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Peach bark aphidsOn this page: Pterochloroides persicae
Pterochloroides aphids are large, with the body of apterae about 4.0 mm long. The head is sclerotic, with thick and blunt dorsal hairs. The eyes are large, and bear ocular tubercles. Antennae are 6-segmented, less than 0.46 times as long as the body, and with a terminal process 0.60 times as long as the base of segment VI. There are secondary rhinaria on segments III-IV. The rostrum reaches to the middle of the abdomen, with the apical rostral segment at most 0.80 times as long as the second segment of hind tarsus. Meso- and metathoracic tergites and abdominal tergites I-VI each have a pair of large sclerotic spinal tubercles (cf. other genera in the Lachnini, such as Lachnus, Longistigma & Maculolachnus, which do not have a series of sclerotic spinal tubercles). There are also pleural sclerites, at least up to tergite II, and transverse sclerotic bands or a paired patch on tergites VII & VIII. Hairs on the flagellum (=ANTIII-VI) and dorsum are thick, usually shorter than the basal diameter of antennal segment III. The siphunculi are set on dark sclerotic cones. The caudaa is dark sclerotic, and bears many fine hairs.
Pterochloroides alatae also have secondary rhinaria on antennal segments III-IV. The forewings have the media vein once or twice branched, and the pterostigma, and areas between medial branches, and between anal and cubitus vein are pigmented. The hind wings are hyaline, with both obliques present.
In cooler regions Pterochloroides aphids are monoecious holocyclic on woody Rosaceae, especially Prunus. In warmer countries populations are mainly anholocyclic.
Pterochloroides persicae (Black peach aphid) East, Central & South Asia, North Africa, Middle East, Southern Europe
Adult apterae of Pterochloroides persicae (see first picture below) are oval in shape, with a double row of large pigmented spinal tubercles on the dorsum. The body colour is dark grey with transverse rows of dark spots with brown centres. The antennae and legs are barred with red-brown and black bands. The siphunculi are large pores on broad dark hairy cones. Pterochloroides persicae are large aphids, with body length of the adult apterae between 2.7 and 4.2 mm.
First image above, copyright Anton Gjeldum, second image copyright Simon Oliver,
Alate Pterochloroides persicae (see second picture above) have a short blunt pterostigma.
Pterochloroides persicae form dense colonies preferably in the shaded part of the tree. They produce copious amounts of honeydew and are usually attended by ants. Populations in cooler regions are monoecious holocyclic, but those in warmer countries are anholocyclic. They probably originated from East-Central Asia and dispersed westwards along traditional trade routes in past centuries along with their host trees. In recent decades Pterochloroides persicae has spread westwards and southwards into Europe and the Middle East where it has become an important pest of peach and almond trees.