How to keep casters alive

A caster is a maggot that has pupated, and its value depends entirely on being caught at the right point in that process. A fresh caster is dense, dark red-brown and SINKS, which is what makes it fish as a bottom bait and as loose feed that stays where it is put. As it ages it fills with gas and begins to FLOAT, and a floating caster is a different bait fished in a different way and is useless as feed on the bottom. So keeping casters is not keeping them alive; it is holding them still at a stage they are actively trying to leave.

A sealed, watertight container with as little air in it as possible, or a container of water. Casters are the one bait in this family where excluding air is correct rather than fatal, because oxygen is what allows development to continue. A bag pressed flat to expel air, or a tub filled to the lid with water and sealed, are the two standard approaches. Shallow layers again beat a deep mass, because a deep mass generates heat in the middle.

As cold as possible without freezing. Cold is the primary control on how fast a caster develops, and the difference between a bait fridge and a warm shed is the difference between casters that hold for days and casters that are floaters by the morning. The principle rather than a number: colder is slower, and a steady temperature produces a more predictable bait than a cold average with warm periods in it.

Deliberately excluded, which reverses the rule for every other bait in this family. Development from pupa towards the adult fly requires oxygen, so sealing casters in water or in an airtight bag arrests it. This is why casters are the only bait here where an airtight container is the recommendation rather than the classic mistake.

Nothing, or water. Casters need no bedding — they are sealed pupae rather than feeding larvae. Water is used precisely because it excludes air, and it has the useful side effect of separating floaters from sinkers immediately: the ones that rise are the ones that have gone too far. Some anglers keep them dry in a sealed bag, which works and makes the floater test a separate step.

Days rather than weeks, and it is entirely a function of temperature. Judge by the bait rather than the calendar: a caster that still sinks and is dark and firm is usable, and a batch that has begun floating in numbers has moved on. Casters cannot be held indefinitely in any conditions, because pupation is a one-way process being slowed rather than stopped.

In a cool box, sealed and full, and out of the sun. The journey is where most casters are lost, for the same reason as maggots: a warm car does days of development in an afternoon. Keeping them submerged during transport both excludes air and buffers the temperature, which is why the water method suits a long journey.

Casters are a commercially produced bait rather than one collected from a water, which removes the commonest transfer route but not the obligation. The container water is water, and water carries organisms: it must never be tipped into any watercourse and should be disposed of well away from one. Unused casters must not be released into a water, and any that reach the adult fly stage should be dealt with in domestic waste rather than emptied on the bank. Containers, tubs and riddles used at one water and then at another are a vector like any other equipment, and check, clean and dry applies to them.

A caster is a pupa — an insect part-way through metamorphosis — and proportionate care means not subjecting it to conditions that are simply pointless cruelty: no heating, no freezing and back, no crushing a mass while it is still developing. The realistic welfare position is that this is an invertebrate pupa produced commercially as bait, and the honest guidance is proportionate handling rather than an argument this platform is in a position to settle.

Unused casters keep for another session if they are still sinking, so the first answer is to take them home and keep them cold rather than to dispose of them at all. What must not happen is tipping them, or the water they are in, into the venue at the end of the day: that is the same introduction pathway as any other bait release. Anything genuinely finished goes into domestic waste, sealed, away from any watercourse.

Collecting, transporting, keeping and using live bait are regulated differently almost everywhere, and some of these baits may not be used at all in some waters. Restrictions commonly cover where and how much may be collected, whether live bait may be moved between waters, whether a species may be used as bait at all, and whether a licence or permit is required. FishingHQ does not state what any rule is or where it applies — check with the authority responsible for the water and the shore you intend to use before collecting or using live bait.