Melon fly

Bactrocera cucurbitae

1. Identification

• Common name: Melon fly
• Scientific name: Bactrocera cucurbitae Coquillett
• Order: Diptera
• Family: Tephritidae

2. Pest description

• Adults 5–7 mm, yellowish-brown body with dark markings.
• Transparent wings with subtle patterns.
• White, legless larvae develop in the fruit pulp.
• Brown pupae, formed in the soil.
• Eggs laid beneath the epidermis of young or ripe fruits.

3. Main hosts

• Cucurbits: melon, watermelon, cucumber, squash, courgette/zucchini.
• May attack other thin-skinned fruit species.
• Preference for tender and ripening fruits.

4. Symptoms and damage

• Small punctures on the fruit epidermis.
• Softening and discoloration of the pulp.
• Presence of larval galleries.
• Premature fruit drop.
• High economic losses in cucurbits.
• Facilitation of secondary infections by fungi and bacteria.

5. Biological cycle

• Several generations per year in warm climates.
• Adults active for much of the year in tropical and subtropical regions.
• Oviposition in young or ripe fruits.
• Larvae develop in 5–10 days.
• Pupation in the soil, where they remain 1–3 weeks.
• Cycle accelerated by high temperatures and high fruit availability.

6. Monitoring

• McPhail-type traps with food attractants.
• Yellow chromotropic traps.
• Specific attractants (e.g. cue-lure) for males.
• Weekly counting of catches.
• Fruit sampling for larval detection.
• Continuous monitoring throughout the cucurbit cycle.

7. Management measures

• Cultural: collection and destruction of fallen fruits; removal of remaining fruits after harvest; rigorous field sanitation; vegetation management to reduce shelter sites.
• Biological: use of natural parasitoids; application of entomopathogens to the soil; conservation of natural enemies.
• Integrated protection: continuous monitoring; bait treatments during critical periods; mass trapping; attract-and-kill strategies; judicious application of authorized insecticides; integration of cultural practices to reduce sources of infestation.

Bibliographic references

• EPPO Global Database – Bactrocera cucurbitae.
• CABI Invasive Species Compendium – Bactrocera cucurbitae.
• Ekesi, S. et al. (2006). Fruit fly management in tropical horticulture.
• Vargas, R. I. et al. (2015). Biology and control of melon fly.