Every serious Parosphromenus breeder should have four cultures of food:
– Moina
– Grindal
– “Micro” (worms)
– vinegar eels
– and Artemia (naupliae)
But: The last three are rather small. They are good for growing small young fish, and they are taken readily by adults, too, but they are a little too small for them as a sufficient base for their diet. (Of course, raising Artemia is possible, and adults love such bigger ones very much because they are similar to those young stadiums of shrimps that they are accustomed to in their home ranges. But it makes things still more inconveniant and troublesome; so only a few people do that).
Vinegar eels have two big advantages to the similar looking micro worms: they stay alive much longer in the fish tank than those. This is a big advantage for all new Paro friends who have not yet learned the art of adapted feeding: feed more often but each time only very small amounts of food because of the water quality. When you have learned that lesson you will love vinegar eels. The second advantage is that they will live for hours and longer in all parts of the aquarium, whereas Micro sinks down to the gravel and gets lost there and decay. (One reason for breeders to omit gravel altogether and to dislike too big tanks for Paros).
Nevertheless, with these cultures you are independent from the seasons, and with Moina and Artemia you will be even successful in getting your females ripe for egg-laying. (You will not be successful in this with the other alone, or, with Dapnia. So you don’t need a culture of Daphnia).
But: In the warmer season you have an easy to harvest source of food which is the best you can offer: mosquito larvae. You can harvest them in big quantities out of small containers with a bit stinky water in the garden, in all sizes, for young and for adult Paros. If you have ever seen an adult Paro chasing for such a larvae you know for all times that Artemia naupliae are are good, but not its favourite prey.
There is no risk to catch dragonfly larvae. They need clear and clean water without smell, quite the contrary to what mosquitos prefer. And they live at the bottom or at plants. If you want to omit the last risk that some could hide in the nettles that Bernd recommended for producing that stinky milieu, take the nettles out when they have done their duties. One can rule out the possibility that afterwards any drangonfly will lay eggs in that container. Their needs are completely different. Nobody should neglect the advantages of mosquito larvae. You get your females ripe within two weeks.
Of course, there are other good food items only to be caught in the open nature: Cyclops for instance, Bernd favourite food, or what we call “glassworms” (factually larvae of non-stinging midges). They are wonderful food but not as easy to be cultured in your garden or on your balcony. You can find them in bigger ponds and small lakes only. And there you must look afterwards; a dragonfly larvae could have been harvested. too. But the risk is low. The bad experiences told her are of quite different source: exotic dragonfly larvae imported be the trade with aquarium plants. You can minimize that risk by nou using imported plants from the trade or using only items that you have scrutinized closely for dragonfly larvae. They are big enough to be found easily.