Studies on biology, population dynamics and screening of sugarcane genotypes against Early Shoot Borer, Chilo infuscatellus Snellen
Loading...
Date
2017
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CCSHAU
Abstract
The present investigations entitled “Studies on biology, population dynamics and screening of sugarcane
genotypes against early shoot borer, Chilo infuscatellus Snellen” were conducted during 2016-17 in laboratory and
research area of CCS Haryana Agricultural University, Regional Research Station, Karnal. The biology of C.
infuscatellus was studied in laboratory under room temperature (33.4-38.6o C) with a relative humidity of (33-62
%) on sugarcane genotype CoH 119 (mid). The incubation period varied from 3 to 5 days. The egg hatchability
was 74.4 per cent. The total larval duration of C. infuscatellus ranged from 18 to 26 days. The larva moulted four
times and passed through five instars to become pre-pupa. The mean duration of first to fifth instars larvae
averaged 2.67, 3.29, 3.94, 5.49 and 6.92 days. The larval survival of C. infuscatellus was 49.6 per cent. The prepupal
period varied from 1 to 2 days. Pre-pupal survival was 94.4 per cent. The duration of male and female pupae
ranged from 4-5 and 4-6 days, respectively. The adult emergence of C. infuscatellus was 79.6 per cent. The sex
ratio of C. infuscatellus was 1:1.53 (M: F). The copulation period of C. infuscatellus ranged from 112-186 minutes.
The number of eggs laid ranged from 280 to 345 eggs/female when 10 per cent honey solution was provided as
food for moths and 24 to 42 eggs/female under unfed conditions. The adult longevity of male and female ranged
from 3 to 4 & 3 to 5 days (fed conditions) and 1 to 3 & 2 to 3 (unfed conditions), respectively. The total life span
ranged from 29 to 42 days for male and 29 to 44 days for female. Studies on population dynamics revealed that
highest incidence of C. infuscatellus was recorded 3.81 per cent in CoH 160, 4.60 per cent in CoH 119 and 3.12
per cent in CoS 767 during 24th SMW. Correlation of C. infuscatellus population with various environmental
factors revealed that there was a significant positive correlation with maximum temperature (Tmax.) and had a
non-significant & positive correlation with minimum temperature (Tmin.) & sun shine hours (SSH) (r= 0.513,
0.287 & 0.452) on CoH 160, (r= 0.504, 0.321 & 0.431) on CoH 119 & (r= 0.537, 0.276 & 0.445) on CoS 767,
respectively whereas it has non-significant and negative correlation with relative humidity (morning), relative
humidity (evening) & rainfall (r= -0.172, -0.206 & -0.147) on CoH 160, (r= -0.147, -0.172 & -0.130) on CoH 119
& (r= -0.187, -0.223 & -0.160) on CoS 767. Among the 19 genotypes screened against C. infuscatellus, fifteen
genotypes viz. Co 0238, CoH 167, Co 0237, CoH 160, Co 0118, CoH 56, CoH 92 ,CoJ 64, CoH 110, CoS 767,
CoH 119, Co 1148, CoH 150, CoH 99 and Co 5011 were found least susceptible against this pest and 4 genotypes
were found moderately susceptible. The information so generated on biology, population dynamics and relative
susceptibility of different genotypes is of great practical importance so as to evolve a sustainable strategy to
manage this menacing pest.
Description
Keywords
null