Mango leafhopper prevention

Mango flower hopper (Idioscopus clypealis) attacks flower chains and buds, causing flower drop and ruining the entire crop. Instructions for identification, spray thresholds and general prevention measures for mango orchards in the Mekong Delta.

Summary: Mango flower hopper is the number one pest in the flowering stage. A heavy infestation of leafhoppers can cause 50-80 percent of flowers to drop in a few days — losing the entire crop. Unlike bollworms that can cover fruit, cotton hoppers must be treated at the right time — spraying 5-7 days late is too late. This article guides early identification + correct spraying techniques + pollination protection.

Applies to: Hoa Loc mango, Cat Chu mango, Taiwanese mango, Keo mango in the Mekong Delta, Southeast.

Duration: Monitor from 2 weeks before flowering until fruit set.

Difficulty level: Medium. The important thing is early detection.

Estimated additional costs: 1-2.5 million VND per hectare for the crop.

Characteristics of mango flower hopper

*Idioscopus clypealis* and *Idioscopus nitidulus* are two common leafhopper species on Vietnamese mangoes:

• Adults are 3-5 millimeters long, yellow-brown or brown-green in color, jump quickly.
• Lays eggs on flower stalks + buds.
• Larva and adult together suck sap from flower stalks, blooms, and buds.
• Life cycle 18-25 days — there are many generations during the flowering season.

Harmful effects:

• Sucks sap from flower stalks — flowers dry, fall off.
• Honey honey secretion + sooty mold — buds and leaves turn black.
• Buds are attacked — do not develop, leaves turn yellow.
• Failed flowering — no fruit.

Why must early detection

Mango planthoppers spread very quickly:

• A female lays 100-200 eggs. Eggs hatch in 5-7 days.
• In 18-25 days, a pair of leafhoppers produces thousands of insects.
• When you see a lot of flowers falling — leafhoppers have had many generations in the orchard.

Need to be detected within the first 5-7 days of appearance. Counting hoppers on flower chains and buds:

• Count 10 random flower chains on 5 plants.
• Tap the string lightly, count the hoppers to jump out or fall.

Stage Room

Before flowering 2-3 weeks

• Pruning dense branches in the canopy — reduces places for leafhoppers to hide.
• Whiten the base of the stem — prevent ants (ants accompany leafhoppers).
• Spray the foundation once if the orchard has a history of heavy planthoppers.

When buds and flower buds appear

This is the most dangerous stage:

• Monitor weekly.
• Start counting leafhoppers on buds + flower chains.
• Spray when there are signs — don't wait for the flowers to fall.

When the flowers bloom

• Do not spray while flowers are blooming — kills pollinating insects (honey bees, flies).
• Spray before flowers bloom or after flowers set young fruit.
• If aphids break out strongly when flowers are blooming — accept partial damage, prioritize protecting pollinators.

After setting young fruit

• Continue to monitor — leafhoppers can attack young leaves + fruit stems.
• Spray the correct target if detected.

Spraying

Effective active ingredients

Group of growth regulators:

• *Buprofezin* — kills leafhoppers, does little harm to natural enemies.
• *Pyriproxyfen* — similar.

Group of plant absorbents:

• *Imidacloprid* (neonicotinoid) — fast effective, risk of resistance.
• *Acetamiprid* (neonicotinoid with different mechanism) — alternately.
• *Thiamethoxam* — kills both adults and larvae.

Coordination:

• *Buprofezin + Imidacloprid* — highly effective + low resistance.
• *Spirotetramat* — penetrates into plants, kills leafhoppers in difficult-to-spray locations.

Spray technique

• Spray in the cool afternoon from 16-18 hours.
• Spray evenly throughout the canopy — especially flower chains and buds.
• The pressure is strong enough — the hoppers cling tightly to the stem.
• Water volume 600-1,000 liters per hectare.
• Repeat after 7-10 days, change active ingredients.

Avoid spraying during the sensitive period

• When flowers are 50-70 percent blooming: kill pollinating insects.
• Early morning with dew + active bees: harmful to bees.
• 4-6 hours before heavy rain: treatment washes away.

Biological measures

Protect natural enemies

Natural enemies of mango flower hoppers:

• Ladybug: eats young leafhoppers.
• Wolf spider: hunts leafhoppers in the canopy.
• Parasite wasp: lays eggs on aphids.

Protect by:

• Limit broad-spectrum spraying outside the necessary period.
• Plant trees on the edge of the orchard with small flowers.
• Intercropping plants to attract natural enemies.

Ant control

Ants protect leafhoppers from natural enemies + move young leafhoppers:

• Whitewash the base of the stem.
• Place ant-proof ring around the base.
• Destroy the ant nest in the orchard.

Coordinate with orchard management

Mango leafhopper is related to many factors:

• High nitrogen fertilization: the tree produces many young shoots — food for leafhoppers. Reduce nitrogen before flowering season.
• Thick canopy: blocks light, high humidity — strong leafhopper growth. Prune branches for ventilation.
• Unhygienic orchard: dense grass is where leafhoppers reside. Clear grass before flowering season.

When the leafhoppers had a strong outbreak

If the orchard has widespread flower fall:

Step 1: immediately spray the highest dose allowed on the label.

Step 2: combine 2 active ingredients with different mechanisms — *Buprofezin + Imidacloprid*.

Step 3: spray the entire orchard, including plants that have not yet seen their flowers fall.

Step 4: 7 days later, check. If there are still many hoppers, repeat with another active ingredient.

Step 5: organic fertilizer + potassium to restore plants if many flowers are lost.

Note: losing flowers this time is acceptable. The plant will flower next in 1-2 months if well cared for.

Monitor every 5-7 days during the risk period

• [ ] Counting hoppers on a string of flowers.
• [ ] Observe the buds — are there any signs of yellowing or wilting?
• [ ] Flowers falling in the canopy — rate.
• [ ] Number of natural enemies — ladybugs, spiders in the orchard.

Common mistakes

Spraying when flowers are in full bloom: kills pollinating bees, reduces fruit setting rate.

Skip counting hoppers, spray according to schedule: not timely when hoppers flare up, wasteful when hoppers are low.

Using the same active ingredient multiple times: hoppers develop resistance quickly.

High nitrogen fertilizer before flowering: creates many young buds — food for leafhoppers.

Spray lightly, do not cover the flower chain: leafhoppers cling tightly to the stem — must spray with enough pressure.

Take notes

• Butterfly outbreak — date, severity.
• Active ingredient sprayed + date.
• Proportion of flowers falling due to leafhoppers.
• Fruit setting rate at the end of the season compared to the previous year.

References

• *Mango planthopper prevention* — Plant Protection Department, 2022.
• *Integrated pest management on mango* — Southern Fruit Institute, 2023.

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• Prevention of yellow fruit flies in mangoes
• Mango stem borer prevention
• Instructions for caring for mango trees during business period
• Tracking agricultural product prices