Acmaeodera
Creators: name: Davidson, J. M.
Publisher: name: Zenodo
Year: 2003
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Buprestidae
Acmaeodera

description: Acmaeodera (Squamodera), stat. nov.
Squamodera Nelson, 1996:167.
Type species: Acmaeodera vanduzzei Van Dyke, 1934 (original designation).
Nelson (1996) described the genus Squamodera to accommodate four previously described species of A cmaeodera: A. barri Cazier, 1940, A. constricticollis Knull, 1937, A. ephedrae Barr, 1943 and A. vanduzzei Van Dyke, 1934 and its three synonyms (see below). The decision to erect a new genus for these species appears to have been based mainly upon anatomical characteristics which are sometimes found in other species of Acmaeodera as well as in related genera. The squamose setae or scales common to all species of Squamodera are also found on Acmaeodera mimicata Knull, 1938, A. fattigi Knull, 1953 and A. lauta Barr, 1972, as well as a few other species of Acmaeodera and related genera such as Acmaeoderopsis Barr, 1974 and Acmaeoderoides Van Dyke, 1942. The latter genus is placed into a separate subtribe from the other genera discussed herein. The s errate parts of the antennae are indeed somewhat subcylindrical in Squamodera, but this feature is not unique to this small complex of species. The combination of characteristics used to define Squamodera is not sufficient to justify a genus separate from Acmaeodera.
Therefore, I propose Squamodera, and the four species and synonyms contained therein, be transferred to Acmaeodera as a subgenus (listed below). Unlike the Palearctic and Afrotropical Acmaeodera faunas, which have been well studied and divided into several subgenera (e.g. Volkovitsh, 1979, Holm, 1978, Holm & Schoeman, 1999), no comprehensive study of Nearctic or Neotropical A cmaeodera has been conducted with the objective of determining whether closely related species or species complexes should be placed in separate subgenera. Except for the four species in the subgenus Acmaeodera (Squamodera), no Acmaeodera species known from the Nearctic or Neotropics have yet been placed into particular subgenera. Bellamy (1995) succinctly illustrated the very difficult task facing researchers who are working on the huge genus Agrilus Curtis, 1815, in trying to divide this group into more manageable segments, i.e. subgenera. In his closing arguments, he suggested that we need to agree upon a "… philosophy that will allow researchers from different regions and backgrounds to approach their studies of Agrilus from some point of agreement, despite the fact that no clear definition or agreement has ever been reached about what constitutes a genus as opposed to a subgenus or species group." However, Holm & Schoeman (1999) presented "criteria and considerations on erecting genera" [and subgenera], and my approach here appears to coincide with their criteria for purposes of placing Squamodera as a subgenus of Acmaeodera. The fundamental principles espoused by both Bellamy (1995) and Holm & Schoeman (1999) apply not only to Agrilus, but also to Acmaeodera, Anthaxia Eschscholtz, 1829, Chrysobothris Eschscholtz, 1829, and other genera containing large numbers of species.
It appears that the four valid species included in Acmaeodera (Squamodera) might comprise a monophyletic group, i.e., are more closely related to one another than to any other species or species group, and are adapted to the hot dry deserts of the southwestern United States and adjacent northern Mexico. These species are very closely related and occasionally are difficult to separate from one another, especially A. (Squamodera) vanduzzei from A. (Squamodera) ephedrae. The latter species appears to be restricted to a relatively small sandy area in southern California. The former species occupies a considerably larger distributional range, at least as far north as the lower end of the Owens Valley and is sometimes found in environments with somewhat reduced amounts of sand. It seems to be most frequently associated with plants of the genus Eriogonum (Polygonaceae). Acmaeodera (Squamodera) barri appears to have adapted to the southwestern deserts and occurs mainly on smokebush or smoketree, Dalea spinosa Gray (Fabaceae), but sometimes utilizes other species of Dalea as well. This is a rather whitish or pale, smoky colored plant, and because A. (S.) barri is completely covered in silvery­white scales, may have found protection from predators by using this as an adult host or perch. Knull (1950) recorded Dalea as a larval host, and small oval emergence holes in Dalea spinosa I observed while collecting this species might indicate that A. (S.) barri uses this plant as a larval host as well. Acmaeodera (Squamodera) barri is found in western Arizona as well as in southern California. Acmaeodera (Squamodera) constricticollis appears to occupy a more restricted distribution in southeastern California, and appears to be allopatric with A. (S.) ephedrae, but partially sympatric with A. (S.) barri and A. (S.) vanduzzei. It occurs in areas where flowering arrow weed, Pluchea sericia (Nutt.) Coville (Asteraceae) is found, and it is evident this is at least one of its adult host plants. Thus, species of Acmaeodera (Squamodera) have radiated not only in differences in form and scale structure, but also to different geographic areas and adult (and perhaps larval) hosts, insuring that they do not compete with one another for resources.
In the recent past, approximately 5,000 to 10,000 years ago, the area in which these species are now found was much wetter than it is today, and the host plants that occur today did not exist at that time (Betancourt, et. al, 1990). Many desert shrubs and small trees that exist in the southwestern deserts today originated much further south and invaded northward as temperatures warmed and the land became more arid. Whether these beetles are recently derived from a species or species complex from that period and adapted to gradual climatic and changes in plants, or whether these are merely invaders from Mexico cannot be determined with certainty. A similar situation is known from extreme southern Europe and North Africa, where the climate was more mesic over the same time period. Where the Sahara Desert now exists, a savanna with trees, shrubs and grasses occurred. Species of Buprestidae extant in North Africa are adapted to a much more xerophytic environment than in the previous ten millennia. Species of Acmaeodera (Squamodera) are slightly elongate, with white scales on various or all body parts. However, as previously mentioned, scales are not unique to A. (Squamodera) spp., and neither is their somewhat elongate body form. The species of the A cmaeodera faceta, A. bivulnera, A. acanthicola complex are elongate but all are without scales. Clearly, scales are a type of setae, almost always flattened, exhibited in various shapes and sizes, and are likely used as a mechanism of reflecting heat from the body parts as well as possibly "hiding" them from predators on similarly colored plants. The elongate body form is found in many genera of Buprestidae, from all parts of the world, and its derivation and particular function is not understood. Whether understood or not, the elongate 'morphotype' has adaptive survival value because it is found in so many unrelated taxa throughout so much of the world. (e.g. Agrilus spp., Coraebus spp., Dinocephalia spp., Iridotaenia spp., Mixochlorus spp., Philandia spp., Phrixia spp., Ptosima spp., Synechocera spp.)
The species of Acmaeodera (Squamodera) are:
A. (S.) barri Cazier, 1940
A. (S.) constricticollis Knull, 1937
A. (S.) ephedrae Barr, 1943
A. (S.) vanduzzei Van Dyke, 1934 Syn. A. fisheri Cazier, 1940
Syn. A. vermiculata Knull, 1947 Syn. A. nanbrownae Figg­Hoblyn, 1953 A checklist of the species of Acmaeodera known from Mexico
acanthicola Barr, 1972:177 actites Westcott, 2002:23
acuminata Kerremans, 1900:378 adenostomensis Knull, 1941:691 adusta Barr, 1972:183
aeneoflava Westcott, 1998:9 alacris Horn, 1878:25
alicia Fall, 1899:29
amplicollis LeConte, 1866:383 angelica Fall, 1899:16
apiata Nelson, 1994:277
aquila Nelson, 1994:279
aurantiofasciata Westcott and Noguera, 1995:39 aurantiomarginata Westcott, 1997:98 aurora Fall, 1922:88
bacchariphaga Westcott & Verity, 1977:149 barri Cazier, 1940:58
bivulnera Horn, 1894:371
cactophila Westcott & Noguera, 1995:36 cazieri Knull, 1960:6
chemsaki Barr, 1992:75
clausa Horn, 1894:374
clypeata Barr, 1972:181
comata LeConte, 1858:70 convicta Fall, 1899:11
cordatistigma Westcott, 1998:9 corrosa Thomson, 1878:58 cribricollis Horn, 1894:375 croceonotata Gory, 1840:27 crossi Barr, 1992:72
crotonae Westcott & Noguera, 1995:41 cuprina Spinola, 1838:367 davidsoni Barr, 1972:179
decipiens LeConte, 1866:383 delectabilis Waterhouse, 1889:180 delumbis Horn, 1894:378
digna Barr, 1992:71
discalis Cazier, 1940:24
discolor Barr, 1992: 79
disjuncta Fall, 1899:9
divina Théry, 1926:43
dolorosa dolorosa Fall, 1899:25 dozieri Barr, 1992:78
ephedrae Barr, 1943:113
exilis Waterhouse, 1882:27 faceta Fall, 1907:241
fenyesi Fall, 1899:12
flavomarginata (Gray), 1832:538 flavopicta Waterhouse, 1889:180 flavosparsa Waterhouse, 1882:22 flavosticta Horn, 1878:15 gibbula LeConte, 1858:69 gibbuloides Westcott, 1998:10 griswoldi Westcott, 2002:24 haemorrhoa LeConte, 1858:69 hepburni LeConte, 1860:254 hirtula Gory, 1840:29
impluviata Mannerheim, 1837:26 iridea Kerremans, 1902:28 jeanae n. sp.
jocosa Fall, 1899:14
jubata Barr, 1992:73
jucunda Dugès, 1891:14
kathyae Westcott, 1996:22
kaupii Thomson, 1878:58
knabi Fisher, 1949:337
labyrinthica Fall, 1899:21
lagunae Van Dyke, 1945:104 lateralis Chevrolat, 1834:No. 6 latiflava latiflava Fall, 1907:240 lauta Barr, 1972:184
lesnei Kerremans, 1906:72 loei Manley, 1987:22
longipennis Waterhouse, 1882:25 lucana Van Dyke, 1942:103 lysilomae Nelson, 1994:281 maculifera Horn, 1894:372 marginarcuata Westcott, 1998:11 miliaris Horn, 1878:10
mima Gory, 1840:29
mimicata Knull, 1938:136
mimicomixteca Westcott, 1998:8 mixta LeConte, 1860:227
mixteca Westcott, 1998:7
moesta Dugès, 1891:11
montezuma Obenberger, 1924:35 monticola Fisher, 1949:341 mudgei Westcott, 2002:23
neoneglecta Fisher, 1949:336 oaxacae Fisher, 1949:340
opinabilis Fall, 1899:30
paradisjuncta Knull, 1940:36 parkeri Cazier, 1940:22
picta Waterhouse, 1882:24
pinalorum Knull, 1930:15
plagiaticauda Horn, 1878:10 proxima Waterhouse, 1889:178 pubiventris lanata Horn, 1880:148 pubiventris yumae Knull, 1937:301 pueblana Obenberger, 1916:9 pulchella (Herbst), 1801:211 quadriseriata Fall, 1899:18
quadrivittata Horn, 1870:79
quadrivittatoides Nelson & Westcott, 1995:77 recticolloides Westcott, 1971:3 reflexa Barr, 1992:74
resplendens Van Dyke, 1937:106 retifera LeConte, 1859:72
riograndei Nelson, 1980:175
rubescens Schaeffer, 1904:210 rubrocuprea Westcott & Nelson, 2000:302 rubroguttula Nelson, 1994:275 rubronotata Laporte and Gory, 1835:5 rubrovittata Nelson, 1994:272 rufolateralis Westcott, 1998:12 ruricola Fisher, 1949:333
rustica Fisher, 1949:338
sabinae Knull, 1937:15
scalaris Mannerheim, 1837:25 scapularis Horn, 1894:328
serena Fall, 1899:16
setosa Waterhouse, 1882:26
sinaloensis Dugès, 1891:14
singularis Barr, 1992:77
sinuosa Kerremans, 1906:45
solitaria Kerremans, 1897:40 sphaeralcae Barr, 1972:166
stellaris Chevrolat, 1835:No. 189 stigmata Horn, 1894:370
subbalteata LeConte, 1863:82 sulcicollis Kerremans, 1914:258 superba Waterhouse, 1882:23 tarahumara Westcott, 1998:13 tenuidigna Nelson, 1994:276
thoracica Kerremans, 1910:268 tildenorum Nelson & Westcott, 1995:85 transversa Van Dyke, 1945:105 trizonalis trizonalis Kerremans, 1892:181 trizonalis islamariae Westcott, 1998:14 turnbowi Westcott, 1996:25
unica Kerremans, 1897:41
unicolor Fisher, 1949:335
uvaldensis Knull, 1936:73
vanduzeei Van Dyke, 1934:23 venusta Waterhouse, 1882:25 vernalis Barr, 1972:160
vipera Kerremans, 1906:110 viridissima Chevrolat, 1835:No.73 wenzeli Van Dyke, 1919:154 wheeleri Van Dyke, 1919:155 wickenburgana Knull, 1939:28 zacatecana Westcott, 2002:26
description: Published as part of Davidson, J. M., 2003, Mexican Acmaeodera Eschscholtz, 1829: A new species and checklist, with miscellaneous taxonomic and biological notes on other North American Buprestidae (Coleoptera), pp. 1-18 in Zootaxa 201 on pages 5-12, DOI: 10.5281/zenodo.156682