Toxophora is distributed worldwide, being more diverse in the Afrotropical and Palearctic regions. Mexico's fauna includes three Neotropical species and five Nearctic species. All Nearctic species of Mexico were distributed in the western half of the country. These two new records represent the first of this genus in Coahuila and the most eastern distribution of the Nearctic species in the country. The New World species of this genus were keyed using Cunha et al. (2011).

CHU: Jul (1 M); EEO: Jul (2 F, 2 M), Oct (1 F, 3 M).

Mexico (Baja California, Baja California Sur, Coahuila); USA (Arizona, California, Idaho, Kansas, New Mexico, Oklahoma, Oregon, Texas).

In Mexico Toxophora maxima was only known from Baja California Peninsula and now Coahuila. This apparent gap in its distribution is probably due to undersampling. Sampling of the intermediate zones is necessary to know if these populations form a continuous unit as they do in the southern states of USA.

EAM: Jun (1 F, 1 M), Jul (1 F); CHU: Aug (1 M), Oct (1 M); EEO: Jul (1 M), Oct (1 F, 1 M); RLC: Jun (1 M); ROR: Apr (1 F, 2 M); RPA: Oct (1 F).

Mexico (Baja California Sur, Coahuila, Sonora); USA (Arizona, California, Colorado, Georgia, Idaho, Nevada, New Mexico, Oklahoma, Texas, Utah).

Odynerus sp. (Vespidae); Stenodynerus toltecus Saussure (Vespidae).

This species is present in the all southwestern states of the USA and northwest of Mexico. This is the first record in the northeast of Mexico. The species is probably also present in Chihuahua, between Sonora and Coahuila.

With 278 described species, Bombylius is the second most diverse genus of Bombyliidae. It has a worldwide distribution being especially diverse in the Palearctic and Nearctic regions. One endemic species is present in Coahuila: Bombylius (Parabombylius) coahuilensis (Hall & Evenhuis, 1981). Four other species are reported for the state: Bombylius sylphae Evenhuis, 1984, Bombylius aleophilus (Hall & Evenhuis, 1981), Bombylius paradoxus (Hall & Evenhuis, 1981), Bombylius syndesmus (Coquillett, 1894). A review with identification keys for Nearctic species is presented in Hall and Evenhuis (1980), later Evenhuis (1984) revised and present keys for the comanche group of America.

EEO: Aug (1 M), Oct (1 F).

Mexico (Chihuahua, Coahuila); USA (Arizona, New Mexico, Texas).

This species is restricted to the southwest of the USA and north of Mexico.

The genus is only present in Nearctic and Neotropical regions. Although not as diverse as other genera (only 12 species), specimens from some species are abundant in the field. Heterostylum robustum was previously known from Coahuila and was collected during this study. This species is distributed from Canada to central Mexico. There are two revisions for this genus that contains identification keys, one by Hall and Evenhuis (1980) and the more recent by Cunha et al. (2007).

REE: Apr (1 F).

Mexico (Coahuila); USA (Colorado, Kansas, Missouri, New Mexico, Texas).

Heterostylum croceum is recorded for the first time in Mexico; previously known from the southern-central United States. Hall and Evenhuis (1980) suggest that Heterostylum croceum may be related to Heterostylum engelhardti Painter, 1930 or even be a subspecies of that taxon, Heterostylum croceum is the eastern form and Heterostylum engelhardti the western form (Arizona, California, Texas, Utah) although both species are present in Texas. Cunha et al. (2007) comment that Heterostylum engelhardti can be distinguished by the presence of white to very pale yellow hair and brown-tipped hairs on the abdomen compared with the darker yellow hairs in Heterostylum croceum.

Most of the 29 species in this exclusively Nearctic genus are distributed in the southwest of the USA and north of Mexico, although eight species are present in the northwest of the USA (Lordotus apicula Coquillet, 1887; Lordotus bipartitus Painter, 1940; Lordotus diversus Coquillett, 1891; Lordotus gibbus Loew, 1863; Lordotus miscellus Coquillett, 1887; Lordotus pulchrissimus Williston, 1893; Lordotus striatus Painter, 1940; Lordotus zona Coquillett, 1887). The three species present in Coahuila are also found in California; their distribution probably includes all northern states of Mexico. Hall (1954) and Hall and Evenhuis (1982) present reviews of the genus and keys to the species.

CHU: Sep (2 M); RLC: Sep (2 M); RPA: Sep (1 F).

Mexico (Coahuila, Zacatecas); USA (Arizona, California, New Mexico).

ECA: Mar (1 M), Apr (2 M); EEO: Apr (16 M); REE: Apr (4 M); ROR: Apr (1 M).

Mexico (Coahuila, Baja California); USA (Arizona, California, Nevada, New Mexico, Texas).

CHU: Apr (1 H), ECA: Apr (1 H); EEO: Apr (4 F); REE: Apr (7 F); ROR: Apr (1 F).

Mexico (Baja California, Coahuila, Sinaloa, Sonora); USA (Arizona, California, Nevada, Texas).

Lordotus perplexus has the most southern distribution in the genus, reaching Sinaloa on the Pacific coast.

Four species of Triploechus are present in Nearctic region: Triploechus luridus Hall, 1975; Triploechus novus (Williston, 1893); Triploechus sackeni (Bigot, 1892); Triploechus stagei Hall, 1975. Of these Triploechus stagei is endemic to Mexico and Triploechus novus has the widest distribution of this genus, being present in the south of the USA and center of Mexico. Hall and Evenhuis (1981) present a revision and key for species for this genus.

CHU: Apr (7 F, 6 M); REE: Apr (1 M); RPA: Apr (1 M).

Mexico (Coahuila, Durango, San Luis Potosí, Sonora); USA (Arizona, California, Nevada, New Mexico, Texas).

This is a widespread and apparently common species. All specimens were collected in April so it may have a short flight season.

The only two species in this genus have been collected from the neotropical part of Mexico to north of the USA and Canada. Ogcodocera leucoprocta (Wiedemann, 1828), not sampled during this study, is present in the whole Nearctic region from Canada to south of Mexico.

EEO: Aug (2 M), Oct (1 M).

Mexico (Coahuila, Guerrero, Morelos); USA (Arizona, Texas).

This record is the first of this species in the north of Mexico, but it has been previously collected in the south of Mexico and in the south of USA, and thus is probably distributed across the whole country. Unlike Ogcodocera leucoprocta, Ogcodocera analis has its most northern distribution in Arizona and Texas.

All five extant species of Paracosmus have Nearctic distributions, and all are present in California. Two of these species have been collected in the northwest of Mexico (Paracosmus (Actherosia) rubicundus Melander, 1950 and Paracosmus (Paracosmus) morrisoni Osten Sacken, 1887).

EAM: Apr (1 F, 1 M); CHU: Apr (2 M), Jul (1 F), Aug (2 F); ECA: Apr (1 M); EEO: May (1 F); REE: Apr (1 F); ROR: Apr (2 M), May (1 F, 3 M); RPA: Apr (1 F).

Mexico (Coahuila, Sonora); USA (Arizona, California, Nevada, Texas).

Paracosmus (Paracosmus) morrisoni has the widest distribution within this genus, but in Mexico had previously only been recorded in Sonora. This record represent the most eastern distribution for the genus in the country.

This is a diverse genus with 248 species worldwide. Two old but complete revisions of the genus, including distribution maps and keys, were made by Marston (1963, 1970). Thanks to these Anthrax species can be easily identified. Some Anthrax species are widely distributed occupying two biogeographic regions. From the seven Anthrax species collected in this study in Coahuila, just Anthrax cybele (Coquillett, 1894) has a restricted distribution. The other six species are widespread across the Nearctic region. Two species of Anthrax are reported for the first time for Mexico.

EAM Apr (1 F); ROR: Oct (2 M); RPA: Aug (1 M); Sep (1 M); Oct (1 F, 2 M).

Mexico (Baja California Sur, Coahuila, Durango, Sonora, Tamaulipas); USA (Arizona, California, New Mexico, Oregon, Texas, Utah).

Megachile gentilis Cresson (Megachilidae).

This species may be present in all the north of Mexico, including Chihuahua, Nuevo León and possibly Sinaloa.

ECA: Apr (2 F); EEO: Apr (1 M).

Mexico (Coahuila); USA (Arizona, California).

This is a rare species flying in April. Its distribution is disjunct so far, present in the southwest of the USA and northeast of Mexico. It is probably also found in New Mexico and Texas in the USA and Sonora and Chihuahua in Mexico.

EAM: Mar (1 F), Apr (1 M), Jun (1 F, 2 M), Jul (2 F), Sep (2 M); ROR: Apr (1 F), Sep (1 M); RPA: Mar (1 M), Apr (1 F, 1 M), Jul (2 F, 1 M), Sep (6 F, 3 M), Oct (6 F, 3 M).

Canada (Alberta, British Columbia, Manitoba, Northwest Territory, Ontario, Quebec, Saskatchewan); Mexico (Coahuila, Guerrero, Michoacán de Ocampo, Morelos, Nuevo León, Puebla, Sonora, Veracruz); USA (Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Idaho, Illinois, Iowa, Kansas, Kentucky, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming).

The range of Anthrax georgicus includes all North America and Central America (Nicaragua, Costa Rica) covering a wide diversity of habitats and environmental conditions. Common in the rainy season and present in the dry season (March), this species is probably present in most if not all states of Mexico, but has only been collected in eight of them.

EAM: Apr (1 M), Aug (2 M), Oct (1 M); ECA: Apr (1 F), May (1 F, 1 M); EEO: Apr (2 F), Jul (4 F), Aug (1 M); REC: Apr (3 F, 10 M), Aug (1 M); REE: Aug (1 M); RLC: Jul (6 F, 10 M); ROR: Feb (1 M), Aug (5 M), Sep (1 M); RPA: Apr (1 M), Aug (2 M).

Canada (Alberta, British Columbia, Manitoba, Northwest Territory, Nova Scotia, Ontario, Quebec, Saskatchewan); Mexico (Baja California, Baja California Sur, Coahuila, Colima, Guerrero, Michoacán, Morelos, Nayarit, Puebla, San Luis Potosí, Sinaloa, Sonora, Veracruz, Zacatecas); USA (Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Idaho, Illinois, Indiana, Kansas, Maryland, Massachusetts, Michigan, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Tennessee, Texas, Utah, Virginia, West Virginia, Wyoming).

Megachile gentilis Cresson (Megachilidae); Megachile mendica Cresson (Megachilidae); Dianthidium heterulkei fraternum Timberlake (Megachilidae); Aschmendiella bucconis denticulata Cresson (Megachilidae); Hylaeus asininus Cockrell and Casad (Colletidae). Scott and Strickler (1992) also reared Anthrax irroratus from Megachile relativa Cresson (Megachilidae) and Megachile inermis Provancher (Megachilidae).

Anthrax irroratus, like Anthrax georgicus (above), is present in all of North America and reaches Central America and Caribbean islands (Honduras, Puerto Rico). More abundant than its congener, this species has been collected in 15 states in Mexico (including Oaxaca of the Neotropical region not listed above) and all regions of the USA. Anthrax irroratus should be collected in any systematic, long term Bombyliidae sample in Mexico and the USA.

ECA: Apr (1 F, 1 M), Jul (1 F); EEO: Apr (2 F, 1 M), May (1 F, 4 M), Jul (1 M); REC: Apr (1 F); REE: Apr (2 M); RLC: Jul (2 F, 4 M), Sep (1 F); RPA: Apr (1 M), Aug (1 M).

Mexico (Baja California, Coahuila, Nayarit, Morelos, Sinaloa, Sonora); USA (Nevada, Texas).

Apparently closely related to Anthrax irroratus, Anthrax oedipus has a narrow distribution in the Nearctic region but is widely distributed in all South America. In the USA it has been collected only in two southern states, while it occurs in most of the northern states of Mexico and one central state (Morelos); it may be present in most areas from Texas to Argentina.

CHU: Apr (1 F, 1 M).

Canada (Ontario); Mexico (Coahuila); USA (Alabama, Colorado, Illinois, Indiana, Kansas, Maryland, Massachusetts, Michigan, Nebraska, New Jersey, New Mexico, New York, Oklahoma, Pennsylvania, Texas, Utah, Vermont, Virginia, Wisconsin).

With just two specimens collected, Anthrax pauper appears to be a rare species in this region. This population is the most southern recorded of this species, mostly present in the center and east of the USA. Presumably adapted to colder climates, it is no coincidence that it was collected in the most elevated site sampled.

EAM: Jun (1 M); CHU: Apr (1 F), Aug (1 F), Sep (1 F); ECA: Jun (1 M); REE: Aug (1 F); RLC: Jun (1 F), Jul (1 F, 2 M).

Mexico (Baja California Sur, Coahuila, Sonora, Puebla); USA (Arizona, Nevada, New Mexico, Texas).

This species is recorded mostly from the south of the USA and north of Mexico, but its presence in Puebla in central Mexico suggests a wider distribution within the country, at least in all northern states.

Dipalta is a small genus with just two species. Dipalta banksi Johnson, 1921 is only present in eastern Canada and USA, while Dipalta serpentina is distributed from Central America to the northern USA.

REC: Aug (1 M); RLC: Jul (1 M).

Mexico (Coahuila, Guerrero, Hidalgo, México, Morelos, Puebla, San Luis Potosí, Sinaloa); USA (Arizona, Arkansas, California, Colorado, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Mexico, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, South Dakota, Tennessee, Texas, Utah, Washington, Wisconsin, Wyoming).

Myrmeleon immaculatus De Geer (Myrmeleontidae).

This species is probably present in all of Mexico, but this is the only record in the north of Mexico.

Hemipenthes is equally diverse in the Nearctic (29 species), Neotropical (26 species) and Palearctic (37 species) regions, with just six species in the Oriental region and one in the Afrotropical region. Four species of this genus were collected in Coahuila. All of these have broad distributions but apparently from poor sampling because records are not continuous, especially in Mexico. Ávalos-Hernández (2009) recently published a revision of Hemipenthes, with a key for Nearctic species.

REC: Apr (18 F), Aug (4 F); REE: Feb (3 F); RLC: Mar (7 F), Jul (23 F, 3 M), Sep (3 F).

Mexico (Coahuila, Morelos, Sonora); USA (Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Texas, Utah).

Present mainly in the Pacific coast states of the USA and Mexico, from Oregon as far as Morelos in the center of Mexico. This record is the most eastern record in Mexico.

EAM: Apr (1 M), Aug (1 F); CHU: Apr (1 F, 3 M), Aug (1 M); EEO: Jul (1 F, 4 M), Aug (1 F); REC: (1 M); REE: Apr (11 F, 2 M), Aug (1 F); RLC: Jun (1 F), Jul (3 F); RPA: Apr (1 F), Sep (4 F), Oct (2 F).

Canada (Alberta); Mexico (Baja California, Baja California Sur, Coahuila, Chihuahua, Guerrero, Morelos, Puebla, San Luis Potosí, Sonora, Tamaulipas); USA (Arizona, California, Colorado, Idaho, Louisiana, Nevada).

This species is abundant in the rainy season in most of the Nearctic region but has not been collected in many states of Mexico or the USA where it probably is present.

REC: Apr (23 M), Aug (7 M); REE: Feb (5 M), Apr (2 M); RLC: Mar (8 M), Jul (8 M), Sep (9 M).

Mexico (Coahuila, Morelos, Guanajuato, Sonora); USA (Arizona, Texas).

Males of this species are abundant all year long but females are unknown. There is no explanation for this lack of females in the collections. Extreme sexual dimorphism and misidentification of females can be dismiss, since there is no Hemipenthes species from which only females are known. One possible explanation is that females life span is too short and therefor encounter probabilities are low. Distribution is discontinuous with populations present in central and northern Mexico and the southern USA; it is unknown whether this species is present in between these areas.

REC: Apr (3 F); REE: (Feb (1 F), Apr (2 F); RLC: Jul (1 F, 1 M), Sep (1 M); RPA: Sep (2 F).

Mexico (Coahuila, Morelos); USA (Alabama, Arizona, Arkansas, Connecticut, Delaware, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Massachusetts, Minnesota, Mississippi, Missouri, Nebraska, New Jersey, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Vermont, Virginia, West Virginia, Wisconsin).

Neodiprion sertifer Geoff. (Diprionidae).

Hemipenthes sinuosa is only known from Morelos in the center of Mexico and Coahuila in the northeast, but can be found almost in all of the USA. It is clearly undersampled in Mexico.

Forty seven of the 52 species of Lepidanthrax are from the Nearctic region. Hall (1976) published a revision of this genus including keys for species.

EEO: Mar (1 F); Oct (2 M).

Mexico (Coahuila); USA (Arizona).

Lepidanthrax arizonensis has a restricted distribution, being present only in Arizona and Coahuila, but probably is also present in Chihuahua, Texas and New Mexico.

REC: Aug (2 F, 1 M).

Mexico (Coahuila, Distrito Federal, Guerrero, Veracruz); USA (Arizona).

The distribution of Lepidanthrax disiunctus has its northern extreme in Arizona and its southern extreme in Oaxaca, in the southeast of Mexico. It seems this species is rarely collected, but widely distributed.

EAM: Apr (2 M); CHU: Apr (2 F, 5 M); ROR: Apr (1 F, 3 M), May (1 F, 1 M); RPA: Apr (1 F, 14 M).

Mexico (Baja California, Coahuila, Sinaloa, Sonora); USA (Arizona, California, New Mexico, Texas).

This record is the first in northeastern Mexico.

RLC: Sep (4 F, 15 M).

Mexico (Coahuila, Guerrero, Morelos, Puebla).

Lepidanthrax hyposcelus is endemic to Mexico, previously only known from the southwest of the country; this record extends its distribution to the northeast of the country.

ECA: Sep (1 F, 2 M); EEO: Apr (1 F), Aug (1 F, 1 M), Oct (4 F, 15 M); ROR: Sep (2 M); RPA: Sep (2 M), Oct (1 M).

Mexico (Baja California, Baja California Sur, Coahuila, Durango, Guerrero, Morelos, Sonora); USA (Arizona, California, Nevada, New Mexico, Utah).

Lepidanthrax proboscideus, Lepidanthrax fuscipennis Hall, 1976 and Lepidanthrax disiunctus are the only species of this genus distributed in both the Nearctic and Neotropical regions. Of these Lepidanthrax proboscideus extends as far as El Salvador, the most southern distribution for a Nearctic species of this genus. This is the first record of this species in the northeast of Mexico.

Neodiplocampta is a small American genus, more diverse in the Neotropical than the Nearctic region. Hull and Martin (1974) described seven of the 16 species and published a key for all species of the genus.

CHU: Aug (1 F); EEO: Aug (1 F, 1 M); ROR: Jul (1 F); Oct (1 M); RPA: Aug (1 F, 2 M).

Mexico (Coahuila, Guerrero, San Luis Potosi, Sinaloa, Sonora); USA (Arizona, California, Florida, Texas).

Neodiplocampta (Neodiplocampta) miranda and Neodiplocampta (Agitonia) sepia Hull, 1966 are the only two species distributed in both biogeographic regions (Nearctic and Neotropical). This species is distributed from the south of the USA to Nicaragua, but has not been collected in most Mexican states. This lack of records is possibly due its low abundance.

Fifty five of the 58 species of the genus are Nearctic. All species of Paravilla collected in Coahuila were exclusively collected in the summer months from April to July. Hall (1981a) reviewed this genus and presented a key for species and description of new species.

EAM: Jun (1 M); CHU: Apr (1 F), Jul (2 F, 1 M); ECA: Apr (1 F, 1 M), Jul (1 M); EEO: Apr (1 F, 10 M), May (1 F, 2 M), Jul (9 M); REE: Apr (1 M); RLC: Jun (2 F, 5 M), Jul (1 F); ROR: Jul (1 F, 3 M); RPA: Oct (1 M).

Canada (Saskatchewan); Mexico (Chihuahua, Coahuila, Durango, Jalisco, México, Zacatecas); USA (Arizona, Colorado, Idaho, Kansas, Montana, Nebraska, New Mexico, Oklahoma, Utah, Texas, Wyoming).

This species is very abundant and present in most of North America, from Canada as far as Jalisco in central Mexico.

CHU: Apr (1 M); Jul (1 M); ECA: Apr (1 M); EEO: Apr (7 M), May (11 M); ROR: Apr (2 M); RPA: Apr (1 M).

Mexico (Baja California Sur, Coahuila, Nuevo León); USA (Arizona, California, Colorado, Texas).

Paravilla flavipilosa is abundant and restricted to the south of the USA and north of Mexico.

EAM: Apr (1 F); CHU: Apr (1 M); RPA: Apr (7 F, 13 M).

Mexico (Chihuahua, Coahuila, Durango, Guanajuato, Hidalgo, Jalisco, México, Michoacán, Nuevo León, San Luis Potosí, Sonora, Zacatecas), USA (Arizona, New Mexico, Texas, Utah).

Paravilla parvula is relatively well collected in northern and central Mexico. Its distribution also includes the south of the USA but no farther north than Utah.

CHU: Apr (1 F); EEO: Apr (3 F); REE: Apr (5 F, 3 M); RPA: Apr (1 M).

Canada (Ontario, Manitoba); Mexico (Coahuila); USA (Alabama, Florida, Georgia, Iowa, Kansas, Michigan, Minnesota, Mississippi, Nebraska, Ohio, South Dakota, Wisconsin).

Paravilla separata is present mainly in the eastern half of the USA, and southeastern Canada. This record in Coahuila represents the southern extreme of the distribution of this species, and is the first in Mexico. It may also be present in Tamaulipas and Nuevo León but doubtfully in the northwest of Mexico.

Four species from this mainly Nearctic genus are recorded in Coahuila for the first time. Painter and Hall (1960) published a review of Poecilanthrax with a key and images of the species.

EAM: Apr (1 F, 1 M), Jun (1 F, 1 M), Sep (1 F); CHU: Jun (1 F); ROR: May (10 F, 5 M), Jul (2 F, 3 M), Aug (1 M); RPA: Jun (4 F, 1 M), Jul (6 F, 6 M), Aug (1 F, 1 M), Sep (4 F), Oct (2 F, 1 M).

Mexico (Baja California Sur, Chihuahua, Coahuila, Sonora, Tamaulipas); USA (Arizona, California, New Mexico, Oklahoma, Texas).

This record fills a gap in Poecilanthrax effrenus distribution between northwest and northeast populations of Mexico. This species is probably present in Baja California and Nuevo León, but has not yet been recorded.

EAM: Sep (1 M); CHU: Oct (1 M); ROR: Oct (1 M); RPA: Oct (1 M).

Mexico (Coahuila); USA (Colorado, Kansas, Texas).

Chorizagrotis auxiliaris Grote (Noctuidae).

Poecilanthrax fasciatus is collected in Mexico for the first time, and this extends the southern limit of this species distribution.

EAM: Mar (3 M), Oct (1 F); CHU: Oct (1 M); ROR: Oct (4 M); RPA: Sep (1 F), Oct (2 F, 6 M).

Mexico (Coahuila); USA (Arizona, California, Nevada, Utah).

This record extends the distribution of Poecilanthrax hyalinipennis into the northwest of Mexico. Considering its distribution in the USA, this species may also be present in the northeast of Mexico.

REE: Apr (2 M).

Canada (Alberta, Manitoba, Ontario, Saskatchewan); Mexico (Coahuila, Morelos, Nuevo León, Sonora); USA (Arizona, California, Colorado, Idaho, Nevada, New Mexico, Oregon, Utah).

Most of the records in the USA and Mexico of this rarely collected but widespread species are from Pacific Coast states, although, there are records from Nuevo Leon and Coahuila in northeast Mexico.

Of the seven species of this exclusively Nearctic genus, six are present in Mexico, with Rhynchanthrax maria (Williston, 1901) and Rhynchanthrax nigrofimbriatus (Williston, 1901) being endemic to this country. Only Rhynchanthrax parvicornis (Loew, 1869) has not been collected in Mexico, but it is distributed across the southern USA and may also occur in the north of Mexico.

CHU: Apr (1 M), Aug (13 F, 6 M), Jul (12 F, 6 M), Sep (1 F, 3 M).

Mexico (Coahuila); USA (Arizona, California, Colorado, Nebraska, Nevada, New Mexico, Utah).

This is the first record of this species in Mexico. Rhynchanthrax capreus is the only species occurring in the northwest of the USA, while the other species in the genus are present mainly in the south and east of the country. This species may also be present in the northwest of Mexico (Baja California, Sonora, Chihuahua).

EEO: May (1 M); RLC: Jun (1 F, 11 M), Jul (3 M).

Mexico (Coahuila, Sonora); USA (Kansas, New Mexico, Texas).

This is the most eastern record in Mexico for this species. In the USA it is distributed in the southern-center of the country, but in Mexico it has been collected in Sonora so it probably also occurs in Arizona.

Thyridanthrax has twice as many species in the Palearctic region as in the Nearctic and Neotropical regions combined. All 12 species in North America are present in the USA with five also in Mexico. These are the first records of this genus in Coahuila. The distribution of Thyridanthrax selene (Osten Sacken, 1886b) and Thyridanthrax pallidus (Coquillett, 1887) are very similar, being present in all of the southern USA and probably also in all of northern Mexico, although they have been only collected in Sonora and Coahuila to date. Both species are rare and were collected only in April.

REE: Apr (4 F, 1 M).

Mexico (Coahuila); USA (Arizona, California, Nevada, Texas, Utah).

This represents the first record of this species in Mexico.

EAM: Apr (1 M); REE: Apr (2 F, 2 M).

Mexico (Coahuila, Sonora); USA (Arizona, California, Texas).

This is the most eastern record in Mexico.

Of the five species that constitute this genus, four are present in Mexico.

ECA: Sep (1 M).

Mexico (Chihuahua, Coahuila, Sonora), USA (Arizona, New Mexico, Texas).

Xylocopa micheneri micheneri (Hurd) (Apidae) as reported by Minckley (1989).

Xenox xylocopae appears to be restricted to the northeast of Mexico and south of the USA. Three of the other species also have restricted and separate distributions: Xenox delila Loew, 1869 is present in the northwest of Mexico and California; Xenox nigritus (Schaeffer, 1768) occurs from the northeast of Mexico (Veracruz and Tamaulipas without overlap with Xenox xylocopae) to South America; and Xenox tigrinus (De Geer, 1776) is present in the eastern USA and southern Ontario. Only Xenox habrosus (Marston, 1970) has a distribution overlapping with the other four species, being present in all of Mexico and the southwest of the USA.