I wanted to re-use last years compost,it's all in pots & potato bags,previously used for potatoes then tomatoes/pepper/basil/petunia/geranium. So I was sifting through a bag & found lots of tiny,thin,red/brown pupa,the size of a grain of pilau rice,but I imagine could get bigger,it looks like cut worm? In which case re-using the compost would devastate roots of anything planted in it. I wanted to use it for carrots but can imagine whatever they are eating through the carrots? Any idea what to do? Boiling water or abandon it to the border edge?