BIOLOGY AND SEASONAL FLUCTUATION OF COTTON MELON
APHID, APHIS GOSSYPII CLOVER (HEMIPTERA: APHIDIDAE) ON
BRINJAL, SOLANUM MELONGENA
Uzma Manzoor*, Samreen Khanam, Masarrat Haseeb
Department of Plant Protection, Faculty of Agricultural Sciences, Aligarh Muslim University,
Aligarh
Email: khan_uzma11@yahoo.co.in
Telephone: 07417802796
ABSTRACT
Studies on biology of Aphis gossypii on brinjal under laboratory conditions revealed that the
total nymphal period was 9.1 ±1.10 days. The adult period was found to be 15.1 ± 4.63 days.
Pre-reproductive, reproductive and post-reproductive periods were evaluated to be 2.7 + 0.82,
16.3 ± 3.97 and 5.2 ± 1.68 days, respectively. The total life-span was recorded as 24.2 ± 4.85
days. Incidence of A. gossypii was observed from last week of December to First week of
April. Peak population was recorded at 354.3 per three leaves per plant in mid-February.
Aphid population exhibited positive non-significant correlation with temperature whereas it
exhibited significant negative correlation with minimum humidity and non-significant
negative correlation with maximum humidity.
Key words: Aphis gossypi, Brinjal, Biology, Correlation, Seasonal incidence, Solanum
melongena
INTRODUCTION
Aphis gossypii (Hemiptera: Aphididae) is cosmopolitan in nature. It is polyphagous but
attacks cotton and solanaceous crops in particular (Ghosh and Laskar, 2004). Among
solanaceous vegetables, brinjal is a preferred host of this insect. These aphids are found on
the underside of the leaves. The brinjal crops infested with this aphid become weak and
stunted due to excessive sap-sucking. Honeydew secretion which acts as a substrate for
sooty-mold formation causes further deterioration by interrupting the photosynthetic activity
thus reducing the overall growth of the plant and rendering fruits unmarketable (Capinera,
2001).
The increasing infestation of this pest in brinjal fields has raised a number of questions
regarding the factors responsible for its population build up under natural conditions. To
suppress the insect pest population below economic injury level, management practices need
to be developed through regular crop pest surveillance and monitoring. The basic information
on biology and seasonal incidence in relation to prevailing environmental conditions is
required for the development of pest forewarning system. Keeping this in view, the present
studies were undertaken so as to formulate efficient pest management tactics for this pest in
Aligarh region.
MATERIAL AND METHODS
The present studies were carried out under controlled conditions in the Department of Plant
Protection and at the experimental fields of the Faculty of Agricultural Sciences, AMU,
Aligarh, (India) during 2011-12.
Biology of A. gossypii on brinjal
The stock culture of A. gossypii was maintained under laboratory conditions. For this
purpose, aphids
were
collected
from
unprotected
brinjal
crop
planted
in
the
experimental field and kept individually in Petri plates lined with moist filter paper to
maintain humidity. Daily fresh brinjal leaves were provided to aphids until nymph were laid.
Progeny of laboratory reared A. gossypii was used in the experiment. Freshly emerged first
instar nymphs produced by the mother aphids under laboratory conditions were sorted out
from the stock culture. Ten leaf discs of brinjal were cut and placed individually in Petri
plates each lined with moistened filter paper. On each leaf disc, first instar nymph was
released and each Petri plate was designated as a replicate. Nympnal food was changed
everyday and duration of development of different nymphal instars, total nymphal period,
natality and adult longevity was recorded. The number of nymphs laid by each female during
whole life-span was observed to study the natality. Average of each observation was taken
and standard deviation was calculated.
Seasonal fluctuation of A. gossypii on brinjal
Seasonal incidence of A. gossypii was studied on the cultivar ‘Navkiran’ raised during
November 2011 to April 2012 with recommended cultural practices in 3m x 3. 5m plots
replicated 9 times without any plant protection measures. Observations on the aphid
population were recorded at 7 days interval by selecting three leaves (upper, middle and
lower) each from ten randomly selected plants.
The population of brinjal aphid was correlated with abiotic factors (weather factors viz.,
maximum temperature, minimum temperature, maximum relative humidity and minimum
relative humidity) and biotic factors (predators). Meteorological data on weather parameters
was collected from the Observatory of Physics Department, AMU, Aligarh which is near to
the place of experimental field. The data so generated from weekly observations was
subjected to Pearson's Correlation Analysis by using the language programme “SPSS 13.0”
unless stated otherwise.
RESULTS
1. Biology of A. gossypii on brinjal
Nymphal instars
The nymphs varied in color from grey to green and often marked with dark head and
thorax. Distal portion of abdomen was found to be dark green. At first, nymphs appeared
light in color but with successive developmental stages, they became dark-colored. The
average number of days of first, second, third and fourth nymphal instars were found to be 2
± 0.56, 2 ± 0.82, 2.4 ± 0.52 and 2.7 ± 0.48 days, respectively. The total nymphal period was
calculated as 9.1 ± 1.10 days.
Adult
Wingless adults were found to vary in color from light to dark-green with black
cornicles. The body appeared dull due to the presence of dusty secretions. Winged adults
were observed with black head and thorax and yellow-green abdomen. The adult period was
found to be 15.1 ± 4.63 days. Pre-reproductive, reproductive and post-reproductive periods
were evaluated as 2.7 ± 0.82, 16.3 ± 3.97 and 5.2 ± 1.68 days respectively. Total natality and
the total life-span were recorded as 71.5 ± 12.8 and 24.2 ± 4.85 days, respectively.
Seasonal fluctuation of A. gossypii on brinjal
The temperature varied from 6.8°C (minimum) to 37.30C (maximum) whereas humidity
ranged between 34.5% (minimum) and 96.5% (maximum) during the whole experiment. The
incidence of A. gossypii on brinjal commenced from 52nd std. week (Dec’ 11) and gradually
increased and reached its peak in the 9th std. week (Feb’ 12). Highest population recorded
was 354.3 per three leaves per plant. During this period the temperature and humidity ranged
from 11.8°C - 26.5°C and 42.0% - 69.8%, respectively. Thereafter, the population gradually
declined and almost vanished in the 15th SW (Apr’ 12) with temperature and humidity in the
range of 21.oC - 33.6°C and 47.8 %-64.4 %, respectively. Correlation of pest population with
weather parameters revealed that the population of A. gossypii exhibited positive nonsignificant correlation with both minimum and maximum temperature whereas it exhibited
significant negative correlation with minimum humidity and non-significant negative
correlation with maximum humidity respectively.
DISCUSSION
The present findings on biology of the aphid are in conformity with the studies of
Jhansi and Subbaratnam (2005). On the contrary, Kumar et al, (2001), Rathod and Bopadra(2006) and Shah et. al., (2009) conducted similar studies and found the total life span of A
gossypii shorter on brinjal. This difference may be attributed due to change in climatic
conditions at different places.
The present study on seasonal incidence of A. gossypii is in complete corroboration with the
findings of Roy and Behura (1979), Banerjee and Raychaudhuri (1985), and Karim and
Rahman (2000). Trumble et al., (1983) observed the population A. gossypii on strawberries
and found similar results.
CONCLUSION
Studies pertaining to life cycle parameters gave the survival rate, duration of nymphal period
and adult period which can be helpful in construction of mathematical models for providing
information on population build up of the pest whereas studies related to seasonal incidence
gave information about the time of occurrence, peak period of activity and duration of the
occurrence of the pest in nature. This in turn will be helpful in devising a proper IPM strategy
for the management of pest in Aligarh and its surrounding areas.
REFERENCES
Capinera JL. 2001. Handbook of Vegetable Pests. Academic Press, San Diego. 729 pp.
Devi, M. N. Singh, T. K. and Chitra Devi, (2002). Field density of Aphis gossypii Glover on
brinjal in relation to predatory and biotic factors. Ultar Pradesh J. of Zool. 22:
1, 67-71.
Sunil Kumar Ghosh, N. Laskar (2001). Seasonal fluctuation of A. gossypii on brinjal and
evaluation of some pesticides against A. gossypii under Terai region of West
Bengal. Indian J. Agri.Res. 38(3): 171-177.
Hughes, R. D. (1972). Population dynamics in aphid technology, Ed. Van. Emden, Academic
Press. London, pp: 334.
Jhansi, K. and Subbaratnara, G. V. (2005). Effect of insecticide resistance on the biology
morphometrics of Aphis gossypii Glover. Pesticide Res. J. 17: 2, 67-69.
Karim, K. N. S. Das, B. C. and Khalequzzainan, M. (2002). Impact of ecological factors on
the morphology of Aphis gossypii Glover (Homoptera: Aphididae) at
Rajshahi, Bangladesh. J. of Pak. Entomol. 24: 1, 1-22.
Kumar, M, Chinamen, M. and Prasad, B. (2001). Studies on the comparative biology of
Aphis gossypii Glover (Aphidae-Homoptera) on two host plants-brinjal and
chilli in Manipur. J. of Exp. Zool. 4: 2, 291-293.
Lokeshwari, R. K. Devikarani, K. H. and Singh, T. K. (2010). Seasonal dynamics of Aphis
gossypii and relative abundance of its coccinellid predators on cucumber. Ind.
J of Entomol. 72: 2, S14-116.
Rathod, R. R. Bapodra, J. G. (2006). Bionomics of aphid, A. gossypii, on cotton. Ind. J. of
Entomol, 68: 2, 113-116.
Roy, D. K. and Behura, B. K. (1979). Seasonal variation in the population of A. gossypii on
brinjal, Proc. Symp. On aphids. Ed. B. K. Behura. Zoo. Soc. Orissa, pp : 6064.
Shah, M. A. S. Singh, T. K. Radhakrishore, R. K. (2009). Comparative biology of cotton
aphid, Aphis gossypii Glover (Homoptera-Aphididae) on okra and brinjal.
J. of Exp. Zool, 12: 2, 373-37.
Table 1: Biological attributes of Aphis gossypii on brinjal
Biological Attributes
Time in days (Av±Sd)
Nymphal Period
1st instar
2±0.56
2nd instar
2±0.82
3rd instar
2.4±0.52
4th instar
2.7±0.48
Total nymphal period
9.1±1.10
Adult period
15.1±4.63
Total life period
24.2±4.85
Pre-natal period
2.7±0.82
Natal period
16.3±3.97
Post natal period
5.2±1.68
Natality
71.5±12.8
Table 2: Correlation of biotic and abiotic factors with the population of A. gossypii
Population
Aphid
Maximum
Minimum
Maximum
Minimum
Rainfall
temperature
temperature
humidity
humidity
0.282
0.200
-0.513*
-0.674**
-0.066
0.892**
0.948**
-0.845**
-0.631**
0.307
population
Predator
Population
**correlation is significant at 0.01 level
*correlation is significant at 0.05 level