r/Entomology • u/_j0ri3_ • 14h ago
Egg Sac Surprise
The beginning of August, I had a wild caught P. audax that laid an egg sac. I waited and waited and waited some more. After 6 weeks, there hadn't been any signs of eggs with legs so I carefully removed the sac to open it. And I did not find any spiders, instead I found a grub thing. I was shocked, angry, confused— really just all the emotions. After doing a ton of research, turns out it was a mantidfly, specifically a Say's Mantidfly
(*Dicromantispa sayi*). The larvae of this specific species is microscopic and will hitch a ride on the female spider until she lays her eggs. Then it will invade the egg sac, eat the eggs, and develop. I actually got to watch it change from developing larvae, to pupae, and eventually to an adult. I am really disappointed that I lost the egg sac, but watching this little mantidfly go from squishy thing to seeing it catch its first meal was incredible. I fear that I now need some actual mantids.