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Aphididae : Aphidinae : Aphidini : Braggia
 

 

Genus Braggia

Buckwheat aphids

On this page: Genus Braggia columbiana deserticola eriogoni longicauda urovaneta

Braggia [Macrosiphini]

Braggia are medium-sized aphids which have the dorsal cuticle strongly reticulated, often with white, and have variably developed dark sclerotization heavily set with coarse blunt spines or plates. The antennae are short, with a very short terminal process which is always less than twice the base of antennal segment VI. The apterae often have secondary rhinaria on antennal segments III or III-V. Antennal tubercles and median frontal tubercles are poorly developed. The apical rostral segment is long and narrow, more than twice as long as its width. Abdominal tergites I & VII usually have marginal tubercles. The siphunculi are short, dark, coarsely imbricated, and less than 3 times longer than the width at base. The cauda is short, broadly triangular, usually equal to or less than 1.25 times its width at base. They are apparently quite closely-related to Aphis, but have a shorter terminal process, short siphunculi, and a very short broad cauda.

There are about 12 species in the genus which live without host alternation on buckwheat (Eriogonum) in western USA.

 

Braggia columbiana (Arrowleaf buckwheat aphid) Pacific Northwest USA

Adult apterae of Braggia columbiana (see first picture below) are black or blackish-brown with a white or whitish-gray pattern of wax on the dorsum. Their appendages are brownish-black to brown, except for a pale basal half of antennal segment III, pale middle areas of front femora and tibiae, and a dusky cauda. The dorsal integument is faintly to moderately reticulate on the head and abdominal dorsum. The antennal tubercles are weakly developed. The antennae are short, 0.51-0.83 times the body length, with the terminal process 1.77-2.90 times the base of antennal segment VI. The longest hair on antennal segment III is slightly longer than basal diameter of that segment. There are usually secondary rhinaria on antennal segments III-V (cf. Braggia longicauda, which usually has no secondary rhinaria on these segments). The rostrum extends to the metacoxae, and the apical rostral segment is 0.19-0.24 mm long with 2 accessory hairs (cf. Braggia agathona & Braggia eriogoni, which have RIV+V usually less than 0.19 mm long). The first tarsal segments all have 2 hairs. There are marginal tubercles on the pronotum, and abdominal tergites I & VII. The siphunculi are imbricated, subcylindrical, tapering and flanged. The cauda is wider than long, with a total of 5-15 hairs. The body length of adult Braggia columbiana apterae is 1.41-2.56 mm. Immatures are black with transverse stripes of whitish wax.

First image above copyright Andrew Jensen, second image copyright Ken Chamberlain,
both under a cc by-nc-sa licence.

Alate Braggia columbiana viviparae (not pictured) have secondary rhinaria on antennal segments III-V. The abdominal tergites have definite pigmented marginal spots and usually transverse dark stripes.

Braggia columbiana is monoecious on buckwheat (Eriogonum spp.), predominantly Eriogonum compositum (see second picture above), less commonly Eriogonum umbellatum and infrequently on Eriogonum elatum, Eriogonum pyrolifolium, and Eriogonum strictum. It is assumed to be holocyclic, but sexual morphs are so far undescribed. It is presently known only from Oregon and Washington states, USA.

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Braggia deserticola ( Californian buckwheat aphid) Southwest USA, Mexico

Adult apterae of Braggia deserticola (see pictures below) have the head, prothorax and tergite VIII wax-dusted; abdominal tergite I has reticulations lightly bordered with secreted wax, but the remaining tergites are shining dark brown (cf. Braggia eriogoni, which has much of the dorsum covered with wax-bordered reticulations). The antennae are about 0.62-0.67 times body length. They are mainly dusky or dark, but the basal 0.2-0.5 of segment III is transparent to yellowish. The legs are mostly dark pigmented, but sometimes with part of the tibiae and fore femora rather pale to yellowish. Marginal tubercles on abdominal tergite VII are normally absent (cf. Braggia eriogoni, which has marginal tubercles on tergite VII). Dorsal hairs are short & inconspicuous, at most equal to the basal diameter of antennal segment III (cf. Braggia eriogoni, which has dorsal hairs mainly longer than the basal diameter of antennal segment III). The siphunculi are volcano-shaped to strongly tapering, and are very short, at most about as long as their basal widths (cf. Braggia eriogoni and Braggia urovaneta, which have siphunculi longer than their basal width). The cauda is black, half as long as its basal width, with 7-11, rather inconspicuous hairs. The body length of adult Braggia deserticola apterae is 1.1-1.8 mm. Immatures are deep chestnut brown, and are wax dusted.

Images above copyright Jesse Rorabaugh under a public domain (CCO) licence.

The alate Braggia deserticola is black dorsally, and greyish ventrally. The antennae have only the very base of segment III somewhat transparent; segment III bears 9-16 flattish secondary rhinaria, IV has 3-6 rhinaria, & V has 0-4. The abdomen has rather large, darkish, marginal sclerites, pleural intersegmental sclerites, some poorly defined spinal sclerites on tergites III-V and rather narrow dusky bars across tergites VI, VII, & VIII. The siphunculi are much less tapering and much narrower at base than in apterae. The cauda is slightly narrower than in apterae.

Hille Ris Lambers (1966) recognised two subspecies of Braggia deserticola, based primarily on leg colour, albeit Pike (2009) noted that further justification of these subspecies is required. Hille Ris Lambers (1966) found Braggia deserticola in small numbers in flowerheads of California buckwheat (Eriogonum fasciculatum, and Eriogonum fasciculatum subsp. polifolium). He notes that Braggia eriogoni was also present, often in larger numbers, on the same plants, but could be easily distinguished from Braggia deserticola because of its waxiness. Colonies are not attended by ants. This is a southern species being found in southern California & Utah in the USA, and in Mexico.

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Braggia eriogoni ( Reticulated buckwheat aphid) Western USA

Adult apterae of Braggia eriogoni (see pictures below) are black or brownish black with a strong dorsal pattern of reticulation, accentuated by a white wax secretion (cf. Braggia deserticola, which has most of the dorsum shining dark brown). The wax-bordered reticulations cover all of the dorsum except dorsolateral areas of the mesonotum, the median portions of abdominal tergites II and III, and all of tergite V. The antennae beyond the middle of segment III are dusky. Antennal segments III & IV have conspicuous secondary rhinaria (cf. Braggia longicauda and Braggia urovaneta, both of which usually have antennae without secondary rhinaria). The rostrum is slender, reaching between the second and third pairs of coxae. The apical rostral segment (RIV+V) is usually less than 0.19 mm long (cf. Braggia columbiana in Oregon & Washington, which has RIV+V 0.19-0.24 mm long). The first tarsal segments are all with 3 hairs, or with 3 hairs at least on fore tarsi (cf. Braggia agathona in Colorado & Utah, which has first tarsal segments all with 2 hairs). The siphunculi are dark and strongly tapering. The cauda is dark, short, and less that 0.75 times its basal width. The body length of adult Braggia eriogoni apterae is 1.1-2.1 mm. Immatures (see pictures below) are reddish and wax dusted.

Images above copyright Jesse Rorabaugh under a public domain (CCO) licence.

The alate Braggia eriogoni has the head and thorax blackish brown, and the abdomen yellowish olive-green mottled with olive-yellow, with dark bands on abdominal tergites VI-VIII and dark marginal sclerite on all segments. There is some reticulation on the dorsum, but much less than on the aptera. There are marginal tubercles on the prothorax, and on abdominal tergites I and VII.

Most Braggia species have a fairly narrow host range, but Braggia eriogoni is the exception. Pike (2009) has reported it as feeding on up to 17 different Eriogonum species. Colonies of aphids are found on the leaves, stems and especially the flowerheads of buckwheat. Braggia eriogoni is assumed to be monoecious holocyclic, but sexuales have not been described. Palmer (1952) reported the species as fairly common in Colorado & Idaho, with both apterae and alatae present from May to September. Braggia eriogoni is found in most of western USA.

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Braggia longicauda ( Woolly buckwheat aphid) Western USA

Adult apterae of Braggia longicauda (see first picture below) are black, blackish grey or blackish brown, with dense white wax powdering over the whole body, and antennae that are dark except for the basal half or more of antenal segment III. The antennae are quite short, 0.550.90 times the body length, with the terminal process 1.301.94 times the base of segment VI. The longest hair on antennal segment III is always shorter than the basal diameter of that segment. The antennae are without secondary rhinaria (cf. Braggia eriogoni and Braggia columbiana, which have secondary rhinaria on segments IV & V). The rostrum extends to the metacoxae. The dorsal integument is faintly to moderately reticulate on the head and abdominal dorsum. The pronotum, and abdominal tergites I & VII have marginal tubercles. The legs are mostly brown to black, but sometimes with the femora basal parts, and the tibiae middle areas are paler. The siphunculi are relatively short, subcylindrical, tapering and flanged. The cauda is long at 0.13-0.23 mm (cf. Braggia urovaneta, which has the cauda 0.08-0.12 mm) and bears 411 hairs. The body length of adult Braggia longicauda apterae is 1.5-2.9 mm.

Images copyright James Bailey, under a under a Creative Commons License.

Braggia longicauda alate viviparae (see second picture above) have similar morphological features to those of apterous viviparae. They have 8-14 secondary rhinaria on antennal segment III, and 0-1 on segment IV. There are irregular stripes and marginal sclerites on the abdominal terga.

Braggia longicauda is mainly found on the stems of tall woolly buckwheat (Eriogonum elatum) (see third picture above) and, less frequently, on arrowleaf buckwheat (Eriogonum compositum). They are monoecious holocyclic, with apterous and alate viviparae occuring from late May to early October, and oviparae and alate males occuring in September-October. Pike (2009) found Lysiphlebus testaceipes to be the predominant primary parasitoid of Braggia longicauda, and suggests Braggia species may be useful as a host source for this parasitoid, which is broadly oligophagous and an important agent for natural biological control of many economically important aphids. The woolly buckwheat aphid is found in western USA, namely Washington, Oregon and California.

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Braggia urovaneta (Crispleaf buckwheat aphid) Southwestern USA

Adult apterae of Braggia urovaneta (see pictures below) have the head, thorax and abdomen black. The body is partially covered with powder-like grey wax in a more or less regular pattern leaving the mid-dorsum from tergites II to VI largely wax free. The siphunculi and cauda are black. Antennal segments I and II are black, segments III, IV, and the base of V are pale to dusky, and the apical portion of V and all of VI are dusky to light black. The antennae are without secondary rhinaria (cf. Braggia agathona, which usually has rhinaria on segments III & IV). The rostrum reaches to the metathoracic coxae. The prothorax has marginal tubercles. The femora and tarsi are dark, but the tibiae are pale with dusky apices. The abdominal dorsum is reticulated, and dorsal hairs are thin, without tuberculate bases (cf. Braggia uncompahgrensis, which has dorsal hairs very thick, arising from tuberculate bases). The siphunculi are quite long, but the rim is very poorly developed. The cauda is almost as wide at base as long, has a pointed tip, and bears 3-4 inwardly curving hairs. The body length of adult Braggia urovaneta apterae is 0.9-1.9 mm.

Images above copyright Jesse Rorabaugh under a public domain (CCO) licence.

The alate vivipara of Braggia urovaneta has the head, thorax and abdomen black, and the antennae almost uniform dusky. The femora are dusky, the tibiae dusky at base and apically with the region between light yellowish, and the tarsi dusky. The siphunculi and cauda are dusky to black.

Braggia urovaneta is monoecious holocyclic on three species of wild buckwheat (Eriogonum corymbosum, Eriogonum latifolium, Eriogonum racemosum). Oviparae and alate males have been collected in Colorado on Eriogonum corymbosum in early October. Hottes (1950) noted that the species was, as a rule, very abundant, often encrusting the lower stems and upper portions of its host. Braggia urovaneta is restricted to the southwestern states of the USA. Colonies are usually attended by ants.

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Acknowledgements

We have made provisional identifications from high resolution photos of living specimens, along with host plant identity. In the great majority of cases, identifications have been confirmed by microscopic examination of preserved specimens. We have used the keys and sp accounts of Blackman & Eastop (1994) and Blackman & Eastop (2006) supplemented with Blackman (1974), Stroyan (1977), Stroyan (1984), Blackman & Eastop (1984), Heie (1980-1995), Dixon & Thieme (2007) and Blackman (2010). We fully acknowledge these authors as the source for the (summarized) taxonomic information we have presented. Any errors in identification or information are ours alone, and we would be very grateful for any corrections. For assistance on the terms used for aphid morphology we suggest the figure provided by Blackman & Eastop (2006).

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References

  • Hille Ris Lambers, D. (1966). Notes on California aphids, with descriptions of new genera and new species. Hilgardia 97(15), 569-623. Abstract

  • Hottes, F.C. (1950). Descriptions of Western Colorado Aphididae. Proceedings of the Biological Society of Washington 63, 15-30 (p.24). Full text

  • Palmer, M.A. (1952). Aphids of the Rocky Mountain Region: including primarily Colorado and Utah, but also bordering area composed of southern Wyoming, southeastern Idaho and northern New Mexico. Full text

  • Pike, K.S. et al. (2009). New species of Braggia (Hemiptera: Aphididae) on buckwheat in western North America. The Canadian Entomologist 141(6), 561-581. Full text