Managing Insect-Pests and Diseases in Sapota and Jackfruit Orchards

Sapota (Manilkara zapota) and jackfruit (Artocarpus heterophyllus) are two of the most economically significant tropical fruit crops grown across South and Southeast Asia. While both trees are hardy and productive under the right conditions, they face persistent pressure from a range of insect pests and fungal diseases that can sharply reduce fruit quality and yield. Research published in Frontiers in Plant Science confirms that climatic factors – humidity, temperature, and rainfall patterns – directly influence when and how severely these pests and pathogens strike, making timely identification and management non-negotiable for any serious orchard grower.

Insect-pests of sapota 🔗

Sapota is vulnerable to pest attack at nearly every growth stage – from flowering and shoot development through to fruit maturation. A pest succession study from Karnataka recorded fifteen insect species on sapota, of which eight attained major pest status, including scale insects, mealy bugs, leaf miners, and borers.

Stem borers 🔗

Stem borers are among the most destructive pests in sapota orchards. The larvae bore into the collar region and main stem, disrupting the transport of water and nutrients. The telltale signs are the presence of small entry holes at the collar region along with extrusion of frass – the powdery excrement pushed out of boreholes. In severe cases, branches wilt and the tree may die. Management involves scraping out the frass and larvae from boreholes, plugging the holes with a paste of copper oxychloride, and applying systemic insecticides when infestations are heavy.

Scale insects 🔗

Scale insects such as Coccus viridis (soft green scale) and Icerya sp. (cottony cushion scale) were found to persist across vegetative, flowering, and fruiting stages of sapota. These small, immobile sap-suckers attach to stems and leaves, causing yellowing, stunted growth, and reduced fruit set. Horticultural oil sprays at 1-2% concentration effectively smother the insects. Introducing natural predators like Cryptolaemus montrouzieri (the mealybug destroyer, a ladybird beetle) has also shown good results in biological control of soft scale on sapota.

Mealy bugs 🔗

Mealy bugs secrete a white, waxy material that is easy to spot on stems, leaves, and fruit clusters. They weaken the plant by sucking sap and also excrete honeydew, which promotes the growth of sooty mold. Cultural management includes collecting and destroying mealy bug-infested plant parts and flooding the orchard in October to kill eggs, followed by ploughing in November. Insecticidal soap sprays and neem-based products work well for moderate infestations.

Fruit borers and seed borers 🔗

The sapota fruit borer (bud worm, Anarsia epotias) bores into flower buds and developing fruits, causing premature drop and rendering affected fruits unmarketable. The seed borer (Trymalitis margarias) shows the highest damage from November to February, coinciding with cooler, drier months that favour its life cycle. Larvae enter fruits, feed on internal seed contents, and cause rotting, leading to premature fruit fall. Key management steps include removal and destruction of fallen infested fruits, use of pheromone traps (one per acre) to monitor adult moth populations, and application of Bacillus thuringiensis (Bt) at 1 g per litre as a targeted biocontrol measure.

Leaf miners 🔗

Leaf miners (Acrocercops gemmoniella) tunnel inside leaf tissue, creating characteristic serpentine mines. Heavily mined leaves lose photosynthetic capacity and drop prematurely. The sapota variety PKM-1 has been reported to be tolerant of leaf miner attack. For severe infestations, spraying lambda-cyhalothrin 5 EC at 0.5 ml per litre or quinalphos 25 EC at 2 ml per litre is recommended.

Diseases of sapota 🔗

Leaf spot 🔗

Leaf spot is caused by fungal pathogens and presents as deep purplish-brown spots that are white at the centre, round in shape. Long spots may also appear on fruit stalks and petals. Copper oxychloride at 400 g per acre is the standard chemical treatment. Infected leaves should be removed and destroyed promptly to reduce the spread of inoculum in the orchard.

Sooty mold 🔗

Sooty mold is not a primary pathogen – it develops on the honeydew secreted by sap-sucking insects like mealy bugs and scale insects. A black, powdery coating covers leaves and stems, blocking sunlight and reducing photosynthesis. Effective management requires controlling the insect populations that produce honeydew; once the honeydew source is removed, the mold can be washed off or treated with mild fungicides.

Heart rot and anthracnose 🔗

The main diseases reported in sapota include leaf spot, base rot, heart rot, and anthracnose. Heart rot causes wood decay at the centre of the trunk and branches. Carbendazim at 400 g in 150 litres of water per acre is an effective treatment. Anthracnose, caused by Colletotrichum species, produces dark, sunken lesions on leaves, flowers, and fruits, with fruit rot worsening during the monsoon. Copper oxychloride (0.3%) or Mancozeb (0.2%) applied at 15-day intervals during the rainy season helps keep anthracnose in check.

Insect-pests of jackfruit 🔗

About 38 species of insect pests are known to attack jackfruit, though only a few cause economically significant damage. The major ones are the shoot and fruit borer, trunk borer, bud weevil, and mealy bugs.

Shoot and fruit borer 🔗

The shoot and fruit borer, Diaphania caesalis (Walker), is the single most damaging pest of jackfruit. It alone can cause up to 30% yield loss. The pest is active from May to October. Eggs are laid on tender shoots and buds; hatching caterpillars bore into shoots, flower buds, and developing fruits. Shoots wilt and buds dry up, while affected fruits develop internal tunnels and drop prematurely. The pest has been recorded across Assam, Bihar, Uttar Pradesh, Tamil Nadu, and other Indian states, as well as in Bangladesh, Japan, Indonesia, Malaysia, and Australia. Pruning and destruction of infested shoots, combined with spraying Bt or neem oil (3%) on young growth, forms the backbone of management. Pheromone traps help monitor adult moth populations.

Trunk borer 🔗

The trunk borer, Batocera rufomaculata (De Geer), is a cerambycid beetle whose larvae feed on the vascular tissues of the trunk. Infestation interrupts nutrient and water transport, causing drying of terminal shoots, wilting of branches, and in heavy attacks, death of the entire tree. Frass oozes from several bore holes, and sap may also seep out. Management involves injecting a kerosene-soaked swab or insecticide solution into bore holes and then plugging them with mud or Bordeaux paste to prevent further tunnelling.

Brown weevil (bud weevil) 🔗

The bud weevil, Ochyromera artocarpi, is a precise pest of jackfruit. The small whitish grubs bore into tender flower buds and fruits, inducing premature drop. Greyish-brown adult weevils also nibble on leaves. Handpicking adults, destroying infested buds, and applying neem oil sprays deter weevil populations. Chemical control with targeted insecticide sprays is warranted when infestation crosses the economic threshold.

Mealy bugs and spittle bugs 🔗

Mealy bugs such as Drosicha mangiferae, Nipaecoccus viridis, and Planococcus lilacinus are recorded as major mealy bug species on jackfruit. They suck sap from tender parts and produce honeydew that promotes sooty mold. Spittle bugs (Cosmoscarta relata and Clovia lineaticollis) are sap-feeders whose nymphs produce characteristic frothy masses on shoots; sooty mold may develop wherever this spittle drips onto lower branches. Both pests are managed through pruning, good orchard sanitation, and introducing coccinellid predators.

Diseases of jackfruit 🔗

Pink disease 🔗

Pink disease, caused by Pellicularia salmonicolor, is among the major diseases of jackfruit. The fungus infects the bark of branches and the main stem, initially producing a pinkish encrustation that later cracks and peels off. Affected branches die back progressively. Management involves scraping off infected bark, applying Bordeaux paste to the exposed wood, and removing heavily infected branches to prevent spread to healthy tissue.

Rhizopus rot 🔗

Rhizopus rot (Rhizopus artocarpi) is a post-harvest and on-tree fungal disease that causes fruits to decay rapidly with a foul odour. Soft, watery lesions appear on the fruit surface, and the flesh deteriorates quickly. Studies have reported 15-32% crop loss due to Rhizopus rot in some regions. Removing and destroying diseased fruits from both the tree and the ground, maintaining good orchard hygiene, and applying Bordeaux paste or copper-based fungicides are the recommended management steps.

Leaf spot 🔗

Leaf spot in jackfruit is caused by Phomopsis artocarpina and produces brown or black spots on leaves, leading to premature defoliation that weakens the tree over successive seasons. Bordeaux paste is a common fungicide used for managing leaf spot, dieback, and gummosis in jackfruit. Removing and burning infected leaves, improving canopy ventilation through pruning, and applying copper oxychloride sprays during the onset of disease are effective controls.

Gummosis and dieback 🔗

Gummosis (caused by Phomopsis artocarpi) is marked by canker-like wounds on stems and branches from which gum oozes. Dieback progresses from the tips of branches inward. Both conditions are worsened by wounds, water stress, and dense canopy conditions. Pruning to remove dead wood, application of Bordeaux paste on cut surfaces, and overall improvement of tree health through proper nutrition reduce the incidence of these diseases.

Integrated pest and disease management: the practical approach 🔗

Regardless of whether you are growing sapota or jackfruit, the fundamentals of good orchard management stay the same. Adopting integrated pest and disease management (IPDM) practices that combine cultural, biological, and chemical approaches leads to healthier orchards and higher profitability compared to reliance on pesticides alone.

Cultural practices 🔗

Regular orchard sanitation – removing fallen fruits, infected leaves, and dead wood – cuts the inoculum load significantly. Adequate spacing between trees improves air circulation and reduces the humid microclimate that favours fungal diseases. Timely pruning opens up the canopy and allows better light penetration, which also discourages pest buildup. The National Institute of Plant Health Management (NIPHM) recommends growing border crops like marigold and maize to conserve populations of natural predators and parasitoids in and around fruit orchards.

Biological and botanical control 🔗

Bacillus thuringiensis (Bt) at 1 g per litre is effective against most lepidopteran borers in both sapota and jackfruit without harming beneficial insects. Neem oil at 3-5 ml per litre acts as both a repellent and a contact insecticide for soft-bodied pests. Pheromone traps used at one per acre help monitor and suppress moth populations before they reach damaging levels. Encouraging natural enemies like ladybird beetles (Cryptolaemus montrouzieri), lacewings, and parasitoid wasps (Bracon sp.) adds a sustainable layer of pest regulation.

Chemical control 🔗

Selective insecticides and fungicides should be used only when pest or disease levels exceed the economic threshold, and chemical groups should be rotated to prevent resistance development. For sapota, quinalphos 25 EC (2 ml per litre) and systemic insecticides like imidacloprid (0.3 ml per litre) are used for sucking pests and borers. For diseases, copper oxychloride (0.3%) and Mancozeb (0.2%) are standard fungicides. In jackfruit, Bordeaux paste remains the workhorse for both fungal diseases and as a wound dressing after pruning or borer removal.

Monitoring and early warning 🔗

Forecast models that factor in minimum temperature and relative humidity can be embedded into early warning systems or mobile advisories for sapota growers, enabling timely application of biocontrol agents or insecticides. Weekly scouting of orchards – checking shoots, leaves, fruits, and the base of trees – is the simplest and most cost-effective form of monitoring. Maintaining disease scouting records over time helps identify seasonal patterns unique to a specific orchard location.

What do you think? Given that both sapota and jackfruit face some overlapping pests like mealy bugs and sooty mold, do you think a shared IPM calendar for mixed orchards would be practical? And with climate change pushing pest activity into unexpected seasons, how prepared are orchard growers in your region to adapt their management schedules in real time?

References

1. https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2025.1659709/full
2. https://www.researchgate.net/publication/383155454_Pest_Succession_of_Sapota_Manilkara_achras_Mill_Forsberg_under_Hill_Zone_of_Karnataka_India
3. https://www.agrifarming.in/sapota-pests-diseases-chiku-sapodilla-control-methods
4. https://www.khethari.com/blogs/news/sapota-chikoo-pests-and-diseases-and-their-management-a-complete-guide-for-farmers-and-agri-input-sector
5. https://www.researchgate.net/publication/326761556_Pests_of_Jackfruit
6. https://www.researchgate.net/publication/349703520_MANAGEMENT_OF_INSECT_PESTS_AND_DISEASES_OF_JACKFRUIT_ARTOCARPUS_HETEROPHYLLUS_L_IN_AGROFORESTRY_SYSTEM_A_REVIEW
7. https://revues.cirad.fr/index.php/fruits/article/download/34390/36604/40239
8. https://www.khethari.com/blogs/news/jackfruit-artocarpus-heterophyllus-pests-and-diseases-identification-symptoms-and-integrated-management-practices
9. https://www.actajournal.com/article/29/2-1-1-938.pdf
10. https://www.actajournal.com/archives/2021.v2.i1.A.29
11. https://niphm.gov.in/IPMPackages/Sapota.pdf