physicochemical

ABSTRACTS
“Seasonal occurrence and evaluation of eco friendly insecticides against pest
complex of sunflower”
Student : Sanjaya Topagi
Major Advisor : Dr. G. Ramachandra Rao
Department of Entomology
Studies on the seasonal occurrence and
evaluation of eco-friendly insecticides against pest
complex of sunflower were undertaken during rabi, 2007-
2008 at Agricultural College Farm, Baptla.
The seasonal occurrence of the pest complex
on sunflower was recorded at weekly intervals on 50
plants from five different locations @ ten plants per
location while for evaluation of eco-friendly insecticides
and their safety to natural enemies the data were
recorded one day prior to application of treatments and
at one, five, ten and fifteen days after spraying on ten
randomly selected and tagged plants per plot. The data
with regard to seasonal occurrence indicated that
December, January and February months were
favourable for the multiplication of Spodotera litura
(Fabricius), Amrasca biguttula biguttula (Ishida), Bemisia
tabaci (Gannadius) and Aphis craccivora (Koch).
The peak occurrence of S. litura was recorded
during the second week of February while, sucking pests
viz., A. biguttula biguttula and B. tabaci was observed
during third week of January and for A. craccivora during
the first week of January.
Pertaining to field evaluation of eco-friendly
insecticides, spinosad 0.015% and B.t.k 0.2% were
highly effective in reducing the population of S. litura on
sunflower.
Pertaining to sucking pests viz., a. biguttula
biguttula, B. tabaci and A. cracciviora the data revealed
that Neemazal 0.03% and Nivaar 0.2% were highly
effective in reducing the pest population.
Nimbecidine 1%, N. rileyi 1.2x10* spores m1-1
and B. bassiana 1z1013*** conidia ml-1** were relatively
sare to both coccinellids and spider population on
sunflower, where as spinosad 0.015% and B.t.k 02%
were found highly toxic to coccinellids and spiders.
Spinosad 0.015% and B.t.k 0.2% recorded higher yields.
M.Sc (Ag),2008
Seasonal incidence and management of pink bollworm
Pectionophora gossyiella (Saunders) on cotton
Student : Sandhya Rani. B
Major Advisor: Dr. N.V.V.S.D. Prasad
Department of Entomology
Cotton ‘white gold’ is and important mainstay
of Indian economy. The pest spectrum of the cotton is
quite complex, bollworms being the major biological
constraints in cotton cultivation. Among the bollworms,
pink bollworm is more serious and challenging with the
destructive larval stage usually secluded with in the
cotton fruiting bodies and not accessible to traditional
control measures.
Field and laboratory investigations were carried
out to elicit information on seasonal incidence, biology
and management of pink bollworm, at the Regional
Agricultural Research Station, Lam, Guntur, Andhra
Pradesh, India during 2007-2008 crop season for
evolving implementable and sustainable management
strategies.
Studies on seasonal occurrence of pink
bollworm by pheromone monitoring revealed that the
catches of male moths of pink bollworm on cotton started
from the months of September with a peak level of pest
activity in the 2 nd fortnight of December and again in last
week of January to first fortnight of February.
Studies on biology and bionomics under
laboratory conditions revealed that eggs were laid mostly
in small groups which were creamy white in colour
initially and turned to pink colour before hatching. The
egg period varied from 4-6 days with an average of 5.2
days. The neonate larva was semi-translucent, light
yellowish with distinctly dark brown head and thoracic
shield. The larvae completed development in 5 stages
of growth (instars) and herned to pink colour in third
instar.
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