Article 1 – Japanese Beetles

Description: 

Japanese beetles measure 7/16-inch long and have copper-brown wing coverings. In June, adults emerge from the earth and begin eating on plants. Beginning in late June, activity is at its peak for 4 to 6 weeks. They often feed in groups, beginning at the top of a plant and working their way down. A single beetle does not consume much food; it is the collective feeding of numerous insects that causes serious harm. Japanese beetles can entirely consume rose petals and leaves with fine veins. This results in a lace-like or skeletonized look for the leaf.

Japanese beetle Life Cycle:

After the adults emerge from the earth and mate, the egg-laying process begins. Females leave plants in the afternoon, dig 2 to 3 inches into the earth in a suitable place, and deposit 40 to 60 eggs during their lifetime. The growing beetles spend the following ten months as white grubs in the soil. The grubs grow fast and are nearly full-grown by late August. Grubs eat on the roots of turfgrasses and vegetable seedlings, preferring high-quality turf in backyards, golf courses, parks, and cemeteries. They can, however, thrive in virtually any soil that plants can live in.

How do Japanese beetles attack and Damage the plants? 

Adult Japanese beetles do not harm turf but instead feast on the leaves and blooms of over 350 different types of fruits, vegetables, ornamentals, field and fodder crops, and weeds. The ideal hosts include Norway and Japanese maple, birch, crab-apple, purple-leaf plum, rose, mountain ash, linden, grapes, and basil. Adults feed on the top surfaces of most plant leaves, eliminating soft tissues between the veins and leaving a lace-like skeleton in their wake. They frequently eat in the higher canopy first. Trees that have sustained significant damage become brown and shed their leaves. Japanese beetle grubs feed on the roots of turf and ornamentals below ground. They impair a plant’s capacity to absorb adequate water and nutrients to endure hot, dry conditions. Initial grub injury in turf causes isolated areas of pale, withering grass, similar to drought stress damage. Damaged areas quickly grow and combine as grubs mature and feed, to the point where the grass is not so well and maybe rolled back like a carpet. Animals (e.g., raccoons, skunks, crows, etc.) digging through the turf to feed on the grubs can cause further harm.

How can we remove beetles from plants?

Physical removal:

Physically removing insects can be a feasible and successful management strategy for smaller landscapes or a few plants, especially when just a few Japanese beetles are present. To destroy Japanese beetles, pick them up or knock them into a pail of soapy water. Remember that beetle-damaged leaves exude compounds into the air that attract additional beetles. You may decrease the number of new beetles attracted to your plants by physically removing them. When beetles are cold and passive, the ideal time to remove them is in the evening or early morning.

Physical barriers and traps:

 To prevent beetle damage, do not cover blooms that require pollination with thin netting. Instead, handpick insects until the plant has finished flowering and begins to bear fruit before covering it. Using a trap in a home garden to protect plants against Japanese beetles is ineffective. The traps attract insects by utilizing a synthetic female sex pheromone and a chemical mixture. This generally causes greater harm to neighbor gardens than would have occurred if no traps were installed.

Chemical removal:

If physical removal and barriers are impractical or to enhance non-chemical management, you can apply an insecticide to preserve valuable plants. Keep in mind that insecticides might endanger beneficial insects such as pollinators and fish, birds, and mammals. Many pesticides are approved for use on adult Japanese beetles. Pyrethroid products such as cyfluthrin lambda-cyhalothrin (Scimitar, Spectracide Triazicide), esfenvalerate (Ortho Bug-B-Gon Garden & Landscape Insect Killer), permethrin (Spectracide Bug Stop Multi-Purpose Insect Control focus and other brands) usually provide 2-3 weeks coverage of plant foliage while carbaryl affords 1-2 weeks protection. Insecticidal soap, orange peel extracts, garlic, hot pepper, or orange peel extracts, and companion planting, on the other hand, are typically useless. Check to see if the pesticide is approved for use on the plant or crop you intend to spray. If it is a food crop, take note of the minimum number of days that must elapse between the last application date and the harvest date. Follow the label’s instructions and avoid spraying when it’s windy or when bees are foraging.

Article 2 – Japanese Beetle: Appearance, Territory, Damage and Life Cycle

Latin Name: Popillia Japonica

Appearance: Popillia japonica Newman, sometimes known as the Japanese beetle, is a common and damaging pest of grass, landscape, and ornamental plants in the United States. It is also a pest of various fruit, vegetable, and field crops, with a host range of over 300 plant species. Japanese beetles eat on foliage, flowers, and fruits as adults. Typically, leaves are skeletonized or left with merely a tough network of veins. The larvae, sometimes known as white grubs, feed largely on grass roots, frequently ruining turf in lawns, parks, and golf courses. The Japanese beetle is currently the most common pest of turfgrass, costing the turf and ornamental industries roughly $450 million each year in control alone.

Hosts Plants: More than 300 plant species have been identified as hosts for the Japanese beetle. Small fruits, tree fruits, truck and garden vegetables, decorative shrubs, vines, and trees are all hosts. Feeding experiments reveal a host range of over 300 plants from 79 plant groups. Grape, apple, cherry, peach, plum, rose, and maize are among the chosen plants.

Territory: The Japanese beetle is a species of the white grub complex, whose larvae feed on the roots of turfgrasses common in eastern North American lawns, golf courses, and athletic fields.

Damage Insect Cause: In the northern United States, damage caused by larvae can begin in mid-to-late August and can last into the fall if not handled appropriately. Damage resembles drought and is frequently aggravated by drying circumstances. Damaged regions may spread further as the larvae continue to develop and eat throughout the fall. Large patches of turf can be readily hauled out in severe infestations because the connective roots and tissue are damaged. This can cause uneven footing and injuries on sports turf, since the grass is prone to sliding and giving way.

Aside from larval harm, adults of the Japanese beetle graze on the leaves of over 250 different ornamental plants. This damage can potentially be substantial, causing irreversible harm to some tiny trees that cannot withstand defoliation.

Life History and Habits: Each year, Japanese beetles generate one generation. In June and early July, adults emerge from the earth, mate, and deposit eggs. In July, the eggs hatch, and the small larvae, known as white grubs, begin feeding on the turfgrass roots. When the temperature drops in the fall, the grubs dig down to a depth of 8 inches and spend the winter there. In the spring, when temperatures increase, the grubs resume eating in the rootzone. Following a pupation phase in May, the adults emerge and begin the process all over again for a new generation.