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Aphis schinivoraDark-cornicle peppertree aphidOn this page: Identification & Distribution Other aphids on the same hostIdentification & DistributionAdult apterae of Aphis schinivora are shiny black with partially white legs (see clarified slide mount of aptera in first picture below). The antennae are 6-segmented, but antennal segments III & IV sometimes coalesce. Antennae are 0.47-0.67 times the body length, and lack secondary rhinaria. The rostrum reaches or overlaps the hind coxae, with the apical rostral segment 1.0-1.3 times the second hind tarsal segment. Dorsal abdominal pigmented sclerotic areas are very variable, from minimal coverage to broken large spinal-pleural patches on tergite IV, small patches on tergites I-III & V-VI and bars on tergites VII-VIII. There are large marginal tubercles on the prothorax and tergite I, and numerous conspicuous marginal tubercles on other tergites. The siphunculi are dark brown to black (cf. Aphis schinifoliae on other Schinus spp., which has pale siphunculi). Siphunculi are cylindrical, and rather short, only 0.3-0.7 times the cauda, with a small apical flange (cf. the polyphagous species Aphis aurantii, Aphis craccivora, Aphis fabae, Aphis gossypii & Aphis spiraecola, whose siphunculi are more than 0.7 times the cauda). The cauda is brown to dark brown, more pigmented on the margins and with 4-8 hairs. The body length of adult Aphis schinivora apterae is 0.9-1.4 mm.
Both images above by permission copyright Ortego, Nieto Nafria & Mier (2007), all rights reserved. Alate viviparae of Aphis schinivora (see clarified mount of alate in second picture above) have somewhat less abdominal sclerotization than the aptera, with a broken bar on tergite VII and a bar on tergite VIII. Secondary rhinaria are distributed 5-8 on antennal segment III, and 0-1 on segment IV. The male is apterous, with brown antennae and legs. Dorsal sclerotization and pigmentation is more extensive than in the apterous vivipara, with spinal plates on tergites II-VI coalescing to make a spinal plate, and bars on tergites VII and VIII. The ovipara resembles those viviparous apterae that have poor sclerotization & pigmentation. Antennal segments III and IV are joined.
Image above copyright Dick Culbert, under a Creative Commons 3 licence. Aphis schinivora is a South American species, monoecious on Johnstone's molle (Schinus johnstonii, see picture above). This is a shrub over 1 m high with hard, elongated single leaves and spiky thorns at the ends of the twigs. The aphid forms very dense colonies on the stems and leaves. The fact that no other aphid species has been found feeding on this Schinus, and both aphid and ripe (overripe?) fruit are glossy blue-black, suggests that the color may be aposematic coloration to discourage bird predation. The plant has a traditional use as a purgative. Populations are holocyclic, with oviparae and apterous males being found in late January. Since that is mid-summer in Argentina, it indicates that the life cycle is abbreviated. Aphis schinivora is currently only known from western Argentina, but its host also occurs in Chile. Other aphids on the same hostAphis schinivora has so far been reported on only 1 pepper-tree species (Schinus johnstonii). Blackman & Eastop list 1 species of aphid as feeding on Schinus johnstonii worldwide: Aphis schinivora. It does not occur in Britain.
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_Culbertew.jpg "Schinus johnstonii (Johnstone's molle) in Southern Argentina; Dick Culbert")