Apply carbaryl, sold under the name Sevin, to the base of the plant, lightly covering the bottom of the stems when the plants begin to vine. Avoid contact with the flowers and leaves of the plant. Pyrethum and malathion spray or dust is also effective in killing squash borers.Click to see full answer. Then, how do you kill vine borers? Control and Prevention If you catch them VERY early, you can manually remove the squash vine borer. Or, if you spot entrance holes and “sawdust,” try inserting a wire and thread through the stem for some distance to kill the inside larvae. Sprinkle diatomaceous earth around the stalks when the squash vines are small. Similarly, will Sevin dust kill cucumber beetles? Sevin® Insect Killer Ready to Spray attaches to a common garden hose and mixes and measures as you spray. Cover all plant surfaces thoroughly to kill existing cucumber beetles and protect against new generations. Subsequently, question is, what insecticide kills squash vine borers? Common names of active ingredients effective against squash vine borers are: carbaryl, permethrin, bifenthrin and esfenvalerate. If your crop is still successfully attacked by borers, you can try to kill the borer inside the vine. Keep in mind that you may not be able to save the plant.How long does Sevin dust last on plants?There are many variables contributing as to how long Sevin Concentrate stays on a plant. Please review the product label. You will find a very helpful table listing the Pre Harvest Interval and number of applications allowed for each plant. You can reappy 14 days after initial application.