Toxicity of Insecticides to Cotesia plutellae, a Parasitoid of Diamondback Moth

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1 32 Toxicity of Insecticides to Cotesia plutellae, a Parasitoid of Diamondback Moth Suey-Sheng Kao and Ching-Chou Tzeng Biopesticide Department, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Wufeng, Taichung, Taiwan, ROC Abstract Toxicity of 17 commonly used insecticides used to control diamondback moth, Plutella xylostella (L.) was evaluated against adults of Cotesia plutellae Kurdjumov. The insecticide concentrations studied were equivalent to those recommended in the field. Adults of the parasitoid were released into exposure kits with fresh dry insecticide film for 24 hours, at which time mortalities were noted. The surviving adults were supplied with larvae of diamondback moth for parasitism. Results revealed that carbofuran, cartap, mevinphos, quinalphos, methomyl, methamidophos and deltamethrin were harmful (mortality >99%) to adults of C. plutellae, while the remaining insecticides proved to be harmless (mortality < 50%). The effects of insecticides in reducing parasitism of C. plutellae in decreasing order were as follows: fenvalerate > acephate > Bacillus thuringiensis subsp. kurstaki strain NRD-12 (SAN 415) > teflubenzuron > permethrin > chlorfluazuron > acephate > B. thuringiensis subsp. kurstaki strain HD-1 (Dipel) > fenvalerate > teflubenzuron. Most of these insecticides were considered harmless to parasitism of C. plutellae on larvae of diamondback moth except fenvalerate, acephate and B. thuringiensis which were classified as slightly harmful. Seven insecticides (quinalphos, deltamethrin, carbofuran, methomyl, cartap, mevinphos, methamidophos) were highly toxic to adults of C. plutellae and were used to test their toxicity to the pupal stage of C. plutellae. Cocoons at different ages (1-, 2-, 3-, 4-dayold) were sprayed with insecticides at recommended concentrations, and emergence of adults and mortality 24 hours after emergence were recorded. All insecticides tested were harmless to pupae of C. plutellae, except quinalphos which was ranked slightly harmful. These results provide further information on the selectivity of insecticides in integrated management of diamondback moth. Introduction The diamondback moth (DBM) Plutella xylostella (L.), (Lepidoptera: Yponomeutidae) is one of the most important pests of cruciferous vegetables in Taiwan. It has several natural enemies (Wu 1968), and inundative releases of the larval parasitoid Cotesia plutellae Kurdjumov apparently exert an effective check of this pest (Chiu et al. 1974). However, it appears unlikely that C. plutellae alone could achieve the desired level of control of DBM (Chua and Ooi 1986). Regular insecticide spray to control DBM therefore seems inevitable. However, there is little information available on the toxicity to C. plutellae of insecticides commonly used in cruciferous vegetable cultivation (Fan and Ho 1971; Chang 1974; Feng and Wang 1984; Mani and Krishnamoorthy 1984). This may cause serious damage to C. plutellae if insecticides applied are not safe for this parasitoid. It will be possible to practice integrated control measures against DBM only if selective insecticides are chosen. Therefore, investigations were undertaken to develop a standard testing 287

2 288 Kao and Tzeng method to determine the side effects of insecticides on C. plutellae and to evaluate toxicity of insecticides against adults and pupae of this parasite with the objective of finding selective insecticides for this parisitoid. Materials and Methods Exposure of parasitoids to insecticide was carried out in cages developed by Hassan et al. (1985). The cage consists of an aluminum frame (13 cm long x 13 cm wide x 1.5 cm high) with two square glass plates (13 cm x 13 cm) as ceiling and floor. The walls have ventilation holes coated with black cloth and a slit opening to introduce the parasitoids. The insecticide treatment was conducted with a Potter Spray Tower (Burkard Co.). Seventeen insecticides were applied at recommended concentrations (Table 1) on the inner surfaces of two glass plates (0.012 ml/cm² surface). Water-treated glass plates were used as a control. All tests were replicated five times. Cotesia plutellae adults were reared on DBM larvae, which in turn were reared on rape seedlings using the method developed by Liu and Sun (1984). Adults ( pairs, 1-2 days old) were introduced into the exposure cage lined with fresh, dry insecticide film (30 min after spray) and supplied with honey-agar for food. Determination of mortality was made 24 hours after initial exposure. The average number of dead parasitoids was expressed as a percentage of the number released at the beginning of the experiment. The results were compared with the control. The surviving adults were transferred to a screened parasitism cylinder cage (height 15 cm, diameter 21 cm) and offered honey-agar for food and DBM larvae for oviposition. One hundred 2nd-instar larvae of DBM were offered on the 2nd, 4th, 6th and 8th day after treatment. The number of DBM larvae parasitized was calculated for each cage. The reduction in parasitism is expressed as percent of untreated control (= 0%). Common name Commercial name Table I. List of insecticides tested. Recommended Source Formulation concentration (ppm) (% a.i.) deltamethrin Decis Teh-Hua 2.8% E.C permethrin Kestrel Te-Cheng % E.C fenvalerate Sumicidin Ruey-Feng 20% W.P Sumicidin Ruey-Feng % E.C mevinphos Phosdrin Shinung 25.3% E.C methamidophos Tamaron VETERANS~ 50% E.C I67 quinalphos Bayrusil VETERANS~ 25% E.C acephate Orthene Great-Victory 75% S.P Orthene Great-Victory 25% E.C I25 carbofuran Furadan Shinung 40.64% F.P methomyl Lannate Shinung 24% S cartap Padan Lih-Nung 50% S.P teflubenzuron Nomolt BAS F 13.57% F.P Diaract San-Lee 5% E.C chlorfluazuron Atabron TPFAACP 5% E.C I Bacillus thuringiensis subsp. kurstaki strain NRD- I2 SAN-4 I5 Agro Chem IU/mg ISC 5.33 IU/mg Bacillus thuringiensis subsp. kurstaki strain HD-I Dipel Nung-Tai IU/mg W.P. 16 IU/mg ªVETERANS Chemicals, VACRS., R.O.C. Taiwan Provincial Farmer s Association Agricultural Chemical Plant.

3 Insecticide Toxicity to C. plutellae 289 All the testing kits and insects were maintained during the observation period at 25 C, 80% RH and at a photoperiod of 12L: 12D in a walk-in growth chamber. The effect of the insecticides on C. plutellae was classified by reference to the categories proposed by IOBC/WPRS Working Group (Hassan et al. 1985). Data were statistically analyzed by applying analysis of variance (ANOVA) and Duncan's multiple range test (DMRT). Seven insecticides which were harmful to C. plutellae adults - methomyl, deltamethrin, methamidophos, cartap, carbofuran, mevinphos, quinalphos - were prepared as aqueous solutionbased on recommended concentration. Twenty cocoons (1-, 2-, 3-, and 4-day-old) were spread uniformly in a petri dish and sprayed with a Potter Spray Tower with 2 ml of insecticides emulsion. The cocoons were air-dried and kept individually in 24-well culture-plates and placed in chambers at 25 C, 80% RH and 12L: 12D. Honey-agar was provided as food. The lid of the culture-plate was punched with needles for ventilation. Cocoons treated with water served as controls. Each treatment was replicated five times. Adults emergence and dead adults 24 hours after emergence were recorded daily. The data were converted to percent mortality and corrected with Abbott's formula. Data were statistically analyzed by applying ANOVA and DMRT. Results and Discussion Mortality of C. plutellae as a result of exposure to different insecticides is presented in Table 2. Carbofuran cartap, mevinphos and quinalphos caused 0% mortality. Methomyl, methamidophos and deltamethrin caused the second highest mortality of 99.8%, 99.8 % and 99.6% respectively. Fenvalerate (40 ppm) caused 30.1 % mortality, whereas the remaining insecticides resulted in less than 7% mortality. Among them, Diaract E.C. (teflubenzuron) (25 ppm) and fenvalerate (33.3 ppm) caused no mortality. There were no significant differences between sexes on mortality with all insecticides tested. Based on the criteria suggested by Hassan et al. (1985) to evaluate the toxicity of insecticides to natural enemies, carbofuran, cartap, mevinphos, quinalphos, methomyl, methamidophos and deltamethrin were rated as harmful. The remaining insecticides, fenvalerate (40 ppm), acephate (500 ppm), teflubenzuron (Nomolt F.P., 33.9 ppm), B. thuringiensis subsp. kurstaki strain Table 2. Effect of insecticides on adults of C. plutellae 24 hours after exposure. Insecticides Mortality (%)ª Evaluationb Furadan (carbofuran) 0 a 4 Padan (cartap) 0 a 4 Phosdrin (mevinphos) 0 a 4 Bayrusil (quinalphos) 0 a 4 Lannate (methomyl) a 4 Tamaron (methamidophos) a 4 Decis (deltamethrin) 99.58% 4 Sumicidin (fenvalerate) b I Orthene (acephate) 6.49 c 1 Nomolt (teflubenzuron) 4.55 cd 1 SAN 4 I5 (B. thuringiensis subsp. kurstaki strain NRD- 12) 2.85 cde I Atabron (chlorfluazuron) I.84 cdef I Kestrel (permethrin) 0.81 def I Dipel (B. thuringiensis subsp. kurstaki strain HD- 1 ) 0.20 ef I Orthene (acephate) 0.20 ef 1 Sumicidin (fenvalerate) Of I Diaract (teflubenzuron + fluvalinate) Of I ªData were transformed to sin- 1 prior to statistic 1 analysis. Values in the column followed by the same letter are not significantly different at 5% level by DMRT. 1 = harmless (<50%). 2 = slightly harmful (50-79%). 3 = moderately harmful (80-99%). 4 = harmful (>99% mortality). Hassan et al. (1985).

4 290 Kao and Tzeng NRD-12 (SAN 415 ISC, 5.33 IU/mg), chlorfluazuron ( ppm), permethrin (50 ppm), B. thuringiensis subsp. kurstaki strain HD-1 (Dipel W.P., 16 IU/mg), acephate (312.5 ppm), fenvalerate (33.3 ppm) and teflubenzuron + fluvalinate (Diaract E.C., 25 ppm) were considered as harmless to adults of C. plutellae. The mortality of C. plutellae adults caused by quinalphos is consistent with results reported by Mani and Krishnamoorthy (1984), and Chang (1974). They indicated that adults of C. plutellae were highly susceptible to quinalphos. Peter and David (1988) reported that quinalphos caused 0% mortality to Apanteles taragamae adults. Our results showed that methomyl and mevinphos had adverse effect on C. plutellae adults and are in accord with those of Chang (1974) who found the above-mentioned insecticides to be highly toxic to C. plutellae. Our results showed that C. plutellae was extremely susceptible to cartap, carbofuran and methamidophos. It is not suitable to use cartap, carbofuran, methamidophos, deltamethrin, methomyl, mevinphos, and quinalphos in IPM involving mass release of C. plutellae adults, although observations made by Chang (1974) showed that tertiary amines cartap caused only 60 % mortality to C. plutellae adults. The pyrethroids were harmless to adults of C. plutellae. This agrees with earlier observations on Apanteles sp. (Waddill 1978), A. murginiventris (Wilkinson et al. 1979), C. plutellae (Mani and Krishnamoorthy 1984; Feng and Wang 1984), and A. taragamae (Peter and David 1988). However, deltamethrin (Decis E.C., 28 ppm), which caused 0% adult mortality in our study, is an exception. Peter and David (1988) demonstrated that deltamethrin (Decis 2 ppm) killed only 14% of A. taragamae adults. Mani and Krishnamoorthy (1984) showed that deltamethrin (Decis E.C., 1.4 ppm) caused % mortality of C. plutellae adults. The higher dose of deltamethrin used in our study probably caused the higher mortality. A reduced dosage of deltamethrin may have greater potential for use as a selective insecticide in cruciferous ecosystems. Acephate was one of the least toxic conventional insecticides tested. Our results agree with the previous study of Feng and Wang (1984). Insect growth regulators (IGRs) including teflubenzuron (Diaract), chlorfluazuron (Atabron) and teflubenzuron (Nomolt) are safe for adults of C. plutellae. Our studies also indicated that B. thuringiensis subsp. kurstaki strain HD-1 (Dipel, SAN 415 ISC) had no effect on adults of C. plutellae. The effect of insecticides on parasitism by surviving C. plutellae at different time intervals following treatment is shown in Fig. 1. Generally 4 days after treatment the parasitism was highest, followed by 2, 6 and 8 days after treatment. Substantial differences in parasitism were recorded in comparison with the check within each time interval. Diaract showed the highest and fenvalerate (Sumicidin W.P., 40 ppm) showed the lowest parasitism. There was no significant difference in parasitism between the control and Diaract exposure at the 2nd, 4th and 8th days. Results of the reduction in parasitism by insecticides are shown in Table 3. Based on the criteria proposed by Hassan et al. (1985), most of the insecticides were harmless to C. plutellae. Only three out of insecticides were classified as slightly harmful. They were fenvalerate (Sumicidin W.P. 40 ppm, 2 and 8 days after treatment), acephate (Orthene S.P., 500 ppm, 2 days after treatment) and B. thuringiensis subsp. kurstaki strain NRD-12 (SAN 415 ISC, 6 days after treatment). The effects of the insecticides in reducing parasitism of C. plutellae in decreasing order were as follows: fenvalerate (Sumicidin W.P, 40 ppm) >acephate (Orthene S.P., 500 ppm) > B. thuringiensis subsp. kurstaki strain NRD-12 (SAN 415 ISC, 5.33 IU/mg) > teflubenzuron (Nomolt F.P., 33.9 ppm) > permethrin (Kestrel E.C., 50 ppm) > chlorfluazuron (Atabron E.C., ppm) >acephate (Orthene E.C., ppm) > B. thuringiensis subsp. kursraki strain HD- 1 (Dipel W.P, 16 IU / mg) > fenvalerate (Sumicidin E. C., 33.3 ppm) > teflubenzuron (Diaract E.C., 25 ppm). Concentrations and formulations of IGRs, pyrethroids and B. thuringiensis subsp. kurstaki appear to have a significant impact in the reduction of parasitism. The effects of different insecticides on pupae are expressed in percent emergence (Fig. 2). The results revealed that there were significant differences between the seven insecticidal treatments with respect to percentage adult emergence.the maximum toxicity of insecticide to 1-day-old pupae was that of quinalphos followed by mevinphos, carbofuran, cartap, methamidophos, deltamethrin, and methomyl. With few exceptions (Fig. 2), the toxicity of

5 Insecticide Toxicity to C. plutellae TWO DAYS AFTER TREATMENT CK DlAR SU DlPE OR25 ATAB KEST NOMO SAN OR75 SU20 INSECTICIDES FOUR DAYS AFTER TREATMENT N CK DIAR SU DlPE OR25 A INSECTICIDES SIX DAYS AFTER TREATMENT CK SU DlPE OR25 ATAB KEST NOMO SAN OR75 SU20 INSECTICIDES EIGHT DAYS AFTER TREATMENT 30 0 CK DIAR SU DlPE OR25 ATAB KEST NOMO SAN OR75 SU20 INSECTICIDES Fig. I. Effect of insecticides on parasitism of C. plutellae. DlAR = Diract; SU IO = Sumicidin % E.C.; DlPE = Dipel; OR25 = Orthene 25% E.C.; ATAB = Atabron; KEST =Kestrel; NOMO = Nomolt; SAN = SAN4 15; OR75 = Orthene 75% S.P.; SU20 = Sumicidin 20% W.P. The values in bars with dissimilar letters significantly differ at 5% level according to Duncan's multiple range test.

6 292 Kao and Tzeng Table 3. Reduction in parasitism by insecticides. Insecticides recommended (concentration) 20 % Sumicidin W.P. (40 ppm) 75% Orthene S.P. (500 ppm) 8000 IU/mg SAN 4 I5 ISC (5.33 IU/mg) 58.7 a 50.7 ab 45.0 abc Reduction (%) after treatment (days)ª a 45.7 ab 52.7 a 25.5 ab 49.7 ab 46.7 a 24.5 ab 51.0 a 40.6 a 13.57% Nomolt F.P. (33.9 ppm) 41.3 bc 22.8 ab 46.7 ab 40.9 a % Kestrel E.C (50 ppm) 36.6 bcd 22.2 ab 48.3 ab 44.0 a 5% Atabron E.C. (1 0 ppm) bcd 22.7 ab 36.5 bcd 34.2 ab 25% Orthene E.C. (312.5 ppm) 3 I.6 cde 25.6 ab 42.6 abc 22.7 b lu/mg Dipel W.P. (16 IU/mg) 25.0 de 15.3 bc 30.8 cd 21.4 bc Sumicidin E.C. (33.3 ppm) 18.9 e.3 cd 26.4 de 8.8 cd 5% Diaract E.C. (25 pm) 8.0 f 4.9 d 19.4 e 6.9 d ªData were transformed to prior to statistical analysis, and the values in each column followed by the same letter were not significantly different at 5% level by DMRT. insecticides to 2-, 3-, and 4-day-old pupae exhibited similar trends as to the 1-day-old pupae. The comparison of percent emergence from 1- to 4-day-old pupae treated with each insecticide is reported in Fig. 2. Results showed that 3- and 4-day-old pupae were more tolerant to methamidophos, cartap and carbofuran than 1- and 2-day-old pupae. However, there were no significant differences of percentage emergence between four pupal ages in the other treatments. The system for grading the toxicity of insecticides to beneficials suggested by Hassan et al. (1985) was also adopted to evaluate the toxicity to pupae in our study (Table 4). Quinalphos, which caused 54.9% mortality to 4-day-old pupae, was rated as slightly harmful. The remaining insecticides were considered harmless to pupae of C. plutellae.

7 Insecticide Toxicity to C. plutellae day 2 days 3 days 4 days control metho delta metha cartap carbo mevin quina Insecticides Fig. 2. Effect of various insecticides applied to 1-4 day-old C. plutellae pupae on the emergence of adults. The bars with dissimilar letter are significantly different at 5 % level according to Duncan s multiple range test. Table 4. The effects of insecticides on pupae of C. plutellae. Mortality (%)ª and toxicity ratingb at different pupal ages Insecticides I day 2 days 3 days 4 days Lannate (methomyl) Mort. Rating Mort. Rating Mort. Rating Mort. Ratinn 6.5 I 0 I 5.2 I 1.1 I Decis 7.5 I 2. I I 4.2 I 0 I (deltamethrin) Tamaron 7.5 I 11.5 I 0 I 0 I (methamidophos) Padan (cartap) 17.2 I 3. I I 4.2 I 7.7 I Furadan 18.3 I 16.7 I 3. I I 4.4 I (carbofuran) Phosdrin 22.6 I 17.7 I 25.0 I 14.3 I (mevinphos) Bayrusil 30. I I 39.6 I 39.6 I (quinalphos) ªMeans of five replications. Mortality is expressed in percent of control. = harmless (< 50%), 2 = slightly harmful (50-79%). 3 = moderately harmful (80-99%), 4 = harmful (>99% mortality). Hassan et al. (1985). Mortality of newly emerged adults (1-day-old) from insecticide-treated pupae is shown in Fig. 3. Mortality with quinalphos and mevinphos was the highest. The remaining treatments

8 294 Kao and Tzeng caused < 5 % mortality. Mortality of newly emerged adults from 2-day-old pupae treated with mevinphos was the highest (%). However, mortality of newly emerged adults from 3- and 4-day-old pupae treated with insecticides was very low. A comparison of mortality of newly emerged adults (1-day-old) between four pupal ages affected by each insecticide is shown in Fig. 3. There was a general tendency for the mortality to decrease as the pupae grew older. Once the adults emerged from the insecticide-treated pupae, the chances of being affected by the insecticide residue from cocoon within 24 hours seemed relatively small. 24 I 18 2 days 3 days 4 days a a metho delta metha cartap carbo mevin quina Insecticides Fig. 3. Mortality of newly emerged C. plutellae adults, the pupae of which were treated with various insecticides when they were 1-4-day-old. Values in bars with dissimilar letters are significantly different at 5% level according to Duncan's multiple range test. Conclusions Adults were susceptible to insecticidal treatment but the robust life stage-the pupal stage - was relatively tolerant. This agrees with earlier observations on C. plutellae (Fan and Ho 1971; Mani and Krishnamoorthy 1984). Judging from direct contact toxicity to pupae and residual toxicity from treated cocoons, with the exception of quinalphos, the insecticides tested harmful to adults but harmless to all pupal stages of C. plutellae. Although the insecticides were applied in recommended concentrations, the test methods must nevertheless be regarded as more stringent despite the optimal conditions under which the natural enemies were kept (feeding, ventilated cages). Compared with the insects kept in the glass cage with its contaminated surface, organisms in the field have a chance to survive on noncontaminated parts of the plants. Therefore, it can be concluded with a high degree of certainty that insecticides which proved to be harmless in the laboratory tests are also harmless in the field (Hassan 1983). IPM will be most effective if the insecticides are effective against pests and relatively safe for beneficials. Insecticides with these desirable attributes go well with biological control, and will reduce the side effects of insecticide usage. The variations in the response of the parasitoids to test insecticides may help in management of DBM. Selection of the right insecticide and proper timing of application would also be useful tools, both in conserving beneficials and achieving good control (Lingren et al. 1972). We suggest rotational application both in time and/or space, of selective insecticide, i.e. teflubenzuron (IGR), fenvalerate (pyrethroid), B. thuringiensis subsp. kurstaki and acephate (OP) in combination with inundative release of C. plutellae adults to achieve

9 Insecticide Toxicity to C. plutellae 295 sound IPM of DBM in cruciferous ecosystems. Application of commonly used insecticides (except quinalphos), though harmful to adults of C. plutellae, could be timed to coincide with the Occurrence of high population densities of cocoons which are less affected by insecticides. These results further selectivity in IPM for DBM. Acknowledgments This research was financially supported by the Council of Agriculture of Republic of China. The Asian Vegetable Research and Development Center, Shanhua, supplied stock culture of Cotesia plutellae for this project. We would also like to thank Dr. S.A. Hassan, Institute for Biological Pest Control, BBA, for constructive comments on this manuscript, and Miss L. Y. Tseng and Miss S. L. Chen, of TACTRI, for their enthusiastic assistance. References Chang, L.C Studies on the toxicity of insecticides to parasite (Apanteles plutellae) of diamondback moth. J. Taiwan Agri. Res., 23, (in Chinese). Chua, T.H., and Ooi, P.A.C Evaluation of three parasites in the biological control of diamondback moth in Cameron Highlands, Malaysia. In Talekar, N.S., and Griggs, T.D. (ed.) Diamondback moth management: Proceedings of the first international workshop, Asian Vegetable Research and Development Center, Shanhua, Taiwan, Chiu, S.C., Chien, C.C., Chou, K.C., Chang, L.C., and Chiu, S.C Mass production and field liberation of a larval parasite (Apanteles plutellae) of the diamondback moth. J. Taiwan Agri. Res., 23, (in Chinese). Fan, S.H., and Ho, K.K A preliminary study on the life history, rearing method of Apanteles plutellae Kurdj and the effects of different insecticides to it. Plant Prot. Bull., 13, (in Chinese). Feng, H.T., and Wang, T.C Selectivity of insecticide to Plutella xylostella (L.) and Apanteles plutellae Kurdj. Plant Prot. Bull., 26, Hassan, S.A Results of laboratory tests on the toxicity of a series of pesticides against egg parasites of the genus Trichogramma (Hymenoptera, Trichogrammatidae). Plant Res. Develop., 18, Hassan, S. A., Bigler, F., Blaisinger, D., Bogenschutz, H., Brun, J., Chiverton, P., Dickler, E., Easterbrook, M.A., Edwards, P.J., Englert, W.D., Firth, S.I., Hung, P., Inglesfield, C., Klingauf, F., Kuhner, C., Ledieu, M.S., Naton, E., Oomen, P.A., Overmeer, W.P.J., Plevoets, P., Reboulet, J.N., Rieckmann. W., Samsoe-Petersen, L., Shires, S.W., Staubli, A., Stevenson, J., Tuset, J. J., Vanwetswinkel, G., and van Zon, A. Q Standard methods to test the side-effects of pesticides on natural enemies of insects and mites developed by the IOBC/WPRS working group Pesticides and Beneficial Organisms. Bull. OEPP/EPPO, 15, Lingren, P.D., Wolfenbarger, D.A., Nosky, J.B., and Diaz, M.D. Jr Response of Campoletis perdistinctus and Apanteles murginiventris to insecticides. J. Econ. Entomol., 6-55, Liu, M.Y., and Sun, C.N. 1984, Rearing diamondback moth (Lepidoptera: Yponomeutidae) on rape seedlings by a modification of the Koshihara and Yamada method. J. Econ. Entomol., 75, Mani, M., and Krishnamoorthy, A Toxicity of some insecticides to Apanteles plutellae, a parasite of diamondback moth. Trop. Pest Mgmt., 30, Peter, C., and David, B.V Comparative toxicity of some insecticides to Apanteles taragamae (Hymenoptera: Braconidae). Trop. Pest Mgmt., 34,

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