Browsing by Author "Eastop, V.F."
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Item The East African Aphids (Hem, Aphididae)(1955) Eastop, V.F.Thanks are due to Mr. J P. Doncaster of the British Museum (Nat. Hist.) and to Mr. D. Hille Ris Lambers of Bennekom for information about species related to those described here, to Dr. H. K. Munro of Pretoria for the opportunity to study about thirty aphid samples from South Africa which included one species also found in East Africa and here described as new, and to Mr. B. Verdcourt of the East African Herbarium for determining many host plants. This work was done while the author was in possession of a Colonial Research Fellowship.Item New East African Aphids(1953) Eastop, V.F. ; East African Agriculture and Forestry Research OrganizationBody elongates oval, in life brown with darker transverse dorsal abdominal bands and the whole body dusted with greyish powder.Item New East African Aphids (Hem.: Aphididae).(1956) Eastop, V.F.; East African Agriculture and Forestry Research OrganizationTHE following aphids were collected while the author was in possession of a Colonial Office Research Fellowship. The type specimens have been deposited in the British Museum (N.H).Item Notes on East African Aphids IV - Aphids of leguminous crops(1953) Eastop, V.F.; East African Agriculture and Forestry Research Organization; East African Agriculture and Forestry Research OrganizationOne root-feeding and five leaf- and stem feeding aphids are described here. Trifidaphis phaseoli (Pass.), a white globular aphid without siphunculi and with short legs and antenme, occurs on the roots of many dicotyledons in addition to Leguminosa: and is sometimes a pest of potatoes. This aphid, like a number of other root-feeding Fordini, has the cauda and sub-anal plate placed dorsally and enclosed on three sides by the inverted U-shaped eighth tergite (Fig. N). Macrosiphllln nigrinectaria.Item Notes on East African Aphids Grass and Cereal Stem- And Leaf-Feeding Species(1955) Eastop, V.F.There are several very similar species of tribe Rhopalosiphina which resembles the Macrosiphum (Sitobion) in East Africa Aphidina but differs in that the lateral resembling the European M. (S.) fragaritE tubercles of the seventh abdominal segment (T) (Walker), which, since they differ only slightly are placed dorsally or posteriorly (on the row in such characters as the shape of the rostrum of crosses in Fig. A) to the spiracle (S). In the and the length of the body hairs, should be Aphidina the tubercle is placed ventrally to the submitted to a specialist for identification. spiracle. Most Rhopalosiphina feed only on Microscope preparations resemble M. (S.) grasses and sedges, while the Aphidina are nigrinectaria, figured in Part III of this series. usually found on Dicotyledons. The They may be black, blue, brownish, yellow or Rhopalosiphina may be separated by means of green in life. M. (S.) aventE (Fabr.) (granarium the following key to the wingless adults. Both Kirby, of some authors), only once recorded aerial and root-feeding species are included, as from East Africa (perhaps a misidentification), are a few species not known from East Africa differs from the fragaritE group in that the but important elsewhere. A short key for the siphunculi are only about one and one-quarter identification of the winged forms is also given. times as long as the cauda. M. (Sitobion) sijuiItem Notes on East African Aphids III-Aphids of Cruciferous Crops(1953) Eastop, V.F.; Kenya Agricultural Research Institiute; East African Agricultural and Forestry Research OrganizationOnly two aphids are known to be specific on Cruciferous crops in East Africa. They are the Cabbage Aphid, Brevieoryne brassiere (L.) which is covered with grey wax dust in life, and Lipaphis pseudo brassiere (Davis), a greenAphid sometimes called the False Cabbage Aphid. The relative size and shape of the siphunculi and cauda may also distinguish the two species. In microscope preparations brassiere shows a dorsal abdominal pattern of transverse black bars which is absent in pseudo brassiere.Item Notes on East African Aphids VI- Cereal and Crass Root-Feeding Species(1954) Eastop, V.F.; East African Agriculture and Forestry Research OrganizationAbout 15 cereal and grass feeding aphids are known to occur in East Africa. Five of them live only at or below soil level and these are described here, together with a few other species that may have been overlooked in the past or be introduced in the future. There is little information about the economic importance of grass and cereal root aphids in the Old World, but in America several species are recognized as pests. The root aphids may be divided into two groups. The sub-family Eriosomatince contains white, very pale green, pale yellow or pink aphids, with short antennw, the last segment of which has only a short processus terminalis (Figs. A-N), whose adult apterx and immature stages of all forms have eyes of only three facets, whose siphunculi are small or absent and the winged forms of which have the media of the forewing unbranched. The second group comes in the sub-family Aphidince and resembles the ordinary" greenfly" in having longer antennw with a slender processus terminalis (Figs. PZ), siphunculi elongate, all stages of all forms with large compound eyes and the alatee have the media of the brewing once or twice forked. These aphids may be of various colours but are not white, very pale green or yellow or completely pink like the Eriosomatimr. Ancecia, a genus of the sub-family Thelaxince, contains wheat, barley and grass root-feeding aphids with black adult apterx and white larvw. The antennw and eyes are similar to those of the Eriosomatince, but the genus may be recognized by the presence of flat cone-like siphunculi and conspicuous lateral abdominal tubercles which are absent in grass root-feeding Eriosomatince, first tarsal segments with seven hairs and with 12 to 20 hairs on the second antennal segment. The media of the forewing of the alatx is once forked. Ancecia is not known from East Africa but is recorded from Egypt, Europe, Asia and North America.Item Notes on East African Aphids VII-Crass and cereal ctem- and leaf-feeding species(1955) Eastop, V.F.There are several very similar species of Macrosiphul1l (Sitobion) in East Africa resembling the European M. (S.) fragarire (Walker), which, since they differ only slightly in such characters as the shape of the rostrum and the length of the body hairs, should be submitted to a specialist for identification. Microscope preparations resemble M. (S.) nigrinectaria, figured in Part III of this series. They may be black, blue, brownish, yellow or green in life. M. (S.) avenre (Fabr.) (granarium Kirby, of some authors), only once recorded from East Africa (perhaps a misidentification), differs from the fragarire group in that the siphunculi are only about one and one-quarter times as long as the cauda. M. (Sitobion) sijui Eastop, known only from Kenya where it feeds on Cenchrus and Setaria, differs from other Macrosiphulum in the much shorter siphunculi (Fig. E), the apices of which bear only a few rows of hexagonal reticulation; and the shorter antennre (Fig. D), the third segment of which does not bear rhinaria.Metopolophiul1l dirhodum (Walker), known in Kenya only from Bromlis catharticus, also occurs on cereals in Europe, but this may be a distinct sub-species. M etopolophilll1l differs from Macrosiphulum in that the siphunculum are not reticulated at the apex. Metopolophilum festucre (Theobald), not known from East Africa but important in Europe on cereals, differs from dirhodlll1l in having evenly pigmented antennre, gradually darker from base to apex, whereas in dirhodlll1l the base of the sixth antennal segment is paler than the apex of the fifth; siphunculum three to four and onehalf times as long as the second segment of the hind tarsi and one and one-half to twice as long as the cauda which bears five to eight hairs. In dirhodllm, the siphunculum are two and one-half to three and one-quarter times as long as the second segment of the hind tarsus and one and one-fifth to one and three-quarter times as long as the cauda which bears seven to twelve hairs. The winged forms differ in that festucre has a dorsel abdominal pattern of transverse black bars, while the dorsum of dirhodlum is uniformly pale.Item Notes on East African, Aphids IV-Aphids of Leguminous Crops(Taylor & Francis, 1953) Eastop, V.F.; East African Agriculture and Forestry Research OrganizationOne root-feeding and five leaf-and stemfeeding aphids are described here. Trifidaphis phaseoli (Pass.), a white globular aphid without siphunculi and with short legs and antennae, occurs on the roots of many dicotyledons in addition to Leginninostr and is sometimes a pest of potatoes. This aphid, like a number of other root-feeding Fordini, has the cauda and sub-anal plate placed dorsally and enclosed on three sides by the inverted U-shaped eighth tergite (Fig. N). Macrosiphuin nigrinectaria Theobald is known only from East Africa and occurs most commonly on cow pea, Cajanus indicus. This aphid differs most obviously from M. euphorbice (described in Part 11 of this series) by the completely black siphunculi and the short antennal hairs. Acyrthosiphon pisum (Harris), a large green aphid with a long green cauda and long slender green to dusky siphunculi without hexagonal reticulation at the apices, occurs on many legumes as does Aphis craccivora Koch, the vector of groundnut rosette. A. craccivora is not figured as it resembles A. gossypii (figured in Part II) except that craccivora is a shiny black aphid in life while the black forms of gossypii are dull. Therioaphis spp. are recorded from many countries (but not yet East Africa) as pests of legumes, particularly clovers, mostly under the name T. ononidis. It is not known how many of these ornate black and yellow or black and white aphids occur in Africa. The species figured here (Figs. H—L) is T.(Pterocallidium) maculatum (Buckton). Megoura vicke Buckton, a large bright-green aphid with jet black legs, long cauda and swollen siphunculi, is not recorded from East Africa but is common on Leguminosce in other parts of the world.
