Biology of polyommatus boetius (L.) on fieldpea and evaluation of various genotype against major insect pests
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Date
2016
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CCSHAU
Abstract
The present studies entitled “Biology of Polyommatus boeticus (L.) on fieldpea and evaluation of various
genotypes against major insect pest” was carried out during rabi 2015-16 at Reseach farm of Pulses Section,
Department of Genetics and Plant Breeding and Laboratory of Department of Entomology, CCS HAU, Hisar. For
conducting biological studies, rearing was done in laboratory at 28±10C and relative humidity (60-70%). Results
revealed that pre-oviposition, oviposition and post-oviposition period ranged from 1 to 2, 2 to 3 and 2 to 3 days,
respectively. A single female could lay maximum of 15 eggs and minimum of 13 eggs (average 14 eggs) during
her life time. On fieldpea, the longevity of male moths was ranged from 7 to 9 days (average 8 days) and longevity
of female moths varied from 9 to 10 days (average 9.5±0.42 days). Incubation period varied from 2 to 3 days
(average 2.5±0.7 days). The total larval period ranged from 11 to 13 days (average 12±0.22 days). Average Prepupal
period ranged from 2 to 3 days (average 2.22±0.13 days) and pupal period ranged from 6 to 9 days (average
8±0.22 days). Average female to male sex ratio was 1.0 to 1.5. It was found that the mating of adults of P. boeticus
occurred in day time only. When the mating was disturbed the pair flew without separation and continued mating.
Mating period of P. boeticus varied from 48 to 64 minutes (average 54.3 ±0.07 minutes). Results revealed that the
total life cycle varied from 29 to 35 days (average 32.8±4.24 days). Morphometric studies on P. boeticus revealed
that the eggs measured 0.47 to 0.57 mm in diameter (average 0.52 mm). Average body lengths of 1st, 2nd, 3rd and
4th instar larvae were 1.17, 2.10, 7.59 and 11.09 mm and average body width of 1st, 2nd, 3rd and 4th instar larvae
were 0.16, 0.69, 1.15 and 1.39 mm. Average head capsule length of 1st, 2nd, 3rd and 4th instar larvae were 0.22,
0.70, 1.25 and 1.46 mm. Average head capsule width of 1st, 2nd, 3rd and 4th instar larvae were 0.15, 0.64, 1.10 and
1.34 mm. On an average, pre pupa measured 10.80 mm in length and measured 4.94 mm in width and pupa
measured 10.62 mm in length and measured 4.45 mm in width. On an average 1st, 2nd, 3rd, 4th larval instar, pre
pupa and pupa male weighted 0.004, 0.021, 0.064, 0.170, 0.155 and 0.088 mg, respectively. Immature stage was
not distinguishable in male and female. Adult antennae, fore leg, middle leg and hind leg measured 7.93, 5.78,
6.05, 6.28 mm long in female and 7.02, 5.63, 5.91 and 6.15 mm in male. The average wingspan measured 29.90
mm in male and 33.28 mm in female. Out of the 18 genotypes screened against pod borer complex comprising H.
armigera, E. zinckenella and P.boeticus at green pod stage, the infestation ranged from 0.11 to 1.22, 0.00 to 1.44
and 00 to 0.33 larvae/ 3 plants, respectively, whereas at maturity it varied from 0.48 to 7.53, 7.31 to 22.10 and 0.50
to 1.60 per cent, respectively. Genotypes HFP-1137, HFP-530B, and HFP-529 were least susceptible and
genotype HFP-8712 was highly susceptible against H. armigera. There was positive and significant correlation of
50 per cent flowering with H. armigera and E. zinckenella. Pod wall thickness had negative and significant
correlation with H. armigera and E. zinckenella. Pod length was positive and significantly correlated with P.
boeticus pod damage. Trichome density was negative and significantly correlated with E. zinckenella larval
population and P. boeticus pod damage. Seasonal incidence studies revealed that C. indicus population had
significant negative correlation with temp (min.). H. armigera and P. boeticus population had non- significant
correlation with abiotic factors. E. zinckenella larval population had significant positive correlation with
Temperature (Tmax.). C. horticola population had significant negative correlation with temp.(max & min) and
significant positive correlation with morning relative humidity.