Pelidnota punctata

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Geographic Range

Pelidnota punctata, the grapevine beetle, is native to the Nearctic region. It is widespread throughout the eastern United States and Canada. It ranges as far west as Texas in the United States. In Canada, it is found mainly in Ontario. (Hayes, 1925; Hicks, 1965)

Habitat

Pelidnota punctata adults can be found wherever cultivated and wild grapes grow. They live in temperate regions, agricultural vineyards, forests, meadows, and suburban gardens.

Larvae usually live in decaying wood, such as in deciduous tree stumps. Pelidnota punctata larvae can live in the center of the stump, but more commonly, they dig tunnels in the tree roots. (Hoffmann, 1936)

Physical Description

Pelidnota punctata is about 20 to 25 mm long and 13 to 15 mm wide. Its elytra are yellowish orange, with a slight metallic tint. There are three black spots on the lateral edges of each elytra, and a single black spot on both lateral edges of the thorax. The ventral side of P. punctata is brownish black, with a green tint. Like all Scarabaeidae beetles, the antennae, which are orange in this species, have a clubbed end that actually consists of several plates called lamellae. The lamellae can be either unfurled or composed together into a ball.

Eggs of P. punctata are white, elongated, and oval-shaped, measuring 2 mm long and 1.5 mm wide when they are first laid; they grow in size before hatching. A larva is white when it first hatches, and the head later darkens to brown. Pupae also are white at first, and later change to brown. The pupae are about 22 mm long.

This species likely is polymorphic, with many physical variations. In 1915, 10 different species names were assigned to insect variants that were all later determined to be different forms of the same species, Pelidnota punctata. Some forms have less distinct spots, while some have smaller spots. The leg color also varies among populations, with some grapevine beetles having legs that are the same color as the elytra, while others have legs that are the same color as the ventral part of the body. (Bogue, 1897; Hardy, 1975; Hayes, 1925; Hoffmann, 1936)

  • Range length
    20 to 25 mm
    0.79 to 0.98 in

Development

Pelidnota punctata is holometabolous. Eggs are laid in June, July and August. They hatch after an average of 15 days, though this time is highly variable. The larvae emerge and develop through 2 to 3 instars. This species overwinters as a larva in decaying stumps and logs. The second and third instars can occur either before or after overwintering. Larvae can overwinter for up to 2 years. Larval development time also is variable, but can take over 600 days to complete. A prepupal stage occurs during development, wherein the larva makes a cocoon out of small pieces of wood and becomes mostly inactive. After 3 to 10 days in the prepupal stage, pupation occurs in the cocoon. After 16 to 24 days of pupating, the adult emerges. Adults live for about 30 more days, during which time they reproduce and lay eggs. (Hayes, 1925; Hoffmann, 1936)

Reproduction

Little information is available about reproduction in Pelidnota punctata. Mating usually takes place on host plants at night, though some mating during the day has been observed. (Hayes, 1925)

Little information is available about reproduction in Pelidnota punctata. It is known that oviposition occurs in June, July, and August. Eggs are laid one at a time in moist soil, usually under logs and other decaying wood. This ensures that the larvae will have a source of food upon hatching. (Hayes, 1925)

  • Breeding season
    Breeding takes place in early summer.

Parental care in Pelidnota punctata likely is limited to females provisioning eggs and laying the eggs in the soil under decaying logs and stumps, which provides larvae with a food source upon hatching. (Hayes, 1925)

  • Parental Investment
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female

Lifespan/Longevity

Though the development time of Pelidnota punctata varies widely among individuals, the growth from egg to adult takes about 2 years. An adult lives for about 30 days after completing the pupal stage. (Hayes, 1925; Hoffmann, 1936; Ritcher, 1958)

  • Average lifespan
    Status: wild
    2 years
  • Average lifespan
    Status: captivity
    2 years

Behavior

Pelidnota punctata is largely nocturnal and often gathers at lights at night. During the day, it stays on the leaves of its host plant and is mostly inactive. These beetles fly quite often at night to find host plants and mates. (Hayes, 1925)

Communication and Perception

Specific information about communication and perception in Pelidnota punctata is scarce; however, because P. punctata is a scarab beetle, it is safe to assume that it uses the ends of its antennae for olfaction. The lamellae that make up the club at the end of the antennae of Scarabaeidae beetles function as sensory organs, primarily olfactory. Pelidnota punctata likely can detect host plants by olfaction. Other related Scarabaeidae beetles also use their lamellae to detect pheromones that are important for mating, which also may be true for P. punctata.

Additionally, grapevine beetles likely perceive their environment and mates visually. (Larsson, et al., 2001)

Food Habits

Pelidnota punctata is phytophagous and mostly feeds on the cultivated and wild grape (species of the genus Vitis), which gives the grapevine beetle its common name. It mainly eats the leaves of Vitis plants, but will also eat the fruit. It also has been observed feeding on spinach and Virginia creeper.

Larvae feed on the decaying stumps and wood in which they live. Larvae have been collected from the decaying wood of elm, walnut, cherry, and birch trees, among many others. (Hayes, 1925; Hoffmann, 1936; Ritcher, 1958)

  • Plant Foods
  • leaves
  • fruit

Predation

Raccoons are known to prey on Pelidnota punctata occasionally. Blue jays also have been observed feeding on grapevine beetles, and it is likely that many other bird species also are predators of these beetles. In Texas, the remains of P. punctata have been found in nests of the pallid bat, Antrozous pallidus, suggesting that A. pallidus is another predator.

In defending itself against predators, the grapevine beetle may take advantage of the bright color and slight metallic tint of its elytra. Other brightly colored, shiny beetles in the family Rutelinae have been shown to reflect polarized light, which helps them blend in with the greens and browns of their environment. Other theories have suggested that the metallic tint can cause a glare of light to temporarily blind predators, or that the metallic tint reflects the colors of the environment, providing camouflage. Pelidnota punctata is not as metallic as other species, however, so these defensive strategies may not hold true for the grapevine beetle. (Beal, 1896; Giles, 1939; Herreid II, 1961; Thomas, et al., 2007)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Pelidnota punctata feeds almost exclusively on wild and cultivated grape plants in the genus Vitis. During some outbreaks, Pelidnota punctata can damage grape crops by skeletonizing the leaves, but the beetle does not cause significant damage in most years.

Larvae can benefit the environment by speeding up the decomposition of the old wood in which they live.

These beetles are prey to many species of animals, including raccoons, blue jays, and pallid bats. The parasitic mite Caloglyphus phyllophagianus is known to use Pelidnota punctata as a host. This mite lives under the wings of the beetle and is thought to use P. punctata more for dispersal than for food. Parasitic Rickettsia bacteria have been found in the gut of some grapevine beetles. The yeast Candida maltosa also has been found in the gut of P. punctata, likely functioning as a symbiont by helping to digest plant material. (Cowdry, 1923; Crocker, et al., 1992; Hayes, 1925; Suh, et al., 2008)

Species Used as Host
  • Grapes (Vitis species)
Mutualist Species
  • Candida maltosa
Commensal/Parasitic Species
  • Caloglyphus phyllophagianus
  • Rickettsia

Economic Importance for Humans: Positive

There are no known positive effects of Pelidnota punctata on humans.

Economic Importance for Humans: Negative

During outbreaks, Pelidnota punctata can substantially defoliate grape crops. In 1965, P. punctata was considered a pest of the grape industry in southern Ontario, Canada. In general, however, the grapevine beetle usually does not present much of a threat to grape crops, but it does have the potential. The suggested method of removal is to pick the beetles off the plants by hand, which is possible due to their relatively large size. (Bogue, 1897; Hayes, 1925; Hicks, 1965)

  • Negative Impacts
  • crop pest

Conservation Status

Pelidnota punctata has no special conservation status.

Other Comments

Pelidnota punctata was the likely inspiration for the beetle in Edgar Allen Poe's short story "The Gold Bug". (Thomas, et al., 2007)

Contributors

Angela Miner (author), University of Michigan-Ann Arbor, Elizabeth Wason (editor), Animal Diversity Web Staff.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

agricultural

living in landscapes dominated by human agriculture.

biodegradation

helps break down and decompose dead plants and/or animals

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

detritus

particles of organic material from dead and decomposing organisms. Detritus is the result of the activity of decomposers (organisms that decompose organic material).

diapause

a period of time when growth or development is suspended in insects and other invertebrates, it can usually only be ended the appropriate environmental stimulus.

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

herbivore

An animal that eats mainly plants or parts of plants.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

internal fertilization

fertilization takes place within the female's body

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

polymorphic

"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

suburban

living in residential areas on the outskirts of large cities or towns.

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

References

Beal, F. 1896. The Blue Jay and its Food. Washington, D.C.: U.S. Department of Agriculture.

Bogue, E. 1897. Some Injurious Orchard Insects. Stillwater, Oklahoma: Oklahoma Agricultural and Mechanical College.

Cowdry, E. 1923. The distribution of Rickettsia in the tissues of insects and arachnids. The Journal of Experimental Medicine, 37/4: 431-456. Accessed June 07, 2013 at http://jem.rupress.org/content/37/4/431.full.pdf.

Crocker, R., H. Cromroy, R. Woodruff, W. Nailon, M. Longnecker. 1992. Incidence of Caloglyphus phyllophagianus (Acari, Acaridae) on adult Phyllophaga spp and other Scarabaeidae (Coleoptera) in North Central Texas. Annals of the Entomological Society of America, 85/4: 462-468.

Giles, L. 1939. Fall food habits of the raccoon in central Iowa. Journal of Mammology, 20/1: 69-70.

Hardy, A. 1975. A revision of the genus Pelidnota of America north of Panama (Coleoptera: Scarabaeidae: Rutelinae). University of California Publications in Entomology, 78/1: 1-43.

Hayes, W. 1925. A comparative study of the history of certain phytophagous Scarabaeid beetles. Kansas State Agricultural College Experiment Station Technical Bulletin, 16: 1-146. Accessed June 07, 2013 at http://www.ksre.ksu.edu/historicpublications/pubs/stb016.pdf.

Herreid II, C. 1961. Notes on the pallid bat in Texas. The Southwestern Naturalist, 6/1: 13-20.

Hicks, S. 1965. The Northern Limits of Several Species of Coleoptera with Special Reference to Their Occurrence in the Ottawa District, Ontario. The Coleopterists' Bulletin, 19/2: 37-42.

Hoffmann, C. 1936. Additions to Our Knowledge of the Biology of Pelidnota punctata Linn. (Scarabaeidae- Coleoptera). Journal of the Kansas Entomological Society, 9/3: 103-105.

Larsson, M., W. Leal, B. Hansson. 2001. Olfactory receptor neurons detecting plant odours and male volatiles in Anomala cuprea beetles (Coleoptera: Scarabaeidae). Journal of Insect Physiology, 47/9: 1065-1076.

Ritcher, P. 1958. Biology of Scarabaeidae. Annual Review of Entomology, 3: 311-334.

Suh, S., N. Nguyen, M. Blackwell. 2008. Yeasts isolated from plant-associated beetles and other insects: seven novel Candida species near Candida albicans. FEMS Yeast Research, 8/1: 88-102. Accessed June 07, 2013 at http://onlinelibrary.wiley.com/doi/10.1111/j.1567-1364.2007.00320.x/full.

Thomas, D., A. Seago, D. Robacker. 2007. Reflections on golden scarabs. American Entomologist, 53/4: 224-230. Accessed June 07, 2013 at http://www.entsoc.org/PDF/Pubs/Periodicals/AE/AE-2007/Winter/Thomas.pdf.