N. Bakthavatsalam ¹, G. Ravi ², Deepa Bhagat ¹, P. L. Tandon ¹

Affiliations
1 National Bureau of Agriculturally Important Insects, Post Bag No. 2491, H. A. Farm Post, Bellary Road, Hebbal, Bangalore 560 024, Karnataka, IN
2 Tamil Nadu Rice Research Institute, Aduthurai 612 101, Tamil Nadu, IN

Abstract

Tetrastichus schoenobii Ferriere is an efficient egg parasitoid on rice yellow stem borer, Scirpophaga incertulas (Walker). The electrophysiological response of females of T. schoenobii to the extracts of plants collected from rice fields was studied under laboratory conditions. The highest response was noticed to the host plant of the pest, S. incertulas and honey solution. Response was also noticed to the flowers of Hyptis suaveolens, a common weed in rice fields, mostly by female parasitoids to the flowers of the non-crop vegetation.

Keywords

Tetrastichus schoenobii, Scirpophaga incertulas, Electrophysiology, Hyptis suaveolens.

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P. L. Tandon ¹, N. Bakthavatsalam ¹

Affiliations
1 Project Directorate of Biological Control, Post Box No.2491, H. A. Farm Post, Bellary Road, Hebbal, Bangalore - 560024, Karnataka, IN

Abstract

Evaluation of 15 tomato genotypes (Varieties/hybrids) for their influence on the parasitization efficiency of Trichogramma chilonis Ishii on Helicoverpa armigera (Hubner) eggs under screen house condition revealed significant differences in terms of per cent parasitization. Least parasitization was recorded on Arka Abha (20%) and highest on Arka Ahuti (50%), followed by Anand-1 (46.66%). Olfactory response of T. chilonis to tomato fruit volatiles did not show significant differences. However, leaf volatiles showed significant differences in their attraction to T. chilonis. The fruit volatiles identified from different genotypes comprised 16 compounds, which include alkane hydrocarbons, monoterpenes, sesquiterpenes, diterpenes and other metabolites. It revealed great fruit volatile diversity in terms of number of compounds (qualitative) and their proportions (quantitative). Maximum compounds were identified from variety Ramya and Pusa Ruby (12 each). The major compound present in the fruit volatiles was Linalool-L and its proportionate concentration varied from 1.79 (Pusa Ruby) to 91.12 per cent (Arka Abha). This was followed by heptadecane (present in all the genotypes) and the proportionate concentration varied from 2.89 (A. Saurabh) to 62.9 per cent varalakshmi. The leaf volatile profiles of the genotypes evaluated include 19 compounds. Except genotype varalakshmi in which a-pinene constituted 69.69 per cent of total volatiles, in all other genotypes heptadecane was the main compound and the concentration varied from 21.72 (in Ramya) to 60.75 per cent (in A. Abha). Some of the compounds identified α-phellandrene, a-pinene, trans-caryophyllene, (Z)-α-farnesenc, trans-α-ocimene and selinene are known for their synomonal activity.

Keywords

Genotypes, Helicoverpa armigera, Parasitizing Efficiency, Tomato, Trichogramma Chilonis, Volatile Diversity.

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P. L. Tandon ¹, N. Bakthavatsalam ¹

Affiliations
1 P. B. No. 2491. H.A. Farm Post, Bellary Road, Hebbal, Bangalore, 560 024, Karnataka, IN

Abstract

Experiments were done on electro-physiological and olfactometeric responses of Helicoverpa armigera (Hiibner) and its egg parasitoid Trichogramma chilonis Ishii to leaf and floral volatiles of Tagetes erecta Linnaeus and Solanum viarum Dunal. H. armigera female moths exhibited highest mean absolute net electrophysiological response (−0,462mv) to floral volatiles of T. erecta followed by volatiles from leaves (−0.395mv), In case of olfactometric responses, T. chilonis showed maximum net response to hexane extract of T. erecta flower bud (47.5%), followed by floral and leaf volatiles. However, statistically all these cues were on par. The volatile compounds identified from leaves and flowers of T. erecta, and leaves of 5. viarum were 16, 17 and 21 in number, respectively. The compounds found common in both the trap crops were: 1, 2, benzenedicarboxylic acid, cis-a-bisabolene, eicosane, hexacosane, heptacosane, pentacosane, tetradecane and nonadecane. Among the floral volatiles, piperitenone was in the highest proportion (25.5%), followed by piperitone (5.39%), limonene (4.83%), trans- b-ocimene (3.35%), cis-epoxy-ocimene (4.83%), myrcene (1.13%) and BHT-aldehyde (0.34%). Studies revealed that both the trap crops -T. erecta and S.viarum are Trichogramma friendly.

Keywords

Electrophysiological and Olfactometric Responses, Helicoverpa armigera, Solanum viarum, Tagetes erecta, Trap Crops, Trichogramma chilonis, Volatile Compounds.

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N. Bakthavatsalam ¹, P. L. Tandon ¹

Affiliations
1 Biological Control (ICAR), P. B. No 2491, H. A. Farm Post, Bellary Road, Hebbal, Bangalore, 560 024, Karnataka, IN

Abstract

Trichogramma chilonis Ishii is an effective egg parasitoid for the management of several lepidopterous borer pests. With a view to improve its efficiency further, study was conducted on the influence of strain variability and kairomonal substances on its parasitization under multiple-choice assay using an 8-arm olfactometer. The results revealed that irrespective of treatment with kairomonal substances, highest mean parasitization of Corcyra cephalonica (Stainton) eggs (21.5%) was done by strain collected from the sugarcane borers (Strain IS). Least mean parasitization was observed in eggs exposed to Strain 22. Among the five kairomonal substances tested, hexacosane (0.1%) induced highest mean egg parasitization, The interaction between T. chilonis strains and kairomones indicated that the combination of Strain 15 and hcxacosane (0.1%) was most effective and registered highest egg parasitization (36.6%), followed by the combination of Strain 15 and tricosanc (0.1%). The scope of selecting and utilizing the behaviorally responsive strains in combination with their effective kairomones for field release is discussed.

Keywords

Kairomonal Substances, Parasilization Efficiency, Strain Variability, Triehogramma chilonis.

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N. Bakthavatsalam ¹, P. L. Tandon ¹, S. B. Patil ², Bhemanna Hugar ³, A. Hosamani ³

Affiliations
1 Project Directorate of Biological Control, Post Bag No, 2491, H. A. Farm Post, Bellary Road, Bangalore, 560 024, Karnataka, IN
2 Department of Entomology, University of Agricultural Sciences, Dharwad, Karnataka, IN
3 Regional Agricultural College (UAS, Dharwad), Raichur, Karnataka, IN

Abstract

Adults and larvae of Chrysoperla carnea (Stephens) utilize different kairomones for oviposition, prey selection and acceptance. The larval kairomones containing scale extracts fortified with tricosane along with the eggs of Corcyra cephalonica (Stainton) as the supplementary diet, and the adult kairomone, acid hydrolyzcd L-tryptophan were studied to increase the predatory activity of the C. carnea in cotton ecosystem at three locations during 2002-2004. Controls were maintained with the two releases of C. carnea and without any treatment. In all the locations, the number of eggs, larvae, pupae or adult C. carnea was more than the treated control and control. The number of aphids, jassids, and the incidence of bollworm were significantly less in kairomone treated plots, compared to other plots. However, no difference was observed in the activity of coccinellids predators. The scope for utilizing the kairomones as reinforcing agents for C. carnea is discussed.

Keywords

Abundance, Chrysoperla Carnea, Cotton, L-Tryptophan, Scale Extract, Tricosane.

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N. Bakthavatsalam ¹, P. L. Tandon ¹

Affiliations
1 Project Directorate of Biological control (ICAR) P. B. No. 2491, H. A. Farm Post, Bellary Road, Hebbal, Bangalore 560 024, Karnataka, IN

Abstract

Studies to identify effective kairomones, their optimum doses and appropriate application techniques with a view to increase the parasitizing efficiency of T. chilonis were conducted during 2005-06 in the laboratory. Fresh hexane extract of Corcyra cephalonica (1%)+hexacosane (0.3%) and C. cephalonica scale extract (1%)+nonacosane (0.3%) were the most attractive and recorded the highest egg parasitization (77.25% in both) when applied in impregnated rubber septa. The second effective kairomone was C. cephalonica scale extract (1%)+pentacosane (0.3%). Kairomone impregnated septa as dispensers proved better over paper strips. No significant difference in parasitizing efficiency was recorded between ochre and orange septa kairomone dispensers.

Keywords

Hexacosane, kairomones, Nonacosane, Pentacosane, Rubber Septa, Scales Extract, Trichogramma chilonis, Tricosane.

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S. K. Jalali ¹, S. P. Singh ¹, P. L. Tandon ¹

Affiliations
1 Project Directorate of Biological Control Post Bag No. 2491, H.A. Farm Post, Bellary Road Hebbal, Bangalore 560024, Karnataka, IN

Abstract

Field life tables of Chilo partellus (Swinhoe) were constructed for 6 generations from summer 1994 to rabi (winter) 1995 in Bangalore on fodder maize. Positive trend indices were obtained in the 2^nd , 3^rd and 4^th generations, which corresponded to late summer to kharif (monsoon) seasons and negative trend indices in the 1^st, 5^th and 6^th generations corresponding to late kharif (late monsoon) to rabi seasons. Positive trend indices signified greater pest activity during those generations. Maximum contribution to real generation mortality was in egg stage in all the generations as k_s of egg period were invariably closer to generation K in each season. Key mortality factor analysis revealed direct density dependence in egg stage with egg parasitoids having highly significant regression coefficient. Mortality due to unknown causes in younger larvae exhibited inverse density dependence. During larval stage, hatching failure, and in pupal stage all mortality factors exhibited delayed density dependence. The result provided rational ecological basis for developing biocontrol - based programme for suppression of C. partellus on fodder maize.

Keywords

Abiotic Factors, Biotic Factors, Chilo partellus, Field Life Tables, Population Dynamics.

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P. L. Tandon ¹, N. Bakthavatsalam ¹

Affiliations
1 Project Directorate of Biological Control (lCAR), H. A. Farm Post, P. B. No. 2491, Bellary Road, Hebbal, Bangalore 560 024, Karnataka, IN

Abstract

Two experiments were conducted on the effect of sunflower genotypes (21 nos.) on the parasitization efficiency of Trichogramma chilonis Ishii on Helicoverpa armigera (Hubner) under screen house conditions at Project Directorate of Biological Control (lCAR), Bangalore, Karnataka during 1999-2000. Pooled analysis of the data generated under these experinIents revealed significant difference in per cent parasitism of H. armigera eggs by T. chilonis on these genotypes. Highest parasitism was observed on sunflower hybrid MSFH 17 (53.50%) among all the genotypes evaluated. Second best performance was on variety Morden (42.50%), followed by RHA-274 (41.00%) and hybrid KBSH 1 (38.00%). However, statistically all these were on par. Least parasitism was recorded on hybrid BSH-I (8.00%), followed by variety 6D·l (9.50%) and accession no. 109 (12.50%). Strangely, both parent lines of this hybrid, namely, CMS 234A and RHA 274, recorded much higher parasitism. All other genotypes recorded low to moderate parasitism ranging from 16.00 to 34.50 per cent. The sunflower genotypes (hybrids, cultivars, inbred lines), which are found T. chilonis friendly, are also agronomically acceptable. Among them, two are important national high yielding (seed and oil) hybrids (MSFH 17 and KBSH 1).

Keywords

Genotypes, Helicoverpa armigera, Parasitization Efficiency, Sunflower, Trichogramma chilonis.

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N. Bakthavatsalam ¹, S. P. Singh ¹, P. L. Tandon ¹, M. Chaudhary ¹, S. Preethi ¹

Affiliations
1 Project Directorate of Biological Control (ICAR) P. B. No. 2491, H. A. Farm Post, Bellary Road Hebbal, Bangalore 560 024, Karnataka, IN

Abstract

Chrysoperta carnea (Stephens) is considered as an important predator against Helicoverpa armigera (Hii bner) and other sucking pests. The behavioural response of adult of C. carnea to the volatiles of plants infested by H. armigera was studied under laboratory conditions through electroantennogram and olfactometer. The adults showed good electroantennogram response to volatiles from flowers and bolls of cotton infested by H. armigera. Highest response was noticed to tbe infested bolls than flowers and leaves. In zone resident period studies, the adults spent distinctively more time in the zone 6 (nearest to source) when infested bolls were tested. In dual choice methods, significantly more number of adults reached the synomone arm than the control arm, when infested eotton bolls were tested. The response to infested leaves was very poor.

Keywords

Chrysoperiu carnea, Electroantennogram, Helicoverpa armigera, Infested Cotton, Synomone, Olfactometer.

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N. Bakthavatsalam ¹, S. P. Singh ¹, P. L. Tandon ¹, M. Chaudhary ¹, S. Preethi ¹

Affiliations
1 Project Directorate of Biological Control (ICAR), Post Bag No. 2491, H. A. Farm Post, Bellary Road, Hebbal, Bangalore 560024, Karnataka, IN

Abstract

Hexane wash of gallery and body of Opisina arenosella Walker elicited positive response from the parasitoids namely Goniozus nephantidis (Muesebeck), Brachymeria nephantidis Gahan and Elasmus nephantidis Rohwer, in terms of more number of parasitoids entering the kairomone arm than hexane arm in 'Y' tube olfactometer. Although, numerically, the gallery wash elicited higher response than larval body wash of the host O. arenosella to G. nephantidis, statistically, the treatments were on par. Chemical analysis of kairomonal substances using GCMS revealed the presence of 13-tetradecenal and myristic acid in the gallery wash, in addition to dodecane, pentadecane, hexadecane, heptadecane, eicosane and tricosane. Larval wash showed terpenoids like alpha-terpinene and alpha humulene.

Keywords

Behavioural Responses, Brachymeria nephantidis, Elasmus nephantidis, Goniozus nephantidis, Kairomones, Opisina arenosella.

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