Organic Grubworm Control?

Question:

Grubworms have taken over my lawn but I have no extra money to purchase Milky Spore. I am also all organic for 15 years now. How is it made? It sounds like a bacteria colony, is it? Is is made from milk? How long would it take to produce some should one get the formula?

Why is it the best, perhaps only, natural treatment for grubworms? I'm familiar with the "life cycle" of the Japanese Beetle from which it comes, but since I live on a corner under a bright street light, it draws them to all our homes. Others may be able and not want to be organic but I was almost killed SEVERAL times, accidentally, from pesticides, twice in my yard, and once in a garage sale accident.

Perhaps you can understand why it is especially important to stay organic? I firmly believe that when the yard is in balance, such pests can't get such a grip. However, as you remind us, this last dry spell/heat wave, water restriction really did damage to that balance. My beds are all Zeriscaped, but the lawn remains vulnerable. I am considering expanding into the lawn around the house/shrubs, beneath the trees, with a natural zeriscaped walking path and free organic mulch from the city. One home has the entire lawn area in grasses/ plantings, but it seems out of control.

I have plenty of Lirope Grass/Asian Jasmine to do the same, but I don't like it. I love a more natural, not messy, look and environment. Can you help?

Also, would the grubs be attracted by any particular plant other than grass and light? Is there any research on it?

Hardiness Zone: 8a

Lynda from TX

Answer

Lynda,

You're covering two different topics here, so let's take them one at a time.

Mily Spore

Regarding milky spore, you asked:

1. How is it made? It sounds like a bacteria colony, is it? Milky disease spores consist of 2 types of bacteria (Bacillus popilliae and B.lentimorbus) that are combined as a microbial insecticide product called milky disease or mild spore disease. Beetle grubs eat spores that have been sprayed on lawns while feeding on grass roots. The bacteria kill grubs of Japanese beetles and several related beetles but are harmless to other organisms.
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2. Is it made from milk? The "milk" in milky spore actually comes from the fact that the bodies of the grubs infected with the bacteria become filled with an opaque, milky white liquid that remains in the soil after the grubs die.

3. How long would it take to produce some should one get the formula? This formula is produced commercially. Once the grubs are infected, they continue to inoculate the soil as they travel until they die. The spores are usually carried over from year to year by new generations of beetles. Northern zones may need repeated applications, but for southern gardens, usually only one application is necessary. Once established, milky spore can help control grub populations for a decade or more.

4. Why is it the best, perhaps only, natural treatment for grubworms? There are many ways to naturally control Japanese beetle populations. Among natural controls, Milky disease spores are just one method of biological control and not necessarily any better or any worse than other "natural" methods. The best way to keep things naturally in balance is to use a combination of cultural and biological methods.
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   One cultural technique for controlling beetles is to hand pick them as adults or shake them onto drop cloths and then to dispose of them in a pail of soapy water. This is best done early in the morning when the beetles are least active. Two other biological means of control include attracting native species of parasitic wasps and flies or releasing parasitic nematodes into the soil.

5. Also, would the grubs be attracted by any particular plant other than grass and light? Larvae will feed on whatever is available. They tend to prefer the roots of lawn grasses, but they will also feed on the roots of other garden plants.

6. Is there any research on it? Because this beetle is so common and also damages some agricultural crops commercially, scientists continue to research their habits and life cycles in order to find better ways to control their populations. Several studies have suggested that the adult beetles are most strongly attracted to light-colored flowers and those with stronger fragrances.
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   Certain cultivars also seem to show more resistance to attacks. Search for Japanese beetles on http://scholar.google.com for current research studies. Here is an interesting link discussing some research being done by the University of Kentucky: http://cipm.ncsu.edu/ent/Southern_Region/99Programs/kentucky.html

Walking Path

Regarding a walking path - You said: I am considering expanding into the lawn around the house/shrubs, beneath the trees, with a natural zeriscaped walking path and free organic mulch from the city. One home has the entire lawn area in grasses/ plantings, but it seems out of control.

I have plenty of Lirope Grass/Asian Jasmine to do the same, but I don't like it. I love a more natural, not messy, look and environment. Can you help?

I think Xeriscape landscaping is a wonderful idea for your garden-especially in Texas, where demands on fresh water have become a critical issue. If you're looking for low-growing ground covers and plantings that will give a more tidy, yet natural looking path, you might consider vinca, English ivy or little bunny dwarf grass. Texas A & M has a wonderful site on Xeriscape landscaping that lists of all types of plants, including ground covers, grasses and perennials and what part of Texas they are best adapted to.

Pictures of native Texas wildflowers can be found here:
http://hotx.com/wildflowers/

You can also find ideas for drought resistant plants by zone here:
http://classygroundcovers.com/

Hope this information helps!

Ellen