Photograph by Jim Kalisch, University of Nebraska-Lincoln. Damage to the lawn is not easily recognized at this stage. Ritcher PO. During this stage, the larva begin to take the shape of the adult beetle. Beneficial nematodes seek out and kill all stages of harmful soil-dwelling insects. The adults mate in the evening and, at dawn, females return to the ground to deposit 15 to 20 eggs, 1 to 8 inches deep in the soil. Some species of larvae need more than one year to develop, so they hibernate in the soil again once the weather drops in the autumn. The pupa is usually white, faint yellow, or dark brown in color. Natural enemies that control these white grubs include parasitic wasps and flies in the genera Tiphia and Myzinum (Hymenoptera: Tiphiidae), and Pelecinus polyturator Drury (Hymenoptera: Pelecinidae), and the fly, Pyrgota undata (Diptera: Pyrgotidae). Larvae feed on plant roots, carrion, or dung, depending on the type of scarab. Adult Beetle. In late March and April, grubs move back up to the surface of the soil. Periodical Cicada Life Cycle: 5 Key Stages Immature periodical cicadas or nymphs develop underground, sucking root plant juices. Larval June bugs feed in warm summers and under the soil during winter. The large grubs of the chafer feed on the roots of both wild and cultivated cool-latitude grasses, which has made them a critter-non-grata on North American lawns. Immature Insects (Volume 2). White grubs and their allies: a study of North American scarabaeoid larvae. The May or June beetles (genus. In spring and early summer, white grubs pupate 3 to 6 inches deep in the soil. The greatest damage to crops occurs the year after the appearance of the adults. Photograph by John L. Capinera, University of Florida. IDENTIFICATION: White grubs are the larval stage of May or June beetles. Can the June bug insect be dealt with entirely naturally? 241. Grubs feed close to the surface of the lawn and are most vulnerable to chemical control with pesticides at this time. The larvae feed on the ground and pupate in the grub cell where they stay over the winter. Figure 7. WM. Grubs often feed into August, when they change into their second stage of growth. 1951. During the years of heavy May beetle infestation, deep-rooted legumes, such as alfalfa or clovers, should be planted. June Bug Grubs. Larvae develop through 3 larval stages (instars) where they grow then shed their exoskeleton (a process known as moulting) at each stage. As they grow, they feed on the roots of the grass, causing large patches, browning and otherwise ruining the appearance of the lawn grass. Grub will feed until the temperature begins to drop in autumn. Oregon State Monograph Studies in Entomology 4: 1-219. The heavy-bodied June beetles vary from 12 to 25 mm (0.5 to 1 inch) and have shiny wing covers (elytra). This product’s active ingredient is chlorantraniliprole. Grubs begin to feed again, this time more aggressively. All Rights Reserved. The European chafer beetle originated in continental Europe but is now an invasive species found in temperate climates in North America, where they are often called June bugs. Grubs are the larval stage of the common May or June beetle or the Southern masked chafer. Lawn grubs are a common pest of the home lawn. Dubuque, Iowa. Eggs: Eggs are usually 1.5 to 3 mm in diameter and found encased in soil aggregates. It is in the grub stage that these insects do the most damage by feeding on grass roots causing the grass to die. Pupa. The egg hatches and the fly larva enters the body cavity of the beetle, feeding on and eventually killing the host before pupating. Bionomics and control of root feeding insect pests: grubs and billbugs. Grubs often feed into August, when they change into their second stage of growth. Although white grubs can be a problem every year, the most serious damage occurs in regular three year cycles. The ideal conditions are green healthy, irrigated lawns. These white grubs are laid in midsummer in sunny areas of the lawn . The larval stage persists for two to three years. Adult Japanese beetle, Popillia japonica Newman. The larvae will molt twice before winter. Typical white grub of the genus Phyllophaga. Larvae are white with a C-shaped body, brown head, and three pairs of legs. At the end of summer during its final instar, the grub digs deep into the soil so it is protected from cold weather. If corn or small grains are present, every effort should be made to keep the field free of grass and weed growth to reduce the number of beetle eggs laid. Photograph by Paul M. Choate, University of Florida. The beetles overwinter in the soil, emerging the following year in May or June when feeding, mating, and egg-laying take place. Copyright Leaf Group Ltd. // Leaf Group Lifestyle. Larvae vary in size with age and species. Tashiro H. 1973. Pupa: The length of the pupae varies from 20 to 24 mm long. Photograph by John L. Capinera, University of Florida. Stehr FW. They root around just below the surface, eating the roots of grass and other plants as they grow. Kendall/Hunt Publishing Co. Dubuque, Iowa. Figure 8. The adult beetles emerge from the pupal stage a few weeks later, but they do not leave the ground. Grub is a term used most often to refer to the larval stage of one of three beetle species: the European chafer, June beetle and Japanese beetle. The greatest amount of damage occurs as the larvae move near the soil surface to feed on the roots of the plants. pp. Also, Cordyceps fungus infects the grubs. Lawn grubs are a common pest of the home lawn. The hind portion of the abdomen is slightly enlarged and appears darker due to the soil particles showing through the body wall. Rolston LH, Barlow T. 1980. My Home: Found all over North America, I hide in trees during the day. Some species of larvae need more than one year to develop, so they hibernate in the soil again once the weather drops in the autumn. Grubs feed close to the surface of the lawn and are most vulnerable to chemical control with pesticides at this time. Most beetles pass through 3 – 5 stages during the larval period and some can even have up to 30 stages whereas other beetles can have only 1 stage as larvae. More than 200 species of insect pests from 100 insect families are susceptible to these insect predators. 378-385. Share it! Larvae are characteristically C-shaped with a white body and tan to brown head. McGraw-Hill Book Company, Inc. New York. Insecticide control of a white grub. After two to three weeks, grubs hatch. Green June beetles can be found in the eastern part of the United States. In the southern United States, the name green June beetle is applied to a similar green-and-brown beetle that, in the adult stages, feeds on ripe figs and other fruit. Meanwhile, the grubs or larvae that started life early in spring begin to emerge as lawn foraging beetles. Firefly larvae produce light and are sometimes called glowworms. The larval stage is when June bugs are the most harmful to lawns and gardens. True white grubs are the larvae of May beetles (also called June Beetles) found in the genus Phyllophaga, of which there are over 100 different species. After feeding for several weeks, they lay their eggs in the ground. June bug larva stage The grubs will grow to about 40 mm (1.6 in) and are white with a brownish-black head and brown spiracles along the sides of the body. Davidson RH, Lyon WF. The last larval stage remains in the soil from the fall through spring. During the spring, damage is more apparent than root damage during the fall. If you want to attract wildlife to your yard, … pp. Life Cycle of the European Chafer Beetle. After developing into the third and final instar stage, fully mature larvae are typically 25 mm in length and ready to pupate. Larvae which pupate early enough will emerge in late in the summer. In late March and April, grubs move back up to the surface of the soil. Since the adults are attracted to trees to feed, they tend to lay most eggs in the higher portions of sod near wooded areas. During the first stage of growth the grubs feed on the roots of the grass in the lawn. The fully grown larva color is glassy yellowish white shading toward green or blue at the head and tail. 1979. Photograph by James Castner, University of Florida. The most commonly encountered white grubs are the larvae of June bugs, European Chafers, Masked Chafers, Billbugs, Oriental Beetles and Japanese Beetles. June Bug. The larval stage is the most destructive stage of the insects. June bugs’ larvae are whitish, C-shaped grubs that live underground. During the first stage of growth the grubs feed on the roots of the grass in the lawn. 1966. Adults bury themselves under the dirt during the day, reports the University of Missouri. The common life cycle of the more destructive and abundant of these beetles extends over three years. During late spring and early summer, the overwintering generation of beetles dies. In late June or early July, according to Cornell University, beetles begin to leave the ground and feed on other bugs and plants. Late spring or early autumn plowing destroys many larvae, pupae, and adults in the soil and also exposes the insects to predators, such as birds and skunks. About 75% of all insect species go through the four stages of complete metamorphosis - egg, larva, pupa, and adult. Some, such as the green June beetle, are more brightly colored. Larvae are white with a C-shaped body, brown head, and three pairs of legs. Females can lay up to 75 eggs in their short adult life. Adult beetles are nocturnal bugs and do not appear during the day, making detection difficult. Topics covered include biology of the bug, lawn grub damage and control of white grubs (the name used to cover the larval stages of destructive beetles such as June Beetles, Japanese Beetles, Chafers and others.) This results in drought susceptibility and the ability to easily pull the grass away from the soil surface. Plan the perfect garden with our interactive tool →, University of Illinois Extension: White Grubs in Lawns, Cornell University: A Grub's Life: Egg to Beetle, University of Missouri Extension: White Grubs in the Lawn. An understanding to the life cycle of this insect will be of importance to those responsible for its elimination and control. June beetle larvae, called white grubs, are about 25 mm (1 inch) long and live in the soil. A pyrgotid fly, a natural enemy of white grubs, Phyllophaga spp. 1989.The Scarab Beetles of Florida (USA): (Coleoptera: Scarabaeidae) Part II. They grow exponentially and molt twice before moving on to the next stage of their life cycle. Bulletin of the Entomological Society of America 19: 92-94. During the larval portion of their life cycle, June bugs go through three separate instars, or stages. Grubs feed now for between four and six months. 1991. These products are available commercially. The grubs have excessively high appetites and feed constantly. After about 18 days, the eggs hatch out and the newly hatched larvae spend the next nine months going through three stages of larval growth and finally emerge in the spring as a newly hatched June bug. Scotts GrubEx, 5,000-sq ft against Larvae. Jaques HE. During the first stage of growth the grubs feed on the roots of the grass in the lawn. After hatching, the first instar is 5mm long. Adult green June beetle, Cotinis nitida Linnaeus. Adults emerge the following spring. During their last larval instar the June bugs dig deep into the soil to shield themselves from freezing winter temperatures. The Phyllophaga life cycles vary somewhat because some species complete their growth in one year, while others require as much as four years. How to Know the Beetles. In late June or early July, according to Cornell University, beetles begin to leave the ground and feed on other bugs and plants. Take a look at the life cycle and characteristics of this mini-beast, and also read some interesting facts about it. The outer skin of the grub is thicker than in the fall, making chemical control at this time nearly impossible. Observing Japanese beetles feeding on plants is quite common since the adult beetle feeds on about 300 species of trees, shrubs, ornamental, and fruit trees, in … As an adult, I feed at night and eat vegetation, usually the leaves from trees and bushes. Figure 6. A species of bee fly, Exoprosopa fasciata, is also a parasite of this genera. Adults do not feed on turfgrasses; however, in their larval stage, they tunnel through the soil and feed on plant roots. Phyllophaga spp. Figure 4. White grubs. Adults: May beetles are about 12 to 25 mm long. Larvae: The length of the larvae varies from 20 to 45 mm. Because the grubs have destroyed the roots the grass pulls back easily. Photograph by James Castner, University of Florida. These stages are marked by the grub molting, or shedding its outer skin after growing a new one underneath. The Life Cycle of Scarabs Like all beetles, scarabs undergo complete metamorphosis with four stages of development: egg, larva, pupa, and adult. June bugs, also called May or June beetles, go through a life cycle that spans one to three years. It then enters into the ‘pupal stage’ which can take up to 9 months and usually happens over the winter period. A pelecinid wasp, a natural enemy of white grubs, Phyllophaga spp. They are small, spherical, pearly white eggs that darken just before hatching. This commonly happens in the southern region allowing for two cycles to progress annually. Like it? Parasitic wasp larva feeding externally on white grub, Phyllophaga spp. Typical June beetle, adult of white grub, of the genus Phyllophaga. The last abdominal segment is clear, allowing dark digested material to be seen. Scarab beetles generally lay their eggs in the ground, in dung, or in other decomposing materials including carrion. The River Bug on the Black Sea at midsummer brings down some thin membranes that look like berries out of which burst a four-legged caterpillar in the manner of the creature mentioned above, but it does not live beyond one day, owing to which it is called the hemerobius. The June Bug is a nocturnal beetle that hatches from a larvae in the springtime of the year. Now after 4-8 weeks of chomping away under ground, the larvae will pupate. Fortunately, once you’ve identified the problem, you can get rid of June bugs in both their larval and adult stages, often without costly chemical insecticides. Adults emerge from pupae in about 3 weeks. The worm-like larvae form the pupa or cocoon as it often called, then lay dormant. Destructive and Useful Insects: Their Habits and Control. Once ready, the grubs dig down into the soil to below the frost line, where they go into a third stage of life. Metcalf RL, Metcalf RA. As they grow and feed in July, the females begin laying a series of 60 eggs under the soil. They feed on foliage and flowers at night, sometimes causing considerable damage. The next autumn the larvae again migrate deep into the soil to overwinter, returning near the soil surface the following spring to feed on plant roots until they are fully grown in late spring. Fortunately, there are just a few basic larval types and they are relatively easy to recognize. Two parallel rows of spines seen on the underside of the last abdominal segment distinguish true white grubs from similar-looking larvae. As adult beetles, we swarm in great numbers in early summer, usually at dark and are strongly attracted to lights.. What I eat: As a larva, I live underground and eat the roots of grasses and other plants. Insect Pests of Farm, Garden, and Orchard. Figure 1. The larva is a specialized feeding stage that looks very different from the adult. At this stage, it’s possible to have both adults and larvae feeding on your lawn and if the problem is ignored, dead lawn patches quickly appear. Phyllophaga larvae and other larvae of the family Scarabaeidae are often referred to as white grubs, including larvae of the Japanese beetle (Popillia japonica Newman), annual white grubs (Cyclocephala spp. They can be used to control a broad range of soil-inhabiting insects and above-ground insects in their soil-inhabiting stage of life. In the late summer and fall of their third year (or second year in the case of Phyllophaga tristis), larvae begin pupating in the soil. Adult beetles emerge from the ground at the end of spring or start of summer. In 3 to 4 weeks, small grubs (larvae) hatch from eggs and develop through three stages (instars), with the first two stages lasting about 3 weeks. White grub, Phyllophaga spp., infected with Cordyceps fungus. The female will lay from 60-75 eggs underground. Grubs are the larval stage of the European chafer, June beetle (June bug) and/or Japanese beetle. The egg, larva, and pupa life cycle stages develop underground and unless soil is removed or dug into, these life stages will not be seen. Most adults are yellow to dark reddish-brown to black, robust, oblong, glossy beetles. Larva (Larval Stage) As with many beetles, lightning bug larvae look somewhat wormlike. Eggs hatch about three weeks later into young larvae that feed upon roots and decaying vegetation throughout the summer and, in autumn, migrate downward (to a depth of up to 1.5 meters) and remain inactive until the following spring. After pupating, an adult emerge, and there you have your beetle. North Carolina Corn Information. … (no longer available online). New York. C. Brown Company. Adult Japanese beetles (June bugs) typically lay eggs in lawns in June. ), and the green June beetle (Cotinis nitida Linnaeus). Grubs hibernate during this stage and are impossible to control at this time due to their depth. 126-128. Woodruff RE, Beck BM. This stage of the beetle life cycle is where the greatest change in form takes place. At the second instar larvae burrow into the soil. These grubs then form oval earthen cells and pupate. and related insects are distributed throughout the United States and Canada. White grubs are the slug-like larval stage of many insects. Two parallel rows of spines seen on the undersi… Over the course of the next two years, larvae pass through three stages (called instars) becoming larger and more destructive with each stage. Larvae:The length of the larvae varies from 20 to 45 mm. pp. Within 13 (a 13-year-old cicada) or 17 years (a 17-year-old cicada) in the soil, the mature nymphs emerge and climb right onto some vertical surface or nearby vegetation. The time period to reach adulthood from the pupal stage varies dramatically among different types of beetles. The dorsal segments are flattened and extend to the back and sides, like overlapping plates. Damage to the lawn is not easily recognized at this stage. For this cultural practice to be effective, plowing must occur before the grubs migrate below the plow depth. Some, such as the green June beetle, are more brightly colored. Figure 5. Adults are medium to dark brown. Pest problems? The young beetle will live under the soil until the following spring to develop further before emerging in June or July to lay eggs once more, starting the life cycle over again. June bugs are commonly seen in many areas in the United States, as well as other regions of the world which facilitate their living conditions. John Wiley and Sons. Once larvae have overwintered, they move again to the surface for a brief feeding period before becoming a fully developed adult in September. They have extremely fast metabolisms, and eat nearly constantly. This is the stage that lets them molt from grubs to adult beetles. Figure 3. This is how the grub gets bigger, and it typically happens over the course of two years, depending on the life cycle length of the species. Most adults are yellow to dark reddish-brown to black, robust, oblong, glossy beetles. However, the distribution of individual species usually is more restricted. (1998). Grubs are vulnerable to the changing weather and die if caught by an unexpected frost. No-tillage or reduced tillage crop management encourages grub populations. It's during this period when the larvae pupate. These are the most common in New England. June bug larvae are small white grubs with brown heads. Figure 2. The grubs burrow deep underground to survive the winter. Learn which plants thrive in your Hardiness Zone with our new interactive map! Adults:May beetles are about 12 to 25 mm long. Grubs feed close to the surface of the lawn and are most vulnerable to chemical control with pesticides at this time. The year following heavy flights of May beetles, planting corn or potatoes should be avoided in fields that were previously under sod or grass. 1993. Inoculating the soil with bacterial spores of Bacillus popilliae Dutky and Bacillus lentimorbus Dutky aids in reducing populations. The hind portion of the abdomen is slightly enlarged and appears darker due to the soil particles showing through the body wall. Lay up to 9 months and usually happens over the winter instar larvae burrow into the third final! Different from the pupal stage a few weeks later, but they not! Cultural practice to be effective, plowing must occur before the grubs have destroyed the roots of the beetle cycle... Once larvae have overwintered, they lay their eggs in the fall, making detection.... Hardiness Zone with our new interactive map must occur before the grubs burrow deep underground to survive the.! Cells and pupate in the soil not easily recognized at this stage of the Entomological of... 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The ideal conditions are green healthy, irrigated lawns when they change into second!