Effect of host plant on cornucopia of mango fruit flies (Diptera: Tephritidae) and their triumphant management in context of climate change.

A study was performed to assess the preference of fourteen mango cultivars for fruit flies and their management by bagging. So the choice of Tephritid flies to mango cultivars during fruiting phase is crucial. Fourteen different cultivars of mango viz., 'Dusehri', 'Malda', 'Langra' early cultivars, 'Chaunsa', 'Fajri Klan', 'Sensation' medium whereas 'Sanglakhi', 'Retaul-12', 'Mehmood Khan', 'Tukhmi', 'Kala Chaunsa', 'Chitta Chaunsa', 'Dai Wala' and 'Sobey De Ting' late cultivars were assessed for their suitability for fruit flies. The results indicate that the population density of fruit flies was higher on late cultivars like 'Sanglakhi' (20.61 percent), 'Mehmood Khan' (20.22 percent) and 'Reutal-12' (19.92 percent) were proved to be highly susceptible to fruit flies. Among these the cultivar 'Reutal-12' was selected being commercial and future cultivar for the management of fruit flies through bagging. The results reported that the attack of tephritid fruit flies and other insect pests were zero in bagged fruits as compared with control. It was further recorded that the bagged fruits has maximum average fruit weight i.e. 203.50 and 197.83 g per fruit was noted in those treatments where butter paper bag and brown paper bag was wrapped with better coloration as compared with un-bagged fruit with 159.5 g per fruit. Similarly, on an average fruit length were more i.e. 90.17, 91.33 mm in bagged fruit and 85.33 in un-bagged fruits. Furthermore, bagged fruits have zero incidence of disease with reduced fruit crack, fruit sunburn, mechanical damage, bird damage, fruit blemished and agrochemical residues on the fruit. So, it is concluded that the special attention should be given on 'Reutal-12' for the management of fruit flies when devising an IPM program for the control of fruit flies. Further, bagging has proved to be the good agricultural practices for the production of quality mango.

Introduction

Mango is enriched with many nutrients which enhances its quality. Pakistan is one of the 4th largest mango producing country and amongst top ten mango fruit exporting countries. Pakistan faced some difficulties for exporting mango fruits to other countries. In this way the growers can generate maximum profit by production of fruit (Abdullah and Shamsulaman, 2008). In spite of fruit flies there are some other fruit damaging pests like fruit borer, leaf miner and scales which deteriorate the qualities and quantity of fruit (Rajkumar et al., 2013). These insect pests reduced the quality and production (Pena et al., 1998) which can lessen yield of mango up to 50% or more (Patel et al., 2004). Among insect pests fruit flies and scales are known as quarantine pests, if their presence could be recorded in the exportable products, the consignment can be rejected and exporter bear huge losses. For example, a shipment of 1300 kg of mango was rejected by the UK quarantine department during 2018 over the presence of fruit flies larvae in the mango fruits (Ali, 2018). Moreover, fruit flies are considered a caustic crowd of insects that cause huge financial losses in fruits, vegetables and flowers. Some scientists worked on crop losses by fruit flies and reported that 12–60, 40–90 and 12–60 percent crop losses were estimated in mango, guava and papaya (Allwood and Leblanc, 1997). To produce fruit flies free fruits the uses of bags are considered the more important practice to overcome losses. To protect the fruits, bags are commonly used in Australia, China and Japan on grape, peach, apple, pear, loquat to improve the fruit coloration for better market price and by reducing pathological and physiological disorders (Joyce et al., 1997) leading to better look (Amarante et al., 2002b). A number of countries like Argentina, Mexico and Chile, don’t import ‘apples’ unless they are bagged (Sharma, et al., 2014). To overcome the losses of these pests growers use diverse practices like chemicals, sanitation, pheromones traps and use of protein hrdrolysate but no one approach has proved so much effective. Furthermore the use of insecticides causes residual limits so there is need of some improved type of IPM tools which not only manage these pests but also produce good qualities fruits. Further the bags protect the fruits from insect pests, mechanical, physical injuries, diseases and improve the quality of the fruit for export purposes. These improvements in quality of fruit playing role in development of mango fruit (Sharma et al., 2014). Due to beneficial effects, fruit bagging has become an essential part of quality fruit production for export. The development of varieties resistant to insect pests is chief part of an integrated pest management. The development and then cultivation of pest resistant mango cultivars has been limited, because of the lack of adequate information on the genetic variability and sources of resistance in the available mango genotypes and influence of these sources on the pest multiplication. Though the crop is economically important, the information on the fruit flies and screening of cultivars for the source of resistance to these pests of mango are very much lacking (see Table 1).

Table 1

Mango cultivars characteristics along with their breeding centers.

S/No	Cultivars	Breeding center	Parentage	Leaf		Inflorescence
				Colour	Shape	Length	Colour
1-	Dusehri	MRS-Shujabad	Chance seedling	Medium Green	Elliptical	Medium long	Light green
2-	Malda	Data not available	–	–	–	–	–
3-	Langra	MRS-Shujabad	Chance seedling	Light Green	Elliptical	Medium long	Yellowish pink
4-	Chaunsa	MRS-Shujabad	Chance seedling	Dark Green	Elliptical	Long medium branched	Light pink
5-	Fajri Klan	MRS-Shujabad	Chance seedling	Medium Green	Elliptical	Medium long and medium branched	Yellowish pink
6-	Sensation	MRS-Shujabad	Chance seedling	Dark Green	Elliptical	Long and well branched	Yellowish pink
7-	Sanglakhi	Data not available	–	–	–	–	–
8-	Retaul-12	MRS-Shujabad	Chance seedling	Dark Green	Elliptical	Medium long and medium branched	Light green
9-	Mehmood Khan	Data not available	–	–	–	–
10-	Tukhmi	Data not available	–	–	–	–
11-	Kala Chaunsa	MRS-Shujabad	Chance seedling	Medium Green	Elliptical	Medium long and medium branched	Yellowish pink
12-	Chitta Chaunsa	MRS-Shujabad	Chance seedling	Dark Green	Elliptical	Long	Pinkish Yellow
13-	Dai wala	Data not available	–	–	–	–	–
14-	Sobey De Ting	MRS-Shujabad	Chance seedling	Medium Green	Elliptical	Long and medium branched	Yellowish green

Khan (2012).

Therefore, the present investigations were undertaken to evaluate tolerance in prominent mango cultivars against fruit flies, for timely management. Further it is urgent to find some efficient and environmental friendly control strategies in present climate scenario that guarantee a sustainable production of fruits to full fill the need of world market.

Material methods

Screening of cultivars against fruit flies

A study was carried out at Mango Research Institute, Multan (30.1575°N, 71.5249°E) Punjab, Pakistan on stone fruit stage during, 2016–18. Fourteen most popular commercial cultivars i.e. ‘Dusehri’, ‘Malda’, ‘Langra’ (early cultivars), ‘Chaunsa’, ‘Fajri Klan’, ‘Sensation’ (medium) whereas ‘Sanglakhi’, ‘Retaul-12’, ‘Mehmood Khan’,‘Tukhmi’, ‘Kala Chaunsa’, ‘Chitta Chaunsa’, ‘Dai Wala’ and ‘Sobey De Ting’ known late cultivars (different time of harvesting) were selected and tagged for recording the data of fruit flies. Fifty fruits per tree were observed randomly from height of 5–6 feet above ground level weekly from three directions i.e. east, south and west. The data was recorded from three trees of the cultivars under three replications. The fruit showing the symptoms like oozing of water from the fruit were considered as infested by fruit flies. Similarly dropped mango fruits on the ground under the tree were collected and cut for recording the data of fruit flies larvae. Further the most susceptible cultivar was undertaken for the management of fruit flies. The data was compiled and analyzed statistically.

Laboratory studies

The preferences of fruit flies to different cultivars were tested at MRI laboratory. The fruits of all the mango cultivars were collected from the MRI orchard as well as from grower orchard. The collected fruits were ensured free from the infestation of fruit flies and were arranged cultivar wise in two cages of size 1.5 × 1.5 feet on one inch sand layer for the period of three days. After three days the fruits were re-examined for the presence of fruit flies. Two pairs of newly emerged fruit flies adult were released in each cage. The walls of the cages were impregnated with honey solution at five different places as food for female. After ten days the fruits were cut and larvae were counted from each cultivar separately.

Wrapping of bags

A highly susceptible mango variety to fruit fly ‘Retaul-12’ was selected for bagging with the collaboration of Mango Research Institute, Kinzo agro chemicals and Muhammad Nawaz Sharif, University of Agriculture, Multan. The fruits were wrapped on 1st June 2018 when the fruit was at stone stage before the attack of pest and harvested on 20th of August 2018. There were three treatments i.e. T1: Brown paper bag with black layer inside, T2: Butter paper bag and T3: Control (with no bag). The trees of 15–20 feet height were selected for the bagging. Three hundred bags were wrapped on uniform hanged fruits either single or in bunches and left were remained un-bagged as control treatment on the same tree. The bags were closed properly as per instructions from the stalk of each fruit of all the treatments. There were no spaces left behind for invasion of any foreign substances. At the time of harvesting fifty fruits of each treatment were taken as sample randomly to study weight, physical and chemical parameters. From fifty fruits percent damage fruits were calculated.

Statistical analysis

After compiling the raw we used the ANOVA with help of Stat version 9 and then means were separated with the help of HSD.

Results

Infestation of fruit flies on the trees

The data regarding abundance of fruit flies on mango cultivars remained zero on dated 17.06.16 and 24.06.16. The infestation was started on 1st July 2016 on ‘Retaul-12’ with 0.30 percent infestation and go on increasing with the passage of time. The data regarding the fitness of host plant on fruit flies populations revealed a highly significant differences (F = 146.40; df = 11, 22; P < 0.01) (Table 1) among treatments. The results revealed that average maximum fruit flies infestation i.e. 0.90 percent were recorded on cultivars 'Mehmood Khan’ and ‘Retaul-12’which differed significantly from those of recorded on all other cultivars of mango followed by 'Sanglakhi’ and ‘Sohbay Wali Ting’ i.e. 0.50 and 0.44 percent infestation. All other cultivars showed zero infestation till 08.07.16. The data recorded on 15.07.2016 regarding the fitness of host plant revealed a highly significant differences (F = 128.76; df = 10, 20; P < 0.01) (Table 2) among treatments. The data revealed that average maximum fruit flies infestation i.e. 14.23, 13.76, and 13.24 percent were recorded on cultivars ‘Retaul-12’, ‘Sanglakhi’ and ‘Mehmood Khan which differed significantly from those of recorded on all other cultivars of mango followed by ‘Tukhmi’ and ‘Sohbay Di Ting’ with 8.76 and 6.40 percent infestation. The cultivars ‘Chaunsa’, ‘Fajri’, ‘Chita Chaunsa’, ‘Kala Chaunsa’ and ‘Sensation’ showed 0.00–0.89 percent infestation. The data on fruit flies populations revealed a highly significant differences (F = 156.41; df = 10, 20; P < 0.01) (Table 3) regarding the fitness of host plant among treatments. The data showed that average maximum fruit flies infestation i.e. 19.13 and 17.39 percent were recorded on cultivars, ‘Sanglakhi’ and ‘Mehmood Khan’ followed by ‘Retaul-12’ i.e. 15.32 percent infestation which differed significantly from those of recorded on all other cultivars of mango. The cultivars ‘Tukhmi’ and ‘Sohbay Di Ting’ showed similar fruit flies infestations with 10.39 and 9.43 percent infestation followed by, Fajri, ‘Chaunsa’, ‘Dai wala’, ‘Sensation’, ‘Chita Chaunsa’ and ‘Kala Chaunsa’ showed 0.00–2.12 percent infestation on 22.07.2016. Further the suitability of host plant on fruit flies infestation revealed significant differences (F = 255.20; df = 10, 20; P < 0.01) among treatments (Table 4). The data revealed that average maximum fruit flies infestation (23.13 and 21.22 percent were recorded on variety 'Sanglakhi ' and Retaul-12 which differed significantly from those of recorded on all other varieties of mango followed by ' Mehmood Khan' and Sohbay Di Ting (16.90 and 14.97 percent). The ‘Tukhmi’ has 12.92 percent infestation (see Table 5).

Table 2

Data regarding fruit flies infestation recorded hanging fruits on trees.

Cultivars	Average percent damage of fruit flies recorded on the mango trees
	17.6.16	24.6.16	1.7.16	8.7.16	15.7.16	22.7.16	29.7.16	5.8.16	12.8.16
Dusehri	0.00	0.00	0.00
Malda	0.00	0.00	0.00
Langra	0.00	0.00	0.00	0.00
S.B. Chaunsa	0.00	0.00	0.00	0.00	0.89	1.15d	2.27 d
Fajri	0.00	0.00	0.00	0.00	0.39	2.12 d	1.57 d
Sensation	0.00	0.00	0.00	0.00	0.00	1.04 d	1.19 d	1.98c
Sanglakhi	0.00	0.00	0.00	0.50	13.43	19.13 a	23.14 a	29.33 a	39.14 ab
Retaul-12	0.00	0.00	0.30	0.90	14.23	15.32b	21.22 a	32.47 a	35.40b
Mehmood Khan	0.00	0.00	0.00	0.90	13.23	17.39 ab	16.90b	31.25 a	44.77 a
Tukhmi	0.00	0.00	0.00	0.00	8.76	10.39c	12.92c	15.65b	32.75b
Kala Chaunsa	0.00	0.00	0.00	0.00	0.00	0.00 d	0.89 d	3.23c	9.19c
Chita Chaunsa	0.00	0.00	0.00	0.00	0.00	0.00 d	1.50 d	2.76c	9.13c
Dai wala	0.00	0.00	0.00	0.00	4.34	1.12 d	0.78 d	4.35c	12.34c
Sohbay Wali Ting	0.00	0.00	0.00	0.44	6.40	9.43c	14.97 bc	19.65b	33.98b
F-Value						156.41	255.20	113.47	79.98
Tukey’s HSD @ 5%						3.08	2.88	6.17	8.08

Table 3

Data regarding average fruit flies infestation recorded on dropped fruits of mango.

S/No.	Cultivars	Date of observation of fallen fruits of late varieties to fruit flies
		15.7.16	22.7.16	29.7.16	5.8.16
1-	Sanglakhi	45.00 a	53.24 a	72.34 a	73.28 ab
2-	Retaul-12	35.00b	44.44 abc	78.89 a	81.00 a
3-	Mehmood Khan	27.16 bc	49.67 ab	51.29b	71.99b
4-	Tukhmi	34.00b	36.11 cd	46.67 bc	55.49c
5-	Kala Chaunsa	13.00 de	26.67 d	31.42 d	35.29 e
6-	Chita Chaunsa	5.10 e	5.23 e	16.25 e	29.21 e
7-	Dai wala	27.00 bc	38.29 bc	41.23c	44.87 d
8-	Sohbay Wali Ting	19.87 cd	24.85 d	39.60 cd	45.02 d
F-Value		43.38	46.62	125.46	148.59
Tukey’s HSD @ 5%		9.75	11.41	9.15	7.83

Table 4

Data regarding of different pest on covered vs uncovered fruits of Retaul-12.

Types of bags	Average percent insect attack per fruit		Average number of pests per fruit			Diseases	Colour of fruits	Attraction of Exporter/purchaser
	Fruit flies	Fruit borer	Thrips	Scales	Mites
Brown paper bags with inner black paper bag	0.00	0.00	0.00	0.00	0.00	0.00	Yellowish with red bluish	Very attractive
Butter paper bags	0.00	0.00	0.00	0.00	0.00	0.00	Greenish	Normal
No bags	17.23	4.57	7.29	3.21	2.97	0.00	Greenish	Normal

Table 5

Cost benefit ratio of mango variety Retual-12 bagging and without bagging.

S/No	Cost benefit ratio	Fruits covered with bags		No bags/ Control
		Brown paper	Butter paper
1-	Average rate of fruit per kg	77.50	55.00	47.50
2-	Rate per mound	3100	2200	1900
3-	Difference with control	1200	300	0.00
4-	Cost per bag (Rs.)	2.00	1.50	0.00
5-	Labor rupees charges per fruit (Rs.)	0.80	0.80	0.00
6-	Average cost of 2 sprays per fruit (Rs.)	0.00	0.00	3.00
7-	Average price per fruit (Rs.)	15.33	11.19	7.58
8-	Benefit per fruit = Price per fruit-labor charges per fruit-cost of spray per fruit (Rs.)	12.53	8.89	4.58
9-	Benefit over control (Rs.)	7.95	4.31	0.00
10-	Cost benefit ratio	2.73 (2.73:1.00)	1.94 (1.94:1.00)	1.00

The average minimum infestation of fruit flies was recorded on all other cultivars ranging from 2.27 to 0.78 percent infestation on 29.07.16. The data recorded on 05.08.2016 on the suitability of host plant on fruit flies infestation revealed significant differences (F = 113.47; df = 8.16; P < 0.01) among treatments. The data revealed that average maximum fruit flies infestation i.e. 32.47, 31.25 and 29.33 percent were recorded on variety ‘Retaul-12’, ‘Mehmood Khan’ and ‘Sanglakhi’ which differed significantly from those of recorded on all other varieties of mango followed by ' Sobey Di Ting' and ‘Tukhmi’ (19.65 and 15.65 percent). The average minimum infestations of fruit flies were recorded on all other cultivars ranging from 4.35 to 1.98 percent infestation on 05.08.16. The data on fruit flies infestation revealed significant differences (F = 79.98; df = 7, 14; P < 0.01) among treatments. The data revealed that average maximum fruit flies infestation (44.77 and 39.14 percent were recorded on variety Mehmood Khan and 'Sanglakhi' which differed significantly from those of recorded on all other varieties of mango followed by ‘Retaul-12’, ‘Sobey Di Ting’ and ‘Tukhmi’ (44.77, 39.14 and 32.75 percent). The average minimum infestation of fruit flies was recorded on all other cultivars ranging from 12.34 to 9.13 percent infestation recorded on 12.8.16.

Cumulative damage on trees

The cumulative data of all dates reported that three cultivars i.e. ‘Sanglakhi’, ‘Mehmood Khan’ and ‘Retaul-12’ were reported to the highly susceptible to fruit flies i.e. 20.61, 20.22 and 19.92 percent infestation as compared with other cultivars. The ‘Retaul-12’ being commercial cultivars was selected for the management of fruit flies (Fig. 1).

Fig. 1

Average percent damage of fruits on the trees by fruit flies.

Infestation of fruit flies on dropped fruits

The early cultivars were escaped from the infestation of fruit flies so the late cultivars were considered for further studies. The data regarding the suitability of host plant to fruit flies infestation recorded from fallen fruits found under the tree populations revealed a highly significant differences (F = 43.38; df = 7, 14; P < 0.01) (Fig. 2) among treatments. The average maximum infested fruits i.e. 45.30 were recorded from the cultivar 'Sanglakhi’ followed by 'Retual-12’, ‘Tukhmi’, ‘Mehmood khan’ and ‘Dai wala’ i.e. 34.82, 34.00, 27.16 and 27.00 percent on 15.07.2016. The cultivar ‘Sobay Wali Ting’ has less infested fruits i.e. 19.87 percent statistically similar to ‘Kala Chaunsa’ with 13.00 percent infested fruits. Cultivar ‘Chitta Chaunsa’ has low infested fruits i.e. 5.10 percent found under tree. Similarly the data regarding the suitability of host plant to fruit flies infestation recorded on dated 22.7.2016 from fallen fruits found under the tree populations revealed a highly significant differences (F = 46.62; df = 7, 14; P < 0.01) (Fig. 3) among treatments. The average maximum infested fruits i.e. 53.24 percent were recorded from the cultivar 'Sanglakhi’ statistically similar to ‘Mehmood khan’ and 'Retual-12’ with 49.67 and 44.44, followed by ‘Dai wala’ having 38.29 percent on 22.07.2016 statistically similar to ‘Tukhmi’ having 36.11 percent infested fallen fruits. The cultivar ‘Chitta Chaunsa’ has low infested fruits i.e. 5.23 percent found under the tree. The data recorded on dated 29.7.2016 from fallen fruits found under the tree populations revealed a highly significant differences (F = 125.46; df = 7, 14; P < 0.01) (Table 2) among treatments.

Fig. 2

Average percent damage of fallen fruits by fruit flies.

Fig. 3

Average numbers of larvae per fruit on different cultivars of mango.

The average maximum infested fruits i.e. 78.89, 72.34 percent were recorded from the cultivar 'Retual-12’ and 'Sanglakhi’ followed by ‘Mehmood Khan’ and ‘Tukhmi’ with 51.29 and 46.76 percent infested fruits. The cultivar ‘Dai wala’ have 41.23 percent infested fallen fruits statistically similar to ‘Sobay Wali Ting’ with 39.60 percent followed by ‘Kala Chaunsa’ have 31.42 percent infested fruits. The cultivar ‘Chitta Chaunsa’ has low infested fruits i.e. 16.25 percent found under the tree. The data recorded on dated 05.08.2016 from fallen fruits found under the tree populations revealed a highly significant differences (F = 148.59; df = 7, 14; P < 0.01) (Table 2) among treatments. The average maximum infested fruits i.e. 81.00 percent were recorded from the cultivar 'Retual-12’ statistically similar to 'Sanglakhi’ with 73.56 percent followed by ‘Mehmood Khan’ with 71.99 percent infested fruits. The cultivar ‘Tukhmi’ has 55.49 percent infested fallen fruits followed by ‘Sobay Wali ting’ and ‘Dai wala’ having 45.02 and 44.87 percent infested fruits. The cultivar ‘Kala chaunsa’ and ‘Chitta Chaunsa’ has low infested fruits i.e. 35.29 and 29.21 percent found under the tree (see Fig. 8).

Fig. 8

Average acidity percentage of mango fruits.

Cumulative fruit flies damaged fruits under the tree

The damaged fallen fruits by fruit flies reveal that average maximum 60.97, 59.83, 50.03 and 43.07 percent damaged fruits were recorded under the tree of cultivar ‘Sanglakhi’ ‘Retaul-12, ‘Mehmood Khan’ and ‘Tukhmi’ Whereas less damaged 13.95 percent fruit were recorded under the ‘Chitta Chaunsa’ tree. The cultivars ‘Kala Chaunsa’, Dai wala’ and ‘Sobey Wali Ting’ has damaged fruit flies fruits were 26.60, 37.85 and 32.34 percent were found under the trees as shown in Fig. 1.

Preference of fruit in laboratory

The graph shows that in laboratory the fruit flies preferred the late cultivars ‘Sanglakhi’, ‘Mehmood Khan’ and ‘Retaul-12’ for egg lying. It was recorded with average 17.29, 14.23 and 11.87 numbers of larvae per fruit was observed as compared with early cultivars. More number of fruit flies larvae was detected in late cultivars.

Effects of bagging on fruit quality

The data in the Table 4 reported that covered fruits either with brown paper or butter paper were remained free from all types of insect pest and diseases. The colour of the fruits was attractive with red blush was recorded in those bags where brown paper bags wrapped. These fruits were gorgeous to purchaser and exporter. Whereas the fruits wrapped in butter paper bags also free from pests but their colour remain green as was in control. It was further observed that were no physical, mechanical injuries, bird damage and blemishes were recorded on bagged fruits. In case of those fruit which was uncovered having 17.23 and 4.57% fruit flies and fruit borer attack and other insect like thrips, scales and mites 7.29, 3.21 and 2.97 mites per fruit were recorded on the fruits at the time of harvesting.

There was no bird damage on wrapped fruits but 2.00% damage was recorded on control fruits as shown in Fig. 4.

Fig. 4

Average percent fruit damage due to birds.

Bagging of fruits had a significant role in growth and development of fruit. Those Fruits which were wrapped with brown paper bags and butter paper shows weight i.e. 197.83 and 203.5 g on an average per fruit where as 159.5 g weight was recorded in un-bagged fruits as shown in Fig. 5.

Fig. 5

Average fruit weight (g) and length (mm).

The pulp, stone and peal ratio was recorded from covered and uncovered fruits. It was found that ration of pulp, was 84.89: 113.44: 76.52 g of brown, butter and uncovered fruits. Similar peal ration was 57.81:62.86:46.81 g. The stone ratio was 35.84:40.37:28.65 g was recorded in covered and uncovered fruits as shown in the Fig. 6.

Fig. 6

Average pulp, peal and stone in gram of mango fruits.

The total soluble solids content (TSSC) of the fruit wrapped in brown paper was 26.06 and 24.47% of those fruits which were wrapped in butter paper bag whereas the fruits with no bag have 19.30% as shown in (Fig. 7).

Fig. 7

Average TSS percentage of mango fruits.

Similarly in case of acidity 0.18, 0.18 and 0.19 percent was recorded in brown paper, butter paper bag and control.

The fruits produced by such technique are very much attractive for purchasers, because of beautiful colour development and fine quality of the produce. The cost benefit ratio of the fruits covered with brown paper bags were (2.73:1) compared with fruits with butter paper bags (1.94:1) and control treatment (1.00) respectively. So one can earn money by spending Rs. 1.00 per fruit and gaining Rs. 2.73/fruit, so net profit is Rs.1.73 per fruit in brown paper bags and Rs.0.94 /fruit in butter paper when compared with control.

Discussion

This pest cause huge losses for growers internationally in changing weather and are known as quarantine pests. The peach fruit fly, B. zonata infestation is more i.e. 92 percent whereas oriental fruit fly, B. dorsalis is less that is only 8 percent. The results of our study similar to Qureshi et al., 1991. To overcome fruit flies losses so many practices are adopted like sanitation, use of traps, protein hrdrolysate and chemicals, contagion of soil and water, health problems for the growers, insecticide resistance and decrease in parasites and predators populations. Further it was noted that the residues of chemicals can alter the market value of the product (Daff, 2010). The practice of growing resistant varieties of agricultural crop is considered one of the superior management practices which is environmentally, naturally and economically beneficial. In this way the crop is saved from insect pest and yield can be protected without or minimum use of insecticides. By the use of such type of practice one can decrease the use of broad spectrum insecticides resulting in decreased soil, water contamination and reduced negative effects on non-target organisms including beneficial insect fauna and labor (Krattiger, 1997). Plants that are less susceptible to injury caused by insect pests are important for more production and better quality of the produce. Further commercial, high value susceptible varieties can also be protected with some other kind of practices like use of bags on fruits. In our project, fourteen most popular commercial cultivars of mango i.e. ‘Dusehri’, ‘Malda’, ‘Langra’ (early cultivars), ‘Chaunsa’, ‘Fajri Klan’, ‘Sensation’ (medium) whereas ‘Sanglakhi’, ‘Retaul-12’, ‘Mehmood Khan’, ‘Tukhmi’, ‘Kala Chaunsa’, ‘Chitta Chaunsa’, ‘Dai Wala’ and ‘Sobey De Ting’ were known as late cultivars (different time of harvesting) were evaluated for their screening against fruit flies. The results suggested that that there were significant differences among different varieties of mango regarding infestation of fruit flies. Some varieties were vulnerable to fruit flies infestations while others were tolerant. Our results suggested that the early maturing mango cultivars escaped from the infestation of fruit flies whereas medium varieties suffered less and late varieties had more infestation of fruit flies. Among late varieties ‘Retaul-12’ was proved to be the most susceptible to fruit flies. The present findings can be compared with those of Karar et al., 2016 who reported that Retaul-12, a late variety of mango has more infestation of fruit flies and having more number of larvae per fruit as compared with other varieties of mango. Our results suggest that some varieties are susceptible while others are tolerant, so there is significant difference among different varieties of mango. The current findings add significantly to those of (Karar et al. 2012), concluded that pecan varieties responded different to pecan black aphids, onion varieties against thrips (Karar et al. 2013) mango varieties against mango mealy bug and mango hoppers (Karar et al., 2015, Karar and Bakhsh, 2018). For sustainable management practices our results suggests bagging of fruits proved to be the best practice for insect pest of mango. In our experiment two types of bags are used for the protection of fruits from insect pest complex i.e. brown paper bag with inner layer black and butter paper bags. These bags managed the infestation successfully and show high degree of protection not only from fruit flies but also other pests of mango fruit like fruit borer, mealy bugs, thrips, mites, leaf miner and birds. Our results are in line with that of Johnson et al. (2006) who concluded that bagging discourage the birds and avoidance of toxin while Sarker et al. (2009) reported 100 percent protection from fruit flies. Further it was found that brown paper bags improve the quality of fruits and results can be compared Sarker et al. (2009), who found that by the use of bags the better physical quality of mango can be achieved. Our results recommend that the bags not only control the insect pests but also increase in weight and size of the fruits. So keeping in mind the production cost of the produce, bagging is much more reasonable. In this technique, no insecticide application is required whereas in control treatment the average numbers of 3–4 sprays are required to overcome insect pest complex. On the other hand, the average rate of fruits per kg is higher of bagged fruits as compared with control treatments. The reason could be due to micro environment created by the bagging material that plays a significant role in growth and development of fruits (Sharma et al., 2014) as well as fruit coloration.

Conclusion

It is confirmed that only exportable fruits for getting more income. This is only possible in case of late varieties. In this experiment our results suggested that late varieties infested by fruit flies severely. So if we protect the late varieties from the attack of fruit fly, the more income can be generated. Consumers also like to buy high quality fruits free from pests, blemishes, sunburn, spray and of good outlook. These qualitative characteristics fruits can be produced by the use of bags. In this way more income can be generated by exporting high quality fruits with increased volume and consignment can be saved from destruction.