16.3 Braula Fly Overview

Understanding the Braula Fly

The Braula fly (Braula coeca), often referred to as the bee louse, is a small, wingless insect that resides exclusively within honey bee colonies. Unlike true parasites that feed on bee tissue or blood, this insect is a commensal organism that relies on bees for shelter and transport. It does not present a severe biological threat to commercial or backyard beekeeping because it does not damage or feed upon any active stage of the honey bee life cycle. Instead, it is considered a minor pest that occasionally disrupts the visual appeal of honeycomb capping.

The lifecycle of this wingless fly begins when an adult female deposits eggs directly onto the inner surfaces of the hive, specifically targeting the wax capping over honey cells. These eggs require a period of two to seven days to hatch, depending closely on the internal temperature maintained by the cluster. Once hatched, the larvae excavate tunnels immediately beneath the delicate wax capping, consuming a mixture of wax grains and trapped pollen. After reaching maturity within these tunnels, the larvae transform into pupae and eventually emerge as adult insects to begin the cycle anew.

Identifying the Pest

For a beginner, the key point is to observe the physical characteristics of the insects moving across your adult bees. Adult braula flies are reddish-brown, roughly one and a half millimetres long, and completely lack functional wings. They possess six stout legs covered in gripping hairs, which function to keep them securely anchored to the thorax of worker bees and queens. They can easily be confused with destructive varroa mites at a quick glance, but their rapid scurrying movement and clear segmentation reveal them to be true insects rather than eight-legged arachnids.

In practice, this means checking the bodies of your queens and nurse bees during your regular hive examinations. Adult braula flies obtain their food through a process called kleptoparasitism, which involves crawling onto the mouthparts of a bee to steal a droplet of regurgitated honey or nectar. While individual worker bees suffer very little from this theft, a queen heavily burdened with multiple flies may experience minor disruptions to her laying schedule. Over time, you will begin to recognise their presence by watching for small, clustered figures riding atop the queen's back.

Assessing and Managing the Impact

For a beginner, the key point is to evaluate the appearance of your honey storage frames rather than panicking over adult fly counts. The primary impact of this insect is aesthetic, as larval tunnelling creates fine, intersecting white lines across the dark face of capped honeycomb. While this tunnelling action leaves the liquid honey perfectly safe for extraction and human consumption, it reduces the market value of pristine comb honey intended for direct sale. If you do not produce comb honey, the presence of a few braula flies requires no intervention or chemical treatment at all.

This naturally leads to simple, mechanical management strategies when fly populations happen to increase during peak honey production seasons. The standard practice of slicing away the wax capping with an uncapping knife prior to extraction reliably removes and destroys the larval stage of the insect. For beekeepers wanting to preserve unextracted comb honey, freezing the harvested frames at zero degrees Fahrenheit for a minimum of forty-eight hours kills all life stages cleanly. Through clean equipment management and regular harvesting schedules, you can easily ensure this uncommon visitor remains nothing more than a harmless curiosity.

Summary

The braula fly is a small, wingless insect that lives on adult honey bees and consumes food droplets directly from their mouthparts. Its larval stage constructs thin tunnels beneath the wax capping of honey cells, which can affect the visual presentation and marketability of specialty comb honey. Despite its status as a colony parasite, it does not inflict direct damage on bee brood or mature bees. Population management is easily achieved through mechanical methods, such as standard honey extraction procedures that slice away capping or by freezing harvested comb honey frames for forty-eight hours.

References

• Braula Fly – Bee Aware: https://beeaware.org.au/archive-pest/braula-fly/ (Examines life cycle, identifying features, larval tunnelling, and simple freezing controls).

• Beekeeping in the United States – USDA: https://books.google.com/books?id=1-Beekeeping-in-the-United-States (Section on adult bee lice distribution, food-stealing behaviour, and host impacts).