Lighting for Grafting

Light sources for grafting, such as head torches, adjustable desk lamps, magnifier lamps and hand torches, are the lighting tools that make a day-old larva visible at the bottom of a comb cell during grafting. Good light lets you pick a larva of the right age and lift it without damage, so it directly affects acceptance and quality in queen rearing and royal jelly production. The light should be bright, shadow-free, easy on the eyes and, above all, give off no heat.

Why is light so important in grafting?

The larva sought for grafting is newly hatched, less than 24 hours old and only slightly larger than a pinhead. It lies at the bottom of the comb cell in a shiny drop of jelly. Because the cell is deep and narrow, its bottom is often in shadow; in dark combs that have reared brood, picking out the larva with the naked eye is especially difficult.

In poor light two mistakes are made: either an older larva, which is easier to see, is chosen, or the larva is damaged while being groped for blindly with the tool tip. Both lower queen quality and royal jelly yield. Queen breeders agree that the most useful aid in grafting is strong, correctly directed light.

Which light sources are used for grafting?

Head torch

The most common and most practical solution. Because the light comes from the same direction as your line of sight, it reaches the bottom of the cell without shadow and leaves both hands free. It can also be used for grafting in the field, beside the apiary. Models with stepped brightness and a choice of narrow and wide beams are preferred.

Adjustable-arm desk lamp

Suitable for those who want a fixed set-up in an enclosed grafting room. The lamp is positioned above the comb and slightly behind you; your hand and tool must not cast a shadow in front of the light.

Magnifier lamp

Lamps with a ring of LEDs around a magnifying lens. They provide light and magnification together; very useful for people with near-vision problems and for long sessions. The working distance between lens and comb must be enough for you to use the tool tip comfortably.

Hand torch

Useful in the field for small jobs, in mating nucs or for looking at a detail inside the hive. Because one hand has to hold the torch, it is only used for grafting when working with a helper or when the torch is fixed in place.

Daylight

A bright but shaded spot gives indirect daylight and can be enough for most beekeepers. Direct sun, however, must never be used: it dries the larva within minutes, heats the comb and dazzles.

What should you look for when choosing a light source?

Bees do not perceive red light well, so red light disturbs them less at the hive. But since the grafting comb is worked with the bees brushed off, this advantage is irrelevant; red light makes the larva harder to distinguish. White light is used for grafting.

How do you position the light? Step by step

1. Prepare the space: Choose a cool, shaded, wind-free or enclosed place. If the ambient light is slightly dim and the working light strong, the larva stands out more.
2. Tilt the comb: Hold the comb at a slight angle or place it on a grafting stand so that the bottoms of the cells face the light and your line of sight.
3. Bring the light into your line of sight: The light should come from the same direction as your eyes or just above them. Light from the side leaves a shadow on the cell wall.
4. Adjust the brightness: If there is a dazzling glare off the drop of jelly, reduce the brightness or change the angle slightly.
5. Check the heat: Hold your hand under the lamp; if you feel warmth, the lamp is either too close or unsuitable.
6. Take breaks: Rest your eyes during long sessions; with tired eyes you tend to pick older larvae.

How do you recognise a larva of the right age in the light?

• Suitable larva: A thin, crescent-shaped larva floating in a generous, shiny pool of jelly at the bottom of the cell, covering only a small part of the cell floor.
• Older larva: A larva that has closed into a full "C", reaches the edges of the cell and has less jelly beneath it. In good light the difference is obvious at once.
• Egg: A thin, white, rod-shaped object standing upright or lying at the bottom of the cell; it is not grafted.

Cleaning and care

• Keep the lamp body and lens clean, free of jelly and wax smears.
• A head torch strap should be washable; sweat and propolis get onto it.
• Test rechargeable lamps before the season; replace the battery if its life has shortened.
• In a humid grafting room, keep lamps away from water and feeders.

Common mistakes

• Grafting in direct sun: The larva dries out, the comb heats up, your eyes are dazzled.
• A lamp that gives off heat: An old-style bulb at close range dries the larva.
• Lighting from the side: The bottom of the cell stays in shadow and older larvae get chosen.
• Having no spare light: A lamp that dies mid-session costs you the larvae left waiting in the open.