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Warty hickory aphidsOn this page: Protopterocallis gigantea
All Protopterocallis adult viviparae are alate. The head is broad, and the antennal tubercles are undeveloped. Antennae are 6-segmented, with the terminal process about half as long as base of antennal segment VI (cf. Monelliopsis which has the terminal process similar in length to the base of antennal segment VI). The median and paired ocelli are prominent. Two brown muscle attachment plates usually show beneath the integument of the prothorax. They are crescent-shaped with concave sides facing, and lie mainly outside the dorsal tubercles. The wings have thicker than usual cubital veins. The fore coxae are enlarged. The thorax and abdomen bear prominent hair-bearing tubercles on all segments except the last three. The spinal tubercles of abdominal segments are much larger than those on each side. The abdomen bears >40 spots of dorsal pigment. The siphunculi are rounded, pore-like, about as large as the ocular tubercle. The cauda is knobbed, and the anal plate is bilobed. Immatures have tubercles bearing thick fan-shaped hairs prominent on all segments, from head to anus.
There are 4 species of Protopterocallis, which are monoecious on hickory (Carya spp.). All stages live on the upper surface of the leaf, and usually along the midribs of the basal leaflets. Sexuales have been found for 3 of the species, so it is likely that all species are holocyclic. They are mainly found in Eastern North America
Protopterocallis gigantea (Red-stained hickory aphid) Eastern North America
All adult viviparae of Protopterocallis gigantea are alate. Alatae (see pictures below) are broad-bodied, with a dull yellow abdomen and irregular streaks of orange or red on the mid-dorsum. The dorsal abdominal tubercles are brown-tipped and the forewing veins, especially Cu1b, are narrowly bordered with dark brown. The prothorax has two anterior tubercles and three to five posterior plus one on each posterior angle (cf. Protopterocallis quadrata, which has only 2 posterior hair-bearing tubercles on its prothorax; and cf. Pterocallis pergandei, which has 6-7 posterior tubercles on the prothorax). The mesothorax has 10-16 small tubercles, and the metathorax two to five large tubercles medially, as high as the ones on prothorax, plus 2 smaller ones. The abdomen has many rough tubercles dorsally, with much the largest on tergites I-III, crowded together on common bases and terminated by thick hairs.
Images above copyright John Morgan under a Creative Commons Attribution 3.0 License.
The siphunculi are poriform (=pore-shaped) on round swellings comparable in size to a marginal tubercle. The anal plate is bilobed, indented over half its length, with parallel sides. The cauda is broadly knobbed. Both the anal plate and cauda bear sharp hairs, the greatest of which is longer than the caudal width. The body length of adult Protopterocallis gigantea viviparae is 2.5-3.0 mm. Immatures (not pictured) are translucent with two internal red areas across the middle, overlaid by dusky tubercles.
Protopterocallis gigantea is monoecious holocyclic on several hickory (Carya) species, but has not been recorded on pecan (Carya illinoinensis). The aphids feed on the upper leaf surfaces, usually along mid-ribs of basal leaflets. Oviparae and males occur in October. It is found in eastern states of USA such as Maryland and Georgia.