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Aphidinae : Macrosiphini : Illinoia crystleae
 

 

Illinoia crystleae

Pale-streaked honeysuckle aphid

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

Identification & Distribution

Adult apterae of Illinoia crystleae (see first two pictures below) are pale yellowish green, with whitish streaks along the margins of the abdominal tergum and bluish-white wax-dusting on the femora. The femora are pale green, the tibiae pale brown and the tarsi dark. The antennae are 1.3-1.5 times the body length. Antennal segment III has 18-40 small scattered secondary rhinaria on one side of the basal 0.62-0.75 of the segment (cf. Macrosiphum raysmithi on Lonicera ledebourii in California, which only has 0-4 very small rhinaria on segment III). The longest hairs on antennal segment III are 0.42-0.75 times the basal diameter of that segment. The apical rostral segment (RIV+V) is 0.9-1.1 times the second hind tarsal segment (HTII), and bears 13-24 accessory hairs.

First image above copyright Andrew Jensen under a creative common licence;
second image above copyright Jesse Rorabaugh, no rights reserved.

The legs are mostly pale including the apex of the tibia (see first picture below), apart from the tarsi which are dark (cf. Macrosiphum euphorbiae, which has the apices of the tibiae dark like the tarsi). The first tarsal joints have 5 hairs. The siphunculi (see second picture below) are about 0.12-0.28 times the body length, with the apical 0.08-0.12 reticulated. They are swollen on the distal quarter, up to 1.1-1.3 times the smallest diameter basal to it. The cauda (twisted over backwards in the slide mount) is elongate conical with faintly convex sides, at base usually slightly constricted, slightly pointed, about 0.40-0.44 the siphuncular length, with 10-16 hairs. Illinoia crystleae are unusually large, the adult apterae have a body length of 3.7-5.0 mm.

Both images above copyright Jesse Rorabaugh, no rights reserved.

The alate viviparous female Illinoia crystleae has been described from only one specimen. It is similar to the apterous viviparous female, but antennal segment III bears 42-47 rhinaria scattered along one side over most of its length. The cauda is shorter and more slender.

We have described the nominate species above. However, Essig (1942) described Illinoia crystleae subsp. bartholomewi (as Amphorophora bartholomewi) from specimens collected in California. The subspecies differ from the nominate species in having only 3 hairs on the first tarsal joints (cf. 5 in crystleae s.s.), 19 caudal hairs (cf. 10-16 in crystleae ss.), and only 11-15 secondary rhinaria (cf. 18-40 in crystleae ss.). The subspecies is only known from the west coast of America.

Illinoia crystleae is monoecious holocyclic on the leaves of bearberry honeysuckle (Lonicera involucrata). It normally feeds on the undersides of the leaves. Oviparae and alate males occur in August-September. The pale-streaked honeysuckle aphid occurs in western North America.

 

Other aphids on the same host

Blackman & Eastop list 9 species of aphid as feeding on bearberry honeysuckle (Lonicera involucrata) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 4 as occurring in Britain (Show British list).

Acknowledgements

We are grateful to Andrew Jensen and Jesse Rorabaugh for making their images of Illinoia crystleae available for use under creative commons and public domain licences respectively.

We have used the species accounts of Smith & Knowlton (1939) (as Amphorophora crystleae) and MacGillivray (1958) (as Masonaphis (Amphorinophora) crystleae) 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

  • Essig, E.0. (1942). New species of the genus Amphorophora (Hemiptera: Aphididae). Ann. ent. Soc. Amer. 35, 2-4. Full text

  • MacGillivray, M.E. (1958). A study of the genus Masonaphis Hille Ris Lambers, 1939 (Homoptera, Aphididae). Temminckia 10, 1-131 (p. 36.)

  • Smith, C.F. & Knowlton, G.F. (1939). Three intermountain aphids. The Canadian Entomologist 71(11), 241-243. Abstract