Journal of Biological Control

Number 32 (4), 2018

215-223
Morphological and molecular characterization of Microplitis maculipennis Szépligeti (Hymenoptera: Braconidae) from India with notes on its generic placement

Authors: Thiruvengadam Venkatesan, Ankita Gupta, Ravi P. More, Preethi Raguraman, Reeta Baskhar

Abstract

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Microplitis maculipennis Szépligeti is an important parasitoid of castor semilooper Acanthodelta janata (L.) (Lepidoptera), a major pest of castor (Ricinus communis L.). Microplitis Förster shares remarkable morphological resemblance with moderately diverse genus Snellenius Westwood. In this study, molecular characterization of M. maculipennis was done using Cytochrome Oxidase I (COI) to confirm its generic placement in the respective genus. The Bayesian Inference (BI) and Maximum Likelihood (ML) phylogenetic analysis performed with a total of 354 published BOLD database sequences (after pre-processing of a total of 2257 COI sequences) of Microplitis and Snellenius species, representing 129 named species and 226 species determined only to genus raises doubts on the retention of both these genera separately. Our studies reveal that COI gene could not discriminate Microplitis and Snellenius species clearly.

224-229
Biology and rearing protocol for Dortus primarius Distant, a predatory mirid (Hemiptera: Miridae)

Authors: Richa Varshney, H. M. Yeshwanth, Chandish R. Ballal

Abstract

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Dortus primarius Distant (Miridae: Deraeocorinae) was observed to feed on thrips and other soft bodied insects in the field. Biology, morphology and feeding potential of this species were studied for the first time in the laboratory (at 26 ± 2˚C and 65 ± 2% RH) on UV irradiated Corcyra cephalonica (Stainton) eggs. A total of five instars were observed, with nymphal duration of 17.2 days. Mean fecundity was 127.6 eggs per female. Female longevity was higher than male. One nymph could consume a total of 363 C. cephalonica eggs in its life span. Adult male and female fed on a total of 713 and 1014.75 eggs, respectively. Cost of producing 100 D. primarius nymphs and adult nymphs neonate/first instar was INR 10.34/- and INR 200/-, respectively. In this paper all immature stages, eggs and adults are described with live images. Results showed that this species could be reared on UV irradiated C. cephalonica eggs and bean pieces successfully. Further studies are needed to evaluate this species against insect pests in field.

230-238
Pathogenicity and field efficacy of the entomopathogenic fungus, Lecanicillium saksenae Kushwaha, Kurihara and Sukarno in the management of rice bug, Leptocorisa acuta Thunberg

Authors: S. S. Hari Sankar, O. P. Reji Rani

Abstract

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A new indigenous isolate of Lecanicillium namely L. saksenae was tested for its efficacy against rice bug. Lecanicillium lecanii was non pathogenic to rice bug. Peculiar pre mortality symptoms like ataxis, aggregation, convulsions were exhibited by test insects upon infection. L. saksenae was characterized by it's quick kill effect, causing 100 per cent mortality of adults and nymphs within 72h after treatment with high spore doses of 108 and 107 spores mL-1. Furthermore, probit analysis done at 6 days of treatment, revealed the LC50 as 2.99 x 104 and 1.72 x 104 spores mL-1 for nymphs and adults respectively. LT50 (108spores mL-1) was 17.58 and 18.58 hours for nymphs and adults respectively. Although the quick kill effect was not exhibited in field, the count of rice bugs in plots treated with oil formulated L. saksenae were significantly lower (1.33 bugs per plot). Moreover, all the bioformulations applied as treatments were evidently safe to natural enemies present in rice ecosystem. The yield recorded from plots treated with oil formulated L. saksenae was also higher (3.48 kg per plot of 2 x 2 m). This study projects the prospect of utilizing L. saksenae, and its oil formulations as an effective biocontrol agent against rice bug which is a major sucking pest of rice.

239-245
Morphology and performance specifications of Blaptosthethus pallescens Poppius (Heteroptera: Anthocoridae) when reared on two alternate laboratory hosts

Authors: Tripti Gupta, Chandish R. Ballal, Shashikala S. Kadam

Abstract

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The present research paper provides detailed morphology and morphometrics of an anthocorid predator, Blaptostethus pallescens Poppius. To identify the alternate laboratory host to be utilized for mass production, biological parameters of the anthocorid were evaluated by rearing on UV irradiated eggs of two alternate laboratory hosts, Corcyra cephalonica (Stainton) and Sitotroga cerealella (Motsch.). Five nymphal instars were recorded on both hosts. No significant differences were observed in incubation period, nymphal duration, total developmental period and sex ratio when reared on the two hosts. However, significant differences were observed in two biological parameters i.e., adult longevity and fecundity. Longer life span and higher fecundity of B. pallescens was recorded when reared on C. cephalonica eggs in comparison to S. cerealella eggs, indicating the suitability of C. cephalonica eggs for mass rearing B. pallescens in the laboratory. B. pallescens could be reared continuously for 7 generations on C. cephalonica eggs.

246-251
Molecular characterization of an indigenous lepidopteran toxic Bacillus thuringiensis strain T532

Authors: K. V. Nayan Ganesh, A. L. Reyaz, N. Balakrishnan

Abstract

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Bacillus thuringiensis Berliner (Bt) being an eco-friendly bioinsecticide is effectively used in pest management strategies and, therefore, isolation and identification of new strains effective against a broad range of target pests is important. In the present study, four indigenous Bt isolates (T489, T491, T495 and T532) were taken and investigated for their properties such as crystal morphology, cry gene(s) content and insecticidal activity. Bipyramidal, cuboidal and spherical crystals were observed. Among the four isolates only one isolate was found positive for lepidopteran specific cry genes. The isolate T532 which showed the presence of cry1, cry2Aa and cry2Ab genes was selected for protein profiling and bioassay. The isolate showed the presence of two proteins of molecular weights at ~135 and ~65 kDa sizes. Artificial diet based bioassay resulted in 100% mortality of the neonate larvae of H. armigera and S. litura for the isolate T532 which was comparable to that of the positive control (HD1). The full length cry2A gene was amplified and cloned into E. coli DH5α strain. The recombinant plasmids were sequenced and the sequence was deposited in GenBank nucleotide database. The accession number of the gene is MH475905. The gene was named by the Bacillus thuringiensis delta endotoxin nomenclature committee as cry2Aa23.

252-256
Prevalence and molecular characterization of viruses causing diseases in Bombyx mori L. (Lepidoptera: Bombycidae) from different climatic regions of India

Authors: Mudasir Gani, A. V. Mary Josepha, L. Satish, Sahadev Chouhan, Mallikarjun Gadwala, Mir Nisar Ahmad, V. Sivaprasad

Abstract

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Number of views: 332

A number of viruses are known to cause the disease in mulberry silkworm, Bombyx mori L. and cause significant cocoon crop loss to the farmers. The study has been undertaken to assess the prevalence of silkworm viral diseases caused by B. Mori Nucleopolyhedrovirus (BmNPV), B. mori Infectious Flacherie Virus (BmIFV) and B. mori Densovirus1 (BmDNV1) through external symptoms and molecular characterization from different climatic regions of India. During the intensive exploratory surveys in 2017, silkworm larvae with typical symptoms of BmNPV, BmIFV and BmDNV1 were collected across seven provinces from North India [Kashmir (temperate), Jammu, Ghumarwin in Himachal Pradesh, Dehradun in Uttarakhand (subtropical) and South India [Karnataka, Andhra Pradesh and Tamil Nadu (tropical)]. Dissection of diseased specimens confirmed the presence of virus through anatomical changes viz, size, shape and colour of organs after disease attack. The viruses were isolated and identified through PCR amplification of highly conserved genes. The results reveal that BmNPV, BmIFV and BmDNV1 are evenly prevalent across India. The infection percentage of BmNPV, BmIFV and BmDNV1 in North India (11.41 ± 1.21, 7.81 ± 0.67 and 7.40 ± 0.61) was significantly higher than South India (1.61 ± 0.17, 1.52 ± 0.14 and 1.62 ± 0.14), respectively. The highest prevalence of these viruses was observed from subtropical followed by temperate and tropical climate. The knowledge of the prevalence of these viruses in India and their synergism with bacteria and influence of other possible factors is important for preventing cocoon crop losses caused by viral diseases in India.

257-263
Evaluation of phyllosphere antagonistic bacteria on the management of Fusarium ear rot of maize caused by Fusarium verticillioides

Authors: Konda Sameer, G. Sobanbabu, K. G. Sabarinathan, V. K. Parthiban, V. Ramamoorthy

Abstract

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Fusarium verticillioides is an insidious fungal pathogen of maize associated with diseases such as ear rot and kernel rot. It attacks the phyllosphere region of the maize plant especially on inflorescence and cobs. Thus, this study was conducted to isolate potential phyllosphere colonizing antagonistic microbes for the management of Fusarium ear rot. Four phyllosphere colonizing antagonistic bacteria were found to be effective in suppression of the growth of Fusarium verticillioides. Based on 16S rDNA analysis, these bacterial isolates were identified as Pseudomonas aeruginosa isolate 1, P. aeruginosa isolate 2, Bacillus subtilis isolate and B. amyloliquefaciens. Among these four phyllosphere bacteria tested against F. verticillioides, the maximum inhibition of mycelial growth of F. verticillioides and production of volatile compounds was exhibited by P. aeruginosa isolate 1. Application of P. aeruginosa isolate -1, as seed treatment @ 10 g/kg of seeds, soil application @ 5 g/pot and foliar spray @ 0.2 per cent, recorded the minimum PDI with the maximum disease reduction over control. Thus, the present study showed that P. aeruginosa isolated from agricultural ecosystem could be a potential phyllosphere antagonistic bacterium for the management of maize ear rot disease.

264-269
Integrated disease management approaches for control of late blight of potato and enhancing the growth of potato

Authors: Sumit Kumar, S. K. Biswas, H. G. Prakesh

Abstract

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Number of views: 416

Experiments were conducted to study integrated approach in the management of potato blight. The result showed that T1 treatment (soil application of FYM @ 125gm/pot + waste of mushroom cultivation with Trichoderma harzianum @ 5gm/kg + tuber treatment with Azotobacter @ 5% + foliar spray with Ridomil @ 0.25%) was the best to show minimum disease severity, representing 9.16% as against 76.40% in case of control at 21 days of observation. The treatment also exhibited increased tuber germination and plant height of potato showing the value 100 per cent and 44.5 cm at 30 days age of plant. The maximum number of large size tuber and total yield with 668.6g was also recorded from treatment T1. Thus, integration of FYM + mushroom waste as soil application + bio formulation as tuber treatment + fungicides as foliar spray can be efficiently applied for management of late blight and also get enhanced yield of potato.

270-274
Natural enemies of whitefly, Bemisia tabaci (Gennadius) on cotton in Punjab, India

Authors: K. S. Sangha, P. S. Shera, Sudhendu Sharma, Rabinder Kaur

Abstract

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The whitefly, Bemisia tabaci (Gennadius) is a polyphagous pest, widely distributed in diverse agroecosystems across the globe. Several bioagents including predators and parasitoids from diverse groups have been recorded against whitefly worldwide. A field survey was conducted during 2016 and 2017 in different cotton growing districts of Punjab to record the natural enemies associated with whitefly. Sixteen species of natural enemies were recorded, including 7 species of insect predators; 2 species of parasitoids and 7 species of spiders. Coccinella septempunctata Linneaus, Cheilomenes sexmaculata (Fabricius) and Brumoides suturalis (Fabricius), Serangium parcesetosum Sicard, Chrysoperla zastrowi sillemi (Esben-Peterson), Zanchius breviceps (Wagner), Geocoris sp. and spiders were most commonly recorded predators. Out of these, Chrysoperla was the predominant species. Encarsia lutea (Masi) and Encarsia sophia (Girault & Dodd) were the two parasitoids that emerged from whitefly pupae. The mean parasitization of whitefly by Encarsia spp. in different cotton growing areas of Punjab was 5.20 per cent (range = 1.5 to 9.1 %).

275-278
The nematicidal property of aqueous crude extract of Calotropis procera on tomatoes (Lycopersicum esculentus)

Authors: C. Anih Agatha, V. Lawal Thank God

Abstract

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Number of views: 413

The Efficacy of the aqueous crude extract from Calotropis procera Linn. on the growth and production of tomatoes Lycopersicum esculentus Mill. infested by Meloidogyne javanica was investigated. An aqueous crude extract of Calotropis procera Linn. was prepared by soaking 2kg of dried powdered leaf in the ratio of 1:5mg/ml for 24 hours; this was sieved and concentrated with water bath at a controlled temperature of not above 60°C also freeze dried to obtain 487g of the dried crude extract. The plant pot of tomatoes infested with Meloidogyne javanica was treated with different concentration of the extracts. Treatment with 50% concentration of the stock solution of C. Procera showed significant growth and yield of tomato. Plant height was 83.3cm whereas in control it was 68.3cm. Significant differences in all other parameters were also obtained. Plant height at final harvest was 89.6cm as compared to control (74.3cm). A positive effect was seen in reducing the number of nematodes both in the soil and in the root. The treatment showed a root gall index of 2.3 which was lowest as compared to control (7.3). Hence at adequate concentration of C. procera extract it is possible to inhibit the nematode attack in tomato.