Praying mantid (mantis) egg case from reader.  Q. I would like to know what this was on my Royal Blenheim apricot tree in my backyard in North Las Vegas. It appeared to be hard and had circular markings on the part attached to the tree as thought it was an egg casing. I removed it and hopefully it was not a helpful insect. You may use the picture as you wish. A. It looks like a mantid egg case to me. Please be careful. These are good guys and in the future leave the egg cases where they are or move them to a location where they will find lots of food and help you beat the bad guys. Praying mantis (mantid) released on to sweet acacia to battle cicadas.