Technology transfer of Cotesia-based IPM for diamondback moth on lowland crucifers in the

B. Morallo-Rejesus1, E. L. Inocencio2, J. E. Eusebio3, and S. F. Barroga4 1 & 2Department of Entomology, University of the Philippines at Los Banos, College, , Philippines and 3Crop Research Division, PCARRD, Los Banos, Laguna, Philippines 4Mariano Marcos State University, , Norte, Philippines

Abstract The components of the integrated pest management (IPM) technology for diamondback moth (DBM), Plutella xylostella in the lowland are the release of larval parasitoid, Cotesia plutellae supplemented with selective insecticide through training of trainers (technicians of the local government units (LGU) and researchers of state colleges and universities (SCU) and farmers followed by farmer participated demo farms (FPDF). The training was conducted in cooperation with LGU, SCU and farmer associations. A total of 1 154 farmers and 176 trainers from 31 municipalities of 9 provinces of , Camarlines Sur, , , Ilocos Norte, Laguna, , and were trained and 49 FPDF were set-up in 7 provinces. High C. plutellae parasitism and cocoon formation and lower DBM population were noted in IPM than FCP fields. The farmer adoption of IPM technology resulted in the increase net income ranging from US$2 781.25 to US$10 984.46/ha, 5Ð78% higher than FCP due to lower production cost and higher yield. The production cost per hectare range from US$1 104.16Ð3 902.34, 2Ð45% lower than the FCP. Insecticide application was reduced from 1Ð4 times in Quezon and to 3Ð9 in Ilocos Sur and Norte from 15Ð36 times before the piloting of the technology. The increase net income varied with the location, season, production cost and price of cabbage. Seventy to 100% of the cooperators regularly visited by the AVNET personnel and trainers implemented properly the IPM technology. While cooperators that were not regularly visited only 30% succeeded.

Key words: Cotesia plutellae, Plutella xylostella, IPM, parasitoids, technology.

Introduction important use is as a component of an IPM program In the Philippines, the diamondback moth (DBM), or in combination with other natural enemies like an Plutella xylostella (Linn.) was first observed as the effective pupal or egg parasitoid of DBM. most destructive pest of crucifers in the highland in The integration of the use of microbial insecticides 1960 (Barroga, 1967) and in the lowland in 1970 and the parasitoids, D. semiclausum and C. plutellae, (Cadapan and Gabriel, 1972). Since then, farmers was reported as promising in the highland and lowland relied heavily on chemical application to control this areas of Taiwan by Talekar (AVRDC, 1990). insect pest leading to the development of resistance to Subsequently, these parasitoids were introduced into organophosphates, carbamates and pyrethroids the Philippines in 1989 from Taiwan through the Asian (Barroga and Morallo-Rejesus, 1975; Cardona, 1986, Vegetable Network (AVNET Phase I) collaborative Ebuenga, 1992). project coordinated by the Asian Vegetable Research This leads farmers to spray frequently (15Ð36 and Development Center (AVRDC), Taiwan with the times) during the cropping season with mixed following participating countries: Thailand, Indonesia, insecticides at doubled the recommended rates. These Malaysia, and the Philippines. Locally, the project was practices aggravated the resistance and residue coordinated by the Philippine Council for Agriculture problems in the Philippines. Same problems were Forestry and Natural Resources Research and reported in Asia, thus, the search for biological control Development (PCARRD). agents for the control of DBM ensued. The In the AVNET Phase I, the viability of the Cotesia- introduction of natural enemies of DBM in Malaysia based IPM technology to control DBM was evaluated (Ooi and Lim, 1989); Indonesia (Sastorosiswojo and and demonstrated in farmers’ field in lowland elevation Sastrodihardjo, 1986) and Taiwan (Talekar, 1990; (400Ð800 meters above sea level) of Laguna, Batangas, Talekar et al. 1992) resulted in significant decline in Quezon and Cavite from October 1989 to April 1993 DBM population. Lim (1986) reported that although (Morallo-Rejesus et al., 1994). The technology the solitary larval parasitoids, Diadegma semiclausum reduced DBM population and insecticidal applications, (Hellen) and Cotesia (Apanteles) plutellae (Kurdj.) and increased the net income of farmers. have the greatest potential in the control of DBM, but In May 1993, the project on IPM of Cruciferous their effect is not enough if used alone. Their most Insect Pests (AVNET Phase II) was implemented which aimed to further pilot and promote the concept

Development and implementation of IPM 267 and technology of Cotesia-based IPM for the Fourteen trainers and farmers trainings of one to management of DBM in other lowland areas of , two days were held in six provinces with 465 Philippines. participants. In each training site, at least three farmers served as initial cooperation for demonstrating the IPM The Cotesia-based IPM technology for DBM technology. Each farmer volunteer was requested to For the lowland elevation crucifers, the IPM set aside 500 to 5 000 m2 of his crucifer farm with 2Ð technology of AVRDC (1990) was modified by 3 weeks old cabbage at the time of training. One half incorporating the economic threshold level (ETL), the of the field was set aside as the IPM-managed field tool used for deciding when to apply supplemental while the other half as FCP managed field (farmer insecticidal application (Morallo-Rejesus et al., 1994). applied his usual practices). They provided all the The component of the IPM technology are as inputs except for the C. plutellae and selective follows: insecticides for the IPM-managed fields which were A. The release of C. plutellae (cocoons/adults) at provided by the AVNET. In some places, the farmers 1 2 1 3 000Ð10 000/ha/release ( /2m or /6 plants to only provided the IPM fields. 1 /12 plants) with 3 to 7 releases for the first to The initial release was done in a field planed with second cropping. The number of releases was 2Ð4 weeks old cabbage thereafter at weekly or reduced in the next cropping seasons depending biweekly interval at the rate of 3 000 to 10 000 upon the level of parasitism. The rate of cocoons/hectare. In many cases, 3 to 6 releases were parasitism was monitored by collecting 50 or 100 made on the first cropping, 2Ð4 releases on the second 3rd or 4th instar DBM larvae and reared until cropping and 1 to 3 or no releases in the subsequent adult emergence. If the increase of parasitoid cropping depending upon the build-up of the parasitoid population is slow or parasitism is below 75% population. the same number of parasitoids are released Three to four days after each release of the immediately. parasitoids, 100 3rd or 4th instar DBM were collected to determine field parasitism. Likewise, the DBM B. Spray supplement based on ETL larvae in 50 plants were counted in an “X” pattern; if The ETL are two larvae at seedling to vegetative ETL is reached, the farmer spray with B.t. kurstaki stage (1Ð4 weeks after transplanting (WAT) and (Btk). In the first cropping, the B.t.k. or other selective 5 larvae at vegetative to heading stage (5Ð12 insecticides (teflubenzuron, diafenthiuron) was WAT). It is determined by monitoring the number supplied by the AVNET for the IPM managed field. of DBM larvae 3Ð4 days on 50Ð100 plants, X In the next cropping, the farmer bought their own B.t.k. pattern. If ETL is reached, selective insecticides In Quezon, the AVNET personnel regularly like Bacillus thuringiensis kurstaki and B.t. (weekly) visited and assisted the cooperators in the aizawai (microbial), fenvalerate (pyrethroid), monitoring of DBM and ETL and parasitism carbaryl (carbamate), teflubenzuron (IGR) and determination. In Ilocos Sur, Ilocos Norte, Cavite, diafenthiuron (pyrrole) is sprayed. Rizal, Nueva Ecija, the AVNET personnel visited the cooperators once in two weeks to release the Strategy for transferring the technology parasitoids. In these places, LGU technicians and The Cotesia-based IPM technology for DBM was researchers from RCPC or SCU’s were relied upon to transferred to the farmers by conducting trainers’ and assist the farmers in the monitoring once or two times farmers’ trainings followed by farmer-participated a week. All C. plutellae population released in the demo farms (FPDF). The trainings were conducted in lowland were mass-reared and supplied by the cooperation with local government unit (LGU), State Department of Entomology, UPLB (AVNET Project). College and Universities (SCU) and/or farmer Forty nine farmer participated demo farms were associations or cooperatives. In addition, the set up in 21 barangays of 14 municipalities in Quezon, technology was popularized through the media (radio Cavite, Ilocos Sur, Ilocos Norte, Nueva Ecija and broadcast, TV, printed materials (bulletins and (Figure 1). A total of 182 050 Cotesia handouts). A bulletin “Guide to Control Diamondback cocoons were released in an aggregate area of 74 850 Moth” in English and Pilipino (Morallo-Rejesus and m2. Twenty thousand Cotesia cocoons were provided Sayaboc, 1992) was published and distributed for the to other researchers of government agencies from other first time during the launching of the Farmers’ Field localities upon request. School for IPM on DBM in Cordillera Region in February 1992 by the Department of Agriculture (DA) The level of parasitism and establishment of in cooperation with State University (BSU), C. plutellae La Trinidad and University of the Philippines at Los Level of C. plutellae parasitism Banos (UPLB). Papers and posters or exhibits were The pre-release survey in 1989 indicated the absence presented in conferences, workshops and fairs. of indigenous C. plutellae in crucifer-growing areas Lectures on the IPM technology for DBM were in mid and lowland elevation (Morallo-Rejesus et al., given by the senior author in various trainings/fairs 1994). on vegetable production and IPM with total attendance of 865 persons from 31 municipalities.

268 Proceedings: The Management of Diamondback Moth and Other Crucifer Pests Legend: ▲ Release sites (Phase 1) ¥ Release sites (Phase 2)

NEYVA ECIJA ¥ Bongabon

ILOCOS NORTE ¥ RIZAL ¥ Tanay ILOCOS SUR ¥ San Vicente LAGUNA QUEZON ¥ Sta. Catalina ▲ Los Banos ¥ Dolores ¥ ▲ Cabuyao ¥ Sariaya ¥ San Juan ▲ Nagcarian CAVITE ▲ Liliw ▲ Tagaytay ▲ Majayjay ▲ Silang ▲ Calauan ¥ Tanza ▲ Victoria ¥ Dasmarinas BATANGAS CAMARINES SUR ▲ Balayan ¥ Milaor ¥ Lipa ¥ Iriga ¥ Naga

Figure 1. Release sites of Cotesia plutellae Kurdj. in the Philippines

Development and implementation of IPM 269 The release of Cotesia reduced the DBM Establishment of C. plutellae population below ETL in all release sites. In Quezon C. plutellae is established in release sites in Laguna (1994) the average parasitism in IPM fields of 36% (Liliw, Nagcarlan and Cabuyao), 5Ð6 years after last two weeks after the first release of Cotesia cocoons release with parasitism ranging from 30 to 88% increased to 68% at the heading stage. The highest (Table 1). In Batangas, C. plutellae was already parasitism rate was 83%. established 24 months after the last release in 1991 The rate of parasitism was low in IPM fields in with parasitism of 51% (Morallo-Rejesus et al., 1994) all the release sites in Ilocos Sur (1995) during the but when visited in April 1994, the farmer shifted to first cropping especially if cooperators were not other crops. regularly visited by the agricultural technicians. The C. plutellae is also established in the release sites farmers tend to spray both the IPM and FCP fields; in Quezon (Dolores, Sariaya), 1.2Ð2.6 years after last less than 5 DBM larvae/plant were noted in both fields. release with parasitism ranging from 25 to 50%. In the second cropping, 55% of the original cooperators In Ilocos Sur, no cocoons or parasitized larvae planted cabbage and adopted the technology. The were collected 8Ð12 months after the last release in average parasitism and the number of Cotesia cocoons/ 1995 but adults of C. plutellae were observed in the 50 plants in the IPM managed fields were 68% and 91 field. This is because crucifers are grown after rice in cocoons, respectively, at heading stage. The highest this province. parasitism rate was 86%. The farmers learned to Establishment of C. plutellae is slow in other monitor the DBM population using ETL as basis for release sites in some municipalities due to intermittent insecticide application. In fact, farmers sprayed their plantings, spraying of non-selective insecticides, and FCP fields with microbial insecticides. Thus, Cotesia shifting to crops other than crucifers by the farmers. cocoons developed and an average parasitism of 50% was noted. Farmers' attitudes In Ilocos Norte (1996) during the first cropping The farmer’s attitude based on six years experiences the farmers tend to spray the IPM and FCP fields. But in transferring the Cotesia-based IPM in lowland the application in the former was 3Ð5 times with crucifers could be summarized as follows: microbial insecticides while the latter 5Ð17 times with ¥ Initially, few farmers would like to participate in fenvalerate and methamidophos. DBM population was “on-farm” demonstration of the IPM technology. below ETL of 5 larvae/plant. In spite of the sprayings, Many are skeptical on the effectiveness of the Cotesia cocoons developed (18/50 plants); 15% friendly insects and resort to a “wait and see average parasitism at heading stage was noted in the attitude”. In San Vicente, Sta. Catalina (Ilocos Sur) IPM field while no parasitism in FCP. In the second and Bongabong (Nueva Ecija), more farmers cropping, the average parasitism of 16% and 34 volunteered when informed that the parasitoids and Cotesia cocoons/50 plants were noted at heading stage microbial insecticides will be provided free and in IPM fields. that the differences in yield of IPM (if lower) from FCP due to DBM infestation, will be compensated by AVNET in cash or in kind.

Table 1. Establishment of C. plutellae in release sites of Laguna and Quezon

Location Date of Ave. DBM No. of Cotesia Percent Last date monitoring population cooons/50 plants Parasitism of release LAGUNA Mamatid (Cabuyao) June 93 2.38 36 47 Oct. 91 Mar. 95 1.15 19 30 Oct. 91 Novaliches (Liliw) May 93 4.96 52 58 Aug. 90 May 96 0.62 93 88 Aug. 90 Bucal (Nagcarlan) Mar. 93 3.92 43 69 Feb. 90 May 96 0.32 45 65 Feb. 90 QUEZON Kinabuhayan Jan. 94 1.94 15 40 Apr. 93 (Dolores) Jan. 95 0.72 19 40 Apr. 94 Aug. 95 0.95 11 50 Apr. 94 Mar. 96 1.20 8 25 Apr. 94 Bangkong Kahoy (Dolores) Apr. 96 0.54 16 46 Oct. 93 Mamala Uno (Sariaya) Feb. 95 1.12 10 50 Nov. 94 Oct. 95 1.10 9 52 Nov. 94 Mar. 96 1.12 22 46 Nov. 94

270 Proceedings: The Management of Diamondback Moth and Other Crucifer Pests ¥ Most of the farmers who participated in the on- Impact of IPM technology farm demo were progressive farmers, farmer 1. The philosophy of IPM and the parasitoid-based leaders and high school graduates. Some technology for DBM was imparted to 1 134 farmers progressive farmers with large farms and capital and 176 researchers and technicians (trainers) of 31 tend to be skeptical about the technology. After municipalities and 9 provinces through trainings and all, they could afford the cost of frequent sprayings. lectures. ¥ Farmer cooperators regularly visited and guided 2. The cooperators’ adoption of the technology by AVNET personnel and/or researchers from CSU resulted to: implemented the IPM-DBM technology properly Ð Increased yield ranging from 18.65 to 72.02t/ in their farms and were able to encourage other ha and reduced production cost ranging from farmers to adopt the technology. US$1 04.16 to 3 902.43/ha, 2Ð4% lower than ¥ Farmer cooperators not regularly visited and the farmer control practice (FCP) (Figures 2Ð assisted by the AVNET personnel tended to spray 7). This resulted in the 5 to 78% increase net the designated IPM-managed fields. Without income than FCP ranging from assistance from the trainers, farmers lack the US$2 781.25Ð10 984.48/ha. confidence to rely on parasitoids for fear of crop Ð Reduced insecticidal sprayings from 15Ð36 losses. times to 1Ð9 times before introduction of ¥ The farmer-participated demo farms were very technology and spraying with selective successful (70Ð100%) in municipalities where the insecticides based on ETL. municipal agricultural officers (MAO’s) and 3. The farmer-participated demo farms set-up in 49 agricultural technicians (AT’s) joined hands with farmers’ fields in 21 barangays of 14 the AVNET project personnel and or SCU municipalities in 7 provinces served as a show personnel in visiting and guiding the farmers. window. Those without regular assistance only 30% of the Ð It convinced the cooperators, researchers, cooperators were successful. LGU personnel and other farmers of the Demo farms were discontinued in areas (Cavite, effectiveness of the technology. Nueva Ecija, Rizal, Camarines Sur) where MAO’s/ Ð Farmers learned to monitor for the ETL as AT's could not visit on a weekly basis at least during basis for deciding when to supplement with the initial introduction of the IPM technology. With insecticidal sprays. limited manpower and too many sites to cover, the Ð It influenced other farmers to adopt the release sites could not be monitored regularly by technology or at least reduce the frequency AVNET personnel.

(X100) 20 14 IPM IPM 12 FCP 15 FCP 10 CTRL CTRL 8 10 6

4 5 2

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Per cropping season (X100) 7 30 IPM IPM 6 FCP 25 FCP 5 20 CTRL 4 15 3 10 2

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0 0 Spray frequency Net income/ha (US$) Figure 2. Yield and income of cabbage in IPM and FCP fields in Kinabuhayan, Dolores, Quezon, Philippines

Development and implementation of IPM 271 (X100) 70 20 IPM IPM 60 FCP FCP 15 50

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Figure 3. Yield and income of cabbage in IPM and FCP fields in Sta. Catalina, Ilocos Sur, Philippines

(X100) 70 20 IPM IPM 60 FCP FCP 15 50

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Per cropping season (X100) 12 120 IPM IPM 10 100 FCP FCP 8 80

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Figure 4. Yield and income of cabbage in IPM and FCP fields in San Vicente, Ilocos Sur, Philippines

272 Proceedings: The Management of Diamondback Moth and Other Crucifer Pests (X100) 80 60 IPM IPM

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Per cropping season (X100) 12 120 IPM IPM 10 100 FCP FCP 8 80

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Figure 5. Yield and income of cabbage in IPM and FCP fields in San Juan, Ilocos Sur, Philippines

(X100) 80 50 IPM IPM

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Per cropping season (X100) 12 120 IPM IPM 10 100 FCP FCP 8 80

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Figure 6. Yield and income of cabbage in IPM and FCP fields in Magsingal, Ilocos Sur, Philippines

Development and implementation of IPM 273 (X100) 35 20 IPM IPM 30 FCP FCP 15 25

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Per cropping season (X100) 12 35 IPM IPM 10 30 FCP FCP 25 8 20 6 15 4 10

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Figure 7. Yield and income of cabbage in IPM and FCP fields in Laoag City, Ilocos Norte, Philippines

of sprayings from 15Ð36 times to 8Ð15 times, Since DBM is not the only destructive pest of and the use of selective insecticides especially crucifers, research on the development of IPM for other the microbials. major pests of crucifers should be supported by the Ð Increased awareness by farmers of the role national government and or external organizations. of natural enemies in IPM and conserving The AVNET project with AVRDC and other them by spraying only when necessary and countries, with local coordination by PCARRD, has with selective insecticides. been fruitful and beneficial. Therefore, linkages with Ð Increasing farmers’ awareness on the hazards external organization/institutions that seek to of mixing insecticides, using non-selective rationalize pest management practices in crucifers and and unrecommended insecticides, and using other crops should be given top priority. dosages beyond the recommended rates. 4. C. plutellae is established in release sites, and Acknowledgement present in neighbouring crucifer areas resulting Authors wish to acknowledge the financial assistance to relatively low DBM population. of Asian Development Bank (ADB) through AVRDC 5. The networking with local government units led and the counterpart local funding from the national to increased awareness of government officials on government through PCARRD. The technical the role of the friendly insects in the pest assistance from AVRDC especially Dr. N.S. Talekar management. Thus they supported the initiatives in the implementation of the project in IPM is greatly of trainers from LGU, DA and SCUs in promoting appreciated. the IPM-DBM technology. 6. The transfer of Cotesia-based IPM, subsequently, Literature Cited reduced the hazards associated with consumption AVRDC (1990, 1989). Progress Report. Asian Vegetable of pesticide-ridden vegetables and the pollution Research and Development Center. Shanhua, Taiwan, of the environment. R.O.C. 351 pp. Barroga, S. F. (1967). Screening of chemicals for the control of diamondback moth (Plutella xylostella) attacking Recommendations cabbage. Ann. Rpt. Bu. Plt. Ind. Fy. 1966Ð67.25 pp. The Department of Agriculture and LGUs should Barroga, S. F. and B. Morallo-Rejesus, (1975). A survey of ensure sustainable institutional support for the transfer diamondback moth (Plutella xylostella) population for of the technology and marketing of the vegetables to resistance to insecticides in the Philippines. The Phil. many farmers especially unlettered resource-poor J. Plant Ind. 40Ð41: 1Ð14. farmers.

274 Proceedings: The Management of Diamondback Moth and Other Crucifer Pests Cadapan, E. P. and B. P. Gabriel (1972). Field evaluation of Morallo-Rejesus, B., A. S. Sayaboc, G. P. Fajardo and J.E. Dipel and other commercial Bacillus thuringiensis in Eusebio (1994). Introduction and field releases of larval comparison with standard insecticides used in the parasitoid Cotesia plutellae (Kurdj.) for the control of diamondback moth, Plutella xylostella L. and management of diamondback moth, Plutella xylostella other insect pests affecting crucifers. UPCA Ann. Rpt. (L.) of crucifers in the Philippines. Phil. Agric. 77(4): 1972Ð1973. 15 pp. 481Ð499. Cardona, E. V. (1986). Study on the effective concentration Ooi, P. and G. S. Lim, (1989). Introduction of exotic of Nomolt 5SC and Thuricide WP against DBM parasitoids to control the diamondback moth in infesting head cabbage. Terminal Rpt. Benguet State Malaysia. J. Plant Prot. Trop. 6: 103Ð111. University (BSU). 10 pp. Sastrosiswojo, S. and G. Sastrodihardjo, (1986). Status of Ebuenga, C. (1992). Detection of resistance of diamondback biological control of diamondback moth by introduction moth (Plutella xylostella [linnaeus]) to twelve of parasitoid Diadegma eucerophaga in Indonesia. In: insecticides. M.S. Thesis, Dept. of Entomology, UPLB, N.S. Talekar and Griggs, T. D. (eds.) Diamondback 84 pp. Moth Management. Proc. First International Workshop, Lim, G.S. (1986). Biological control of diamondback moth. AVRDC, Shanhua, Taiwan. p. 50Ð54. In Talekar, N.S. and Griggs, T.D. (eds.), Diamondback Talekar, N. S. (1990). Development of an integrated pest Moth Management. Proc. 1st International Workshop, management program for the control of diamondback AVRDC, Shanhua, Taiwan. p. 159Ð171. moth on cruciferous vegetables. In Opena, R.T. and Morallo-Rejesus, B. and A. S. Sayaboc, (1990). Management Kyomo, M.L. (eds.) Veg. Res. and Dev. in SADCC of diamondback moth with Cotesia plutellae: Prospect countries. AVRDC, Shanhua, Taiwan. p. 147Ð157. in the Philippines. In: Talekar, N.S. (ed.). Management Talekar, N. S., Yang, S. C. and S. T. Lee, (1992). Introduction of DBM and Other Crucifers Pests. Proc. 2nd of Diadegma semiclausum to control diamondback International Workshop, Tainan, Taiwan, AVRDC Publ. moth in Taiwan. In N.S. Talekar (ed.). Diamondback # 92Ð368. p. 279Ð286. Moth and Other Cruciferous Pests; Proc. 2nd Int’l Workshop. Tainan, Taiwan, AVRDC Publ. No. 92Ð368. p. 263Ð270.

Development and implementation of IPM 275