Influence of Herbivores on the Biology of Chrysoperla carnea Stephens 355
obtained were subjected to CRD analysis as per
Gomez and Gomez ( 1984 ).
Incubation Period of C. carnea The minimum
incubation period of 2.93 days was observed
when Chrysoperla was provided with nymphs
and adults of cotton aphids. It was followed by
3.06 days on Helicoverpa (eggs and neonates).
Maximum incubation period of 3.46 days was
recorded on cotton jassids. The present findings
are in accordance with earlier reports by Man-
grule ( 2002 ) and Balakrishnan et al. ( 2005 ).
Larval Period of C. carnea
The larval stage of Chrysoperla had three instars
and the total larval period of Chrysoperla on
different preys ranged between 9.40 and 15.00
days, minimum being on cotton aphids found
at par with Helicoverpa (eggs and neonates) on
which 10.20 days were required to complete the
larval duration. The instar wise larval duration is
given in Table 1 – 7. However, the larval period
was observed to be prolonged when Chrysoperla
was provided with cotton-fed nymphs of jassids
and recorded as 15.00 days. This might be due to
the unsuitability of jassids as prey for Chrysop-
erla and aphids being the most suitable prey
among the three tested preys. Saminathan et al.
( 1999 ) reported 11.37 days of larval duration on
neonates of H. armigera. Similarly, Bansod and
Sarode (2000) reported that the total larval pe-
riod was 9.87 and 12.57 days on nymphs of A.
gossypii and neonates of H. armigera. (Table 1 )Feeding Potential of C. carnea
The predatory potential of Chrysoperla larvae
was significantly influenced by different preys.
Significantly, higher predatory potential
was observed with the cotton-fed nymphs and
adults of aphids recording 198.1 number of
preys/Chrysoperla larva with the highest host
suitability and feeding potential. It was followed
by the eggs and neonates of Helicoverpa record-
ing 181.1 preys per larva, respectively. Kapadia
and Puri (1992) reported that single larva of C.
carnea consumed 765.51 nymph of A. gossypii.
Kabissa et al. (1995) reported that the total con-
sumption of Chrysoperla larvae on eggs of H.
armigera and nymphs of A. gossypii were 169.80
and 171.80, respectively.Table 1 Incubation period of C. carnea
Treatment Incubation period in days
R1 R2 R3 R4 R5 Mean
Cotton aphids 2.67 3.00 2.67 3.33 3.00 2.934
Cotton jassids 3.67 3.67 3.00 3.33 3.67 3.468
Helicoverpa eggs and neonate 3.33 3.00 3.33 2.67 3.00 3.066
‘F’ test Sig.
SE(m) ± 0.132
CD at 5 % 0.398Table 2 Total larval period of C. carnea
Treatment Total larval period of Chrysoperla
R1 R2 R3 R4 R5 Mean
Cotton aphids 9.33 9.67 9.33 9.33 9.33 9.40
Cotton jassids 14.67 15.33 14.33 15.67 15.00 15.00
Helicoverpa eggs and
neonate10.00 10.67 10.33 10.00 10.00 10.20‘F’ test Sig.
SE(m) ± 0.152
CD at 5 % 0.491