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Fruit fly Management Techniques in India

Journal of Entomology and Zoology Studies 2019; 6(1): 245-257

                   Fruit fly management techniques in India : A Review

                                             Anil Kumar

Department of Entomology

Dr Yashwant Singh Parmar University of Horticulture and Forestry Nauni, Solan H.P. 173230

Email: akarorax@gmail.com

 ABSTCACT

Fruit fly belongs to order Diptera and family Tephritidae is distributed widely in tropical, temperate and subtropical area of the world. There are about 4,500 species of fruit flies (Drew and Roming, 1997) among which 2,000 are considered economically important and are widely distributed in the temperate, tropical and sub tropical regions of the world (Christenson and Foote, 1960) of which 5 per cent of these occur in India (Ramani, 1998). The extent of losses vary from 30 -100 per cent depending upon the crop and season. Feeding by fruit fly larvae may cause complete destruction of fruits, rather than cosmetic damage as is caused by many other insect pests. Gupta and Verma (1992) observed about 80 per cent fruit fly infestation on cucumber and bottle gourd, 60 per cent on bitter gourd and 50 per cent on sponge gourd in mid hill conditions of Himachal Pradesh. Keeping in view the economic  importance of fruit fly  and crop, its management could be done using local area management and wide area management techniques (Dhillon et al.,2005). The use of geographical information system could also be used as an IPM tool to mark site- specific locations of traps, land use areas and fruit fly population within a specific operational region.Although, the sterile insect technique has been successfully used in area-wide approaches, the wide area management needs more sophisticated and powerful technologies in their eradication programme, such as insect transgenesis, which could be deployed over wide-area and is less susceptible to immigrants. Since, fruit fly is a pest which cannot be eradicated by opting one method so combination of methods like cultural, physical, biological, chemical, genetic and quarantine methods are adopted to manage fruit fly besides  other local area management options.

Introduction:

Fruit fly pests are members of the Family Tephritidae in the Order Diptera. Fruit flies are one of the most economically important groups of insect pests world wide. There are about 4,500 species of fruit flies (Drew and Roming, 1997) among which 2,000 are considered economically important and are widely distributed in the temperate, tropical and sub tropical regions of the world (Christenson and Foote, 1960) of which 5% of these occur in India (Ramani, 1998). The first detailed report on fruit flies from the Indian sub-continent was made by Bezzi (1913) who enlisted the species from India, Pakistan, Myanmar, Sri Lanka and Nepal. Superior mobility, great dispersive powers, high reproductive rates, movement through market chain and extreme polyphagy are among the common traits of Bactocera species.

Several Bactrocera species are well-documented invaders of horticultural crops and also rank high on quarantine lists worldwide (Clarke et al, 2005). Since these are of quarantine importance they are of great concern to fruit producing countries where these species occur, requiring them to re-evaluate and revise their control strategies. In countries where these species have not been recorded, quarantine measures have been considerably strengthened to minimise the risk of their entry, establishment and spread.

Damage caused by fruit flies to various fruit and vegetable crops has been estimated up to 100 per cent (Dhillon et al., 2005; Philippe et al., 2010). In mid hill conditions of Himachal Pradesh (Gupta and Verma, 1992) observed about 80 per cent fruit fly infestation on cucumber and bottle gourd, 60 per cent on bitter gourd and 50 per cent on sponge gourd. Losses result from direct feeding damage, decay by opportunistic pathogens, and the loss of export market opportunities through quarantine restrictions imposed by importing countries to avoid entry and establishment of these pests. Many species of fruit flies are considered as high priority quarantine pests in various countries.

Fruit fly is a highly polyphagous species (Metcalf and Metcalf, 1992) and can disperse using mosaic of host crops available and take advantage of human agricultural trade. Bactrocera dorsalis infests plants of 40 families including many commercial fruits (Smith, P. H.,1989; Vargas et ah, 1984; Vargas and Carey, 1990). The attack of B. dorsalis on 173 different varieties   of fruit and vegetables has been reported by Metcalf and Metcalf (1992). It is a destructive pest on a wide range of tropical and sub tropical fruits and vegetables (Ye and Liu, 2005a). To name a few, mango {Mangifera indica L.), guava (Psidium guajava L.), custard apple {Annona squamosa L.), apple (Malus pumila M.) star fruit (Averrhoa carambola L.), banana {Musa paradisiacal L.), orange {Citrus sinensis jL.), papaya (Carica papaya L.), peach {Prunus persica L.), plum {Prunus domestica L.),j and tomatoes (Lycopersicum esculentum M.) (Clausen et ai, 1965, Koyama, 1989). In India this species attacks mango and causes serious loss ranging from 5-80% (Kapoor, 1993, 2004; Verghese et a i, 2002, Verghese and Jayanthi, 2001) and damage caused on guava is up to 44 percent (Stonehouse et a i, 1998, 2005).

Almost half of the world's mangoes are cultivated in India alone, with the second-largest source being China (Jedele et al., 2003). Mango is usually available in India from March to mid-August. During off season B. dorsalis survives on its alternative host, guava {Psidium guajava) thereby completing several generations within a year. Guava is an important crop commonly called as the poor man’s apple. In India, guava occupies 3.2% of the total area under fruits contributing about 3.3% of the total fruit production in the country (Indian Horticulture Database, 2011). India is the second largest producer of jbanana after China. These three fruit crops are commercially important hosts which are severely damaged by fruit flies. In India B. dorsalis attacks commercial varieties of mango (Verghese et al., 2002). Fruit fly eggs are laid into unripe or ripening fruit where the larvae develop and feed on the pulp of the fruits. Infested fruits are spoiled quickly and often fall to the ground before ripening. If that controlled, growers may lose the entire crop. Generally, the Oriental fruit flies are able to reproduce in most envirormient and climates. Since, the maggots damage the fruits internally, it is difficult to control this pest with   insecticides.   Therefore,   there   is   a   need   to explore alternative methods of control, and develop an     integrated     control     strategy     for     effective management of this pest.

 Classification:

—  Kingdom: Animalia

—  Phylum: Euarthropoda

—  Class: Insecta

—  Order: Diptera

—  Family:  Tephritidae

Major fruit fly species found in India

Insect

Scientific  Name

Guava  Fruit Fly

Bactocera  correcta

Mango  Fruit fly

B.  dorsalis

Peach  Fruit Fly

B.  zonata

Ber  Fruit Fly

Carpomya  vesuviana

Fruit  fly

B.  cucurbita, B. tau

Citrus  fly

B.  minax

Three  stripped fruit fly

B.  diversa

Olive  fruit fly

B.  oleae

Carambola  fruit fly

B.  carambola

Caryea  Fruit fly

B.  caryeae

Life Cycle of fruit fly:

Under favourable conditions female fruit flies become sexually mature and capable of laying eggs about 5 days after they emerge. After mating they actively seek out ripening fruit, and deposit their banana-shaped eggs in a small cavity just below the skin. Oviposition (sting) sites appear as small brown spots on the surface of the fruit, under which is a cavity with one to more than 20 eggs.

After 2 to 3 days in favourable conditions the minute, transparent larvae hatch and start feeding on the flesh of the fruit, slowly tunnelling towards the core. The larvae have a sharply-pointed front end with no obvious head, and a blunt rear end, and become cream-coloured as they get older. Early infestation is often indicated by a brown colouration of the fruit flesh in the area of feeding due to oxidation of the tissues. From about 7 to 40 days later, depending on fruit kind and temperature, the larvae reach maturity (8 to 10 mm long), when they leave the fruit, fall to the ground and pupate just below the surface of the soil. About 8 to 40 days later, depending on temperature, the adult flies emerge from the pupae, crawl up to the soil surface, and the cycle is complete.

During warm conditions and in ripe fruit, the life cycle can be completed in as little as 3 to 4 weeks. This duration can increase to about 2 or 3 months in winter or where eggs are laid in greener fruit.

Damage:

Fruit fly adults most often lay their eggs in the fresh flesh of fruits and vegetables. Fruit is a term that refers to the fertilized embryo of fruit and vegetable flowers.  The eggs hatch into larvae (maggots) which most often feed on the inside of the fruit, resulting in a soft, mushy mess. The maggot destroy and convert the pulp into a bad smelling, discoloured semi liquid mass unfit for human consumption. The infestation results in fruit drop and start rotting from inside. On complete rotting of the fruits, the damaged fruit develop yellow spots with black centers through which liquid oozes out on pressing.

 MANAGEMENT STRATEGY:

As with the control of many pest species, a single control method by itself is often not sufficient to eradicate (or even effectively control) the fruit fly from an area. The best results are gained from a combination of the methods found in the section below. For example, bait spraying, male annihilation and good hygiene have been used in combination in attempts to eradicate Fruit fly in New South Wales, Australia (Gilchrist, pers. Comm. 2008).

·           Physical

·           Cultural

·           Biological

·           Chemical

·           Genetic

Cultural Control:

·           Sanitation

Sanitation is a method that you can use to help: prevent fruit fly egg and larvae (maggot) development in infested fruit; and deny female adult flies a suitable place for egg laying. This method requires that you collect and destroy all fallen and unwanted fruit from the garden. The destruction of this fruit ensures that larvae do not survive to pupate in the ground, and later emerge as adult flies. Sanitation is considered an essential practice since fruit trees with fallen and rotting fruit around the base are a major source of fruit fly infestations.

·           Trapping

Fruit fly traps can be divided broadly into three groups: monitoring; mass trapping; and liquid protein trapping. With the range of products commercially available there is some overlap in these groupings.

ü   Monitoring

Monitoring traps are simply containers which fruit flies can enter, but which they cannot easily escape from. When combined with a powerful lure (parapheromone), male fruit flies will be strongly attracted into the trap and this will let you know when fruit flies are active. The numbers of flies caught will give you some indication of the level of fruit fly activity, but should only be considered as a guide.The main management advice provided by traps is an awareness of whether fruit flies are active in your orchard and whether it is time to commence other fruit fly management activities.

As a general rule, monitoring traps are deployed at a low rate, often only one or two per hectare or per orchard block. Some types of these traps are also used to monitor and verify that a pest free area truly is pest free.

There are a variety of traps available on the market, including the Lynfield (used primarily for fruit fly pest free area monitoring), the Bugs for Bugs Fruit Fly Trap, Bio-Trap, and the Susbin trap. Forms of stick traps like Jackson traps and the Fruition trap can also be used for monitoring fruit fly activity.

ü   Mass Trapping

Mass trapping can use the same traps as monitoring, but deployed at much higher rates. The theory behind this approach is to attempt to catch as many active flies as possible. However, it must be remembered that the lures used in many traps are specific to male fruit flies and the damaging egg laying females flies will be unaffected. Therefore, mass trapping must be used in conjunction with other proven techniques such as protein bait sprays. Mass trapping for male flies is also similar to another control methods, the Male Annihilation Technique (MAT).

Some fruit fly traps are able to be use a female attracting compound. Bio-Trap also supply a fruit fly attractant gel that attracts both male and female fruit flies. The Fruition trap used a lure sachet and visual cues to attract fruit flies.

ü Liquid Protein traps

Liquid protein traps can be used in some cases for monitoring in pest free areas, but their main use is to capture female fruit flies. They target the female fruit fly’s need to feed on protein in order to develop their eggs to maturity. By using a protein attractant, recently emerged female fruit flies will enter the trap, get caught, and eventually drown. There is a range of different traps and lures, and it is also possible to make these at home. The main shortcoming of liquid protein traps is that they tend to have a limited range of attraction. Commonly these traps will be placed at a 5m interval around the perimeter of an orchard.

·           Covering of fruits

Bagging of fruits on the tree (3 to 4 cm long) with 2 layers of paper bags at 2 to 3 day intervals minimizes fruit fly infestation and increases the net returns by 40 to 58% (Fang, 1989; Jaiswal et al., 1997). Akhtaruzzaman et al. (1993) suggested cucumber fruits should be bagged at 3 days after anthesis, and the bags should be retained for 5 days for effective control. It is an environmentally safe method for the management of this pest.

·           Exposing Pupae to Direct Sun

Deep ploughing is done in summer to expose the pupae to the direct sun. Pupae are killed by deep summer ploighing. In fruit crops raking of soil is done in summer to expose pupae to sun.

·           Early Harvesting

Early harvesting is method that you can use to help prevent adult fruit flies from infesting your crop. It is the practice of picking your fruit and vegetables as early as possible from your garden, even sometimes when it is green. This practice may deny adult flies the opportunity to infest your fruit, depending on fruit fly pressure. Note that early harvesting can also be achieved by planting early fruiting varieties of fruits and vegetables. These plants tend to bare produce before fruit fly populations increase as the season advances and temperatures increase.

·           Host Plant Resistance

Host plant resistance is an important component in integrated pest management programs. It does not cause any adverse effects to the environment, and no extra cost is incurred to the farmers. Unfortunately success in developing high yielding and fruit fly-resistant varieties has been limited. There is a distinct possibility of transferring resistance genes in the cultivated genotypes from the wild relatives of cucurbits for developing varieties resistant to melon fruit fly through wide hybridization.

Crop

Examples of  Resistant Varities

Bitter  Gourd

IHR-89,  IHR-243, Hisar II,

Pumpkin

IHR 35,  IHR 40, IHR 79-2, IHR 83

and IHR  86

Sponge  gourd

NS 14

Round  melon

Arka Tinda

 Physical Control:

·           Disinfestation

Disinfestation is a process which removes all life stages of Fruit fly from fruit, prior to export, to prevent the spread of this pest around the world. The most common, approved methods of pre-export disinfestations are mainly chemical treatments such as methyl bromide fumigation, or the application of insecticides. These chemical are becoming “increasingly unacceptable” to people at all stages of the export process, from the technicians performing the treatments to the end consumer (Jessup et al. 1998a). In recent years there has been an increasing emphasis on finding more consumer-accepted methods of disinfesting fruit prior to export.

Jessup et al. (1998) have shown that sealing fruit in polyethylene bags and storing them at 38°C for 3 days caused 100% mortality of Fruit fly eggs and larvae in a number of fruit. The treatment components, polythene wrap and mild heat, are relatively inexpensive when compared to both cold-storage and chemical disinfestation methods. The 3 day duration of heat treatment is substantially less than the 12 – 16 days needed to achieve 100% mortality in cold treatment programs. The heat treatment process did not promote mould or shrivelling, or negatively affect the colour evenness or taste of the fruit. Some judges used in this experiment “preferred the flavour of sealed, heat-treated tomatoes and apples over that of non-treated fruit” (Jessup et al. 1998).

 ·           Cold Treatment

Fruits are subjected to cold temperature to potentially kill fruit fly in them. Fruits that have been subjected to cold treatment include kiwifruit, pome fruit, stone fruit, citrus and grapes etc. Most of tropical fruits are susceptible to frost injury, are not given cold treatment.

0.0°C ± 0.5ºC for  minimum 14 days.

·           Male Annihilation Technique:

Male Annihilation Technique (MAT) involves the use of a high density of bait stations consisting of a male lure combined with an insecticide (usually technical malathion, and more recently fipronil), to reduce the male population of fruit flies to such a low level that mating does not occur. 

 There are several examples of the successful use of methyl eugenol in the technique.  Oriental fruit fly (Bactocera dorsalis) was eradicated from Guam and the Commonwealth of the Northern Mariana Islands in the 1960s by Steiner and his colleagues.  The insecticide used during the eradication was nailed.  Outstanding successes using this method have been recorded for eradicating oriental fruit fly from California and from the Amami Islands of Japan.

·           Vapor Heat Treatment

VHT is process in which fruits are subjected to hot saturated water vapour, and without the use of any chemicals under controlled temperature and humidity. Fruit fly larvae are sterilised and made incapable of growing and multiplying. VHT is a very important step used in quarantine. This treatment is used to kill many disease causing organisms and different insect pests.

Biological Control

Over 200 hymenopteran parasitoids species have been unequivocally associated with members of the Tephritidae family. Among them, about 150 are Braconidae, most of them belonging to the Opiinae subfamily. Less than a tenth of these Opiinae are commonly used in present biocontrol programs or have the potential to be used in future classical and augmentative projects. Most of these species belong to the genera Fopius Wharton, Diachasmimorpha Viereck and Psyttalia Walker. However the importance of some other families cannot be neglected.

·           Egg-pupal parasitoids

This first category includes the egg-(pre)pupal parasitoids within the genus Fopius. Though Fopius arisanus (Sonan) is the only species in this group commonly used in various biocontrol programmes, F. ceratitivorus Wharton and F. caudatus (Szépligeti) might also be of interest against some Ceratitis spp.. Fopius arisanus has been used in classical biological control for the last 60 years. Diachasmimorpha longicaudata has been the most widely used species in tephritid biocontrol to date. Despite being outclassed by F. arisanus on all studies on competition, D. longicaudata is easier thus less expensive to rear and more efficient in regions where Bactrocera spp. are absent, especially in Florida, Central and Latin Americas.Wharton and Yoder (2007) provide its detailed native distribution as well as the list of countries where it has been introduced. This species has been associated with about 70 Tephritidae including rare cases of gall- forming species used in weed control. It is mainly used to suppress the populations of Anastrepha spp., Ceratitis capitata (Wiedemann) and B. dorsalis. Numerous papers deal with its bionomics, its response to olfactory or visual stimuli, its dispersal or its avoidance of host immune response. Many of the idiobiont parasitoids attacking fruit fly pupae are not specialists on Tephritidae. Most of them are small Chalcidoidea or Evanoidea with a very low dispersion range. Some of them may also hyper-parasitize other primary parasitoids. Coptera haywardi (Oglobin) (Diapriidae) is an exception and has provided promising results during the last decade. Recent studies on its host selection behaviour suggested it could be of great interest to suppress the populations of C. capitata and Anastrepha spp. in augmentative programmes in Central and Latin Americas. The use of fungi for biocontrol purposes pre-dates the first introductions of exotic beneficial insects. However, they received comparatively little attention during the 20th century. This is mainly due to their lack of specificity, to the heavy constraints linked with their mass-production and/or their storage and to their instability under adverse environmental conditions. These general aspects were reviewed in several papers during the last 20 years. These constraints generated a lack of interest, which in turn led to a lack of research.

Against tephritid flies, pre-2000 published works are consequently sparse. Some examples are the experimentation of mycoinsecticides against C. capitata, Anastrepha fraterculus (Wiedemann) , Bactrocera tryoni (Froggatt) or B. oleae . The early 21st century has seen a growing tide of interest for entomopathogenic fungi, particularly to replace parasitoids when or where their use is impracticable. Two fungal species are mainly used: Metharhizium anisopliae (Metschnikoff) and Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Deuteromycotina: Hyphomycetes).

Genetic

·           Genetic analyses to aid management

The relatedness of Fruit fly captured in traps can be examined through the analysis of microsatellite markers. This technique can be used to find out if invasions occurring in different places and at different times involve individuals which are from the same source population and that are related to each other, or if they represent distinct invasions independent of each other. In Adelaide, Australia at least six Fruit fly which were full siblings of each other were caught in traps in the same month, by Gilchrist et al. (2004). These six flies were trapped at a number of sites separated by “distances greater than the unaided dispersal distance of Fruit fly,” which provides evidence for human-aided dispersal of Fruit fly in Adelaide. Previously, many outbreaks occurring at the same time in places separated by large distances were thought to be separate outbreaks, but this research showed that this situation could be a single outbreak, spread around by humans (Gilchrist et al. 2004).

·       Transgenic control strategies

Recent developments have led to the possibility of genetically engineering “factory strains of pest insects which produce male-only broods.” When released into the wild in large numbers, these flies would mate with female flies, but all of the next generation of flies would be male. This would improve the sterile insect technique (SIT) currently used to control Queensland fruit fly (Fruit fly) populations. A 100% male population cannot reproduce, and so the fly species population would collapse. This control strategy has become near-possible due to the development of transformation vectors for insects other than drosophilid flies. There are 5 transformation vectors developed which have the potential to be used in the Fruit fly. The process by which this method works is very complex, but involves ‘RNA interference’ (RNAi) targeting genes critical to early development. The sex ratio of a population could be altered by placing this RNAi under the control of a sex-limited gene promoter. This would mean that no young which were either male or female would develop properly (Raphael et al. 2004).

·       Sterile Insect Techniques (SIT)

A technique called the sterile insect technique (SIT) is used to contain and exclude populations of Queensland fruit fly. The goal of SIT is to release a large amount of sterile males to mate with any introduced wild females, resulting in the production of infertile eggs (Knipling, 1959).  The potential of SIT for controlling pests has been around since the 1960s, when SIT trials first caused large declines in the size of fruit fly populations (Monro, 1966). Compared to insecticidal control methods, SIT has some advantages including increased specificity and can be targeted to affected regions (Knipling, 1959).  SIT programs in the past have failed due to continual immigration into the areas being targeted (Meats et al. 2003). The most common method used to make fruit flies sterile for SIT programs is to irradiate them.  The most effective time of the life cycle for irradiation to occur is when pupation is approximately 70% complete. (Gilchrist & Crisafulli, 2005). The most effective irradiation dose rate for SIT programs should be at a level which makes individuals sterile without reducing its reproductive competitiveness. Irradiated males are not reproductively disadvantaged against normal males in terms of female remating – levels of female remating have been found to be similar for irradiated and normal males (Harmer et al. 2006).

Chemical Control:

·       Cover Spray:

Cover sprays are applied to the whole tree, and target Fruit fly sheltering in the tree canopy and maggots located within host fruit. Insecticide sprays used include dimethoate, fenthion and trichlorfon, depending on the tree being sprayed (Dominiak, 2007). After cover spraying, there is a period of time for which fruit should not be picked or eaten. The length of this withholding period depends on which insecticide was used . As mentioned above, cover spraying is often used in combination with bait spraying to achieve suppression of high populations of Fruit fly.

·       Ground Spray

Ground sprays are done to target larvae and emerging adult in the soil. It is done by drenching the insecticide solution under the tree trunk. Application of insecticide in the soil as trunk of tree and the compost heaped in the viscinity of field. No more than two spray required.

Eg., Chloropyriphos.

·       Bait

This method of Fruit fly control involves the spot spraying of a combination of a dilute protein mixture and an insecticide (eg. Maldison). The protein servers as an attractant, and when the Fruit fly feed on the protein mixture the insecticide component causes death: this method targets both the male and female Fruit fly. A recommended bait spraying regime is 100 ml doses, targeting the shady spots which Fruit fly like to occupy. A density of 100 spot sprays per hectare (around 6 to 8 per residential property) is used in the Fruit Fly Exclusion Zone (FFEZ) of Eastern Australia. This amount of spraying is thought to be effective due to a bait spot being within the “daily wandering range of each fly within the treatment area. The effectiveness of this control method can be reduced by rain washing off bait spots and the pesticide degrading over time (Gilchrist, pers. Comm.. 2008). Maldison is used as an insecticide in bait spraying within the FFEZ, as it has a short residual life and low mammalian toxicity. “Bait spraying alone will not be enough to control high populations of fruit fly. It should be use in corporation with other control methods.

  Local Area management

Local area management means the minimum scale of pest management over a restricted area such as at field level/crop level/village level, which has no natural protection against reinvasion. The aim of local area management is to suppress the pest, rather than eradicate it. Under this management option a number of methods such as bagging of fruits, field sanitation, protein baits and cue-lure traps, host plant resistance, biological control, and soft insecticides, can be employed to keep the pest population below economic threshold in a particular crop over a period of time to avoid the crop losses without health and environmental hazards, which is the immediate concern of the farmers.

Wide area management

Wide area management is not a unitary concept, but incorporates a number of related but distinct methods including local area management. The methods used for a wide area management approach include male-sterile insect release, insect transgenesis, and quarantine control techniques in combination with available local area management options. The aim of wide area management is to coordinate and combine different characteristics of an insect eradication program over an entire area within a defensible perimeter. The area must be subsequently protected against reinvasion by quarantine controls, for example, by pest eradication on isolated islands. The USDA-ARS areawide IPM programs of melon fruit fly started in 1999 in collaboration with the Hawaiian State Department of Agriculture and University of Hawaii, using the environmentally sound strategies such as field sanitation, male annihilation with male lures and attractants, protein bait sprays/traps, augmentative releases of biological control agents (Fopius arisanus and Psyttalia fletcheri), and sterile insect release. It has proved to be economically viable, environmentally sensitive, sustainable, and has suppressed fruit flies below economic thresholds with the minimum use of organophosphate and carbamate insecticides (Wood, 2001; Mau et al., 2003b; Vargas et al., 2003; Klungness et al., 2005). An IPM program that used field sanitation, protein bait applications, male annihilation, and release of sterile flies and parasites reduced fruit fly infestation from 30 to 40% to less than 5%, and cut organophosphate pesticide use by 75 to 90% (Vargas, 2004).

The recent wide area management program eradication program of B. cucurbitae in Seychelles demonstrated a three tier model including a) initial population reduction using bait sprays, b) elimination of reproduction using parapheromone lure blocks to eradicate males and thus prevent oviposition by females, and c) intensive surveying by traps and fruit inspection, until it can be certain that the pest is entirely eradicated (Mumford, 2004). Although, the sterile insect technique has been successfully used in area-wide approaches, the wide area management needs more sophisticated and powerful technologies in their eradication program, such as insect transgenesis, which could be deployed over wide-area and is less susceptible to immigrants. Above all, the use of the geographical information system has been used as a tool to mark site-specific locations of traps, host plants roads, land use areas and fruit fly populations within a specified operational grid.

 CASE STUDIES:

Dr. Rana K and Kanwar HS, (2014) conducted a field trial to evaluate the efficacy of  some eco friendly techniques to manage fruit fly at Dr. Yashwant Singh Parmar University of Horticulture and forestry, Nauni, solan. Treatments were poison bait spray and cue lure baited traps individually and in combination  for the management of melon fruit flies (Bactocera spp.) infesting bitter gourd crop during kharif 2011 and 2012. It was found that all the treatments were effective in reducing the fruit damage during both years.  The combined treatment of cue lue baited traps and poison baited spray proved the most effective for management of fruit flies with significantly less fruit damage(20.92%) as compared to control (45.66%) and their separate application 22.36% and 25.42% respectively.

CBT- Cue lure Bait Trap, PBT- Poison Bait Trap

A field experiment was conducted by Ahmad et al., (2005) at the Arid Zone Research Institute Bahawalpur, during the year 2005 to assess the efficacy of different methods of fruit fly control on Ber. Five different methods namely insecticides, baiting, cultural, Integrated Management and no treatment were compared for percentage fruit damage and Yield. It was concluded that application of integrated pest management methods was most effective than other applied singly.

 Liu et al (1985) reported that cultural operations in guava orchards in Taiwan suppressed the adult population of B. dorsalis temporarily, but as a result of emigration, the number of flies

increased again as soon as conditions became suitable. Hoeing with discs was also found effective in checking the pupating larvae of B. dorsalis (Mann 1989). Larval density and per cent fruit infestation was lower in half and fully ripe fruits collected from the fields where sanitation was practised. Likewise, the relative density of tephritid adults was lower in the orchards with sanitation. The orchard without sanitation had an irregular harvesting pattern which resulted in abundant ripe fruits on trees and fallen rotting fruits on the ground (Liquido 1993). Singh (2004) reported sanitation and tillage practices to be effective against B. dorsalis on guava. The infested fruits particularly the fruits on the tree which have signs of attack should be removed instead of removing fallen fruits on the ground as the larvae from such fruits have already left for pupation. In fields where sanitation measures were practiced, the level of fruit flies decreased significantly (Verghese et al 2004). Different cultural practices like soil raking by hand and, collection and destruction of fallen fruits were also helpful in reducing the damage (Singh 2004, Stonehouse et al 2007, Kumar 2011, Sharma et al 2011b, Kumar and Sharma 2012, Verghese et al 2012).

Methyl eugenol is the most powerful of all the male lures attracting usually the males of Oriental fruit fly and others and is being used for both monitoring and management of fruit flies (Drew 1974, Hardy 1979, Drew and Hooper 1981, Kapoor et al 1987, Drew and Hancock 1994, Verghese et al 2006b, Vargas et al 2009b, Singh and Sharma 2011, Singh et al 2011, Kumar and Sharma 2012, Sharma 2012, Verghese et al 2012). This technique has been successfully used for the eradication and control of several Bactrocera species (Steiner et al 1965, Bateman et al 1973,

It was reported that 1 per cent methyl eugenol alongwith 0.5 per cent malathion or 0.1 per cent carbaryl was most effective against B. dorsalis (Balasubramaniam et al 1972, Lakshmanan et al 1973). It was also advocated the monthly replenishment of methyl eugenol. However, Cunningham et al (1975) used 83 per cent methyl eugenol alongwith 10 per cent naled and 7 per cent thixein for management of B. dorsalis. Methyl eugenol (0.025, 0.05, 0.075 and 0.1 ml) impregnated on 2 cm² cotton wad had no significant difference in their efficacy when replenished at weekly interval (Belavadi 1979). Under field conditions, it was observed that single application of methyl eugenol at 0.075 ml was most effective upto 17 days for capturing B. dorsalis if the population was low (0-22 fruit flies/trap) and upto 32 days when the population was high (0-81 fruit flies/trap).

 Conclusion:

Fruit fly belongs to order Diptera and family Tephritidae. It is a very important group of pests on account of their potential to cause damage to fruits and vegetables. It is a direct pest of the crop as directly feed on the fruit and make it unmarketable hence is a very big problem agricultural point of view. There are 4500 spp of fruit flies in the world out of which 2000 are economic pests of crops and about 5% of these are found in india. Fruit fly is a pest having a wide host range it feeds on fruit crops as well as vegetable crops. The extent of losses vary from 30 -100 per cent depending upon the crop  and season. Feeding by fruit fly larvaemay cause complete destruction of fruits, rather than cosmetic damage as is caused by many other insect pests.   Keeping in view the economic  importance of fruit fly  and crop, its  management could be done using local area management and wide area management techniques (Dhillon et al.,2005).In mid hill conditions of Himachal Pradesh (Gupta and Verma, 1992) observed about 80 per cent fruit fly infestation on cucumber and bottle gourd, 60 per cent on bitter gourd and 50 per cent on sponge gourd. The use of geographical information system could also be used as an IPM tool to mark site- specific locations of traps, land use areas and fruit fly population within a specific operational region. Although, the sterile insect technique (SIT) has been successfully used in wide area approaches, this technique should be used  in eradicating pest from the field. ( Sarwar, 2015) Fruit fly is a pest which can not be eradicated by opting one method so combination of methods like cultural, physical, biological, chemical, genetic and quarantine methods are adopted to manage fruit fly besides  other local area management options and coordination of local farmers are important in eradication of fruit fly. No fruit or vegetable should be exported or imported from other place without undergoing quarantine or disinfestations of fruit or vegetable.