APHID-NATURAL ENEMY DIVERSITY IN HORTICULTURAL CROPS OF HIMACHAL PRADESH AND EVALUATION OF DOMINANT PREDATORS AGAINST ROSE APHID, Macrosiphum rosae L
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Date
2020-10
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NAUNI,UHF
Abstract
ABSTRACT
The present investigation entitled “Aphid-natural enemy diversity in horticultural crops of
Himachal Pradesh and evaluation of dominant predators against rose aphid, Macrosiphum rosae L.”
conducted during the year 2018-2020 at Department of Entomology, Dr. Y.S. Parmar University of Horticulture
and Forestry, Nauni, Solan, Himachal Pradesh. A total 24 aphid species belonging to 16 genera infesting
different horticultural crops were recorded from four agroclimatic zones of Himachal Pradesh. A total of 40
natural enemies belonging to 29 genera were recorded on these aphids. The Zone-II contributed maximum
diversity of aphid species (19) as well as natural enemies (38) followed by Zone-I. The diversity indices of
aphid and their natural enemies were also maximum in Zone-II. The seasonal abundance of rose aphid, M. rosae
was relatively low in first two months (February and March) and negligible in mid of the cropping season, while
the peak was recorded in the last three months (October to December) during both the years. The correlation
was worked out between rose aphid population and weather parameters during the year, 2018 revealed
significantly negative correlation with maximum temperature (Tmax r=-0.482) and minimum temperature (Tmin
r=-0.597) whereas, other weather parameters such as morning relative humidity RHm (r=-0.203), evening
relative humidity RHe (r=-0.199) and total rainfall (Rf) (r=-0.236) showed the non significant negative
correlation (P=0.05). Similarly, during 2019, rose aphid recorded highly significant negative correlation with
maximum temperature (Tmax r=-0.299) and minimum temperature (Tmin r=-0.404) whereas, RHm (r=0.121), RHe
(r=0.022) exhibited non significant positive correlation and total Rf (r=-0.072) showed the non significant
negative correlation. The rose aphid population exhibited significant positive correlation with Coccinella
septempunctata, Hippodamia variegata, Oenopia sauzeti and Oenopia sexareata whereas with Oenopia kirbyi
exhibited negative correlation during 2018 whereas, during 2019, rose aphid population exhibited significant
positive correlation with predators. Among the predatory coccinellids, C. septempunctata was recorded as
voracious feeder on rose aphid, M. rosae followed by H. variegata, O. sexareata, O. kirbyi and O. sauzeti
during grub as well as adult stages. The number of aphids consumed by larval instars, adult female and adult
male of C. septempunctata H. variegata, O. sexareata, O. kirbyi and O. sauzeti consumed on an average 189.90,
115.10, 90.50, 89.20, 90.30 and 1074, 679.83, 602, 560.16, 548.83 and 986.33, 519.5, 539.66, 491, 488.75
aphids, respectively. All the predators i.e. C. septempunctata, H. variegata, O. sexareata, O. kirbyi and O.
sauzeti exhibited the type-II functional response. The attack rate increased and handling time decreased with the
successive developmental stages of the predators. Among the all predators, C. septempuctata and H. variegata
exhibited the maximum demographic parameters indicating effective biocontrol agent. Hence, among predators
C. septempuctata and H. variegata possesses good attributable qualities of biocontrol agents these can be
exploited as a biocontrol agents of rose aphid, M. rosae as one of the componentsin integrated pest management
under mid-hill conditions of Himachal Pradesh.