they are too flakey and easily distracted - especially if the get the whiff of another matis, plus they too get preyed upon by birds(except hummingbirds) and other mantis eaters. lady bugs are the only way to go and they are loyal - they usually hang around until all the aphids are gone, then leave you a present of future generations under a few leaves.
are lady bugs convenient in pots? and where can i find some?
The last time I ordered lady bugs to put into the garden the shipment came with a sheet of paper with tips on how to get them to hang around and possibly establish a colony within the garden. One was to release them when it starts getting dark and the other was to mix 50% cola and 50% water and spray the lady bugs as they run around after putting them on the plants. As the paper stated it would not harm the lady bugs but would cause the wings to stick for a few days to reduce the chance of them flying away and hopefully would lay eggs within that time. I haven't tried it myself but I will with the next order.
-J
I have used both mantids (last season) and ladybugs (this season) and the ladybugs win hands down. The mantids will only eat aphids for the first 2 weeks of their lifecycle, because they eventually get too big and need to eat larger prey. Also, the mantids will eat each other at every stage of their life cycle so their numbers constantly decrease. Also they only breed once per year. Ladybugs will eat aphids at any stage and reproduce quickly making them much more effective aphid killers. Now if I could find something to eat the ants that farm the aphids that also wont eat the ladybugs I would be set.