Integration in Integrated Pest Management
Effect of Chemically Stimulated Entomopathogenic Nematodes For Control Of Insect Pests
1. S.S. Hussaini, Kavitha J. Satya and M. Abid Hussain. 2001. Proceeding of 2nd national symposium on IPM in horticultural crops: new molecules, bio pesticides and Environment. pp: 204-206,Oct 17-19,2001. Bangalore
Entomopathogenic nematodes (EPN) are lethal obligate parasites of insects. Species and strains of Steinernema and Heterorhabditis exhibit differences in survival, behaviour and infectivity. Understanding interaction between nematodes and their insect hosts is critical for effective use as bioinsecticides. EPNs have been used for suppressing soil insect pest populations worldwide and more often evaluated against soil pests including white grubs and cut worms. Several indigenous isolates of Steinernema and Heterorhabditis indica have been evaluated at PDBC against several economically important agricultural and horticultural crop pests including Spodoptera litura, Leucinodes orbonalis. Helicoverpa armigera, plutella xylostella, phthorimea opercullelle, Opisina arnosella and Leucopholis sp. The compatibility of these isolates with pesticides have been reported (Hussaini et al.,2001). However, the pathogenicity varied as per species and isolates. In the present study an attempt is made to enhance the pathogenicity of isolates - Steinernema (SSL2) POBC EN 13.21 and PDBC EN 14.1. H. indica 13.22, 6.71 and 14.3 by treatment with metal ions against larvae of test insect. maize tissue borer Chilo partelus. Ijs exposed to MgS04.7HqO (160 ppm) and MnCIq. 4HqO (2oo ppm) for 96 h at 240C were used to evaluate the synergistic effect. The treatment with either Mg or Mn ions produced marked differences in pathogenicity against C. partellus larvae. H. indica isolates caused highest mortality of 90-100 and 70-100 per cent with Mn and Mg treated ones compared to untreated (60%). In Steinernema spp. isolates mortality tended to increase from 20 per cent in untreated to 40-60 and 30-40 per cent with Mn and Mg ions. respectively. The synergistic action also enhanced penetration rate. The penetration rate increase was higher due to Mn than Mg stimulation and more consistent for H. indica isolates than Steinernema spp. in general. Though both metal ions had a positive influence on IJs, pathogenicity due to Mn ions was found to be superior to Mg ions. This is in agreement with the findings of Jaworska et al. (1999). Higher penetration rates were recorded with stimulated IJ when compared to unstimulated ones. The same trend as that of pathogenicity was encountered. Mn ions were consistently superior to Mg. There was a marked difference in penetration between Steinernema and Hererorhabditis spp. H. indica PDBC EN -14.3 was found to be the best followed by PDBC EN 13.22 and PDBC EN 6.71. In general the progeny production was higher with chemically stimulated nematodes in the test insect. Our results suggest that chemical stimulation have an overriding influence on efficacy of EPN, The continued use of such chemically stimulated IJ could result in significant reduction in pest populations over time. This simple technique could prove to be useful in genetic manipulation of nematodes for commercial purposes.

2. S.S. Hussaini, S.P. Singh and V. Shakeela. 2001. Compatibility of Entomopathogenic Nematodes (Steinernematidae, Heterorhabditidae:Rhabditida) with Selected Pesticides and Their Influence on Some Biological Traits. Entomon 26(1):37-44.
The effect of five pesticides including one botanical pesticide on the biological traits viz., activity, penetration rate, infectivity and progeny production of two Steinernema bicornutum and two Heterorhabditis indica isolates was assessed by using Galleria mellonella L. larvae. The results indicated that the infective Juveniles of both the genera tolerated most of the chemicals tested hut the response to different pesticides appears to be variable. The inactivity per cent increased with increased time and Steinernematids respectively at field recommended dosages. In general, infectivity of pesticide exposed infective juveniles was not adversely affected. Exposure for 72h to pesticides impaired the penetration rate of S. bicornutum isolates (30-40%) while additive response was observed in H. indica isolates. Overall, no additive or synergistic response was observed in progeny production of pesticide exposed infective juveniles. Among the pesticides, mancozeb and neem were safe to all the nematode populations while the latter was deleterious to H. indica PDBCEN 13.3 Fifteen out of twenty combinations tested were compatible and may he included in any IPM schedule. The improvement of susceptible population is highlighted. The entomopathogenic nematodes tested above may be viable candidates for an integrated approach.

3. S.Sitaramaiah, S.Gunneswara Rao, S.S.Hussaini,P.Venkateswarlu and S.Nageswara Rao. Use of entomopathogenic nematode, Steinernema carpocapsae against Spodoptera litura (Fabricius) in tobacco nursery. Bilogical control of Lepidopteran insect pests. Central Tobacco Research Institute, Rajahmundry, Andhra Pradesh, India. pp:211-213.
Steinernema carpocapsae talc based formulation against Spodoptera litura (fabricus) in tobacco nursery was at different concentrations 1 lakh to 4 lakh IJ/ sq.m and St NPV as sequential treatment with EPN. EPN at 4 lakh IJ/ sq.m and the sequential treatment of st. NPV @1.5 x1012 Pt.B/ ha succeeding [email protected] 1 lakh IJ/sq.m contained the S.litura damage very close to ETL. The prospects of utilization of EPN in tobacco ecosystem as a component of BIPM this paper discussed.

4. V. Shakeela and S.S. Hussaini. 2006. Susceptibility of tobacco cutworm, Spodoptera litura, (F) to some indigenous isolates of entomopathogenic nematodes. Journal of Eco-friendly Agriculture 1(1):64-67.
Varying degree of virulence of the species and strains of Steinernema feltiae, S. abbasi, S. riobrave, S. carpocapsae, Heterorhabditis indica and H. bacteriophora (100IJ/larvae) was recorded against Spodoptera litura larvae. Absolute mortality could be recorded 72h post exposure W1der in vitro conditions. The promising nematode species identified in the preliminary screening were compared for pathogenicity, based on their LC50 values. S. feltiae and S. abbasi were highly virulent with lowest LC50 values (41 and 44 IJs at 48hrs. exposure period). Nematode recycling ability was evaluated relative to the common host. Galleria mellonela to find-suitability of the host for nematode multiplication. Reproduction of H. indica and H. bacteriophora was maximum followed by S.abbasi, S.feltiae and S. carpocapsae.

5. S.S.Hussaini, V.Shakeela, C.Sankarayan. 2007. Bioefficiency and progeny production of some entomopathogenic nematode isolates against Lepidopteran insect pests. Trends in Bio-Science 1(1):.
Twelve indigenous entomopathogenic nematode populations were screened for their efficacy against larvae of some important lepidopteran insect pests viz., Plutella xylostella, Opisina arenosella, Helicoverpa armigera, Spodoptera litura and Phthorimaea operculella larvae in lab. Potential of the nematode species and isolates against each pest was assessed by the mortality of host larvae and establishment and development of nematodes in the host. Reproductive capacity of different nematodes species and isolates in each insect was evaluated by estimating the final yield of infective juveniles after infection.

6. Nitin Kulkarni, Sanjay Paunikar, S.S. Hussaini and K.C. Joshi. Susceptibility of entomopathogenic nematode, Heterorhabditis indica Poinar against teak skeletonizer, Eutectona machaeralis Walker.
The herbivorous insects, without exception, damage forest tree species at various stages of its growth, viz., in storage, seedlings in nurseries, plantations, natural forests and timber in depots. Recent realization of hazardous environmental impacts of chemicals has compelled search for bio-rational and ecofriendly alternatives as an IPM component. Entomopathogenic nematodes have emerged as the most recent option as a biological control agent against the insect pests. While there has been good deal of work undergoing abroad, researches in India has been limited to the insect pests of agricultural importance. Despite promising scope of EPNs in managing forest insect pests, no work has yet been taken up in the country. The present paper reports susceptibility of entomopathogenic nematode, Heterorhabditis indica Poinar (PDBC, Bangalore strain) against teak skeletonizer, Eutectona machaeralis Walker. The pest is of great economic importance as it is a major insect pest of teak (Tectona grandis) in central India and inhibits seedling growth. The penultimate instar larvae of the teak skeletonizer were exposed to known number of infective juveniles, viz. 3ijs/larvae, 5ijs/larvae, 10ijs/larva, 20ijs/larva and 30ijs/larva in filter paper bioassay. Results indicated that doses at and above 10ijs/larvae caused 76.47 % mortality within 72 hrs of exposure. There was 100% mortality at 30ijs/larva. The investigation is a significant step towards developing ecofriendly biological control agent against the teak skeletonizer under global concept of IPM.