t i l e Effect of Different Plant Extracts on Olfactory Response of Bactrocera zonata Saunder and Postharvest Quality of Banana ( Musa acuminata Colla)

Bactrocera zonata is an important pest of different fruits in tropical and subtropical regions. It damages the fruits at early ripening stage and reduces the quality and the final yield of fruit crop. Moreover, to maintain the quality parameters of fruits after harvesting, is an important aspect of post-harvest management. For the management of fruit fly and to keep the natural quality of fruit after harvesting different methods are used (cultural practices, mechanical practices, biological practices), but chemical control practices are dominant among all. Besides quick and effective outcomes of chemical control. It also has side effects (residues in fruits, human health issues, resistance, damage to non-target population, environment pollution). In the present study the effect of different botanical extracts on the olfactory response of B. zonata and on the post-harvest quality parameters of banana was evaluated. Extracts of Moringa olifera , Mentha pipertia , Zingiber officinale , and Cinnamomum spp. were prepared in methanol, ethanol, and distilled water. The olfactory response of B. zonata was studied in Y-tube olfactometer and effect on the quality parameters (colour, taste, weight loss, pH, and titratable acidity) of banana was evaluated in laboratory conditions. The olfactory results of the present study showed that all botanical extracts exhibited the repellent effect against B. zonata, but the methanolic extract of cinnamon showed the highest repellence activity against B. zonata . Moreover, no side effects were observed on the post-harvest quality of banana treated to different methanolic extracts as compared to control. This shows that botanical extracts could be used for the control of B. zonata and for the better post-harvest management of fruits.


INTRODUCTION
T ephritidae fruit flies of the genus Bactrocera are destructive pest that have negative effect on fruit and vegetable production worldwide (De Meyer et al., 2007). Bactrocera zonata (Saunder) (Tephritidae, Diptera) commonly known as peach fruit fly is a severe polyphagous pest having more than 50 wild and commercial host plant species (Allwood et al., 1999;White and Elson-Harris, 1992).
B. zonata is considered as one of the most damaging and serious pest of guava, mango, and peach in tropical and subtropical climatic conditions (Choudhary et al., 2012;Sarwar et al., 2013;El-Gendy, 2017). Different control methods have been used for the control of fruit fly such as cultural practices, but these strategies are not very significant as compared to chemical control (Bashir et al., 2005). Several studies have been suggested that different insecticides are used to control the population of fruit flies e.g., malathion (Organophosphates), methomyl (Carbamate), and spinosad (Microbia) (Nadeem et al., 2014). Moreover, the repeated application of insecticides develop resistance in many species of fruit flies (Daane and Johnson, 2010;Jin et al., 2011;Nadeem et al., 2014) .
Extract of different plants such as Curcuma longa L., Acorus calamus L., Azadirachta indica A. Saussurea lappa, Valeriana jatamansi, C. B. Clarke and Peganum O n l i n e

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harmala L. has been reported having the repellent, growth inhibition, and oviposition deterrent effect against B. zonata (Naheed et al., 2004;Rehman et al., 2009). Acetone extract of yellow kaner, Thevetia peruviana (Pers.) K. Schum, datura, Datura alba (Nees) and chloroformed extract of sufaida, Eucalyptus camaldulensis (Dehnh) have the impact of repulsion and oviposition deterrence against B. zonata (Ilyas et al., 2017). Moreover, Siddiqi et al. (2006) have reported strong growth inhibition and repellence effect against B. zonata of turmeric plant extract extracted in acetone, ethanol, and petroleum ether (Siddiqi et al., 2006). However, there is a need to develop safer and reliable methods for the control of fruit flies globally. The use of botanicals as alternative control measure is considering to be more reliable, eco-friendly, and less chance of resistance development in fruit flies (Campos et al., 2019;de Oliveira et al., 2014;Isman, 2006;Khan et al., 2017). The aim of present study was to determine the effect of different botanical extracts (horse radish tree, Moringa olifera (Lam), peppermint, Mentha pipertia (Linnaeus), ginger, Zingiber officinale (Linnaeus), and cinnamon, Cinnamomum spp. on the olfactory response of B. zonata and on the quality parameters of banana fruits.

Insect collection and rearing
Guava infested with B. zonata were collected from the fruit and vegetable market (Sabzi Mandi) Multan. Fruits collected from market were kept in plastic bowls (14×14×7cm) for pupation and employed a period of two weeks for pupation. Pupae were sieved and placed in cage (46×46×52 cm). The adults of B. zonata were reared on artificial diet as described by Khan (2013). A cotton swab soaked in diet solution (sugar, water and yeast) was offered to adult flies and a cotton swab soaked in water given to adult flies as a moisture source. For oviposition fresh bananas were provided to adult flies. Bactrocera zonata was reared under laboratory conditions at 26±2°C and 65 ± 5% RH.

Plant material source and extract preparation
Mentha piperita (peppermint) leaves and Zingiber officinale (ginger) root were purchased from the fruit and vegetable market There were no significant (P=0.981) differences observed among the control and the treated fruits until the 8 th day of storage duration and Cinnamomum spp. (cinnamon) bark was purchased from the grain market Multan (Pakistan). Moringa olifera (moringa) leaves and bark were collected from the Bio-park of Bahauddin Zakariya University, Multan (Pakistan). The extracts were prepared in different solvents (methanol, ethanol, and distilled water) by following the method as described by Ohia et al. (2013).

Olfactometer bioassay
The response of flies to plant extract vs control bananas was evaluated in a Y-tube olfactometer. The olfactometer was made of a glass with 2.5 cm diameter, 22 cm long base, and 21 cm long arms (Abbas et al., 2021). Mix (male and female) population of B. zonata was used in the choice test. Arms of the olfactometer were connected to different odour sources via Teflon tube. Purified air was passed through an air pump (8 kPa s -1 ) into each of the olfactometer arm and exited through a suction pump (Abbas et al., 2021). A 12-watt LED bulb was used as a light source between the two arms of the olfactometer at 24cm distance from the olfactometer. Light source was facilitating the attraction of Fruit fly.
Four flies were released at the base of olfactometer and their response was observed for 2 min. This was repeated ten times. Fruit flies entered in each arm of the olfactometer were recorded by counting. Apparatus was rinsed with the tap water and odour source was changed after each paired olfactory test.

Post-harvest quality test
Banana fruits were purchased from the fruit and vegetable market Multan 'Sabzi Mandi' (N30˚1139.2676, E71˚3058.0788). Fruits were selected carefully to make sure the uniformity in appearance (colour, shape, and size). Banana were separated from the bunch, washed with distilled water, and dried at room temperature. Banana fruit was dipped in the chlorinated water (5% NaOCl) to disinfect from any contamination for 5 min and then rinsed with distilled water and dried at room temperature (Gomez-Lopez et al., 2009). For experiment banana fruit was selected randomly.

Treatments
Methanolic extract exhibited the good repellence effect against fruit flies at 30% concentration as described in earlier studies (Tajdar et al., 2020) , therefore, the effect of methanolic extracts was checked on the postharvest quality of banana. Banana fruits were treated with methanolic extract of M. olifera, Z. officinale, M. pipertia, and C. verm. Each treatment was replicated 3 times and each replication had 12 bananas. Treated bananas were kept in growth chamber (Panasonic) at 20°C and 70% RH. Data were collected on alternative days by selecting the three bananas from each replication of each treatment.

Colour
Changes in colour during storage and ripening stage O n l i n e

Weight loss (%)
Wight loss of fruits was determined by weighing the fruits on each day and compared the weight of each day with initial weight (day 1 weight) (Shrestha et al., 2018).

pH and titratable acidity (TTA)
The weighed amount of banana pulp was taken and diluted in the distilled water (water quantity was equal to the banana weight). Mixture was blended for 1 min until homogenized and become juicy (Liew and Lau, 2012). pH was determined by using the pH meter (Milwaukee, Mi. 180 Bench meter) (Zahoorullah et al., 2017). Titratable acidity was determined by following the method as described by (Ranganna, 2011).

Data recording and analysis
The olfactory data were analysed and compared by using a paired t-test at a 95% confidence level. The data for repellence, oviposition deterrence, and postharvest quality of banana were analysed by using one way analysis of variance (ANOVA), followed by all pair comparison tests of treatment with LSD test (α=0.05). The analysis was performed through SAS v.8 statistical package (SAS institute Inc., 1999).

RESULTS
Flies were given choices between volatile compounds released from the control arm and the arm having volatiles of the treated banana. In all three tests flies preferred the volatiles of control arm over the treated arm significantly. In case of banana treated with EMB, significantly (P=0.047, df=1) higher (26) numbers of flies preferred the control arm while ten numbers of flies opted the treated arm. Similar results were observed when banana treated with MMB and D.W MB was given to flies. In both tests, significantly (P=0.016, df=1; P=0.045, df=1, respectively) higher (24) numbers of flies preferred the control arm while eight and ten numbers of flies selected the treated arm, respectively (Fig. 1A).
In this olfactory test, flies respond to the moringa leaves extract similarly to the moringa bark extract volatiles. When treated banana with EML was given to flies, significantly (P=0.049, df=1) 24 flies preferred the volatiles of the control arm while ten flies were attracted towards the treated arm. Flies exhibited similar response to the banana treated with the MML and D. W ML extracts. In both, significantly (P=0.047, df=1; P=0.034, df=1, respectively) higher (18) number of flies attracted towards the control arm while six and eight number of flies respond to the treated arm, respectively (Fig. 1B). Flies respond to the control arm volatiles more significantly than the arm having the volatiles of treated banana. The banana treated with EC and MC was offered to flies, significantly (P=0.011, df=1; P=0.001, df=1, respectively) 26 flies preferred the control arm while six and eight flies opted the treated arm volatiles. Likewise, significantly (P=0.003, df=1) higher number (22) of flies preferred the control arm as compared to the treated arm ( Fig. 2A).
When olfaction was done with ginger, flies exhibited strong attraction to the control arm than the treated arm. When the banana treated with EG and MG was given to flies, significantly (P=0.047, df=1; P=0.016, df=1, respectively) higher (22)

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exhibited by flies when the banana treated with D. W G was offered. Significantly (P=0.009, df=1) more number of flies (24) exhibited strong preference to the control arm over the treated arm (Fig. 2B).
Olfactory results showed that comparatively more numbers of flies preferred the control arm over the treated arm. When flies were given choices between the control and the treated banana with EM and MM, significantly ((P=0.145, df=1; P=0.034, df=1) higher numbers (22 and 18, respectively) of flies preferred the control arm as compared to the treated arm. Likewise, significantly (P=0.242, df=1) higher number of flies (20) preferred the control arm volatiles as compared to the treated arm volatiles (Fig. 2C).

Postharvest quality of banana Colour
The changes in colour were recorded on numerical scale ranges from 1-7, which represents the fruit's yellowness level. The value of colour scale for all untreated and treated banana gradually increased throughout the storage life, but there were no significant differences in the colour values of all the treatments on the 8 th day of storage was observed (Table I).

Weight loss (%)
In all treatments increase in weight loss was recorded in storage. There were no significant (P=0.981) differences observed among the control and the treated fruits until the 8 th day of storage duration (Table I).

pH and titratable acidity (TTA)
The pH and Titratable acidity (TTA) of banana fruit changes during the storage duration. In all treatments, pH of banana was increased in storage life. There were no significant differences observed in the pH of banana until the 8 th day of storage life. The TTA of fruit is an important aspect related with the maturation and ripening of banana. The values of TTA in banana were reduced gradually with storage duration. There were significant differences observed on the 8 th day of storage life. The lowest values of TTA were observed in moringa leaves and ginger treatments, respectively, on 8 th day of storage as compared to other treatments (Table I).

Taste
The taste scale is an important aspect for fruit taste evaluation related to the sweetness and sourness of the fruit. In storage life the taste scale value was increased significantly. The value of taste scale was reached to maximum in the control, moringa leaves, and peppermint, respectively, on the 6 th day of storage life, but there were no significant differences observed in all treatments. Moreover, skin of fruit was ruptured on 8 th day of storage life, so, no data were recorded on 8 th day of storage (Fig.  3).

DISCUSSION
Fruits are important part of human diet and are good source of vitamins and nutrients (Melse-Boonstra, 2020). Moreover, fruits are good source of foreign exchange and countries can earn a lot of foreign exchange by exporting different fruits (Akgüngör et al., 2002). Orient to the fruit's importance, different control measures were designed and used for the management of pests as well as to increase the shelf life of fruits. In all control practices, chemical control was dominant in both pest management and shelf-

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Plant Extract Response on Insect and Plant 5 life enhancement of fruits. Besides quick control, chemical control has side effects (pest resistance, chemical residues in fruits, human health issues, environmental pollution, etc.) (Wojciechowska et al., 2016). Therefore, in the present study, the role of plant extract in pest management and enhancement of fruit shelf life was evaluated. Moreover, the effect of different plant extracts on the olfactory response of B. zonata adults was assessed. Plants have potential to control insect pests and can effectively be used as eco-friendly insecticides for the control of pests. The olfactory results of the present study revealed that methanolic extracts of M. olifera leaves and bark, Z. officinale, M. pipertia and C. verm have repellent effect on B. zonata adults. The cinnamon extract exhibited the highest repellency against B. zonata adults in all type of solvents. Extracts prepared in methanol were more repellent as compared to other solvents this could be due to that methanol has capacity to extract those compounds from plants which are repellent to insects. In accordance with Nathan et al. (2006) and Prabhu et al. (2011), who recorded that methanolic extract of Melia azedarach and moringa showed the highest repellency to Anopheles stephensi (Liston). Muryati et al. (2012) studied that methanolic extract of citronella grass had no repellent effect against Carambola fruit fly this may be due to the difference in fruit fly species and plant used for extract preparation. However, Palanikumar et al. (2017) recorded that methanolic extract of Callistemon citrinus (Myrtaceae) leaf possessed the larvicidal potential against mosquito Aedes aegypti. Likewise, Hossain and Khalequzzaman (2018) studied that methanolic extract of Azadirachta indica A. have repellent effect while methanolic extract of sweet guard exhibited the oviposition deterrence effect against Bactrocera cucurbitae (Coquillett). Maduagwuna et al. (2020) recorded that the methanolic extract of Caryota no (CN) seeds caused non-significant decrease in total protein levels, AChE activity, negative geotactic behaviour and fecundity of Drosophila melanogaster. The methanolic extract may have compound which repel the dipteran pests such as flies and mosquitoes. Moreover, Ayalew (2020) studied that ethanolic extract of Lantana camara exhibited the highest repellency against Sitophilus zeamais than methanolic extract. The difference in repellency effect to pests could be due to the difference in solvents and their efficiency to extract compounds from different plants. Moreover, this could be due to the difference in pest species and their response to different extracts.
In the current study the effect of methanolic extracts on different physical and chemical properties of banana was evaluated. There were no significant differences observed in the physical and chemical properties of treated and untreated banana ( Table I). The colour of fruit is an important parameter which indicates the fruit ripening stage and shows that fruit is fit for consumption. The values of colour scale were increased gradually as days increased in storage, but in all treatments including control there were no obvious difference observed in colour change of banana. The results are in accordance with Mohammadi et al. (2021) who studied that there were no significant differences observed in the

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A. Tajdar et al. treated and untreated strawberry colour change in storage conditions. Similar results were recorded by Parsa et al. (2020) that in storage the colour become darker and there was no significant difference observed in the treated and untreated cherries colour. Weight loss was recorded in all treatments and increase in weight loss in storage conditions was observed. No significant difference was observed in the weight loss between the treated and untreated banana until 8 th day of storage. The results agree with Contigiani et al. (2020) who studied that non-significant difference in weight loss was observed in plant extracts treated and untreated strawberries. In contrast, chillies coated with ALV gel showed lower weight loss as compared to the control (Ul Hasan et al., 2021). Loss in weight could be due to the fact that fresh fruits respire and as a result loss in moisture occurs. Moisture loss causes the weight loss as well as senescence of fruit. Moisture loss can be reduced through coatings with coating material (Ratra et al., 2016). pH of banana increased as days of storage increased. Moreover, there were no significant differences observed in the pH of treated and untreated bananas. The results coincide with Mohammadi et al. (2021) who recorded that pH of strawberry fruits increased during storage time. Moreover, the treatments did not alter the pH of strawberry significantly. Total titratable acidity (TTA) of all treatments decreased along storage duration except moringa leaves and ginger treatments. The results agree with Nair et al.
(2018) who studied that TTA of guava treated with PPE extract decreased gradually. The decrease in TTA of fruits could be due to that the changes in the metabolic process of fruits during the respiratory process (Rasouli et al., 2019).

CONCLUSION
The outcomes of the present research revealed that botanicals can be used as an alternative of synthetic pesticides for the management of Bactrocera zonata Saund. (Tephritidae: Diptera) to protect the environment from their hazards. Among all extracts, methanolic extract of peppermint is most effective and it also exhibited no effect on the quality of fruit. However, further research is required for isolation and identification of phytochemicals, responsible for such activity so that this may be exploited for the management of B. zonata population in the field.

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A. Tajdar et al.