Journal of Biological Control

178-184

Authors: Lidya Alemayehu, Wondi Mersie

The presence and spread of Listronotus setosipennis (Coleoptera: Curculionidae) and Zygogramma bicolorata (Coleoptera: Chrysomelidae) released in 2017 for the control of Parthenium hysterophorus (L.) (Asteraceae: Heliantheae) at two locations in Ethiopia (Arba Minch and Mojo) were assessed twice (July, September) in 2018. At Arba Minch, no L. setosipennis was found, only Z. bicolorata established and the number of eggs varied from 1.4±0.71/plant (July) to 7.41±4.52/plant (September) at the release site and from 0.52±0.18/ plant (July) and 0.68±0.24/plant (September) at the dispersal site. At Mojo, only L. setosipennis established with 3.87±1.18 eggs/plant (July) at the release spot and 10.76±1.64 eggs/plant in September whereas after dispersal the eggs numbered 8.69±3.2/plant (July) and 14.98±1.73/ plant (September). After one year, L. setosipennis and Z. bicolorata were found 51.75±3.95 m and 94.15±13.66 m away from the release spots, respectively. The results show that the biocontrol agents have started to establish and have dispersed at the two locations in Ethiopia.

193-196

Authors: Ankita Gupta, S. Ramesh Babu, M. Sampath Kumar

Field surveys conducted during 2018-2019 in the maize fields infested with Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) in Karnataka, Tamil Nadu, Rajasthan and Meghalaya revealed that Cotesia ruficrus (Haliday) (Hymenoptera: Braconidae) was the common gregarious larval parasitoid in the maize fields parasitizing S. frugiperda. This is the first report of C. ruficrus parasitizing S. frugiperda in India, earlier reports being from Trinidad and Tobago. The present study (using integrated approach) provides morphological and molecular identification details along with host data, cocoon characters and geographical distribution of C. ruficrus.

217-221

Authors: S. Ramesh Babu, Victor Phani, P. K. Meena, Khushbu Chauhan, M. R. Khan, V. S. Somvanshi

Amyna axis (Lepidoptera: Erebidae), Chrysodeixis spp. (C. acuta and C. eriosoma) and Spodoptera spp. (S. exigua and S. litura) (Lepidoptera: Noctuidae) are important polyphagous insect-pests of leguminous crops. A mermithid (Nematoda: Mermithidae) nematode was found parasitizing the larval stages of these insects in the western Indian state of Rajasthan. Morphological and molecular analysis suggests that the nematode might be a species of the genus Hexamermis. The average length of post-parasitic nematode juveniles was 15 cm, and the average greatest body width was 1.5 mm. The vulva was median (V% = 48) without vulval flap. Approximately 100-125 μm long caudal appendages were present on tail. The cross-section revealed the presence of six hypodermal chords at the mid body region, and stichosome was present. The 18S rDNA sequence showed 99% similarity to mermithid nematode. A phylogenetic analysis of 18S rDNA sequences of mermithids resulted in identification of a new clade “Lineage 3” which included representatives of Mermis sp., Isomermis sp., Limnomermis sp., and Pheromermis sp. This is the first report of natural mermithid parasitism of A. axis and Chrysodeixis spp. along with its molecular characterization.

225-235

Authors: K. Darshan, S. Vanitha, K. M. Venugopala, S. Parthasarathy

Papaya (Carica papaya L.) is one of the important fruits cultivated in the tropical and subtropical regions are widely prone to the post-harvest anthracnose disease. A sum of ten isolates of Colletotrichum gloeosporioides were collected and identified through morphological and molecular method. Morphological characterization of the isolates revealed a wide variation among the isolates with respect to colony colour, topography, margin, pigmentation and zonation. The ITS gene region and the specific primer, MKCgF coupled with ITS-4, which generated amplicons of size 560 bp and 380 bp respectively for C. gloeosporioides. The amplicon (560 bp) of virulent strain Cg1 was partially sequenced [MF062699]. In order to formulate eco-friendly management practices, the in vitro screening of different biocontrol agents viz., Bacillus spp., Pseudomonas spp., plant extracts and essential oils were tested against the C. gloeosporioides. Based on the in vitro efficacy, Bacillus sp. (BSP1) and cinnamon oil were selected and further tested under field conditions as pre harvest spray and after harvest as fruit dipping. The experimental results revealed that pre-harvest spray with Bacillus sp. (BSP1) (5%) + post-harvest dipping with cinnamon oil (0.1%) recorded the lowest PDI of 3.25 when compared to control (70.36) and also increased the shelf life of papaya fruits up to 14 days. Our results show that this novel methodology of use a combination of biocontrol agent as pre-harvest spray and essential oils as post-harvest fruit dipping will protect against post-harvest anthracnose of papaya and use of chemical fungicides can be avoided.

242-252

Authors: R. Rangeshwaran, V. Velavan, Satendra Kumar, V. Apoorva, K. M. Venugopala, A. N. Shylesha, G. Sivakumar

The search for new Bacillus thuringiensis (Bt) strains is a continuous process and researchers are now focusing on finding toxin proteins that are toxic to pests of insect orders that are not reported. In the present study soil and insect cadaver samples were collected from North East India comprising the states of Assam, Tripura and Mehhalaya and native Bt were isolated using standard protocols. At total of 30 Bt isolates were purified and characterized. Various types of crystal morphology were encountered that included bipyramidal, cuboidal, square, rhomboid, spherical and irregular. PCR analysis showed that diverse cry genes were expressed. The cry genes identified were Lepidoptera, Coleoptera and Diptera specific. Detected genes included cry1Ac, cry2A, cry4A, cry10A, cry16A, cry17A, cry19A, cry30Aa, cry44Aa, cry11A, cry4B, cry12A, cry8A and cry7A. Many of them were positive for Vip3A protein. The coleopteran specific Bt were evaluated against Sitophilus oryzae and Callosobruchus chinensis and NBAIR-AgBt6 was found to be toxic. The isolates are being further evaluated for use as biopesticides.

264-270

Authors: V. Sridhar, S. Onkara Naik, K. S. Nitin, R. Asokan, P. Swathi, H. Gadad

South American tomato moth, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is an invasive pest on tomato and other solanaceous crops. In general, 20 to 30 % yield loss is caused by this pest and sometimes it may result in 100% damage, if timely management interventions are not followed. Though the pest was reported in India during 2014, presently it has spread to several tomato growing states. In the present study various IPM tools have been evaluated against this pest. As a long-term strategy of resistance breeding, genotype screening was carried out for identification of resistance sources from wild and cultivated tomato genotypes showing resistance/tolerance against T. absoluta. Among the evaluated wild and cultivated tomato genotypes, Solanum pennellii (Accession, LA 1940) was identified as a resistant source against T. absoluta both under choice and no-choice bioassays and is being used for resistance breeding. Various entomopathogens (Bacillus thuringiensis, Metarhizium anisopliae, Beauveria bassiana and M. rileyi), egg parasitoids (Trichogramma chilonis, T. pretiosum and Trichogrammatoidea bactrae), light traps, pheromone traps, synthetic insecticides, botanical origin insecticides were also evaluated for their relative efficacy. Among the egg parasitoids T. pretiosum and among synthetic chemicals, spinetoram 12 SC@ 1.25ml/l were found very effective for the management of T. absoluta. Yellow light traps were found as an effective component for integrated management of T. absoluta. Azadirachtin 5% EC at the tested concentrations showed highest mean radial growth (24.67 mm) with relatively less inhibition (16.51%) of M. anisopliae indicating these combinations can be effectively utilised in the eco-friendly management of T. absoluta. We reported natural incidence of M. anisopliae on T. absoluta larvae, causing up to 35 per cent mortality during 2016-17.

274-278

Authors: SHIVA Murthy, T. Jiji, N. Anitha

Impact of insecticides on mango pests and their natural enemies was studied at College of Agriculture, Vellayani and Padannakkad during 2015-16. Observations were recorded on pest and Natural Enemies (NEs) population at fortnightly intervals. Management studies were carried out in RBD and observations were recorded before and after spraying on 1,3,5,7,9,10 and 15 days. It was observed that NEs population was closely associated with the occurrence of pest population and found peak incidence during March-2015. Chlorantraniliprole 0.03% SC and flubendiamide 0.01% SC were found to be best treatments by reducing 82.41 and 74.60 per cent larvae/web respectively. Imidacloprid 0.005% and thiamethoxam 0.005% found to be better treatment with 90.64 and 87.40 per cent reduction of leaf hoppers respectively. But they had equally reduced the NEs population. Azadirachtin 1% and Beauveria bassiana 2% found to record highest number of NEs with moderate efficacy against the target pests.

285-290

Authors: A. Suganthi, P. A. Saravanan, S. Sritharan, S. Jeyarajan Nelson

The bud borer and blossom midge are the major pests that attack buds of jasmine, this study represents the effort to demonstrate the potential of biocontrol agents and botanicals on bud damaging insect pests of jasmine at field level. The flower bud damage due to jasmine bud borer and blossom midge were assessed at the bud initiation stage before imposing treatment. Various treatments involving botanicals, biocontrol agents and chemicals were applied to the crop during March month. Application of Beauveria bassiana (NBAIR formulation) at 5g/litre of water three times along with 6 releases of Trichogramma chilonis @100,000/ha at 7 days interval from bud initiation stage was superior in checking the bud borer damage (50 to 86%) and blossom midge (61 to79 %). Regarding yield, treatment with B. bassiana (NBAIR formulation) at 5g/litre of water along with 6 releases of T. chilonis at 7 days interval was superior and gave 2000 kg ha-1 with a cost benefit ratio of 2.50. The study revealed that integrated use of biocontrol agents and biopesticides can provide reliable and effective pest control in jasmine, while reducing pest management cost and chemical exposure to the growers and workers.

295-302

Authors: Farzana Yesmin, M. Nazim Uddin, G. M. Saifur Rahman, M. Hasanuzzaman

Peach fruit fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae) is native to South and South-East Asia. It is a polyphagous species and has a high reproductive potential (approx. 600 eggs in a lifetime), high biotic potential, i.e., several generations of progeny per year. The species has the rapid dispersal ability and can be active throughout the year. Its establishment may have a serious impact on the environment following the initiation of chemical and/or biological control programmes. B. zonata is of quarantine significance to EPPO (European and Mediterranean Plant Protection Organization) countries and it is classified on the A1 list of pests recommended for regulation as quarantine pests by Centre for Agriculture and Biosciences International (CABI). The present study initiates an attempt to identify the larval (3rd instar) salivary gland polytene chromosome arms of B. zonata using Olympus phase contrast microscope CX 41. A photographic representation of the polytene chromosomes of this species associates with identifying tips as well as well defined characteristics of each polytene chromosome arms are described. Five long chromosomes with their identifying tips are recognized in each polytene nucleus. Polytene chromosomes are of special interest to construct a Genetic Sexing Strain (GSS) of a pest species and it can play an important role for the successful application of Sterile Insect Technique (SIT) in field application as part of the biological control programme under Integrated Pest Management (IPM) scheme.