Cotton is one of the important and leading prime cash crops
in the Indian economy. Cultivation of genetically modified Bt cotton resulted
in an increase in yield, and the adoption of Bt cotton has decreased the use of
chemical pesticides, which are much hazardous for the environment and human
health. The cotton ecosystem is a shelter for many pests and predatory
arthropod communities. The aim of the study is to investigate the diversity and
seasonal patterns of arthropod populations in Bt cotton fields in Kalaburagi,
Karnataka, to understand their occurrence, abundance, and impact on the Bt
cotton ecosystem. The Present study was conducted at the Bt-cotton fields of
the opted study area of Kalaburagi. Various sampling techniques were used to
collect arthropod samples, namely, the sweep net technique, pit-fall technique
and the light-trap technique. The results clearly suggest that a total of 21
arthropod species were recorded, among them 13 insects were categorised as
pests and 8 were natural enemies. Apart from that, 3 species of predatory
spiders were recorded. In the Bt cotton agro-ecosystem, leafhoppers,
whiteflies, aphids, thrips, mites, and red cotton bugs were abundant during the
35th, 36th, 40th, 38th, 39th and 46th SMW. On the other hand, natural enemies,
viz, spiders, ladybird beetles, lace wings, hover flies and ants, were found
predominantly for the duration of 34th to 36th SMW. A correlation study shows
that rainfall had a negative correlation with semilooper, whitefly, leafhopper,
hoverfly fly and green lacewings. Significantly positive correlation was
observed between maximum temperature and mealy bug, green stink bug, pink
bollworm and green lacewing, hoverfly, white flies, and chafer beetle and
spider population. Diversity of arthropod fauna was moderate to rich in the Bt
cotton agro-ecosystem of the selected study area (H'=2.09) with higher
abundance of aphids followed by whiteflies, leaf hoppers, mites, thrips and red
cotton bugs. The findings highlight the dynamic interaction between pest and natural
enemy populations under varying climatic conditions, providing useful insights
for integrated pest management strategies in Bt-cotton cultivation.
Author(s) Details
AMBRISHA VENKATESHWAR
Department of P.G. Studies and Research in Zoology, Gulbarga University,
Kalaburagi, 585106, India.
K. VIJAYKUMAR
Department of P.G. Studies and Research in Zoology, Gulbarga University,
Kalaburagi, 585106, India.
Please see the book here :- https://doi.org/10.9734/bpi/rpbs/v7/6225
