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What species is this beetle (trichius family)

What species is this beetle (trichius family)



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I took this picture in Jura region (Northern Switzerland, alt: ~700m) of that beetle (July 2018). It was taking food from a flower of aMorus nigra.

It seems to be part of thetrichiusgenus but I want to report the exact species.

In Switzerland we have mainly:

  • Trichius fasciatus
  • Trichius rosaceus
  • Trichius sexualis

I think by the color of the hairs it would be aTrichius fasciatus.

Can someone confirm the species and what field marks I can use to make the distinction between those three species?


What species is this beetle (trichius family) - Biology

Hypothenemus eruditus is a widely distributed super generalist species, recorded from hundreds of plant species and from all subtropical and tropical regions (Wood 1982). This species is the type species of the bark beetle genus Hypothenemus (Coleoptera: Curculionidae: Scolytinae), which belongs to the tribe Cryphalini, the pygmy borers. With over 180 described species, Hypothenemus is one of the most species-rich genera among bark beetles. In addition, it appears to be the most common scolytine in the world (Wood 2007). In Florida, Hypothenemus are probably the most common bark beetles (Johnson et al., 2016). They are ubiquitous in forests and by far the most common bark beetles in urban and suburban areas, but they are virtually unknown to the public due to their minute size (only up to 1.3 mm). Hypothenemus eruditus is the most common cryphaline species in Florida. It is highly attracted to ethanol and it often hovers above alcoholic drinks.

Despite its prevalence, this species causes no apparent damage to plants. Most economic impacts caused by other Hypothenemus species are attributed to beetles that bore into seeds or fruits, e.g. the coffee berry borer, Hypothenemus hampei (Hulcr 2013), and the tropical nut borer, Hypothenemus obscurus.

In addition to being recorded from diverse plant tissues, e.g. leaf petioles or twigs, Hypothenemus eruditus has also been recovered from many unexpected locations, e.g. galleries of other beetles (Deyrup 1987), fungal fruiting bodies (Browne 1961), manufactured objects such as drawing boards (Browne 1961), and book bindings, from which the name (eruditus, i.e. erudite) was derived (Westwood 1836).

Taxonomy (Back to Top)

The genus Hypothenemus was established based on the type species, Hypothenemus eruditus Westwood (Westwood 1836), and the genus name was given in reference to the downward facing mouthparts ("Hypo" means under, "thenemus" is an unusual variant of a Greek word for "mouth", Westwood 1836). The taxonomic status of Hypothenemus eruditus is extraordinarily complicated, as it includes over 70 taxonomic synonyms. The small body size (1-1.3 mm for female and 0.7 mm for male), and the subtle but extensive within-species morphological diversity may be the explanation for its unclear taxonomic placement.

The large within-species variation of Hypothenemus eruditus is also reflected in molecular markers. Beetles of this species collected at a single locality in Central America had genetic diversity equal to generic-level diversity found in other insects (Kambestad 2011). These results suggest that Hypothenemus eruditus is a complex of many cryptic species. Many of the dozens of synonyms may in fact be different species. Further comparison between morphological and molecular data is needed to resolve the taxonomy of this species.

Distribution (Back to Top)

Hypothenemus eruditus is present in all tropical and subtropical regions of the world and is also known to extend to many temperate regions. It has been recorded across the Americas from Argentina to Michigan (Figure 1). The most comprehensive records can be accessed on the www.barkbeetles.info online database (Atkinson 2016).

Figure 1. Collection localities of Hypothenemus eruditus in the Americas as of January 2016. This species is also widely distributed in other tropical and subtropical regions around the world. Map from Atkinson (2016).

Description (Back to Top)

Adults: The adult females are 1.0-1.3 mm long, and 2.4 times as long as wide. Coloration is variable: dark brown or black. Some individuals are distinctly bicolored with a light brown to orange pronotum (the upper or dorsal surface of the first thoracic segment) and black to brown elytra (the two external and hardened forewings of adult Coleoptera). The pronotum is widest at its base, 0.9 times as long as wide, broadly rounded frontally, highest at middle. The frontal slope of the pronotum is asperate: covered with distinct flat projections bent backwards. The anterior margin of the pronotum bears six such projections (asperities) and the medium pair is usually narrowly separated. The elytra are 1.7 times as long as wide. Elytral striae (longitudinally arranged lines on the elytron) consist of small punctures. The interstriae (spaces between the striae) are twice as wide as the striae, smooth, somewhat glossy, each with a straight row of minute punctures. An important character for this genus is the arrangement of setae on the elytra: they resemble flattened erect scales arranged in simple rows. The elytral end (the &ldquodeclivity&rdquo) is convex and steep.

The adult males are 0.7 mm long. Male eyes are only half as large as female eyes, and many other morphological features are poorly formed. Males do not fly they only have vestiges of wings and their elytra are fused and therefore functionless. The males are less common than females in a single gallery, typically only a single male is produced per family.

Eggs: The eggs are oval in shape, and white in color. They are approximately 0.3-0.5 mm long and 0.2-0.25 mm wide. Eggs are laid loosely in the larger central chamber of gallery system (tunnels engraved by beetles).

Larvae: The larvae are white, C-shaped, and legless. They are approximately 0.6-1.2mm long.

Biology (Back to Top)

A new gallery (the nest of a bark beetle) is initiated with one single entrance hole by an adult female, usually located at leaf nodes or stems of a dead twig (Figure 2). Each initiating female has typically been fertilized by her brother in her natal gallery, so she does not need to attract a mate. If a branch is occupied by multiple families and galleries are intermingled, females can also mate with non-sibling males (Browne 1961).

During gallery excavation, the female pushes frass and debris out of the entrance hole. While excavating, she also lays eggs loosely in the gallery system, typically in the larger central chamber. The eggs are very large in comparison to the size of the female. After hatching, the larvae extend the irregular parental tunnel as they feed (Wood 2007).

In the field, development from egg to adult takes approximately 28 days (Browne 1961). There is a skewed sex ratio favoring females. Sex determination in Hypothenemus is an example of pseudo-arrhenotoky, where the male develops from a fertilized egg but the father&rsquos genome in most cells of his body is never &ldquounfolded&rdquo and remains unused, resulting in an individual that only uses a single copy of its mother&rsquos genome (&ldquofunctional haploidy&rdquo) (Borsa and Kjellberg 1996).

Female adults may remain in the galleries after mating with males, either for maturation feeding or to wait for proper environmental conditions to disperse. Dispersing females may come out via the original entrance hole or through new exit holes.

Figure 2. A typical placement of the gallery of Hypothenemus eruditus in a notch under a leaf node in a dead twig. Photograph by YinTse Huang, University of Florida.

Diagnosis

Hypothenemus eruditus can frequently be confused with two commonly encountered Hypothenemus species in tropical and subtropical regions (e.g. Florida) such as Hypothenemus seriatus and Hypothenemus birmanus. Among adult females of all three species, Hypothenemus birmanus is the largest (1.5-2.2 mm), followed by Hypothenemus seriatus (1.3-1.5 mm), then Hypothenemus eruditus (1.0-1.3 mm) (Figure 3). Hypothenemus birmanus can be easily distinguished by its distinct pronotal asperities: the edge of the pronotum has only four teeth, the median pair is larger than the outer pair. Hypothenemus seriatus and Hypothenemus eruditus usually possess six marginal asperities of similar size and spacing (Figure 4). Hypothenemus seriatus has a groove on its frons (the upper anterior part of the head capsule) the groove is absent or not obvious in Hypothenemus birmanus and Hypothenemus eruditus (Wood 2007) (Figure 5). However, the presence of the groove is variable, even for individuals from the same gallery (A. J. Johnson, unpublished). The interstrial bristles (bristles between the striations) of Hypothenemus birmanus are denser on the abdominal end of elytra than on the top of elytra, while relatively evenly distributed in Hypothenemus seriatus and Hypothenemus eruditus. The end of elytra is less steep in Hypothenemus seriatus, and has distinct strial rows. The elytral declivity in Hypothenemus eruditus and Hypothenemus birmanus is relatively steep, and the strial or interstrial rows are not arrayed as neatly as in Hypothenemus seriatus (Figure 6).

Figure 3. Comparison of the three most common Hypothenemus species (female adults) in Florida. A. Hypothenemus birmanus B. Hypothenemus seriatus C. Hypothenemus eruditus. Photograph by YinTse Huang, University of Florida.

Figure 4. Comparison of the marginal asperities of Hypothenemus species in Florida (female adults). A. Hypothenemus birmanus B. Hypothenemus seriatus C. Hypothenemus eruditus. Photograph by YinTse Huang, University of Florida.

Figure 5. Comparison of the frons groove of Hypothenemus species in Florida (female adults). A. Hypothenemus birmanus B. Hypothenemus seriatus C. Hypothenemus eruditus. Photograph by YinTse Huang, University of Florida.

Figure 6. Comparison of the dorsal view of elytron showing scales and texture of Hypothenemus species in Florida. A. Hypothenemus birmanus B. Hypothenemus seriatus C. Hypothenemus eruditus. Photograph by YinTse Huang, University of Florida.

Hosts

Hypothenemus eruditus is often described as a &ldquosuper generalist&rdquo since it can feed on a wide variety of phylogenetically diverse plants. It can also use various plant organs, from leaf petioles and twigs to seeds and fruits. The most comprehensive host list is available in Atkinson (2016).

Damage and management

Hypothenemus eruditus has been reported inside coffee berries, but it does not consume the seeds and does not reproduce in them (Garcia Martell 1980). The damage caused by this species is quite limited. Actually, the term false coffee berry borer has been used to describe Hypothenemus species that appear in coffee berries without causing significant damage to the host (Garcia Martell 1980).

Despite its abundance in Florida and around the world, Hypothenemus eruditus does not cause any significant economic damage and requires no management.

Selected References (Back to Top)

  • Atkinson TH. 2016. Bark and Ambrosia Beetles. http://barkbeetles.info. (19 September 2019)
  • Borsa P, Kjellberg F. 1996. Experimental evidence for pseudo-arrhenotoky in Hypothenemus hampei (Coleoptera: Scolytidae). Heredity 76: 130-135.
  • Browne FG. 1961. The biology of Malayan Scolytidae and Platypodidae. Malayan Forest Records 22: 1-255.
  • Deyrup M. 1987. Trischidias exigua Wood, new to the United States, with notes on the biology of the genus (Coleoptera: Scolytidae). The Coleopterists Bulletin 41: 339-343.
  • García Martell C. 1980. Falsas brocas del género Hypothenemus detectadas en frutos del cafeto en México. III Simposio Latinoamericano sobre Caficultura, Tegucigalpa, Honduras. 188-195.
  • Hulcr J. 2013. Why is your cup of coffee so expensive? Because of a tiny bark beetle! University of Florida/IFAS. (19 September 2019)
  • Johnson AJ, Kendra PE, Skelton J, Hulcr J. 2016. Species diversity, phenology, and temporal flight patterns of Hypothenemus pygmy borers (Coleoptera: Curculionidae: Scolytinae) in South Florida. Environmental Entomology 45: 627-632.
  • Kambestad M. 2011. Coexistence of habitat generalists in neotropical petiole-breeding bark beetles: Molecular evidence reveals cryptic diversity, but no niche segregation. University of Bergen.
  • Vega FE, Infante F, Johnson AJ. 2015. The genus Hypothenemus, with emphasis on H. hampei, the coffee berry borer. pp. 427-494. In Bark Beetles: Biology and Ecology of Native and Invasive Species. Vega F and Hofstetter R (eds.). Academic Press, San Diego.
  • Westwood JO. 1836. Description of a minute coleopterous insect, forming the type of a new subgenus allied to Tomicus, with some observations upon the affinities of the Xylophaga. Transactions of the Royal Entomological Society of London 1: 34-36.
  • Wood SL. 1982. The bark and ambrosia beetles of North and Central America (Coleoptera, Scolytidae), a taxonomic monograph. Great Basin Naturalist Memoirs. 1356 pp.
  • Wood SL. 2007. Bark and ambrosia beetles of South America (Coleoptera, Scolytidae). Monte L. Bean Life Science Museum, Brigham Young University, Provo, Utah. 900 pp.

Authors: YinTse Huang, School of Forest Resources and Conservation, University of Florida
Jiri Hulcr, School of Forest Resources and Conservation, University of Florida, and the Entomology and Nematology Department, University of Florida, Andrew J Johnson, School of Forest Resources and Conservation, University of Florida, Andrea Lucky, Entomology and Nematology Department, University of Florida
Photographs: YinTse Huang, School of Forest Resources and Conservation, University of Florida
Map: Thomas H. Atkinson, http://barkbeetles.info/
Web Design: Don Wasik, Jane Medley
Publication Number: EENY-664
Publication Date: August 2016. Reviewed: September 2019.

An Equal Opportunity Institution
Featured Creatures Editor and Coordinator: Dr. Elena Rhodes, University of Florida


Trichius fasciatus (Linnaeus, 1758)

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Predaceous Diving Beetles (Water Tigers)

Shiny black, brown to olive beetles, sometimes with yellowish marks. Body is streamlined, oval, with the narrower end at the head. Antennae are threadlike. These beetles hang head downward, with the tip of the abdomen protruding from the water surface. The hindlegs are fringed with hairs and flattened for swimming. When swimming, they kick both hind legs simultaneously (not alternately). The swimming method helps distinguish them from the similar water scavenger beetles, which are in a different family.

Like other beetles, they have membranous hindwings that are covered by forewings that are thick, heavy shields (elytra). When the wings are closed, the elytra create a line straight down the back.

Larvae, called “water tigers,” are elongated, flattened and can be 2 inches long. They commonly come to the surface to draw air into spiracles (like snorkels) located at the hind end of the body. There are 3 pairs of legs, and the jaws are strong pincers that are used to grasp prey.


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What species is this beetle (trichius family) - Biology

Description: Pronotal disc serrate along lateral edges, transverse medial ridges well developed female without pygidial spine first segment of posterior tarsus as long as segments two and three combined in males, as long as two, three and four in females males yellowish-brown with light-colored setae, patches of dark setae on pronotum and elytra, ventral surface with light-colored setae, females reddish-brown with dark setae, patches of light-colored setae on elytra, ventral surface with light-colored setae length 5.0-6.0mm.

Distribution: Eastern United States. States include: ARKANSAS, CONNECTICUT, DISTRICT OF COLUMBIA, GEORGIA, ILLINOIS, INDIANA, KANSAS, KENTUCKY, MARYLAND, MASSACHUSETTS, MISSISSIPPI, MISSOURI, NEBRASKA, NEW JERSEY, NEW YORK, NORTH CAROLINA, OHIO, PENNSYLVANIA, RHODE ISLAND, SOUTH CAROLINA, TENNESSEE, TEXAS, VIRGINIA, and WEST VIRGINIA.

Biological Data: The life history of Valgus seticollis is probably similar to Valgus canaliculatus. Adults and larvae are found in wood infested with termites such as Reticulitermes flavipes (Kollar). Specimens have been collected from oak (Quercus sp.), Pitch Pine (Pinus rigida), American Chestnut (Castanea dentata) and Tulip trees (Liriodendron tulipifera), and from a strawberry plant. Colonies usually contain a majority of females, although colonies have been observed with males and females in almost equal numbers.

Temporal Distribution: Adults are collected from March to July and in October and November.

Larvae:Third-stage larva described by Ritcher (1945, 1966).

References:
CASEY, T.L. 1915. Valgus Scriba. Mem. Col. VI:391-394.

JAMESON, M.L. and K.A. SWOBODA. 2005. Synopsis of scarab beetle tribe Valgini (Coleoptera: Scarabaeidae: Cetoniinae) in the New World. Ann. Entomol. Soc. Am. 98(5): 658-672.

RATCLIFFE, B.C. 1991. The scarab beetles of Nebraska. Bulletin Univ. Nebr. St. Mus. 12:1-333.

RITCHER, P.O. 1945. North American Cetoniinae with descriptions of their larvae and keys to genera and species (Coleoptera: Scarabaeidae). Ky. Agr. Expt. Sta. Bull. 476, 39pp.

RITCHER, P.O. 1958. Biology of Scarabaeidae. Annual Rev. of Entomology 3:311-344.

RITCHER, P.O. 1966. White Grubs and Their Allies. Oregon St. Univ. Press, Corvallis. 219 p.


Author: Katharine A. Swoboda
Generated on: 06/MAR/2002 . Last modified: 26/JUN/2007
University of Nebraska State Museum - Division of Entomology


What species is this beetle (trichius family) - Biology

Description: Pronotal disc serrate along lateral edges, transverse medial ridges well developed, basal margin rounded female with acuminate pygidial spine with central groove near apex, groove lacking irregular lateral serrations, moderately convex (in dorsal view) first segment of posterior tarsus as long as segments two and three combined in males, as long as segments two, three and four combined in females both sexes brown with dark setae, patches of light-colored setae on pronotum, elytra, propygidium, pygidium, females with less light-colored setae than males, males with dense patch of yellow setae on abdominal sternites length 4.0-5.0mm.

Distribution: Eastern United States. States include: ALABAMA, ARKANSAS, DELAWARE, DISTRICT OF COLUMBIA, FLORIDA, GEORGIA, ILLINOIS, INDIANA, IOWA, KENTUCKY, LOUISIANA, MARYLAND, MICHIGAN, MISSOURI, NEW JERSEY, NORTH CAROLINA, OHIO, OKLAHOMA, PENNSYLVANIA, SOUTH CAROLINA, TENNESSEE, TEXAS, VIRGINIA, andWEST VIRGINIA.

Biological Data: Valgus canaliculatus adults feed on the nectar of flowers from sources such as beech (Castanea sp.), buckthorn (Ceanothus sp.), dogwood (Cornus sp.), hawthorn (Crataegus sp.) and mock orange (Philadelphus sp.) trees. Adults have been observed on honeysuckle (Viburnum sp.) and rose (Aruncus and Spiraea spp.) flowers, on Queen Anne's Lace (Daucus carota), and on oak (Quercus sp.) and pine (Pinus sp.) trees. Valgus canaliculatus is common in the nests of Reticulitermes flavipes (Kollar). Valgus canaliculatus is frequently found together with Valgus seticollis. Both species are commonly found with Reticulitermes sp. (Isoptera). Larvae feed on the walls of termite galleries. Pupation occurs in July and early August within small oval cells constructed of wood fragments or soil. Adults emerge in late summer and overwinter. Colonies contain males and females in almost equal numbers, although colonies have been observed in which the male is more abundant than the female.

Temporal Distribution: April-August (adults rarely recorded in February and November).

Larvae: Ritcher (1945, 1966) described the third-stage larvae.

References:
BANKS, N. and T.E. SNYDER. 1920. A revision of the nearctic termites. Bull. U.S. Nat. Mus. 108:1-211.

BLATCHLEY, W.S. 1910.
The Coleoptera or beetles of Indiana. Bull. Indiana Dept. Geol. Nat. Res., No. 1:1-1386.

CASEY, T.L. 1915. Valgus Scriba. Mem. Col. VI:391-394.

JAMESON, M.L. and K.A. SWOBODA. 2005. Synopsis of scarab beetle tribe Valgini (Coleoptera: Scarabaeidae: Cetoniinae) in the New World. Ann. Entomol. Soc. Am. 98(5): 658-672.

RATCLIFFE, B.C. 1991. The scarab beetles of Nebraska. Bulletin Univ. Nebr. St. Mus. 12:1-333.

RITCHER, P.O. 1945. North American Cetoniinae with descriptions of their larvae and keys to genera and species (Coleoptera: Scarabaeidae). Ky. Agr. Expt. Sta. Bull. 476, 39pp.

RITCHER, P.O. 1945.1958. Biology of Scarabaeidae. Annual Rev. of Entomology 3:311-344.

RITCHER, P.O. 1945.
1966. White Grubs and Their Allies. Oregon St. Univ. Press, Corvallis. 219 p.


Author: Katharine A. Swoboda
Generated on: 06/MAR/2002 . Last modified: 26/JUN/2007
University of Nebraska State Museum - Division of Entomology


Two species of striped cucumber beetle (Acalymma vittatum shown here) are key pests of squashes, gourds, cucumbers, melons, and other cucurbit crops. A new guide in the open-access Journal of Integrated Pest Management reviews the beetles’ biology and current and potential management strategies. (Photo by Whitney Cranshaw, Colorado State University, Bugwood.org)

By Ariela Haber, Ph.D.

The sister species striped cucumber beetle (Acalymma vittatum) and western striped cucumber beetle (Acalymma trivittatum) are key pests on crops in the Cucurbitaceae family, which includes squashes, gourds, cucumbers, and melons. Both are native to North America, east and west of the Rocky Mountains, respectively, north to southern Canada, and south to most of Mexico. Damage from both species can kill seedlings, prevent fruit set, transmit pathogens, and make fruit unmarketable.

In a new paper in the open-access Journal of Integrated Pest Management, my co-authors Anna Wallingford, Ph.D., Ian Grettenberger, Ph.D., Jasmin Ramirez Bonilla, Amber Vinchesi-Vahl, Ph.D., Donald Weber, Ph.D., and I review the biology, life stages, damage, and current and potential strategies for managing these important cucurbit pests.

Adult beetles are notoriously skilled at rapidly finding and aggregating on their preferred crops to feed. Females then lay eggs at the base of cucurbit plants below the soil surface. After hatching, larvae feed on roots, pupate in soil, and emerge as the next generation of adults. A female can lay up to 1,500 eggs over her lifetime. The number of generations per year ranges from one in the northernmost latitudes to three in the south.

Both species can kill seedlings and weaken older plants by feeding on cotyledons, leaves, and stems. They also feed on flowers, which inhibits successful pollination and fruit set. Feeding on the fruit can scar or cause rot, making it unmarketable. Both species vector squash mosaic virus, and the eastern species vectors fungal pathogens that cause Fusarium wilt and black rot. Of particular concern, striped cucumber beetle vectors Erwinia tracheiphila, the causal agent of bacterial wilt. Bacterial wilt can destroy susceptible cucurbit crops, as few infected plants recover or produce marketable fruit. Economic threshold levels for these pests are not well established and differ by crop type, variety, geographic region, and plant age.

Growers commonly use synthetic insecticides (organophosphates, carbamates, pyrethroids, and neonicotinoids) to manage cucumber beetles. However, these chemicals can lose efficacy over time as beetle populations develop resistance. Moreover, they can have detrimental effects on non-target beneficial insects, including the squash bees, bumble bees, and managed honey bees that pollinate cucurbit crops. Organic control options (kaolin clay, pyrethrins, and spinosyns) show inconsistent and often limited efficacy. Sustainable control of cucumber beetles on cucurbit crops therefore must incorporate other control measures.

This profile describes candidates for biological control, as well as a variety of cultural and mechanical control tactics that reduce crop exposure to pests. For example, diversified habitats created by polyculture have been found to have lower cucumber beetle populations than cucurbit monocultures. Natural mulches and composts can reduce cucumber beetle interplant movement, support populations of natural enemies that help control cucumber beetle populations, and cycle nutrients into the soil. Row covers prevent beetles from colonizing plants in their early growth stages, when they are most vulnerable. In a number of recent studies, cucumber beetles were highly attracted to traps baited with their male-produced aggregation pheromone, vittatalactone, suggesting that vittatalactone could be used to precisely target these pests.

These approaches show promise in an integrated management program that provides long-term pest control with minimal adverse effects.


Beetle


Photo by:
Dorling Kindersley
Photo by:
Dorling Kindersley
Photo by:
Dorling Kindersley

Beetles vary widely in their habits and are found under the most diverse conditions. A few live in salt water, more in fresh water, and a small number breed in hot springs. Some beetles live under the bark of living and dead trees. Numerous beetles feed on the roots, wood, leaves, flowers, and fruit of living plants, causing great economic damage.


Photo by:
Dorling Kindersley

Scientific classification: Beetles make up the order Coleoptera. The Hercules beetle belongs to the family Scarabaeidae. It is classified as Dynastes hercules.


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To cite this page: Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S. Hammond, and T. A. Dewey. 2021. The Animal Diversity Web (online). Accessed at https://animaldiversity.org.

Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

This material is based upon work supported by the National Science Foundation Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.


Watch the video: Do you recognize this species? (August 2022).