Buy a pint of maggots, leave them in a bait box for a few days and they’ll start to pupate – to change to the next stage before becoming adult flies. At this stage the insects are known as ‘chrysalids’ or ‘pupae’. Anglers call them ‘casters’. Casters are excellent for quality roach, big bream, chub, barbel, tench, carp and even big perch, and they often out-fish maggots.
A fresh caster from a white maggot is creamy coloured but gradually darkens through pale orange, orange-brown, dark brown and finally black before hatching into a fly. During this change the shell becomes crisper and the caster less dense. This means that a freshly turned caster is a soft sinker while one that is about halfway through its development is a crunchy floater. Both sinkers and floaters are useful.
Turning your own
Good quality casters should be fresh, big.and contain no skins, dead maggots or rubbish. If you buy them the quality varies from one shop to another, but it is generally pretty poor compared to casters turned at home. It isn’t difficult to turn your own; all it takes is a bit of planning. Time and temperature If you want some casters for a match or pleasure session at the weekend, when should you buy the maggots?
Take temperature into account: the warmer it is, the quicker they turn. In summer it is easier – you can get a good yield by keeping maggots in a garden shed – but in winter it is more difficult and you may need to bring them into a heated room.
As a rough guide, in summer buy the maggots about five or six days in advance. In winter allow at least eight to ten days. But bear in mind the stage the maggots are at when you get them. The times above are for fresh maggots – ones which still have the black feed spot clearly visible. Sometimes maggots are sold at a more advanced stage. In this condition they start to turn sooner and some tackle shops sell them as ‘caster maggots’. These can be useful if you need casters in a hurry. Otherwise, get fresh bait – it gives you more control over quality.
Quality and quantity It is impossible to get big casters from small maggots. Use the biggest and best maggots you can find. Remember that you never achieve a 100% yield – two pints of casters from three pints of maggots is typical. The yield is higher when maggots are turned very slowly -ideally in a fridge. Unless you need casters urgently and have to turn them very quickly you should not try to force them as this produces inferior casters. Sawdust Riddle the maggots and put them in some fine, slightly dampened sawdust in a shallow tray. Under no circumstances allow them to ‘sweat’. If they do then the result is very small, crinkly casters which are next to useless. It is better to keep the maggots in a lid-less container on a stone floor. Provided they don’t get wet or hot they won’t escape. If they do get wet they’ll crawl up the sides of the container and on to the floor.
Riddling Once the maggots turn you need to separate the casters from the maggots. Do this by tipping maggots and casters on to a riddle with holes large enough for the maggots to force themselves through. The casters are left behind on the riddle. It is important to use the right gauge of mesh. If it is too fine the maggots have difficulty getting through, too coarse and the casters drop through with the maggots.
In the early stages riddle them once a day, but as the number of casters increases riddle them two or three times a day. Keeping them cool When the first few batches of casters come off, put them into a plastic bag, leaving plenty of air. Lightly knot it and put it in a very cool place. At this stage the casters are sinkers. By keeping them cool you retard their development and stop them from becoming floaters. A fridge is ideal for this and, if you are to produce a pint or more of casters, or if the weather is hot, it is essential.
Don’t put a lot of casters into an air-tight bag because even in the fridge casters still ‘breathe’. Once they have used up all the air they develop ‘burn’ marks — ugly brown stripes – and may die.
Washing When you are ready to use the casters take them out of the bag, put them in a sieve and swill them under the cold tap. You can sort out the floaters by putting the casters into a bowl of water and skimming the floaters off. When fished on the hook floaters help to cancel out the weight of the hook and make the bait behave more naturally, so they are worth saving.
In hot weather sinkers turn to floaters within a couple of hours if they are exposed to the full force of the sun. You can prevent this by keeping them in a little water.