Secrets Of Nature - War In The Trees (1931)

British Instructional Films Ltd production. Moving landscape shot. River with mountains either side. Pine tree forests. C/U of a woodwasp boring a hole in a tree trunk. She lays her eggs in the hole. C/U of a grub eating away at the tree. Grub boring through tree. Tunnels it makes ruin the timber. The grub turns into a pupa. C/U of pupae. Turns into a woodwasp, discarding its pupa skin in the tunnel behind it as it crawls out. We see the woodwasps emerging from the tree. C/U of the holes made in the surface of the wood. British scientists study the woodwasps. C/U of microscope. Scientist looking through. Parasite which destroys the woodwasp is bred in British laboratories then sent around the Empire. Parasite - a rhyssa - is packed in moss then liberated in trees. C/U of the parasite crawling over tree bark. The parasite can tell where the wood wasp grub is inside the tree. We see the parasite drill down into the tree. It lays an egg on the pupa after injecting it with anaesthetic to