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Aphidinae : Aphidini : Aphis chrysothamni
 

 

Aphis chrysothamni

Waxy-tipped rabbitbrush aphid

On this page: Identification & Distribution Other aphids on the same host

Identification & Distribution

Adult apterae of Aphis chrysothamni (see first picture below) have a dark red-brown head and prothorax, a pinkish or greenish mesothorax, metathorax and abdomen. There is a large dark spot on the anterior abdomen, and wax powder on abdominal tergites VII-VIII. Antennal segments II & III are pale, but segments I and IV-VI are dark. The antennae are about half as long as the body and are on very low antennal tubercles (see second picture below). The apical rostral segment (RIV+V) is stiletto-shaped (see third picture below), with RV extended as a needle-like tip (cf. Aphis ornata and Aphis gregalis, which do not have RV extended as a needle-like tip). RIV has a pair of very finely pointed accessory hairs, as long as or longer than the subapical (primary) hairs. RIV+V is 0.11-0.18 mm long, and is 1.1-1.4 times the length of the second hind tarsal segment (HTII) (cf. Aphis chrysothamnicola, which has R IV+V 0.21-0.24 mm long, and is 1.75-2.0 times HTII). The dorsal abdomen usually has a dark central sclerite of irregular shape on tergites I-III or I-IV. The siphunculi are dark, fairly short and tapering. The cauda is dark, very short and broadly pointed. The body length of Aphis chrysothamni apterae is from 1.0 mm (summer dwarfs) to 2.4 mm.

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

The alate of Aphis chrysothamni (not pictured) has the antennae, head and thorax black, with the abdomen green or pinkish mottled with darker green; the legs are black with dusky tibiae. The antennae are about two-thirds as long as the body. Segment III has 4-10 secondary rhinaria in a more-or-less straight line, segment IV has 0-5 rhinaria, and segment V 0-1.

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

Aphis chrysothamni is monoecious holocyclic on rabbitbrush (Ericameria & Chrysothamnus spp.). Oviparae and apterous males have been found in late September. Wilson (1915) found the species very abundant on yellow rabbitbrush (Chrysothamnus viscidiflorus ssp. lanceolatus) on side hills along the canyons in Salisbury, Oregon, during July, 1912 and 1914. Palmer (1952) found the species quite commonly on grey rabbitbrush (Ericameria nauseosa) in Utah & Idaho, but in three sites in Utah the apterae were undersized in all parts except the rostrum and terminal process; these are thought to represent variations of Aphis chrysothamni, but further investigations are needed. The species is found in western America.

 

Other aphids on the same host

Aphis chrysothamni has been found on 1 Ericameria species (Ericameria nauseosa).

Aphis chrysothamni has been found on 1 Chrysothamnus species (Chrysothamnus viscidiflorus ssp. lanceolatus).

Acknowledgements

We are grateful to Jesse Rorabaugh for making his pictures available for use under a public domain licence.

We have used the keys and species accounts of Palmer (1952) and along with information from Roger Blackman & Victor Eastop in Aphids on Worlds Plants. We fully acknowledge these authors and those listed in the reference sections 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).

Useful weblinks

References

  • 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

  • Wilson, H.F. (1915).. Miscellaneous aphid notes, chiefly from Oregon. Transactions of the American Entomological Society 41(2), 85-108. (p. 101) Full text