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Lachnochaitophorus [Panaphidini]Lachnochaitophorus apterae have a short robust body, liberally covered with stiff hairs. The antennae are 6-segmented, shorter than the body, and well armed with rather long, thick, bristle-like hairs. The terminal process is very short and thick, Lachnus-like in appearance. Apterous viviparae have no secondary rhinaria, but the alatae have large round rhinaria. The antennal tubercles are undeveloped. The rostrum is 4-segmented, with the apical segment subconical. The prothorax and abdomen are usually without spinal or marginal tubercles. Wing venation in the alate is normal, with broad fuscous bands bordering rather heavy veins of both pairs of wings. The forewing has the media vein twice branched; and the radial sector is present, sharply curved upward, and broadly margined with a smoky band. The terga of the aptera are fused forming a sclerotic carapace, extending laterally, and including marginal sclerites. Terga of alatae each usually have a rectangular sclerite, at least on posterior terga, and pigmented marginal sclerites. Siphunculi are truncate, very short, not as long as wide, and without a flange. The cauda is broadly rounded, semicircular, and not knobbed, and the anal plate is conspicuously, but not deeply, indented. The anal plate and cauda are profusely armed with long bristle-like hairs. Lachnochaitophorus has two species, both monoecious, feeding on the terminal twigs of red oak (Quercus) saplings. They are holocyclic. The oviparae have long drawn out ovipositors and males are wingless. Lachnochaitophorus live in small compactly crowded colonies on young bark, petioles of leaves, and occasionally along the basal part of mid-rib on the lower side of the foliage. They are well attended by ants. Both species are found in North America. Lachnochaitophorus querceus (Shiny brown oak aphid) North-eastern USA, Eastern CanadaAdult apterae of Lachnochaitophorus querceus (see first two pictures below) are dark brown to black, and are, as Granovsky (1933) expresses it, "almost shiny". Their antennae are dusky dark brown, segments I-IV lighter at the base, segments V & VI black. The antennae are densely hairy, with 7-15 hairs on the base of antennal segment VI. (cf. Neomsymydobius species, which have sparsely hairy antennae and 1-3 hairs on the base of antennal segment VI). The aptera has an almost complete dorsal shield from mesonotum to abdominal tergite VII (cf. Lachnochaitophorus obscurus in south-eastern USA, which has separate cross-bands on abdominal tergites I-VII). The siphunculi are truncate, dusky brown without a flange. The body length of adult Lachnochaitophorus querceus apterae is 1.7-1.9 mm. Young immatures have the anterior part of the body reddish (see second and third pictures below).
Images above by permission, copyright Claude Pilon, all rights reserved. Alatae of Lachnochaitophorus querceus (see third picture above) are dark brown to black, with black abdominal cross-bands and wing veins broadly and heavily bordered with fuscous. The dark bordering of the wing veins can be seen most clearly in the first picture below which gives a dorsal view of an alate amongst the tending ants. The wing veins have borders not more than 0.10 mm across, the pigment of veins Cu1a and the media vein not coalescing at their bases (cf. Lachnochaitophorus obscurus in south-eastern USA, which has wing veins with borders up to 0.15 mm across, the pigment of veins Cu1a and media coalescing at their bases). The Lachnochaitophorus querceus alate has 4-8 (usually 5 or 6) secondary rhinaria on antennal segment III. Lachnochaitophorus querceus lives in small colonies, mainly on leaf petioles and young bark of tender one-year-old shoots, of northern red oak (Quercus rubra) and black oak (Quercus velutina). It has also been reported forming dense clusters on twigs and leaf petioles of pin oak (Quercus palustris). These aphids are closely attended by ants, usually Crematogaster lineolata. In many cases the ants construct shelters over the colonies consisting of bits of oak epidermis and mud, over the upper part of leaf petioles just at the base of the leaf blades (Granovsky, 1933). These 'tents' or 'sheds' keep the aphids dry in rainy weather, and conceal them from predators. Lachnochaitophorus querceus is monoecious holocyclic. In autumn it produces oviparae with swollen hind tibiae and a greatly extended posterior abdomen, and small apterous males. It is restricted to north-eastern USA and Canada (Quebec, Ontario).
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