Diversity and Ecology of Insect pollinators in Major seed spices
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Date
2018
Authors
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Publisher
MPUAT, Udaipur
Abstract
Diversity and ecology of insect pollinators in major seed spices
Ms Shivangi Joshi* Dr. R. Swaminathan The investigation on “Diversity and ecology of insect pollinators in major
seed spices” was executed for two crop seasons (2015-16 & 2016-17) at the College
Instructional Farm and Department of Entomology, Rajasthan College of Agriculture,
Maharana Pratap University of Agriculture and Technology, Udaipur, with the
objectives to study the flowering phenology of seed spices; establish species
composition and abundance of indigenous insect pollinators in coriander, cumin and
fennel; develop a pictorial field diagnostic key for identification of insect pollinators
of major seed spices; and study the side-effects of recommended pesticides on the
insect pollinators of coriander.
Flowering phenology reached the maximum 60 to 86 days after sowing in
coriander, 67 to 92 days after sowing in cumin and 103 to 114 days after sowing in
fennel. The effective bloom period ranged from 17 to 24 days in coriander; 16 to 21
days in cumin and 15 to 21 days in fennel.
The indigenous insect pollinators comprised representatives from
Hymenoptera, Diptera, Coleoptera, Hemiptera and Lepidoptera with 4 identified
genera and 3 identified species of Apoidea that were dominant in the three seed
spices. The total insect pollinators collected could be categorized into 12 different
insect groups. The maximum seasonal mean population of insect pollinators was
noted during 12 to 14 hours of the day on the three seed spices. The peak insect
pollinator population was observed in the months of February and March. The insect
pollinators’ diversity manifested through bee bowls as well as the yellow pan traps in
the three seed spice crops as indicated by the diversity indices evinced no significant
difference in the numerical abundance as well as species richness between aphid
management pesticide treated and untreated conditions in both the years. The relative
density values for the 12 different species of insect pollinators had a wide range but
did not differ between the treated and untreated sets of the experiment; however,
differed considerably among the species recorded.
*Ph.D. Scholar, Department of Entomology, Rajasthan College of Agriculture, MPUAT, Udaipur
** Professor of Entomology and Dean, Rajasthan College of Agriculture, MPUAT, Udaipur
The insect pollinator species richness in coriander was 12 and Apis florea had
the maximum relative density; in cumin it was 11 and flies of Sarcophagidae had the
maximum relative density during both the years; but in fennel species richness was 12
and Apis florea had the maximum relative density during rabi 2015-16; while in rabi
2016-17 the species richness was 12 and flies of Sarcophagidae dominated with the
maximum relative density. Yellow bee bowls recorded the maximum collections in
the three seed spices under both treated and untreated conditions in both the years;
whereas, in the yellow pan traps, the numerical abundance of the insect pollinators
differed significantly among the spice crops.
The prevailing mean atmospheric temperature and mean relative humidity did
not influence the insect pollinator population/ activity significantly in both the years
and in the three spice crops. The foraging behaviour as maximum mean time spent per
flower (109.47 seconds), mean numbers of flowers foraged per minute (23.31) and the
maximum mean numbers of flowers visited per plant (18.13) was recorded for T.
iridipennis on coriander and for A. florea on cumin (90.65 seconds, 18.69 and 16.22,
respectively) as well as on fennel (113.50 seconds, 24.97 and 19.97, respectively)
during rabi 2015-16; but the corresponding values were the maximum for Apis florea
on all the spice crops being 117.17 seconds, 23.47 and 19.67 in coriander; 82.07
seconds, 14.10 and 10.43 in cumin; 123.47 seconds, 26.43 and 20.57 in fennel during
rabi 2016-17.
Pesticide application for aphid management showed maximum reduction in
the population of insect pollinators due to dimethoate (0.3%); while, the population
reduction of pollinators due to botanicals after the first and second sprays was
significantly less with the least being for Eucalyptus oil (3%), followed by nirgundi
oil (3%); however, treatment of coriander with nirgundi oil (3%) for aphid
management gave maximum seed yield of 2.42 & 2.29 kg/ 12 sq. m. during 2015-16
& 2016-17, respectively; with a corresponding yield of 2012.50 & 1908.33 kg/ ha.
The common insect pollinators of the seed spice crops: coriander, cumin and
fennel were morphologically characterized to describe the species/ genera/ family of
the identified pollinators and keys to identify the families, genera and species have
been provided.
Description
Diversity and Ecology of Insect pollinators in
Major seed spices
Keywords
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Citation
Joshi. S, and swaminathan. R