorescence Norman, moth’2000). isthe greenish forewing or colouration brown, with of the thin adult red moth, stripes which for Outor ‘fruit of 30moth’ species of palm reported, (Basri one and species, Norman, Tirathaba 2000). femaleis greenish and silvery or brown, gray with for male thin (Figure red stripes 1) (Khoo for rufivenaOut of 30 is species found infesting reported, oil one palm species, in MalaysiaTirathaba etfemale al., 1991; and Basri silvery and gray Norman, for male 2000; (Figure Moore, 1) (Khoo2001). rufivena is found infesting oil palm in Malaysia Accordinget al., 1991; toBasri Yaakop and Norman,et al. (2015), 2000; theMoore, species 2001). of According to Yaakop et al. (2015), the species of * Malaysian Palm Oil Board, 6 Persiaran Institusi, Tirathaba consists of five larval stages, where each * BandarMalaysian Baru Palm Bangi, Oil Board,43000 Kajang,6 Persiaran Selangor, Institusi, Malaysia. stageTirathaba is differentiated consists of five by size larval and stages, body wherelength. eachThe E-mail:Bandar [email protected] Bangi, 43000 Kajang, Selangor, Malaysia. larvaestage is aredifferentiated the destructive by size stage, and body damaging length. bothThe E-mail: [email protected] ** Research and Development Department, malelarvae and are female the destructive inflorescences, stage, and damaging developing both ** LambirResearch Research and Development Centre, Sarawak Department, Oil Palms Berhad (SOPB), male and female inflorescences, and developing 98007Lambir Miri, Research Sarawak, Centre, Malaysia. Sarawak Oil Palms Berhad (SOPB), fruitlets of young bunches (Lim, 2012). On 98007 Miri, Sarawak, Malaysia. developingfruitlets of bunches, young the bunches larvae feed (Lim, and 2012). scrape Onon ‡ Research and Development Department, developing bunches, the larvae feed and scrape on ‡ TaResearch Ann Plantation and Development Sdn Bhd, Department, the fruitlets, later boring holes into the mesocarp up 96000Ta Ann Sibu, Plantation Sarawak, Sdn Malaysia.Bhd, tothe the fruitlets, kernel. later High boring infestation holes can into greatly the mesocarp reduce theup 96000 Sibu, Sarawak, Malaysia. to the kernel. High infestation can greatly reduce the
323 323 JOURNAL OF OIL PALM RESEARCH 29 (3) (SEPTEMBER 2017)
1 cm 1 cm
a b
Figure 1. Dorsal view adults of Tirathaba rufivena. a) Male b) female collected in Sarawak, Malaysia. quality and weight of the fruit bunch and may cause Thus, the main aim of this study is to evaluate malformed and premature bunch abortion (Alouw the effectiveness of microbial agents and chemical et al., 2005). It was also reported that the areas which insecticides to control the population of T. rufivena experienced heavy infestation have recorded lower in oil palm planted on peat. number of bunches per palm and high number of rotten bunches (Idrus et al., 2016). Infestation is characterised by the presence of long tube of silk MATERIALS AND METHODS and frass in the bunch, which are reddish when fresh and brownish-black when old (Lim, 2012). Experimental Site and Design T. rufivena is becoming an important insect pest on oil palm planted on peat in Sarawak (Lim, The study was conducted in two sites namely 2012; Zulkefli et al., 2012). Outbreaks of this pest Site 1 and Site 2. In Site 1, the experiment was have been reported throughout oil palm plantations conducted in Block 305, Kuala Igan Estate, Igan, on peat, with most badly affected areas located on Sarawak, Malaysia from November 2014 to February coastal peat in Mukah, Sibu and Miri (Zulkefli et al., 2015. In Site 2, the study was carried out in Block 2015). A survey in 2016 showed that the estimated K39, Tinbarap 7/9 Estate, Bakong, Sarawak from affected areas were more than 47 700 ha (MPOB, March 2015 to May 2015. In both experimental sites, 2016). The increasing population of bunch moth is the experiment was carried out using a randomised associated to the abundance of food sources such as complete block design with four replications, unharvested ripe bunches, the presence of breeding covering 20 sub-plots. The planting designs in sites such as inflorescences and scarcity of natural both sites were different. In Site 1, each sub-plot enemies (Susanto et al., 2011). comprised of 68 palm with the arrangement of Planters mainly rely on insecticides, particularly four inter-row palms x 17 in between palm, giving cypermethrin, to control the bunch moth (Lim, 2012). an estimate of 1360 treated palms. Meanwhile, in This is due to fast action and low cost as compared Site 2, each sub-plot comprised of 48 palms with to B. thuringiensis (Basri et al., 1991). However, the the arrangement of four inter-row palms x 12 in chemical is adversely affecting the population of between palms, giving a total of 960 treated palms. oil palm pollinating weevil, Elaeidobius kamerunicus The age of palm was four-year old in Site 1 and five- and its rate of degradation is slow when applied year old in Site 2. No guard palms were used in the on peat (Ismail et al., 2012). Efforts to control this study as the spraying drift of treatments moving to pest using biological agents such as the parasitoid, neighbouring palms was considered negligible. Argyrophylax basifulva and nematode, Steinernema feltiae have been unsuccessful (Godfray, 1985; Treatment and Application Zelazny, 1985). Therefore, it is urgently needed to find sustainable measures to control the bunch In each experimental site, five treatments moth T. rufivena, preferably by enhancing the use including untreated control were tested. The active of microbial agents, and extending the interval of ingredient and application rates for each treatment insecticide application. in Sites 1 and 2 are summarised in Tables 1 and 2. The
324 BIOLOGICAL AGENTS AND INSECTICIDES TO CONTROL BUNCH MOTH, Tirathaba rufvena IN OIL PALM ESTATES IN SARAWAK, MALAYSIA
TABLE 1. ACTIVE INGREDIENTS AND APPLICATION ml of the sticking agent, Nufarm Bond® was added RATES OF PRODUCTS TESTED IN SITE 1 into the sprayer tank before application. No. Active ingredient Concentration Application rate/ a.i 16 litres water (ml) Data Recording
1. Control At both sites, pre-census to estimate the 2 Cypermethrin 5.5% 30 3. Chlorantraniliprole 5.0% 8 population of bunch moth and palm damage severity 4. B. thuringiensis ss 17 600 IU mg-1 24 was conducted a week prior to the treatments. The kurstaki randomisation of experimental plots was done (commercial) based on this pre-census data. Data on numbers of 5. Bacillus 16 000 IU mg-1 640 live larvae and developmental stages of bunch moth thuringiensis was recorded from a total of five samples for Site 1 (MPOB- Ecobac 1) and six samples for Site 2, consisting of one post- anthesis male inflorescences in Site 1 and two post- anthesis male inflorescences in Site 2, two each of TABLE 2. ACTIVE INGREDIENTS AND APPLICATION developing bunches and female inflorescences in RATES OF PRODUCTS TESTED IN SITE 2 both sites. The samples in Site 1 had to be reduced due No. Active ingredient Concentration Application rate/ to lack of suitable post-anthesis male inflorescences. a.i 16 litres water (ml) Sampling was conducted at 7, 21, 34 and 84 days 1. Control after first treatment (DAFT) at Site 1 and 7, 21, 35 2. Cypermethrin 5.5% 15 and 49 DAFT at Site 2. Based on the result from Site 3. Chlorantraniliprole 5.0% 8 1, it was felt that the long gap between 34 and 84 4. B. thuringiensis ss 17 600 IU mg-1 24 days after treatment was too long and the gap kurstaki has allowed the larval population to re-establish, (commercial) which also indicates the short efficacy period of 5. Metarhizium the treatments. Therefore, was decided to shorten anisopliae 20% the sampling period gap, which will better reflect (1.1 x 1011 spores kg-1) 150 the field performances of the treatments selected. Each sample was chopped to individual spikelet before the number of live larvae or pupae were treatments selected for trial in Site 1 are commercially counted and sorted according to developmental available cypermethrin 5.5%, chlorantraniliprole stages. 5.0%, Bacillus thuringiensis ss kurstaki 17 600 IU mg-1 and MPOB-produced Bacillus thuringiensis (MPOB- Data Analysis Ecobac 1). Meanwhile, in Site 2, treatments involved were commercially available cypermethrin 5.5%, The number of live developmental stages of chlorantraniliprole 5.0%, Bacillus thuringiensis ss bunch moth at each data recording was analysed kurstaki 17 600 IU mg-1 and Metarhizium anisopliae using one-way analysis of variance. The differences (1.1 x 1011 spores kg-1). After considering the field between means for each data were separated using performances of each treatment in Site 1, it was Duncan’s Multiple Range Test at P=0.05. decided to replace MPOB-produced B. thuringiensis with different biological agent, a commercially available M. anisopliae for testing in Site 2. The RESULT AND DISCUSSION tested product for each treatment was uniformly applied using a 16 litres manual knapsack sprayer Distribution of Population and Developmental with a cone-shaped nozzle. Prior to application, Stages calibration was conducted to ensure uniform and accurate rate of treatments. Based on the The distribution of bunch moth population calibration, 1 litre of product solution was required before treatment at both study sites was estimated. to achieve satisfactory penetration into the palm Infestation of bunch moth in each experimental crown region. Every palm was subjected to four block was assessed from 20 samples of male rounds of treatment application at 14-day intervals inflorescences, and 40 samples of each female at both study sites. Spraying was directed onto all inflorescence and developing bunches in Site 1. The post-anthesising male and female inflorescences lesser number of male inflorescences samples was and fruit bunches in the treated palms. Spraying due to low number of male inflorescences available directed onto anthesising male inflorescences was in the experimental site. Meanwhile, in Site 2, the avoided to minimise the mortality rate of oil palm severity of infestation in the experimental block was pollinating weevil, Elaeidobius kamerunicus. To assessed from 40 samples of male inflorescences, improve adherence and deposition of droplets, 10 female inflorescence and developing bunches. In Site
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1, data recorded from pre-treatment census showed most of the early instar larvae (L1 and L2) of bunch that the experimental area has high infestation of moth were found on male inflorescences, and the live larvae on male inflorescences as compared later instar larvae (L3 and L4) were found on female to female inflorescences and developing bunches inflorescences and developing bunches. Whereas (Table 3). In Site 1, the early larval instars, which in Site 2, the early larval instar (L1 and L2) can be were abundant in male inflorescences, outnumbered found in all types of samples. It was also observed the later stage larvae, which can be mostly found that in Site 2, low number of late larval instar (L3 in female inflorescences and developing bunches. and L4) were found during the pre-treatment However, the number of live larvae collected in Site census. Although reasons on why high number of 2 was more evenly distributed across all types of early instar were found on male inflorescence are samples (Table 4). This indicates that in Site 2, the still unknown, it is possibly because the pest prefers number of early and later instar larvae did not differ to lay eggs and starts to breed on post-anthesis male significantly. inflorescences (PAMI). This observation supports The distribution of developmental stages of live the earlier findings by Wood and Ng (1974), who larvae on each type of samples was also determined reported that the early stage of bunch moth was (Figures 2 and 3). In Site 1, it was observed that abundant on male inflorescences.
TABLE 3. DISTRIBUTION OF LIVE LARVAL POPULATION OF BUNCH MOTH RECORDED ON MALE INFLORESCENCES, FEMALE INFLORESCENCES AND DEVELOPING BUNCHES IN SITE 1
Type of Number of larvae per sample in sample the experimental block
n Block 1 n Block 2 n Block 3 n Block 4
Male inflorescence 5 35.2 ± 11.12 5 30 ± 13.43 5 17.8 ± 8.89 5 78.4 ± 43.51 Female inflorescence 10 9.5 ± 3.16 10 10.9 ± 4.88 10 10.2 ± 3.05 10 17.6 ± 5.77 Developing bunch 10 15.6 ± 5.26 10 17 ± 2.44 10 10 ± 3.37 10 14.7 ± 4.00
TABLE 4. DISTRIBUTION OF LIVE LARVAL POPULATION OF BUNCH MOTH RECORDED ON MALE INFLORESCENCES, FEMALE INFLORESCENCES AND DEVELOPING BUNCHES IN SITE 2
Type of Number of larvae per sample in sample the experimental block
n Block 1 n Block 2 n Block 3 n Block 4
Male inflorescence 10 32.7 ± 14.37 10 7.30 ± 3.54 10 6.6 ± 1.48 10 2.30 ± 1.55 Female inflorescence 10 18.4 ± 5.70 10 14.4 ± 3.60 10 11.9 ± 2.89 10 6.6 ± 0.99 Developing bunch 10 10.1 ± 2.14 10 13.5 ± 3.26 10 7.7 ± 1.89 10 2.40 ± 1.02
100
80
60
40 (numbers/sample) Population of larvae 20
0 L1 L2 L3 L4 L1 L2 L3 L4 L1 L2 L3 L4 Larval stages Larval stages Larval stages Male Female Developing inforescences inforescences bunches
Figure 2. Distribution of developmental stages of bunch moth larvae sampled from male and female inflorescences and developing bunches in Site 1.
326 BIOLOGICAL AGENTS AND INSECTICIDES TO CONTROL BUNCH MOTH, Tirathaba rufvena IN OIL PALM ESTATES IN SARAWAK, MALAYSIA
25
20
15
10 (numbers/sample) Population of larvae
5
0 L1 L2 L3 L4 L1 L2 L3 L4 L1 L2 L3 L4 Larval stages Larval stages Larval stages Male Female Developing inforescences inforescences bunches
Figure 3. Distribution of developmental stages of bunch moth larvae sampled from male and female inflorescences and developing bunches in Site 2.
Impact of Treatments on Larval Population Site 1 showed that every treatment, except MPOB- Bt was able to give satisfactory control over the In Site 1, the pre-census data showed that bunch moth population up to 34 DAFT, before the population of live larvae per sample (LPS) re-emergence of the population occurred. The in each treatment plot was not significantly differences in the efficacy of both Bt products is different (P>0.05). The number of live larvae in possibly attributed to the type of strains and Bt toxin the experimental plots for control, cypermethrin, mixture in each product. MPOB-Bt is a product chlorantraniliprole, MPOB-Bt and commercial that was developed using a local isolate, known as Bt (Bt-COM) was 21.7, 21.3, 14, 47.8 and 19.4 LPS, MPOB B. thuringiensis 1, specifically produced for respectively. At 7 DAFT, the number of live larvae the Integrated Pest Management (IPM) programme in all treatments were reduced and significantly to control bagworm (Metisa plana) outbreak (Siti lower (P<0.05) than control, except for MPOB-Bt Ramlah et al., 2012). The product specificity may (Figure 4). Among the treatments, it was observed cause it to be ineffective in controlling the population that chlorantraniliprole caused a rapid reduction on of bunch moth larvae. Meanwhile, COM-Bt contains the larval population to the lowest level of 1.4 LPS. proprietary, high yielding B. thuringiensis subspecies At 21 DAFT, further reduction on the larval kurstaki and blended with various Bt protein toxins, population in all treatment plots was recorded. which maximise its efficacy against lepidopteran The populations of larvae in all treatment were pests (Valent Biosciences, 2014). significantly lower than control. At 34 DAFT, In Site 2, the effects of treatments in reducing application of cypermethrin and chlorantraniliprole the population of bunch moth T. rufivena are shown has completely controlled the bunch moth. None of in Figure 5. Pre-census showed no significant the bunch moth larvae was found on the samples differences on bunch moth population between collected from plots treated by both products. blocks selected for the study. At seven DAFT, However, the infestation of live larvae of bunch moth all treatments, except for plots treated with B. in all treatment plots increased at 84 DAFT (Figure thuringiensis were able to significantly reduce (P<0.05) 4). At this period, chlorantraniliprole was the only the population of T. rufivena compared to control. The treatment that still gave significantly good control population of bunch moth in all treatment plots was to bunch moth larvae, manifesting the longer effects then maintained significantly lower (P<0.05) than of the insecticide on the pest populations compared control until the end of the experiment at 49 DAFT. to other treatments. It was also recorded that the At 21 DAFT, the lowest population of 0.50 LPS was infestation levels in blocks treated with commercial recorded in blocks treated with chlorantraniliprole. Bt was higher than those in control plots, suggesting At 49 DAFT, blocks treated with cypermethrin rapidly waning effects of commercial Bt on the recorded the lowest bunch moth larvae population population of bunch moth larvae. This also shows of 0.33 LPS, which was not significantly different that another round of commercial Bt application is from other treatments, including both microbial required in the period between 34 and 84 DAFT to agents of commercial Bt and M. anisopliae. Blocks prevent rapid population re-emergence. Study in treated with commercial Bt recorded bunch
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