Studies on insect pest complex of maize crop with special reference to pink stem borer, Sesamia inferens (Walker) and fall army worm, Spodoptera frugiperda (Smith)
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Date
2020
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Indira Gandhi Krishi Vishwavidyalaya, Raipur
Abstract
The present investigation entitled “Studies on insect pest complex of maize crop
with special reference to pink stem borer, Sesamia inferens (walker) and fall
army worm, Spodoptera frugiperda (Smith)” was undertaken in the Research
cum Educational Farm at college of Agriculture, IGKV, Raipur (C.G.) throughout
Kharif, 2018.
The insect pests aphid (Rhopalosiphum maidis), leaf hopper (Cicadulina
sp.), pink stem borer (Sesamia inferens), fall army worm (Spodoptera frugiperda)
and hairy caterpillar (Euproctis spp.) were reported as major insect pests on maize
crop. The highest number of aphid (9.4 aphids / 2cm 2 leaf area), Leaf hopper (36
hoppers/plant) were seen during 35 th SMW respectively. The larval population of
pink stem borer started during 35 th SMW i.e. August 4 th week with a mean larval
population of 0.16 larvae/plant. In the September 4 th week, the population has
peaked with a mean larval population of 0.96 larvae/plant at flowering stage. After
that, the population declined gradually. The fall army worm appeared during 37 th
SMW i.e., September 2 nd week with a mean larval population of 0.12 larvae/plant.
The population gradually grew and peaked at a mean larval population of
0.56larvae/plant in the September fourth week. Thus, the population decreased
slowly and arrived to a minimum larval population of 0.16larvae/plant during
October fourth week (42 nd SMW). During the study period natural enemies viz.
spiders, lady bird beetle (Micraspis sp., Cheilomenes sexmaculata, Adalia sp. and
Aneglies sp.), hover fly (Allograpta sp.) and cantheconid bug (Eocanthecona
furcellata) were also observed.
The correlation between fall army worm, Spodoptera frugiperda and
weather parameters during kharif, 2018 results showed that a non-significant but,
negative correlation with relative humidity in the evening (r=-0.233), total
precipitation or rainfall (r=-0.32) and wind speed or velocity (r=-0.341). However,
the maximum temperature (r=0.586) correlation showed positively significant. The
regression equation being (y=2.099+0.071x) indicating that with an increase in 1℃
temp. there will be increase in population by 0.071 per cent.
Out of twenty five varieties it was seen that, based on overall mean leaf
damage of fall armyworm, thirteen genotypes was least susceptible (1-4%)
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whereas, ten genotypes moderately susceptible (>4-7%) and two genotypes comes
under highly susceptible categories (>7-9%) against fall armyworm on maize.
Leaf damage rating of fall armyworm was showed significant correlation
with leaf area (cm 2 ) (r=0.427). Whereas, leaf trichomes (cm 2 ) showed highly
significant but negative correlation (r =-0.609) at 45DAS respectively.
Ear damge rating of fall army worm was showed significant correlation
with length of central spike (cm) (r=0.447). Whereas, kernel damage rating was
showed significant correlation with cob length (cm) and significant but negative
correlation with cob height (cm).
During the biology study of Spodoptera frugiperda it was seen that the
number of eggs laid by adult female varies from 160 to 200 in batches. Duration of
incubation period varies between 2-4 days. Larval duration completed in 14-16
days. The total pupal duration ranged between 8-10 days The duration of male
pupa was slightly longer (8.5 days) than that of female (7.5 days). The adult female period was 5-7 days and male period was 4-6 days, respectively with an average of 5.86 days and 4.9 days.
Description
Studies on insect pest complex of maize crop with special reference to pink stem borer, Sesamia inferens (Walker) and fall army worm, Spodoptera frugiperda (Smith)
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