In that case, the syringe is pretty handy to have. I got this variety pack from Amazon < link > so I could try different sizes, and the 1ml (smallest one) ended up working the best for me to load the B-coil.

Printer cartridge refill syringes. They make different gauges. I bought mine on Amazon.

Edit: this is the kit I have for injecting BT in my squash plants.

Edit 2: I’d also highly recommend using a pen knife to remove the larvae from the stem until you can get your hands on the syringes. I kick compost over the cuts to keep them moist.