Known as the “floating insect” or simply “con vo,” this rare insect from the Red River is considered a unique culinary delicacy in Hanoi. Appearing only a few times each year, it is highly sought after despite its high price.

A rare and elusive delicacy

In the riverside areas of the Red River in Hanoi, locals have long cherished a peculiar insect known as "con vo" or "vo vo".

This unique insect, which thrives in the clay-rich riverbeds, undergoes a brief and fascinating life cycle, emerging from the muddy bottom just twice to shed its skin before laying eggs and dying.

The entire process from emergence to death takes about one hour. During its first rise to the surface, the insect sheds its initial exoskeleton and briefly hovers over the water for 15 minutes before shedding again.

The mature "con vo" then quickly takes flight, earning it the nickname "flying shrimp" or "heaven-sent delicacy".

Do Thanh, a longtime resident of Thanh Tri District, Hanoi, explains: "Con vo only surfaces for a few hours during the early morning, mostly between February and April. Experienced locals can predict the emergence based on changes in weather and water conditions, especially when it’s warm and humid, followed by rain."

Typically, the insects rise to the surface around 5 AM, blanketing the river in a white haze for 10 to 15 minutes. Their appearance is not uniform across the river but mainly concentrated in confluences and clay-rich areas where they build their nests.

A challenging catch

Harvesting these rare insects is no easy feat. Local fishermen must wake up early, monitor the weather, and prepare boats with large nets or funnel-shaped scoops to capture the insects as they surface.

"In recent years, as con vo has become a sought-after delicacy, people have started using motorboats and specialized nets to collect them faster," Thanh shares. "The entire process has to be quick because the insects can either disappear or become mushy if left too long in the water."

At the beginning of the season, a kilogram of con vo costs around $11-15, but as availability decreases, prices can soar to $20-25 per kilogram. Despite the cost, demand remains high among food enthusiasts in the capital.

A versatile ingredient

Once harvested, con vo must be processed immediately to preserve its freshness. The insects are often rinsed gently to remove any leftover exoskeletons before being dried and prepared for cooking.

According to Thanh Mai, owner of a street food restaurant in Hoang Mai District, con vo can be transformed into a variety of exotic dishes, including:

Vo salad

Vo patties

Stir-fried vo with water spinach

Vo hotpot with crab paste

Vo with catfish stew

Vo stir-fried with crispy prawn crackers

However, the most popular dish remains vo stir-fried with pork fat and lemon leaves. The crunchy texture of the insect, combined with the rich aroma of lemon leaves, creates a soft and creamy flavor that many diners claim is better than shrimp or crab.

"The dish is simple to prepare," Mai explains. "After cleaning, we stir-fry the insects with pork fat and add finely chopped lemon leaves. The result is a crispy, fragrant dish with a distinctly rich taste."

Preserving the taste of spring

Due to its short seasonal availability, many Hanoians buy several kilograms at a time, cleaning and freezing them to enjoy year-round. Despite its appeal, con vo is not for everyone, as some people may experience allergic reactions or digestive issues after eating.

Nguyen Van Tu, a local food lover, says: "It’s truly a unique culinary experience. The texture is soft, the flavor is rich, and the hint of lemon leaf makes it unforgettable. I’ve never tasted anything quite like it."

Experts caution those with sensitive stomachs or allergies to be mindful when trying this exotic dish. Nonetheless, con vo continues to fascinate both locals and adventurous tourists looking to sample Hanoi’s most unusual delicacy.