Using Milk as a Natural, Homemade Pesticide

Most people know the value of milk, but not many know that it is an essential ingredient in basic bug repellent. Learn how to put milk to use to keep your family bug-free.

  • Milk as a Pesticide
    Milk can be used as a natural pesticide.MM

  • Milk as a Pesticide

Spraying your plants with milk won't drive bugs away from your garden, but the dairy product can be used to culture Bacillus thuriugiensis Berliner, a well-known bacterial pesticide sold under such brand names as Dipel, Thuricide and Biotrol. The agent is quite effective in controlling — among a number of insect problems — infestations of loopers, which are those pesky little worms (they're actually moth larvae) that attack broccoli, cabbage, cauliflower and other members of the cole family. Once eaten, the bacteria paralyze the larvae's intestinal tracts and bring about their death in two to four days.
Before you spray your garden with thuringiensis, though, be aware that this bacterial-warfare weapon is fatal to the caterpillars of all Lepidoptera (an order of insects that includes many lovely, and relatively harmless, moths and butterflies) . . . so please don't employ the remedy in cases where simply handpicking the loopers off your plants will do the job. (That rule, of course, applies to the use of any pesticide, natural or otherwise!)

Using Milk as a Pesticide

If the little green caterpillars get completely out of control, you can go to the store and buy some commercially prepared Bacillus thuringiensis (BT) and use the product in conjunction with the pests themselves to brew your own supply from that point on! The basic procedure for doing so was mologist at Louisiana State University's Cooperative Extension Service in Baton Rouge. Dr. Pollet decided that because milk is a good medium for bacterial culture (a fact that not only causes the liquid — especially when unrefrigerated — to spoil, but allows us to harvest such by-products as cheese, yogurt, and kefir), and since Dipel, Thuricide and Biotrol are all bacterial pesticides, it should be possible to use milk to extend the bacteria's useful lives.

According to a report on Dr. Pollet's work, the process goes like this: The pesticide is sprayed on the plants, where it's eaten by the loopers. Then the tiny parasites develop inside the caterpillars' bodies and kill their hosts. When the infected larvae are gathered before the bacteria in them die, and are blended into milk (an effective culture for the microorganisms), the bacteria strain will stay alive and can be used again to kill other loopers.

Experimenting With Natural Pesticides

After reading this report, I decided to conduct my own experiment: I wanted to see for myself whether the system would work. (Besides, I always jump at any chance to save money, and commercial bacterial pesticides are expensive!)

All the project involved was gathering a palm full of infected loopers from a section of my cabbage patch that had been treated with some store-bought BT . . . mashing and blending them into one pint of warm milk (I thought a lukewarm environment would promote bacterial reproduction . . . then letting the looper or milk mixture stand for three day, sure the caterpillars you start with are still fresh. Once the larvae are dried up chances are the bacilli will no longer be active.) Next, I strained the brew through cheesecloth, diluted it with water to make a gallon of liquid sprayed the concoction on some looper-infested broccoli plants.

Two days later, it was evident that the larvae were no longer eating. By the next day they were becoming discolored, and soon thereafter they were very dead. My experiment was a success!

9/10/2017 10:17:28 PM

Could the culture be taken strait from the store bought product, mixed with milk, then allowed to ferment as a means of extending the product?

Subscribe Today - Pay Now & Save 64% Off the Cover Price

50 Years of Money-Saving Tips!

Mother Earth NewsAt MOTHER EARTH NEWS for 50 years and counting, we are dedicated to conserving our planet's natural resources while helping you conserve your financial resources. You'll find tips for slashing heating bills, growing fresh, natural produce at home, and more. That's why we want you to save money and trees by subscribing through our earth-friendly automatic renewal savings plan. By paying with a credit card, you save an additional $5 and get 6 issues of MOTHER EARTH NEWS for only $12.95 (USA only).

You may also use the Bill Me option and pay $17.95 for 6 issues.

Canadian Subscribers - Click Here
International Subscribers - Click Here
Canadian subscriptions: 1 year (includes postage & GST).

Facebook Pinterest Instagram YouTube Twitter flipboard

Free Product Information Classifieds Newsletters