screening elite genotypes and ipm of defoliators in groundnut

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stage, with the female consuming more food than the male. Larval mortality and the sex ratio seem to have no relation with the amount of food consumed per species. According to Ghumare and Mukheijee (2003) the five host plants [castor (Ricinus communis L.), cotton (Gossypium hirsutm L.), tomato (Lycopersicum esculentum M.) mint (Mentha arvensis L.) and cabbage (Brassica oleracea L.)] belonging to different families were used to study the performance of the Asian armyworm, S. litura. Highest consumption of food and dry weight gain was observed in larvae fed on castor. Mint did not support optimum larval growth because of low digestibility and low efficiency of conversion of digested food to body matter. Dry weight gain ranged from 26.64 mg on mint to 86.80 mg in castor. The biological parameters of S. litura were studied on cotton and different weed plants viz., itsit (Trianthema portulacastrum), tandla (Digera arvensis) and thakra (Tribulus terrestris) under laboratory conditions at Entomology Research Farm and Laboratories of the Department of Entomology at Punjab Agricultural University, Ludhiana during 2006 Kharif season. The study suggests that S. litura showed faster larval development on all three weeds as compared to cotton, although the larval and pupal survival was lower on these weeds. These results suggest that the role of weeds in the development of S. litura cannot be overlooked (Inderjit et al., 2006). Dara and Prasad (2007) estimated the population parameters of S. litura on green gram (Vigna radiate L.), black gram (Vigna mungo L.), groundnut (A. hypogaea) and chilli (Capsicum annuum L.) along with castor bean as control in the laboratory. Field-collected egg masses of S. litura were used to start the initial colonies. S. litura population showed a positive trend on all host plants. The population parameters net reproductive rate, intrinsic and finite rates of increase, weekly multiplication rate, and potential fecundity were highest on castor bean, followed by greengram, blackgram, groundnut and chilli. Accordingly, the mean generation time and doubling time were shortest on castor bean, followed by greengram, blackgram, groundnut and chilli. Stable age-distribution showed that egg, larvae and pupae contributed to > 99 per cent of the population stable age. Maghodia and Koshiya (2008) studied that the life history of S. litura at 27.1 0 C in the laboratory on five different crops presumably observed as host plants of S. litura. The data were analyzed based on age-stages and variability of developmental rate among individuals of the pest. The highest intrinsic rate of increase (r), the finite rate of increase and the net reproduction rate (Ro) of S. litura were 0.174, 1.192 females/day, 1370.74 offspring/individual, respectively, observed on castor, while the highest mean generation time (T) 45.48 days was observed on cotton. The life expectancy of newly deposited eggs was 17.34, 17.44, 16.39, 17.45 and 17.98 on castor, tobacco, groundnut, cotton and cabbage, respectively. The age specific fecundity of S. litura was 395.64, 179.32, 186.25, 292.64 and 25.14 progenies per day on the 42 nd , 44 th , 41 st , 46 th and 51 st days for castor, tobacco, groundnut, cotton and cabbage, respectively. Studies on age-specific distribution of the pest on different hosts revealed that the eggs and larvae contributed the highest to the population, whereas the contribution of the pupae and adults was negligible. 2.1.1.2 Biology of Spodoptera litura on different varieties of groundnut Host plant resistance can be exploited as an effective and environment friendly component of pest management. At present, S. litura is a prominent defoliator associated with groundnut crop. So incorporation of resistance to this in suitable varieties has been high priority for groundnut breeders in association with entomologists. Tiwari et al. (1980) studied on the survival and weight gain in larvae of S. litura reared on 9 varieties of groundnut. Four days after feeding, larval survival was similar on all varieties except C-501, where high mortality rate was recorded. This trend was also observed 8 days after feeding, but after 12 days the mortality rate did not change. Larvae feeding on C-501 weighed 1.26 mg after 4 days, while on Dwarf Mutant larval weight was 4.41 mg. Larval weight after 8 days' feeding was significantly greater on Dwarf Mutant than on the other varieties, and was lowest on C-501. After 12 days of feeding, the greatest weight gain was
observed on Dwarf Mutant, the lowest gains were observed in larvae on AH-1192, OG-71-3, JH-62, M-13 and C-501, and moderate gains were observed on J-11, Pol-2 and M-145. Intrinsic rates of increase of S. litura on 9 different varieties of groundnut were assessed in Andhra Pradesh, India. Life-tables were prepared from the results of observations on the development of larvae and on the number and viability of eggs produced by the ensuing adults, the intrinsic daily, weekly and monthly rates of increase being calculated. The duration of a generation was shorter and the intrinsic rate of increase was higher on the varieties, Dwarf Mutant and Pol 2 than on any of the others. Since this indicates a very rapid buildup of populations of S. litura on these 2 varieties, it is recommended that they should not be cultivated in areas where this pest is a common problem on other field crops. Larval mortality was highest on ICGV 86031 (82.8%) followed by ICGV 86350 (53.32%) and Dh-3-30 (43.02%). Development was shortest on Dh-3-30 (32.25 days), and longest on ICGV 86031 (37.5 days) with adults surviving a maximum of 9.5 days. Of the nine groundnut varieties tested in the laboratory for resistance to S. litura, C-501 was most resistant and M -145 was the most susceptible (Tiwari et al., 1989). The biology of S. litura was studied on different groundnut genotypes along with wild tetraploid, Arachis manticola (L.) (Kulkarni, 1989 and Patil et al., 1995). Survival was least on the wild species, while it was maximum on Dh-3-30. The Survivability on ICGV- 86031, 87264 was comparatively low followed by ICGV-86165, 86350, 86699 and GBFDS- 272. The larval duration was short while gain in larval weight and survival percentage were high on susceptible genotypes indicating higher rate of multiplication. On the other hand, these parameters were reversed in resistant genotypes. In laboratory feeding bioassay by Todd et al. (1991), it was found that larval weight (75.7) mg was more in susceptible variety (Southern runner) as compared to resistant genotypes (26.5 mg). Larvae fed on florunner required an average of 3.7 more days to develop, compared to larvae fed on curly leaf. Similarly, Singh and Sachan (1992) identified ICGV-86030, 86031 and NCAC 343 as resistant to S. litura based on survival, weight gain and larval duration. Patil et al. (1991) reported that the performance of 27 and 15 entries in initial and advanced groundnut varietal trials, respectively, for defoliator damage at75 and 90 days after sowing, and productivity during the 1989 rainy season at Dharwad. Entries ICGV-87264, ICGV-86598 (Advanced varietal trial), ICGV-86350 and ICGV-86276 (Initial varietal trial), which combined low leaf damage (
Page 1 and 2: SCREENING ELITE GENOTYPES AND IPM O
Page 3 and 4: CONTENTS Sl. No. Chapter Particular
Page 5 and 6: Figure No. LIST OF FIGURES Title 1.
Page 7 and 8: In some parts of the northern Karna
Page 9: mutants were systematically screene
Page 13 and 14: Singh and Sachan (1991) recorded se
Page 15 and 16: Thontadarya and Nangia (1983) repor
Page 17 and 18: Monitoring with pheromone traps to
Page 19 and 20: 1. JL-24 (Susceptible check) 2. ICG
Page 21 and 22: Observations were recorded daily on
Page 23 and 24: Table 1: Performance of elite groun
Page 25 and 26: Third instar duration was significa
Page 27 and 28: Table 3: Gain in larval weight and
Page 29 and 30: Table 4: Biological parameters of S
Page 31 and 32: Table 5: In vitro biology of Spodop
Page 33 and 34: sunflower and N. rileyi, foxtail mi
Page 35 and 36: Table 7: Leaf hoppers population in
Page 37 and 38: Table 8: Thysanoplusia orichalcea p
Page 39 and 40: Table 10: Spilarctia obliqua popula
Page 41 and 42: 4.2.4.2 50 days after sowing The de
Page 43 and 44: Table 13: The management of Spodopt
Page 45 and 46: The early instar larvae scraped the
Page 47 and 48: Module I Table 16: Natural enemy po
Page 49 and 50: Table 18: Natural enemy population
Page 51 and 52: Table 19: Economics of IPM modules
Page 53 and 54: Per cent defoliation 50 45 40 35 30
Page 55 and 56: Larval period and Total development
Page 57 and 58: Larval Larval weight weight (g) (g)
Page 59 and 60: 5.2.3 Defoliator population in thre
Page 61 and 62:
Pest population 1600 1400 1200 1000
Page 63 and 64:
Gross returns and Net returns (Rs./
Page 65 and 66:
REFERENCES Agasimani, C. A., Ravish
Page 67 and 68:
Kennedy, F. J. S., Rajamanickam. K.
Page 69 and 70:
Prasad, M. N. R. and Gowda, M. V. C
Page 71 and 72:
Tiwari, S. N., Rathore, Y. S. and B
Page 73:
SCREENING ELITE GENOTYPES AND IPM O
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screening elite genotypes and ipm of defoliators in groundnut

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