4 common problems with pine bonsai in spring. What to look for?

How do you handle needle fungal infection on pine? Why are there caterpillars in my pine bonsai? What is eating the needles on my Pinus sylvestris?
Growing a pine bonsai comes with many challenges, and health can be one of them. In spring, it is important to regularly check for problems.
0:00 Pine Bonsai diseases: Check in spring
0:55 Pine needle aphids
2:10 Pine Whoolly aphids
3:05 Pine nest-building sawfly 'caterpillar' larvea
4:20 Yellow needles on pine bonsai: Needle Cast
6:41 A recap of 4 challenges to be identified in spring.