Management of Mango Fruit Borer in Pakistan

Mango is known as the king of the fruits. It is known from the literature that the Vedas and Ramayana showed mango as a well-known fruit during the Vedic and Aryan ages. The world’s first recorded presence of the existence of mango is seen in the text by Ludovico di Varthema in the Italian Language as Manga. Later this text was further translated in post-classical Latin and French language. Mango has been cultivated in the Indian subcontinent for thousands of years and reached East Asia between the fifth and fourth century B.C. India is the largest producer of mango in the world accounting for 52.63% of the total production. Mango cultivation accounts for 37.61% of the total area under fruit cultivation and 22.21% of the total fruit production in the country. The country produced 10.99 million tonnes of mangoes from an area of 1.23 million hectares. The total area under mango cultivation in Bengal is 70,00080,000 hectares, almost 44% of the total area in the state food crop cultivation.

According to statistics of the FAO, more than 92 countries worldwide produce mangoes. India is the largest producer of mango, contributing 54.2% of total world production, but its export hardly crosses 3% of the total international demand. The major mango producing regions in India are Andhra Pradesh, Uttar Pradesh, Bihar, Karnataka, Tamil Nadu, West Bengal, and Orissa & Maharashtra. India’s mangoes are unique in taste and aroma as they represent more than one thousand varieties, a diversity unmatched by any other national production. Two important causes of low share in export of mango in the world markets are the contamination by insect pests and pesticide residues. Despite the largest production base of mango, productivity in our country is rather low. The role of physiochemical characteristics of mango fruits in governing the incidence of fruit borer infesting in different days after fruit set has not so far been investigated. The Mango, Mangifera indica L, which belongs to the family of Anacardiaceae, is one of the most important tropical and subtropical fruits of the world and is popular both in fresh and processed forms. It is called the king of fruits on account of its nutritive value, taste, attractive fragrance and health-promoting qualities. In Uganda, mangoes are by far the most common fruit country-wide. They are ‘volunteer’ fruits growing in all parts of the country by the gift of nature and adapt to all ecological zones of the country, dry or humid, montane and lake shoreline. However, areas of highest intensity are those in the relatively hot and dry Northern, Northeastern and West Nile zones. Traditionally in Uganda, mangoes have been known to grow wildly with little or no husbandry practices. The mango varieties grown are predominantly local. Most local varieties are high in fiber and require less attention in their growing. The Uganda government’s call on households to produce high value and marketable crops has however led to the introduction of exotic mango varieties in the country. The exotic varieties are of superior qualities; they have higher juice yields, good flavor, and no strings; and are more appealing to both the local and the international market. Since their introduction in the country in the late 1980’s, the exotic mango varieties have spread to all mango growing areas of Uganda. Some of the exotic mango varieties grown in West Nile zone of Uganda include; Tommy Atkins, Kent, Haden, Keit, Zillate, Palvin, Palmer, Alphonso, and Irwin among others.

Pests:

Coupled with limitations like an irregular bearing, low yielding varieties, and poor nutrition management, this is a high incidence of insects pest and diseases that really reduces productivity. Mango is attacked by more than 400 pests in the world. Usually, in a particular mango growing area, three or four major pests occur. Amongst them, mango midges and fruit borers (Autocharis albizonalis) are of prime importance along with mango hoppers. Sahoo & Jha reported that the fruit borer, Autocar is albizonalis recently appeared in serious proportion in the major mango growing areas of the West Bengal, particularly in the districts of Malda, Murshidabad, Nadia & Hooghly causing 10-52% damage of fruits from pinhead stage to full maturity. It is revealed that the different physiochemical parameter like TSS, total sugar, reducing sugar and acidity of different mango varieties is changed throughout the developmental period of mango fruit. The infestation and the degree of damage by the borer vary considerably according to the genotypes of the folk varieties of mango plant and their different developmental period. Several insects attack mango from its nursery stage to maturity. Low productivity of mango occurs due to irregular and erratic bearing, damage due to innumerable insect and non-insect pest and damageable diseases. Nearly 400 insects and non-insect pests have been recorded from the Indian subcontinent show records of 260 insects and mite pest of which, according to Kapadia, (2003) thirty pests are serious pests.

Mango fruit borer, commonly known as Red-banded caterpillar Autocharis albizonalis Hampson is thought to be recorded as a new pest, causing alarming losses to mango in Andhra Pradesh and Karnataka, due to the injudicious and improper application of insecticides (Ph.D. thesis submitted by SK. Sahoo in 2006 (Title –“ Studies on Insects Pest complex of Mango with special preference to Management of Mango fruit weevil and Mango fruit borer), to Bidhan Chandra Krishi Viswavidyalaya, Mohanpur , Nadia, West Bengal, India). In West Bengal, it was first recorded in Malda during although a survey of mango orchards in Malda and Murshidabad by Jha et al.,. 10-52% damage of fruits from pinhead stage is noticed in West Bengal, particularly in Malda, Murshidabad, Nadia, and Hooghly. India has the natural advantage of growing all kinds of fruit crops. Mango is called the king of fruits in our country. Mango plant suffers from a number of pests and diseases at all stages of development i.e. right from nursery stage to grown-up tree stage. Even fruits at pre-harvest stages are affected making them unsuitable for marketing and export. Some of the mango pests as reported by different authors include; beetles, fruit flies, red-banded thrips, mango tip borer, scales, and seed weevil.

While the diseases include; Anthracnose caused by fungus Colletotrichum gloeosporioides, bacterial black spot caused by Xanthomonas campestris PV mangiferae-indicate, algal leaf spot caused by green alga parasite Cephaleuros virescens and Powdery mildew caused by fungus Oidium mangiferae. There is generally poor management of mango pests and diseases among farmers in Uganda. As such, some of the mango pests like fruit flies have been reported to have a devastating effect on mango production in Uganda. Consequently, the existing level of productivity in mango growing belt of Uganda is disheartening. Being a new agro-enterprise in West Nile Zone (WNZ), varied knowledge gaps exist on pests, diseases and fruit tree management of exotic mangoes among farmers. This is because possibilities of diseases and pests transfer from the origin of exotic varieties are high. Besides, the crops may also be attacked by pests and diseases that might have been living on alternate wild plants that were of little concern to the farmers. All these are mysteries unknown to exotic mango farmers and researchers in WNZ. Accordingly, there is a dearth of information about exotic mango pests, diseases, and orchard management practices in the zone. This study, therefore, sought to establish farmers’ knowledge and perceptions of mango pests and diseases and examine orchard management practices employed by farmers.

Ascertaining various prevailing mango pests, diseases and orchard management practices in WNZ is useful to set research agendas, for planning campaign strategies and developing messages for communication to the farmers. the district, fifteen mango farmers with orchards under production with trees aged 5 years or older were randomly chosen for interviews guided by a semi-structured questionnaire. Interviews were conducted with the selected individuals because they allowed face to face interaction between researchers and the respondents. This made probing and explanation of unclear questions possible. The major variables covered in the questionnaire included; the socio-demographic factors, agronomic practices, and the major mango pests and diseases. The content of the questionnaire and the type of questions asked were agreed upon after key informant interviews. The questionnaire was pretested and revised. Farmers’ knowledge and perceptions of mango pests and diseases and major orchard management practices received special emphasis. To evaluate farmers’ pest and disease perceptions, they were first asked to record the most important pest and disease problems. For each of the major pests and diseases, their incidence, severity and estimated yield loss were ranked on a 3-level scale (low, moderate and high) following. On average, each questionnaire took 1.5 to 2.5 hours of interview with each farmer, followed by a visit to the orchard.

The visit to the orchard was aimed at cross checking the answers given by the farmers. In every orchard visited, 10 trees were randomly selected and surveyed for pests, and symptoms of pests and diseases. The orchard management practices employed by farmers were also established. Survey data were encoded and statistical analysis was accomplished using the Statistical Package for Social Sciences version 16 software. Percentages were based on the number of respondents rather than using the total sample. In cases where multiple responses were obtained, the total sample size was used. Chi-square tests were used to analyze farmers’ perception on pests and diseases. Multinomial logit was used to analyze factors influencing orchard management practices adopted by farmers. Keeping this in view, the present investigation on the physiochemical characteristics including TSS, total sugar, reducing sugar, titrable acidity and sugar acid ratio of different folk varieties of mango in relation to incidence of fruit borer was carried out. The study on the incidence pattern of mango fruit borer (Autocharis albizonalis Hampson) was carried out along with the different aspects of infestation and their varietal preference. This pest was once regarded as the minor pest in mango orchards had recently gained the major pest status due to the injudicious application of broad-spectrum insecticides in the mango orchards. The first pest brood was seen in the 1st fortnight of March and continued till June. Pest attack had been found to be maximum from the West direction. The larvae bored into the fruits both at the young marble stage to more mature ones producing a tiny pinhead size small circular hole at the point of entry, encircled by a dark brown ring. Larvae feeding on the fruit pulp formed a network of tunnels to reach the seed. The later instar larvae fed on the seed filling up the inner content by their excreta.

Management:

Mango hoppers (Cicadellidae: Homoptera)

Three species of hoppers are found to feed on the inflorescence of mango Amritodus Atkinson (Lethierry), Idioscopus clypealis (Lethierry) and I. niveosparsus (Lethierry). Distribution: In India, these hoppers are widely distributed in all the mango growing regions. A. Atkinson is more common in North India. I. clypealis is found all over India, more predominant in South Gujarat, Maharashtra, and Karnataka. I. niveosparsus is recorded from peninsular India. Nature of damage: The hoppers are found in abundance during November – February synchronizing with the flowering of mango trees. During the remaining part of the year, they occur in small numbers inside barks or on leaves of mango. Both the nymphs and adults suck the sap from the inflorescence in large numbers causing withering and shedding of flower buds and flowers which result in heavy loss ranging from 25 - 60 percent due to poor fruit setting. The honeydew excreted by them affords conditions for the development of sooty mold. Eggs laying also inflicts injury to the inflorescence.

Life history: I. niveosparsus (L.) is slightly smaller with three spots on the scutellum and prominent white band across its light brown wings. I. clypealis (L.) is the smallest with two spots on the scutellum and dark spots on the vertex and is light brown in color. A. Atkinson (L.) is the largest and light brown having two spots on the scutellum. The female hopper inserts the eggs into flower buds and the inflorescence stalk. The nymphs hatch out in 4 to 7 days. Freshly hatched nymphs are wedge-shaped and whitish in color with two small red eyes. Gradually with each molting, the color changes to yellow, yellowish green, green and ultimately greenish brown. The period from egg to adult takes about 12 - 17 days and during a flowering season, two or more broods of the pest may occur.

Management strategies:

(i) Three applications of carbaryl 0.1 % or phosalone 0.05 % at the fortnightly interval, or, two sprays of phosphamidon or monocrotophos @ 0.03% at 13 to 18 days interval at flowering and 2 – 3 sprays in June – July.

(ii) Keeping the orchards clean, avoiding overcrowding of trees and waterlogging keeps the pest at bay.

Gall midges infesting mango inflorescence Distribution: Three species of gall midges viz., Procystiphora mangiferae (Felt), Dasineura amaramanjarae Grover and Erosomyia indicia Gr. & Pr. are found throughout India. Nature of damage: Due to the attack on unopened flower buds, they fail to open and drop down. When the inflorescence stalk is attacked, the inflorescence becomes stunted and malformed.

Life history:

(i) Procystiphora mangiferae (Felt): The light orange colored fly lays the eggs inside immature blossoms. The maggots that hatch out from the eggs feed on stalks of stamens, anthers, ovary, etc. Only one maggot is found in each bud and it pupates inside the bud itself. The life-cycle from egg to adult occupies 12-14 days).

(ii). Dasineura amaramanjarae Grover: The adult flies insert the eggs into unopened flower buds. The maggots feed inside the buds and they fail to open and drop down. The maggots hibernate in the soil and thus carry-over of the pest to the next year is accomplished. When favorable conditions set in they pupate and emerge as adults.

(iii). Erosomyia indica Gr. & Pr.: The maggots attack the inflorescence stalk, flower buds, and small developing fruits. The adult fly is yellowish and lays the eggs on the inflorescence peduncle or at the base of’ developing fruit. The maggots are yellowish and when full grown pupate in the soil.

Management strategies:

(i) Stem injection by making 5 – 10 cm deep holes in the main branches with dimethoate or monocrotophos @ 0.5 ml a.i./cm circumference gave effective control of the pest.

(ii) A single spray of 2, 4-D @150 mg/l in October resulted in the opening of galls causing 90% autocidal mortality of the nymphs.

Fruit fly Bactrocera dorsalis Hendel (Tephritidae: Diptera) Distribution: It is widely distributed in the Orient region from Australia and Hawaii to Pakistan, hence it is also called Oriental fruit fly. The pest is active throughout the year in South India whereas in northern parts the pest hibernates during winter (November to March) in the pupal stage. The flies appear late in spring on such of the fruits that are about to ripe and the population increases rapidly during summer. Nature of damage: The female flies lay eggs just below the fruit epidermis (1 - 4 mm deep). On hatching, the maggots feed on the pulp of those fruits. As a result, a brown patch appears around the place of oviposition and the infested fruits start rotting. These affected fruits drop down prematurely and the maggots come out from these fallen fruits to pupate in the soil. Semi-ripe fruits are attacked usually by April-May. Sometimes it becomes serious.

Life history: The adult fly is light brown with transparent wings. Adult flies are very conspicuous. These are about 7 mm long, with hyaline wings (expanse: 13 - 15 mm), thorax ferrugineous without the yellow middle stripe, legs yellow, abdomen conical in shape and dark brown in color. The pre-oviposition period is 2 - 5 days. A single female can lay 150 - 200 eggs (average 50) in about a month. The eggs are laid in clusters of 2 - 15 eggs and these hatches in 2 - 3 days during March and 1 - 1½ days during April. Maggot duration is 6 days in summer and extends up to 19 days with the fall in temperature. Pupation usually takes place 80 - 160 mm below the soil surface and pupal period range from 6 days (summer) - 44 days (winter). Management strategies:

(i) The best way to avoid infestation of fruit flies is to harvest the fruits before ripening.

(ii) To check the carryover of the pest, collect and destroy all fallen and attacked fruits.

(iii) Plow around the trees during winter to expose and kill the pupae.

(iv) The adult flies may be trapped and killed by poison-baiting or bait-spray (20 gm Malathion, 50% wettable powder in 2 liters of water for baiting and 20 liters of water for spraying.

(v) Spraying with 0.3% oxydemeton methyl or 0.03% phosphamidon or 0.06% dimethoate or 0.2% carbaryl.

Mango nut weevil or stone weevil Sternochetus mangiferae (Fb.) (Curculionidae: Coleoptera) Distribution:

It is widely distributed in the tropics. The pest is more common in South India where late varieties suffer the most. Nature of damage: Eggs are laid singly on the epicarp of partially developed fruits or under the rind of ripening fruits. The grubs as soon as they hatch out from the eggs tunnel in a zigzag manner through the pulp, endocarp and the seed coat and finally reach the cotyledons. As the fruit develops the tunnels get closed up. The grubs feed on the cotyledons and destroy them. The adults which emerge from the pupae also feed on the developing seed and this may hasten the maturity of infested fruits. The adults hibernate in between the crevices on the tree trunks. The weevil attacks the only mango.

Life history:

The dark brownish stout weevil measures about 6 mm long. The female scoop out the surface of the developing fruit (till it is half ripe) and deposits the eggs singly. On a fruit 12 - 36 eggs may be deposited. However, finally, only a maximum of about 7 weevils can be noticed in a highly susceptible variety. The fluid that oozes from the fruit covers the egg. The incubation period is 7 days. The grub is apodous, fleshy, light yellow with a dark head and pupates inside the nut itself. It emerges as an adult in 7 days. The total life cycle from egg to adult occupies 40 - 50 days. The weevils hibernate from July – August till next fruiting season. There is only one generation in a year.

Management strategies:

(i) The damage due to nut weevil can be minimized appreciably by spraying deltamethrin 0.025 % thrice at 15 days interval commencing 45 days after fruit set.

(ii). Carbaryl 0.2% spray when the fruits are lime sized followed by another spray after 15 days.

(iii). Destruction of affected fruits and digging of soil to expose hibernating weevils.

Mango stem borer Batocera rufomaculata DeG. (Cerambycidae: Coleoptera) Distribution:

Widely distributed all over India and Bangladesh attacking apart from mango other trees such as fig, rubber, jackfruit, eucalyptus, mulberry etc. The mango varieties Amlet and Mulgoa are highly susceptible to the attack of this insect. Nature of damage: Eggs are laid singly either in the slits of tree trunks or in the cavities in the main branches and stem which are covered with a viscous fluid. The grubs feed by tunneling through the bark of branches and cause wilting. Though it is an occasional pest of importance, in case of severe attack the trees succumb. Normally, the attack goes unnoticed until the branch starts drying up. Sometimes sap and frass may be seen exuding from the boreholes.

Life history:

The adult beetle has two pink dots and lateral spines on thorax and measures about 50 mm long. The eggs laid singly on the bark or in crevices on a tree trunk or branches hatch in about 1 - 2 weeks. The grub feeds for 3 - 6 months and pupates inside the tunnel itself. The adult emerges in about 4 - 9 months.

Management strategies:

(i) The attacked portions should be removed and destroyed.

(ii) The grubs can be killed by pouring chloroform, petrol or carbon disulfide into the borehole or placing some crystals of paradichlorobenzene and then closing the hole with mud.

Mango mealy-bug, Drosicha mangiferae (Green) (Coccidae: Homoptera) Distribution:

In India, it is widely distributed in the Indo-Gangetic plain and has a very wide range of host plants. This pest has been reported from many places in India, Bangladesh, Pakistan, and China. It is reported to attack a number of fruit crops such as apple, apricot, beer, cherry, citrus, falsa, fig, grapevine, guava, gular, jack-fruit, jamun, litchi, mulberry, papaya, peach, plum, and pomegranate. Nature of damage: These are large, fleshy, flat-bodied creatures measuring about 1.5 cm in length and a little less than a centimeter in width, covered with ashy-white mealy powder and crawling up or down the tree-trunks or on the ground around the tree-base or even invading the houses if the mango trees are near about. These mango mealy-bugs are also referred to as the giant mealy-bugs. They suck the plant-sap and although their name seems to suggest that they are specific pests of mango only, their list of food plants includes at least 62 species of trees, shrubs, and herbs. When they are in large number they devitalize the plant and they produce honeydew which encourages the growth of sooty mold, giving a very unhealthy look to the plant as a whole. At times, they are found clustering in masses on young shoots, like fungus outgrowths.

Life history:

There is a well-established sexual dimorphism in the adult stage which is generally found during the midsummer period, i.e. from April to June. Adult females are wingless and large-bodied. The male is a winged creature with only one pair of wings and a very delicate reddish body which flies actively and fertilizes the females. The adult gravid females after fertilization crawl down along the tree-trunk to the ground where they lay eggs at depths of about 5 - 15 cm and in clusters of 300 - 400 eggs each. The oviposition is generally confined to an area near and around the base of the tree. These activities of migration from the tree downwards to the ground and oviposition in the soil are generally confined to the months of April, May, and June. The males die soon after mating and the females soon after oviposition. The eggs laid in the soil take quite a few months before they hatch and is influenced by the temperature and moisture conditions of the soil. Hatching can be as early as November of the same year or as late as March of the succeeding year. The young nymphs soon after hatching crawl about in search of some suitable food-plant on which, if found, they spend some time. Thereafter, they begin their ascent along the tree-trunks and this upward migration lasts for several weeks. On reaching the fresh growths, the nymphs congregate there and begin to suck the plant-sap. They molt thrice during their nymphal period which lasts about three months or more, depending on the environmental temperature. Thereafter, the nymphs developing into males undergo some sort of pupation and transform themselves into winged adults and the female-producing nymphs do not undergo any appreciable change except in size. Thus, there is only one generation during the year. Unlike many other coccids, the nymphs of this pest do not remain stationary although they are sluggish.

Management strategies:

(i) Raking of the soil around the base of the tree which has been infested, so that the egg-masses get exposed to the sun and heat and get killed. Also, the application of chlorpyriphos 0.05% in the same area when hatching begins or is expected, so that the just-hatched nymphs may be poisoned.

(ii) Application of a sticky band around the tree-trunk so as to check the nymphs from crawling up the trees.

(iii) If nymphs are observed on trees, spray 0.05% monocrotophos or phosalone.