Content uploaded by Dr Haider Karar
Author content
All content in this area was uploaded by Dr Haider Karar on Dec 30, 2015
Content may be subject to copyright.
~2~
Journal of Entomology and Zoology Studies 2016; 4(1): 02-06
E-ISSN: 2320-7078
P-ISSN: 2349-6800
JEZS 2016; 4(1): 02-06
© 2016 JEZS
Received: 01-11-2015
Accepted: 01-12-2015
Amjad Ali
Entomological Research
Institute, Ayub Agricultural
Research Institute, Faisalabad,
Pakistan.
Haider Karar
Entomological Research Sub-
Station, Multan, Entomological
Research Institute, Ayub
Agricultural Research Institute,
Faisalabad, Pakistan.
Muhammad Farooq
Entomological Research
Institute, Ayub Agricultural
Research Institute, Faisalabad,
Pakistan.
Faisal Hafeez
Entomological Research
Institute, Ayub Agricultural
Research Institute, Faisalabad,
Pakistan.
Muneer Abbas
Entomological Research
Institute, Ayub Agricultural
Research Institute, Faisalabad,
Pakistan.
Touseef Khan Babar
Entomological Research Sub-
Station, Multan, Entomological
Research Institute, Ayub
Agricultural Research Institute,
Faisalabad, Pakistan.
Correspondence
Faisal Hafeez
Entomological Research
Institute, Ayub Agricultural
Research Institute, Faisalabad,
Pakistan.
Influence of weather factors on the trapped
population of pink bollworm (Pectinophora
gossypiella) under Multan Agro-ecosystem
Amjad Ali, Faisal Hafeez, Muhammad Farooq, Haider Karar, Muneer
Abbas, Touseef Khan Babar
Abstract
Studies were carried out to evaluate the impact of weather factors on the population dynamics of pink
bollworm for three consecutive years from 2009 to 2011 at Entomological Research Sub-station, Multan.
Pheromone traps charged with Gossyplure [(Z, Z) and (Z, E) 7, 11 hexadecadienyl acetate] were installed
and data for moth catches was recorded regularly at fortnightly basis. Simple correlation and regression
coefficients were also computed to know the relationship between weather factors and moth catches. The
results indicated that highest peaks of pink bollworm appeared during April having 1.1 and 1.13
moths/trap at 37.78 and 36.78 oC (maximum temperature), 22.00 and 20.12 oC (minimum temperature),
29.89 and 28.46 oC (average temperature) and 67% (RH) during 2009 and 2011 respectively whereas
peak appeared in November and December during 2010. Out of weather factors, maximum temperature
and rainfall showed positive response while minimum temperature, average temperature and relative
humidity had a negative impact on the population fluctuation of pink bollworm. Regression coefficient
showed 8.92% impact of weather factors in population fluctuation.
Keywords: Pink bollworm, Multan, Climatic changes, Regression analysis
1. Introduction
Cotton is one of the most sensitive crop to the pest attack and chemically intensive among all
fields. In Pakistan, bollworms are considered as major pest of cotton. Apart from cotton they
also cause serious damage to number of other crops particularly the summer vegetables such as
okra, tomato, tori, chilies and different cucurbits etc. Ahmed [1] reported that cotton crop is the
most susceptible to bollworm, which inflect heavy damage that may vary from year to year but
generally cause 20-30% of yield reduction. Ghouri [8] reported about 20% loss of yield by
different bollworm pest only. Pectinophora gossypiella is one of the major lepidopteron pests
of this region and cause significant infestation throughout the world. It causes an enormous
damage and loss of cotton yield when it neglected [7].
Hutchison et al. [12] reported that young larvae of P. gossypiella penetrate in to the young bolls
and flowers two hours after the hatching. The pink bollworm larvae feed on flower buds,
flowers, bolls and seeds, and the termination of growth results in boll rotting, premature or
partial boll opening, reduction of staple length, strength, and increases trash content in the lint.
Sex pheromones are being used to monitor emergences of over winter population of pink
bollworm (a successful technique for monitoring and mating disruptions) [16, 18]. Hummel et al.
[11] identified the sex pheromones for pink bollworm as 1:1 mixture of (Z, Z) and (Z, E) 7, 11
hexadecadienyl acetate, named gossyplure. Boguslawski [4] used sex pheromones and
pesticides in different plots for control of P. gossypiella, and found sex pheromones more
successful than pesticides. Being cold blooded organisms, the effect of temperature on insects
largely overwhelms the influence of environmental aspects [3]. Temperature exerts great impact
upon the total number of eggs and on the ovipositional behavior of insects [5]. More often
rainfall may have a negative impact on the insect population because eggs and neonates of
some insects may be dislocated or killed by rain [14]. Its population increases during rainy
season and population drop with increase in temperature. Different stages of the insect
prolonged developmental period during winter and coloration also changes with change in
temperature and humidity [17]. Insects are capable of surviving only within certain
environmental limits, so one can predict the occurrence of peak activities of a given pest
~3~
Journal of Entomology and Zoology Studies
through better understanding of preferred environmental
factors. Therefore, the current studies were conducted to
monitor the population of P. gossypiella and its relationship
with weather factors.
2. Materials and Methods
The experiment was conducted for three consecutive years
(2009 to 2011) at Entomological Research Sub-Station,
Multan to monitor the population fluctuation of P. gossypiella
and impact of weather factors on its population. Six
pheromone traps each charged with Gossyplure were installed.
Each trap was installed with the help of bamboo stick at the
height of 1.22-1.55 m from the ground level. The data for
moth catches were recorded fortnightly. The lure was changed
after 15 days interval regularly. To evaluate the effect of
weather parameters on the population of P. gossypiella,
weather data were obtained from the nearby observatory at
Multan.
Statistical Analysis
The data obtained were graphed using MS-Excel-2010 along
with weather parameters. The data was transformed using
square root transformation for calculating correlation and
regression coefficients to check the role of weather parameters
on the population fluctuation of P. gossypiella.
Y=√0.5+x
Where x is the number of P. gossypiella.
3. Results
The results (fig. 1) showed relative influence of weather
factors on the population fluctuation of P. gossypiella. It is
evident from the figure that moth catches of P. gossypiella
trapped were very low (almost zero) during Jan-March of first
year. Maximum moth catches were observed on 30-04-2009
(1.10 moths/trap) at moderate weather conditions (29.89 oC,
51.21% R.H.). Second and third highest peaks of P.
gossypiella population were observed on 15-04-2009 (0.86
moths/trap) and 30-10-2009 (0.78 moths/trap) respectively. No
moth catches were recorded for other months.
During second year of study (fig. 2), moth population was
observed in two peaks i.e. mid-April to mid-May and mid-
October to December. No population was noticed for
remaining months. However, maximum population of 1.00
moth/trap was recorded on15-12-2010.
During 2011, 1.13 moths/trap were observed on 30-04-2011
followed by 0.40 moths/trap on 30-10-2011. Moth catches
remained very low during other period of the year (Fig. 3).
Simple linear correlation was also carried out to know the
relationship between moth population and weather factors as
depicted in Table 1. All the weather factors showed non-
significant correlation with the pest population. Therefore, no
conclusion was drawn from these results.
Multiple linear regression analysis revealed that weather
factors exhibited 15.37% role on population fluctuation during
2009 (Table 2). Table 2 depicted the regression coefficient
values to check the impact of weather factors on moth
population. It is evident from the results that weather factors
exhibited 15.37% role on population fluctuation during 2009.
Minimum impact on moth population was exerted by rainfall
(0.31%) followed by maximum temperature (0.91%) while
relative humidity had great impact (6.93%). During 2010,
weather factors contributed 72.75% variation in population
fluctuation of moth catches which is statistically significant.
Rainfall had maximum role (25.57%) in defining population
variation during this year. Weather factors had non-significant
impact on population fluctuation during 2011 and exerted
12.64% role only. On cumulative basis, the impact of weather
factors was very low (8.92%).
Fig.1: Moth catches of pink boll worm per trap versus weather factors during 2009 at Multan agro-ecosystem.
~4~
Journal of Entomology and Zoology Studies
Fig.2: Moth catches of pink boll worm per trap versus weather factors during 2010 at Multan agro-ecosystem.
Fig.3: Moth catches of pink boll worm per trap versus weather factors during 2011 at Multan agro-ecosystem.
Table 1: Correlation coefficients (r) between trapped population of pink bollworm and weather factors during various study years
Weather Parameters 2009 2010 2011 Cumulative
Maximum Temperature (oC) 0.206 (0.334) 0.022 (0.881) 0.017 (0.892) 0.106 (0.623)
Minimum Temperature (oC) 0.225 (0.290) -0.041 (0.783) -0.065 (0.594) -0.007 (0.972)
Average Temperature (oC) 0.214 (0.314) -0.008 (0.955) -0.024 (0.844) 0.046 (0.829)
Relative Humidity (%) -0.334 (0.111) -0.081 (0.590) -0.088 (0.466) -0.133 (0.534)
Rainfall (mm) -0.022 (0.918) 0.252 (0.087) 0.201 (0.094) 0.207 (0.331)
Table 2: Multiple Linear Regression showing impact of weather factors on trapped population of pink bollworm during 2009-2011
Year Regression Equation, y R2 (%) Impact (%) P
2009 Y=0.504 + 0.0497x1 4.25 4.25 0.334
Y=0.728 – 0.025 x1 + 0.049x2 5.16 0.91 0.573
Y=1.310 + 1.11 x1 + 0.726 x2 - 2.28x3 8.12 2.96 0.629
Y=3.07 + 0.35 x1 + 0.383 x2 - 1.02 x3 - 0.184x4 15.05 6.93 0.516
Y=3.27 + 0.26 x1 + 0.345 x2 - 0.88 x3 - 0.205 x4 + 0.029x5 15.37 0.32 0.663
2010 **Y= 0.924 - 0.0262 x1 1.31 1.31 0.003
Y=0.019 + 0.295 *x1 - 0.2296*x2 26.54 25.23 0.965
~5~
Journal of Entomology and Zoology Studies
*Y= -2.77 - 3.66* x1 - 2.825** x2 + 8.34*x3 46.79 20.25 0.018
*Y= -3.14 - 3.64 8x1 - 2.837 **x2 + 8.36 *x3 + 0.0275x4 47.18 0.39 0.047
*Y= -2.89 - 4.27 **x1 - 3.133 **x2 + 9.44 **x3 - 0.0087 x4 + 0.1758**x5 72.75 25.57 0.016
2011 **Y=0.688 + 0.0143 x1 0.70 0.7 0.690
Y=0.273 + 0.186 x1 - 0.1302x2 11.96 11.26 0.246
Y=0.247 + 0.15 x1 - 0.158 x2 + 0.09x3 11.96 0 0.754
Y=-0.11 + 0.19 x1 - 0.168 x2 + 0.07 x3 + 0.0309x4 12.39 0.43 0.936
Y=-0.15 + 0.22 x1 - 0.155 x2 + 0.01 x3 + 0.036 x4 - 0.026x5 12.64 0.25 0.921
Cum. **Y=0.721 + 0.0098x1 0.20 0.2 0.000
Y=0.345 + 0.1459 x1 - 0.0958x2 5.32 5.12 0.163
Y=0.302 + 0.077 x1 - 0.140 x2 + 0.14x3 5.34 0.02 0.556
Y=0.383 + 0.047 x1 - 0.150 x2 + 0.19 x3 - 0.0074x4 5.36 0.02 0.620
Y=0.490 - 0.121 x1 - 0.223 x2 + 0.46 x3 - 0.0212 x4 + 0.0766x5 8.92 3.56 0.523
Where:
x1 = Maximum Temperature (oC) x2= Minimum Temperature (oC)
x3 = Average Temperature (oC) x4 = Relative Humidity (%)
x5 = Rainfall (mm) R2= Coefficient of determination
4. Discussion
Weather factors are source of variation in population
fluctuation of pink bollworm. In 1994, Jha and Bisen [13]
recorded that seasonal incidence of pink bollworm was largely
influenced by the weather factors. The results revealed high
population of pink bollworm during April and October-
November which are supported by Chaudhary and his co-
workers[6] who reported that maximum population of Pink
bollworm was observed during October, when the temperature
ranges 25.0-35.0 oC and relative humidity ranges from 45.0-
55.0% and there was no rain fall. These findings are in line
with Kae et al. [15] who worked on the population of P.
gossypiella, according to his observation maximum population
took place from July-September. Our findings are also in
accordance with Gupta et al. [9] who reported that peak
populations of adult males were observed from the 2nd
fortnight of August to the 1st week of November and peak
larval populations were observed from the 2nd week of October
to the 2nd week of December. The total rainfall (mm) reduced
adult male populations and total rainfall and temperature
reduced larval populations. These results are also at par with
another study of Gupta et al. [10] who observed that pink
bollworm peak population was noticed between third week of
August and second week of November, indicating six peaks.
Weather parameters viz., average temperature and average
humidity had significant positive impact on the population
build-up of pink bollworm male moths. The total rainfall,
however, had significant but negative impact on its population
build-up whereas our results indicated average temperature
had non-significant negative impact during 2010 and 2011 but
negative impact during 2009 and when computed on
cumulative basis. This anomaly in results may be attributed to
difference in weather conditions of both areas. The results of
Balasubramanian et al. [2] also in conformity with our findings
who reported that Significant positive correlations were found
between the incidence of these pests and the maximum
temperature and hours of sunshine. Significant negative
correlations were found between pest incidence and minimum
temperature, morning relative humidity, evening relative
humidity, intensity of rainfall and number of rainy days.
5. Conclusion
From the present investigation, it can be concluded that
population of pink bollworm builds up during moderate
environmental conditions i.e. April and November-December.
So it is the best time to take preventive measures to keep its
population in check. Also weather conditions greatly influence
the population of pink bollworm so regular inspection of the
pest is necessary.
6. References
1. Ahmed Z. Incidence of major cotton pests and diseases in
Pakistan with special reference to pest management.
Proceeding of First International Consultation on Cotton
Production Research with focus on the Asian Region.
Manila, Philippines. 17-21 November, 1980, 156-179.
2. Balasubramanian G, Balasubramanian M, Kulandaivelu
R. Prediction of bollworms’ damage to cotton in relation
to weather factors. Madras Agric J. 1981; 68:657-659.
3. Baloch AA, Soomroo BA, Laghari MA, Sanjrani MW.
Studies on economic injury levels of insect pests of
cotton. Turkey Ent Dergisit, 1990; 14:131-148.
4. Boguslawski CV, Basedow T. Studies in cotton field I
Egypt in the effect of pheromones mating disruption on
Pectinophoro gossypiella (Saund.) Lepidoptera:
Gelechiidae, on the occurrence of the arthropods. J Appl
Entomol. 2000; 125:327-331.
5. Cammel ME, Knight JD. Effects of climatic change on the
population dynamics of crop pests. Adv Ecol Res
1992; 22:117-162.
6. Chaudhari GB, Bharpoda TM, Patel JJ, Patel KI, Patel JR.
Effect of weather on activity of cotton bollworms in
middle Gujrat J Agro Meteor, 1999; 1(2):137-138.
7. El-Aswad AF, Aly MI. Screening of some insecticides
against the cotton bollworms, Pectinophora gossypiella
(Saund.) and Earias insulana (Boisd.). J Pest Contr
Environ Sci. 2007; 15(2):63-74.
8. Ghouri ASK. Roll of DDT in pest control. Pak. Times
Suppl 1980; 9:4-9.
9. Gupta GP, Katiyar KN, Vashisht AK. Behavior of male
pink bollworm (Pectinophora gossypiella) toward
gossyplure and its relationship with larval population and
weather condition. Ind J Agric Sci. 1990a; 60:411-416.
10. Gupta GP, Kishore P, Vashisht AK. Monitoring of pink
bollworm Pectinophora gossypiella (Saunders) males
through pheromone traps and weather parameters
affecting population build-up. J Ent Res. 1990b; 14:21-29.
~6~
Journal of Entomology and Zoology Studies
11. Hummel HE, Gaston LK, Shorey HH, Kaae RS, Bryne
JK, Silverstein RM. Clarification of chemical status of the
pink bollworm sex pheromone. Science. 1973; 181:873-
875.
12. Hutchison WD, Beasley CA, Henneberry TJ, Martin JM.
Sampling pink bollworm (Lepidoptera: Gelechiidae) eggs:
Potential for improved timing and reduced use of
insecticides. J Econ Ent. 1988; 81:673-678.
13. Jha RC, Bisen RS. Effect of climatic factors on the
seasonal incidence of the pink bollworm on cotton crop.
Annuals of plant protection Science. 1994; 2:12-14.
14. Kadam JR, Khaire VM. Raining and relative humidity:
key factors to suppress Earias vittella (Fabricius)
infestation on ‘okra’ crop. J Ent Res. 1995; 19:201-205.
15. Kae RS, Shorg HH, Gaston LK, Sheller D. Sex
pheromones of Lepidoptera: Seasonal distribution of male
Pectinophora gossypiella in a cotton field. Environ Ent,
1977; 6:264-286.
16. Relofs WL. Chemical control of insects by pheromones.
In biochemistry of Insects. Ed. by Rockstein, M. New
York, NY: Academic Press, 1978, 419-464.
17. Schmutterer H. Properties and potential of natural
pesticides from the neem tree, Azadirachta indica. Annual
Rev. Entomol 1990; 35:271-297.
18. Wene GP, Sheets LW, Woodruff HE. Emergence of
overwintered pink bollworm in Arizona. J Econ Ent.
1961; 54:192.