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Hairy rose aphid, Small green rose aphidIdentification & Distribution Biology & Ecology Damage & Control
Identification & Distribution:Chaetosiphon tetrarhodum adult apterae (see first picture below) are pale green to yellow-green or occasionally reddish. The head is rather smooth with few if any spicules. The antennae are short, only 0.6-0.8 times the body length. The dorsal cuticle is densely covered with flat warts giving it a wrinkled appearance. Each abdominal segment bear 5 pairs of capitate hairs. Their siphunculi are 1.1 to 2.5 times longer than the cauda. The body length of Chaetosiphon tetrarhodum is 0.7-2.1 mm, with the smallest individuals in mid-summer.
Winged viviparae (see second picture above) have a dark head and thorax, a black central patch on the abdomen and dark wing veins. Oviparae are dark olive-green and the apterous males are small and dark.
Chaetosiphon tetrarhodum is found on various species of roses especially the Japanese rose (Rosa rugosa). In spring they can be found on the shoot tips, young leaves and developing flower. Later in the year they can be found singly or in small groups on the undersides of mature leaves. Sexual forms occur in autumn. The distribution of Chaetosiphon tetrarhodum is worldwide.
Biology & Ecology:Jaskiewicz (2003) describes the species composition and number of aphids on rose bushes in urban conditions over three years. Their numbers varied over time with peak numbers in June. Chaetosiphon tetrarhodum comprised 0.8-15.3% of the total number of aphids on roses.
Kmiec (2007) sampled four varieties of rose on 28 occasions over 3 years, and calculated a constancy index for each of seven species of aphids as the percentage of occasions when the species was present. For Rosa rugosa Chaetosiphon tetrarhodum was present in about 70% of samples, higher than any other species for this type of rose.
Barjadze et al. (2010) reported the aphid parasitoid Aphidius eglanteriae attacking Chaetosiphon tetrarhodum, with a parasitism rate of 0-4%. Tomanovic et al. (2009) records Ephedrus laevicolis as a parasitoid of this species.
We have yet to identify the species responsible for parasitizing Chaetosiphon shown in the picture above.
Damage and control
Jaskiewicz (2006) looked at the effect of feeding of Chaetosiphon tetrarhodum and the larger Macrosiphum rosae on the flowering of roses. Both species when found in large numbers (see picture below) caused deformation of the leaf blades, shortening of shoots and petioles and flower deformation.
Chaetosiphon tetrarhodum is one of the main pest aphids of the Damask Rose (Rosa damascena) in Turkey. The plant is weakened by heavy infestations and great quantities of honeydew are deposited on the leaves. It is currently controlled solely by chemical means. Barjadze et al. (2010) suggested that mass rearing and release of Aphidius eglanteriae should be considered.