Hi Kitty-Lover. You're right, the beetles don't come from your plant. Japanese Beetles originate from the larvae(grubs) that actually feed on the roots of your lawn and turf. Their eggs are laid in the turf, where they hatch into the larvae, then to beetles, which then migrate to their favourite feeding spots.
Milky Spore is a naturally occurring bacterium (Bacillus popillae-Dutky). It is lethal to the white grubs of Japanese Beetles.
The adult beetle feeds on fruits, flowers, shrubs, garden plants and the foliage of some field crops. At the immature beetle stage, the grub enjoys feeding on the roots of grass and other vegetation to include stems of plants.
Turf treatments with MILKY SPORE puts in place an on-guard protective blanket in your lawn.
The grubs are considered the weakest link in the chain and the most vulnerable point to introduce an infection. Milky spores in the turf are swallowed by grubs during their feeding, starting the demise of healthy grubs. Milky Spore disease begins to cripple the grub, and within the next 7-21 days it will eventually die. As the grub decomposes, it releases billions of new spores.
Milky Spore is not harmful to beneficial insects, birds, bees, pets or man. The product is approved and registered with EPA, Milky Spore will not affect wells, ponds or streams.
Neem oil is used as a bio-pesticide for organic farming, as it repels a wide variety of pests including the beet armyworm, aphids, the cabbage worm, nematodes and the Japanese beetle. Neem Oil is non-toxic to mammals and birds as well as many beneficial insects such as honeybees and lady bugs. Neem oil also controls black spot, powdery mildew, anthracnose and rust (fungus).
Research shows that neem can impact nearly 200 species of insects.
Neem products work by intervening at several different stages of an insect's life. The pest may not die instantly but be incapacitated.
Insect Growth Inhibiting
Neem Oilworks on juvenile hormone. The insect larva feeds and as it grows, sheds its old skin and again starts growing. This shedding of old skin is the process known as moulting and is activated by an enzyme ecdysone. When the neem enters the body of larve, the ecdysone is suppressed, the larva fails to moult, remaining in the Iarva stage and ultimately dies. If the concentration of azadirachtin is not strong enough, the larva can enter the pupal stage but dies at this stage. If the concentration is still less, the Beetle emerging from the pupa is malformed, sterile and without any capacity to reproduce.
The best property of neem is as a feeding deterent. The Larva feels hungry and begins feeding on the leaf. When the leaf is treated with neem product, this produces something similar to a vomiting sensation in the insect. Because of this the insect will no longer feed on the neem treated surface. Its ability to swallow is also blocked.
Another way in which neem reduces pests is by not allowing the females to deposit eggs.
There are also other modes of action known such as:
-Mating as well as sexual communication is disrupted.
-Adults are sterilized.
-Larvae and adults are poisoned.
Use of neem products will not give immediate results like chemical insecticides. Some patience is required after application of neem products.
Effect of Neem on Different Insects
It is important to understand how neem products act on specific insects.
Orthoptera(Grasshoppers, Crickets, Katydids,etc.)
Neem acts as antifeedants. The insects refuse to feed on plants treated with neem for several days to several weeks.
Homoptera (Cicadas, Aphids,Leafhoppers, etc.)
These insects exhibit sensitivity to neem products to varying degrees. In leafhoppers and planthoppers neem product show considerable antifeedant and growth regulating effects.
Neem products are very effective in controlling thrips larve which are found in the soil. Their effect is more moderate when used on the developed thrips found on plants.
Coleptera (Beetles, Weevils)
Larvae of all kinds of beetles refuse to feed on plants treated with neem. Their growth is retarded and some soft skinned ones are killed on contact.
Neem products act as growth deterrents on the larvae of most lepidopterous pests. It also acts as antifeedant.
Insects like flies, face flies, bot flies, houseflies and horn flies are affected by neem oil.
Hymenoptera(Bees, Wasps, Sawflies, Ants, etc.)
Bugs like rice bugs and vegetable bugs are affected by neem with antifeedant and growth deterrent properties.
Neem kills young cockroaches. Adults are inhibited from laying their eggs. Baits which are injected with neem seed extract retarded growth of Oriental, Brown banded and German cockroaches.
Neem oil is also effective against Brown Planthopper.
Neem is used very well against leaf miners. When neem is added to the soil through the roots and reach the leaves it starts acting on leaf miners feasting on leaves. The moulting hormones of leaf miners trap them in their own juvenile skins.
Larvae of mosquitoes are affected by neem. Crushed neem seeds thrown into pools prevents mosquitoes from breeding.
Spraying a dilute neem solution under fruit trees controls these pests.
Neem affect several types of nematodes providing 100% mortality of nematodes. Hatching from egg masses of nematodes was also reduced.
Neem also kills snails.
Beside the insecticidal and nematicidal properly, neem is also a control of plant disease.
Neem also possesses antifungal activity. It prevents powdery mildew disease when sprayed before the outbreak.Neem leaf extracts do not kill fungi. When treated with neem leaf extracts the fungus does not reproduce.
Effect on Non - Target Species
One of the problems with the use of chemical pesticides has been their impact on "non-target" species. Often they have proved harmful to various other species in the ecosystem that could be beneficial.
Neem when incorporated into potting soil containing earthworms increased the earthworm population by 25%.
Effect on other Beneficial Insects
Neem is remarkably benign to spiders and other insects like bees that pollinate crops and trees, ladybug beetles that eat aphids and wasps which are parasites on various crop pests. Neem has to be ingested to be effective. Insects which feed on plant tissues, are easily destroyed. However natural enemies like spiders feed on other insects and bees feed on nectar. They rarely come in contact with any significant concentration of neem.
I think that about covers it for you. If you have any further questions, feel free to stop in!