Genus Maculolachnus

Genus Maculolachnus [Lachnini]

Maculolachnus are medium-sized aphids, the adult viviparae of which may be winged or wingless. They have no distinct pattern of pigmentation on the forewings but have a black spot at the base of the pterostigma. Dorsal hairs are often placed on dark scleroites. The siphuncular cones are low, hairy and conical.

Three Maculolachnus species feed on members of the rose family (Rosaceae). They have a sexual stage in the life cycle, overwintering as eggs, but there is no host alternation. They are attended by ants.

Maculolachnus submacula (Rose stem aphid)

Maculolachnus submacula apterae (see first picture below) are yellowish-brown, reddish-brown or dark chestnut brown. The dorsum has many fine hairs placed on small scleroites. Their dark brown antennae are about half the body length and the antennal terminal process is less than 0.25 times the length of the base of the sixth antennal segment. The legs of Maculolachnus submacula are dark brown, except for the bases of the femora and middle parts of tibiae. The hairs on the tibia are about half the diameter of the tibia. The siphuncular cones are dark and also have many hairs. The body length of Maculolachnus submacula is 2.7-3.8 mm.

The alate Maculolachnus submacula (not pictured) is dark brown or bronze brown, and has a dark spot on its forewing between the pterostigma and base of media. Antennal segment III has 5-10 secondary rhinaria and segment IV has 1-3. Immatures (see second picture above) are a little paler than the adults.

Maculolachnus submacula feed on Rosa species (including roses). Much of the year they feed on stems near the ground, but in summer they move to the surface roots. Colonies are tended by ants which often tent over the aphids with soil particles. They do not host alternate. Oviparae and apterous males are found in September-October. Maculolachnus submacula are distributed throughout Europe eastward to Ukraine, Kazakhstan and India.

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Acknowledgements Whilst we make every effort to ensure that identifications are correct, we cannot absolutely warranty their accuracy. We have mostly made 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 species 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 Blackman, R.L. & Eastop, V.F. (2006). Aphids on the world's herbaceous plants and shrubs. Vols 1 and 2. John Wiley & Sons.