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In this account a record is given of the food-habits of 12 species of aphidophagous Syrphidae commonly found in crop fields in Nagasaki. Food lists of Ischiodon scutellaris FABR., Paragus quadrifasciatus MEIG., P. tibialis FALLEN, Sphaerophoria cylindrica SAY, Sph, javana WIED., Syrphus torvus O.S. and Epistrophe aino MATS., with notes of their attacking dates of plant-lice, are given. Those of Syrphus ribesii L., S. serarius WIED., S. bilineatus MATS., Metasyrphus corollae FABR., and Epistrophe balteatus DE GEER were previously published by the writer in 1956. The plant-lice attacked by the 12 syrphids amount to 40 species, which belong to 20 genera, Aphis, Macrosiphum, Amphorophora, Capitophorus, Myzus, Rhopalosiphum, Hyalopterus, Macrosiphoniella, Brevicoryne, Phorodon, Pseudocerosipha, Megoura, Acyrthosiphum, Glyphina, Neophillaphis, Periphyllus, Prociphilus, Eulachnus, Lachnus, and Oregma, about 83 per cent of which belong to the tribe Aphidini of the Aphididae, being parasitic on 65 species of plants including common crops. Among these syrphids, Epistrophe balteatus may rank first in attacking as many as 37 species of plant-lice, while Syrphus torvus and Epistrophe aino may be the lowest ranking on the list, devouring merely 4 species of aphids respectively. The nonconcentricity of aphidophagous capacity is also discussed. With regard to to the aphidophagous capacity of syrphids, single aphidophagous capacity may be distinguished from complex aphidophagous capacity, the former consisting of any single species of syrphids and the latter being composed of more than two species of them. Because of their simultaneous employment of single aphidophagous capacity in the destruction of the same or different plant-lice on different kinds of plants, the aphidophagous capacity of syrphids can not be exclusively concentrated on the destruction of a spefcific plant-lice on a specific crop during the same season. Complex aphidophagous capacity, in the same way, can not be exclusively concentrated upon the control of a specific aphid on a specific plant. In other words, during the same season, any single or complex aphidophagous capacity employed in the destruction of a specific aphid on a specific crop may simultaneously be dispersed toward the same or different aphids on different plants.

1. An attempt has been made to elucidate the confusion existing about the biology, morphology and nomenclature of the Oat-Apple Aphis, Rhopalosiphum prunifoliae, Fitch. A close study of the problem confirms the observations made by Börner that at least two distinct species have in the past been included under the name of R. prunifoliae. The names Rhopalosiphum padi, L., and Rhopalosiphum crataegllum, Theo., are adopted for these species.2. Detailed descriptions and figures of the different generations are given and a comparison shows that the two species can readily be distinguished from one another.3. R. padi appears to be of greater importance as a cereal pest than R. crataegllum. The latter species is a widespread pest of pip-fruit.4. An account is given of the overwintering of R. padi on Prunus padus, and the results of experiments on estimating the size of the ova-populations is shown.The author is indebted to Mr. R. A. Harper Gray for allowing him facilities to carry out the investigation; also to Mr. J. A. Dunn for assistance in collecting some of the material and much general help.

The species described herein brings the number of described North American species of Rhopalosiphum Koch to thirteen. Only the apterous alienicolae of this species are known and these can be distinguished from the apterous alienicolae of other North American species by means of the key offered below.

Descriptions of nearly all stages, and notes on the life histories of ten species of Rhopalosiphum Koch are offered. This includes all but two of the species known to occur in North America. Three are described as new. The group as a whole is of little economic importance with the exceptions of R. maidis (Fitch) and R. padi (L.) which are sometimes serious pests of cereal crops and have been shown to be capable of transmitting virus diseases. Keys for nearly all stages are provided.

does not appear. First page follows. Summary Five species of aphids, tested in lots of 20, were demonstrated to be vectors of mild-mosaic virus of annual stock; these are: Bur clover or cowpea aphid, Aphis medicaginis Koch Cabbage aphid, Brevicoryne brassicae Linnaeus Artichoke aphid, Myzus braggi (Gillette) Green peach aphid, Myzus persicae (Sulzer) Turnip or false cabbage aphid, Rhopalosiphum pseudobrassicae (Davis) Of these, only the turnip aphid breeds on annual stock plants under natural conditions. It causes pale-green circular areas around the mouth-part punctures, and, when abundant, dwarfing and yellowing or blanching of the flowers. The turnip aphid failed to transmit the virus to nine varieties of healthy cauliflower. Several infections were obtained with single turnip and green peach aphids fasted for 2 hours, fed ½, 1, 2, 5, or 10 minutes on leaves from infected stock plants, and then transferred to healthy plants, 1 aphid per plant. No infections were obtained with several hundred turnip, green peach, and cabbage aphids tested singly without fasting and with longer periods on infected stock plants. In tests on retention of the virus, turnip aphids, fasted for 30 minutes, then fed singly 5 or 10 minutes on mild-mosaic-infected annual stock and 5 or 10 minutes on 5 or 6 successive healthy stock plants, produced infections only in the first healthy plant. Lots of 20 turnip aphids had lost their infectivity by the fourth day after transfer from an infected to a previously healthy stock plant. If allowed to remain on the plant from 7 to 13 days, however, the aphids were able to recover the virus from the plant they had inoculated; this was long before symptoms appeared. The incubation period of the disease in the original inoculated plants varied from 16 to 22 days.

The factors involved in the natural control of the most numerous aphids on cole crops were studied. During the 1957 season the cabbage aphid ( Brercoryne brassicae (L.)) was the most. abundant aphid followed by the green peach aphid (Myzus persicae (Sulzer), whereas the turnip aphid ( Rhopalosiphum pseudobrassicae (Davis) was least abundant. In 1958 the order of abundance was: the green peach aphid, turnip aphid, and cabbage aphid. A parasite, Proon sp., attacked only . M. persicae. Diaeretus rapae (MeJntosh) and Empusa aphidis Hoffman attacked all three aphids. The ratio of parasitism was greatest the most dense aphid population and smallest in the sparse population. Coceinellids of the following species destroyed aphids: Hippodamia convergens Guerin-Meneville, Ceratomegilla maculate fuscilabris De Geer, and Coccinella transversoguttata Faldermann. Syrphids attacking the aphids were: Splzaerophoria cyclindrica Say, S. menthastri (L.), S. robusta (Curran), and Mesogramma marginata Say.

Independent discoveries of an Aphid attacking the roots of rice and other Gramineae in different parts of the world have led to its description under different names, and its affinity with other species has sometimes resulted in its confusion with them. The literature relating to the species is reviewed and it is shown that the correct name for it is Rhopalosiphum rufiabdominalis (Sasaki), of which Prunus is the primary host.What is believed to be a reasonably complete synonymy is given and this involves the sinking of the two genera Yamataphis Matsumura and Aresha Mordvilko as synonyms of Rhopalosiphum Koch because both of these genera were erected with the Rice Root Aphid as type. A species that was described as Yamataphis rhodesiensis Hall differs in too many respects to permit its inclusion in Rhopalosiphum and a new genus, Hallaphis, is erected for its reception.

The mean weight of seed per plant and the mean plant weight of oats inoculated jointly with a Rhopalosiphum padi-specific isolate and a Macrosiphum avenae-specific isolate of barley yellow dwarf virus or with the R. padi-specific isolate and a non-specific isolate, were significantly less than those of oats singly inoculated with the respective isolates. Values for these criteria for oats jointly inoculated with the M. avenae-specific and the non-specific isolates were intermediate between, or were greater than, those for singly inoculated oats. This was true whether inoculation with the individual isolates was made simultaneously or with an interval of 16 days between the two inoculations.When oats were inoculated jointly with two Schizaphis graminum-specific isolates, seed and plant weights were significantly less than on plants inoculated singly with each isolate.For each combination used, both isolates were transmissible to oats from jointly inoculated plants. It is inferred that interference occurred only between the M. avenae-specific and the non-specific isolates and that a synergistic response resulted with the other combinations.

An attempt was made to show the inhibitory effect of substances secreted by aphids on feeding plants, upon the infectivity of tobacco mosaic virus (TMV).Pressed juice of tobacco plants affected by TMV, was mixed with pressed sap from Japanese radish, turnip or tobacco, on which a number of aphid individuals belonging to Myzus persicae and Rhopalosiphum pseudobrassicae, had been fed for 24 hours. The virus juice was tested for infectivity by local lesion method using Nicotiana glutinosa. The juice produced local lesions on the half leaves of N. glutinosa far less in number than the control, viz., the virus juice mixed with sap from aphid free plants. When pressed sap from radish infected by radish mosaic virus, was mixed with juice of aphid-infested plants and inoculated immediately to radish seedlings, however, no inhibitory effect upon the virus was observed.

During the period 1960-66, a total of 1696 apterous adult aphids were collected in yellow-pan water, wind, and suction traps in Illinois, Indiana, Missouri, South Dakota, Texas, and Wisconsin. The following species were collected: apple grain aphid, Rhopalosiphum fitchii (Sanderson); corn leaf aphid, R. maidis (Fitch); English grain aphid, Macrosiphum avenae (F.); pea aphid, Acyrthosiphon pisum (Harris); yellow clover aphid, Therioaphis trifolii (Monell); and Aphis sp. Notable records of the corn leaf aphid in South Dakota included 664 specimens collected in yellow-pan water traps from 20 June to 8 July 1960, and 4 apterae in a propeller trap on 7 May 1966. In Texas, most records were obtained in March. In the other States the apterae were collected throughout the trapping season, with most records in June and July. The recurring presence of apterous aphids in several types of traps at widely scattered locations strongly indicated that the various records represented samples of airborne populations.

Field experiments were conducted from 1957 through 1959 to determine the effect of phorate in controlling insects on wheat. A randomized block design with all treatments replicated four times was used. Plots were seeded with a grain drill and harvested with a combine. Few insects infested the plots in 1957, but in 1958, heavy infestations of the hessian fly, Phytophaga destructor (Say), the apple grain aphid, Rhopalosiphum fitchii (Sand.), and the English grain aphid, Macrosiphum granarium (Kby.), were encountered. Phorate was applied as a seed treatment to control these insects in the fall. To control the spring brood of hessian fly and also aphids that might infest the plots, granulated phorate was broadcast in early April. Experiments were also conducted to determine the effect of the seed treatment under simulated conditions of grazing by clipping. The phorate seed treatments caused significant losses in stand through reduced germination. However, such losses were not reflected in reduced yields. Both hessian fly and the aphids were controlled with a seed treatment of 0.5 lb. of phorate per 10C 1bs. of seed. The spring brood of hessian fly was controlled by granulated 10% phorate broadcast at the rate of 1.75 lbs. of toxicant per acre. Highly significant increases in yield were obtained with all treatments where insects were controlled. All plots clipped to simulate fall grazing yielded from 4 to 6 bushels more per acre regardless of treatment.

Presents a key to tribes in Aphidae, and covers 55 species in 6 genera in the tribe Aphidini (Siphonophora, Phorodon, Myzus, Chaitophorus, Aphis, and Rhopalosiphum) providing species accounts and descriptions of new species. Also included are descriptions of new species belonging to other tribes, with notes on a few previously described species.

The Ethiopian barley line C.I. 5791, and six hybrids from crosses between this line and commercial cultivars, were tested in growth cabinets for their reaction to barley yellow dwarf virus (BYDV) isolates 6409 (Macrosiphum avenae-specific) and 6515 (nonspecific). C.I. 5791 was highly tolerant to both isolates. Two hybrids, 62-528 and 65-407-3, were highly tolerant to isolates 6409 and 6515, respectively. Herta, included as a susceptible cultivar, showed the least tolerance to each virus isolate. When these two hybrids were tested against BYDV isolates 6524 (Rhopalosiphum padi-specific) and 6716 (R. maidis-specific), tolerance was higher when plants were inoculated at the four- to five-leaf stage than at the two-leaf stage. Tolerance to isolate 6716, characterized as mild on susceptible oats, was lower than to isolate 6524, which was moderately severe on the oats. Tolerance to the four virus isolates was generally highest for hybrid 62-528.

Rotenone at a concentration of 1:100,000, as a contact poison in spray form, was found to compare favorably in toxicity with nicotine at 1: 10,000 and pyrethrins at 1: 74,800, with “Penetrol” at the same concentration (1: 200) in each spray, in tests against the false cabbage aphid, Rhopalosiphum pseudobrassicae , in the field, and the spiraea aphid, Aphis spiraecola , in the laboratory. Against adults of the spotted cucumber beetle, Diabrotica duodecimpunctata , and the Mexican bean beetle, Epilachna corrupta , pyrethrins at 1: 37,400 were effective, while nicotine at 1: 5,000 and rotenone at 1: 50,000 were ineffective, with “Penetrol” at 1: 100 in each spray. A rotenone concentration of 1: 1,000 (plus “Penetrol” 1: 200) was necessary before a mortality above 90% was secured with adults of D. duodecimpunctata . Some preliminary tests with the common red spider, Tetranychus telarius , indicate that the relative toxicity of rotenone, as compared to the toxicity of nicotine and pyrethrins, to this pest, is appreciably greater than its relative toxicity as indicated in the aphid tests.

does not appear. First page follows. Summary ELEVEN SPECIES OF APHIDS that do not multiply on cauliflower plants in nature were demonstrated to be vectors of the cauliflower-mosaic virus, five of them being more efficient vectors than three aphid species that do breed on cauliflower. Of three aphid species that breed on cauliflower under natural conditions, the cabbage aphid, Brevicoryne brassicae (Linnaeus), was a more efficient vector of the virus (in single-insect tests) than the turnip or false cabbage aphid, Rhopalosiphum pseudobrassicae (Davis), and the green peach aphid, Myzus persicae (Sulzer). Natural infectivity of the cabbage aphid was demonstrated. None of twenty-one varieties of cauliflower experimentally infected with the virus by the cabbage and green peach aphids was resistant to the disease. Mechanical inoculation was more efficient than transmission by the cabbage, turnip, or green peach aphid. In tests with hourly transfers, most transmissions occurred within 2 hours after the aphids had fed on a mosaic-infected plant. Aphids acquired the virus in 15 to 25 minutes on a diseased plant (5 to 10 minutes actual feeding time) and transmitted it in feeding periods as short as 5 or 10 minutes. In tests with short feeding periods, most of the transmissions occurred during the first 10 minutes after transfer from the infected plant, but an occasional aphid transmitted the disease during the second or third 10-minute period. The cabbage and green peach aphids recovered the virus from inoculated cauliflower plants many days before the first symptom appeared. Mechanical inoculation of healthy cauliflower seedlings and annual stock plants with the centrifuged virus extract from crushed, infective cabbage aphids produced 18 per cent infection.

A study of screen collections of the turnip aphis ( Rhopalosiphum Pseudobrassicae ) and analyses of the infestations on 30 plantings in several trucking communities show that the infestation of the various plantings has a definite influence on other plantings in the same community. Neglect in controlling an infestation or failure to prevent its spread by plowing the crops under before heavy migration of the aphids begins means the difference between profit and loss to that community.

does not appear. First page follows. Introduction In the canyons of the Montara Mountains and the slopes along the Pacific Ocean, the mild-mosaic virus of annual stock (Matthiola incana var. annua) induces a conspicuous breaking in the color of the flower petals in all but white and yellow flowering types. The breaking renders these affected varieties unmarketable as cut flowers. A severe mosaic disease of annual stock with a striking color-breaking and conspicuous mottling and malformation of the leaves occurs in home gardens and in a nursery at San Pablo, Contra Costa County. The turnip or false cabbage aphid, Rhopalosiphum pseudobrassicae (Davis), breeds on annual stock under natural conditions; the cabbage aphid, Brevicoryne brassicae L., and green peach aphid, Myzus persicae (Sulzer), do not. Review of Literature A review of the literature on virus diseases of annual stock has been published by (Tompkins (1934), (1939)4 and (Severin and Tompkins (1948)). A paper by (Oliveira and Borges (1944)) appeared and was not reviewed in our last contribution. A number of cultivated and wild crucifers, tobacco and Nicotiana glutinosa were tested, by juice inoculation, with nine isolates of an annual-stock virus from Lisbon gardens. The symptoms induced by each of the isolates on the differential hosts were mosaic, rugosity, stunting, chlorosis, necrosis, blistering, and streak. Materials and Methods The virus causing severe mosaic of annual stock was obtained at San Pablo, Contra Costa County. Plants of the Fiery Blood Red variety of annual stock and the February variety of cauliflower grown from seeds were used in all experiments reported in this paper. All inoculated annual stock plants were held for observation after the flowering stage.

The clover aphid (Anuraphis bakeri (Cowen)), the yellow clover aphid (Therioaphis trifolii (Monell)), and the pea aphid (Macrosiphum pisi (Harr.)) transmitted alfalfa mosaic from infected to virus-free Ladino white clover plants, but only the clover aphid and pea aphid transmitted bean yellow mosaic. When fed on plants infected with both viruses, the clover aphid and the pea aphid transmitted each virus separately and indiscriminately. Neither virus was transmitted by the green peach aphid (Myzus persicae (Sulz.)), apple grain aphid (Rhopalosiphum futchii (Sand.)), potato leafhopper (Empoasca fabae (Harr.), clover leafhopper (Accratagallia sanguinolenta (Prov.)), the strawberry spider mite, Tetranychus atlanticus (McG.) or the slug Derocerus reticulatum (L.).

Granular systemic insecticides Were applied to the soil at planting time to evaluate the resulting insect control on okra, southernpeas, cucumbers, lettuce, turnips, and spinach. Insects which were controlled in varying degrees included the leafminer ( Liriomyza munda Frick), tobacco flea bectles ( Epitrix hirtipennis (Melsheimer) and E. parvula F.), turnip aphid ( Rhopalosiphum pseudobrassicae (Davis), thrips ( Frankliniella occidentalis (Pergande)) and the spotted cucumber beetle ( Diabrotica undecimpunctata howardi Barber). Insect control was evident from 19 to 97 days. Parasites of the leafminer were not significantly reduced by the insecticide treatments.

Experimental transfers between hosts showed that Rhopalosiphum padi (L.) overwinters in Manitoba on some Prunus spp. and hybrids, and R. fitchii (Sand.) on species or hybrids of Cotoneaster, Malus, Crataegus, and Sorbus, and that both species of aphids can be reared in the laboratory on wheat, oats, and barley.

Plant nutrient availability to Garry oats ( Avena sativa L.) Var. Garry was controlled by nutrient solutions in the greenhouse. The plants were infested by apple grain aphids, Rhopalosiphum fitchii (Sand.), according to their preference for individual plants and allowed to feed and reproduce thereon for a period of 14 days. The data indicated that there' as a significantly greater population increase potential where nitrogen was available to the plants. Elimination of nitrogen from the nutrient solutions resulted in lower aphid populations and adversely affected the plants, as indicated by decreased plant height, yellowish coloration, and spindly growth. Aphid population on all treatments correlated with plant height to a highly significant degree. Whether population differences reported here were due primarily to nutrient media or plant height (leaf area) has not been determined.

Winged aphid populations collected on black sticky traps were compared with collections in yellow and white water-pan traps. In another test, collections of winged aphids from bean leaves were compared with collections from black sticky traps. Although sampling differences were noted, these were not profound, and all identified species collected by one technique were collected also by the others. Proportionately more corn leaf aphids, Rhopalosiphum midis (Fitch), were caught in yellow water pans than by white water pans or black sticky traps. The apparent attraction of this species to yellow does not agree with the observations by earlier workers.

SUMMARY The longevity of Sitobion avenae varied inversely with temperature from 25 to over 100 days when reared outdoors on barley under lantern jars, being longest between December and April–May. This was due mainly to changes in the length of the pre- and post-reproductive periods rather than the length of the period of reproduction. Fecundity varied directly with temperature, from eight to sixty-seven nymphs per female. When reared on winter wheat and sheltered from wind, rain and snow, S. avenae survived best, Metopolophium dirhodum survived less well and Rhopalosiphum padi worst; when exposed in the open none of the three species survived. Close relationships were not demonstrable between the numbers of alate M. dirhodum, S. avenae and Rhopalosiphum spp. trapped in any year, between the abundance of these aphids and weather conditions between January and April, or between the numbers of these alatae and the size of crop infestations. This was probably because insufficient information was available about their biology, both inside and outside the crop.

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The trend to earlier planting dates for winter grains has increased the probability of insect infestations in Indiana (Wilson 1959). This is no less true in South Dakota where greenbugs, Schizaphis graminum (Rondani), have become a problem on winter wheat, and particularly so on early-seeded fields. Systemic insecticides have been found effective against small-grains insects including the Hessian fly, Mayetiola destructor (Say) (Guyer et al. 1958); the apple grain aphid, Rhopalosiphum fitchii (Sanderson); the English grain aphid, Macrosiphum avenae (F.) (Wilson et al. 1960); and against greenbugs (Daniels 1960). Wilson et al. (1960) observed that yields can be increased greatly by controlling insects in the fall on early-seeded wheat. In addition to insect control, incidence of disease was greatly reduced on phorate-treated plots when aphids were controlled (Wilson 1959).

When the chorion is opaque the original deposition color of the egg usually remains unchanged during incubation. Many examples of these occur among the Orthoptera, Coleoptera, Hemiptera, Homoptera and Lepidoptera, but there are some exceptions to this generalization such as the exposed overwintering eggs of many Aphididae (Homoptera) which are black or a very deep brown. At deposition time they may be cream colored, green or a light brown. For example the eggs of the apple grain aphid, Rhopalosiphum fitchii (Sanderson) and the apple aphid, Aphis pomi DeGeer, on twigs of apple trees are green when deposited, while the eggs (3)2 of Longistigma caryae (Harris) on twigs of sycamore (plane) trees are light brown. A few days to several weeks after deposition these colors change to black or near black. The pigment in these eggs is located in the tough, membranous chorion which is completely covered with a thin, transparent, adhesive coat secreted by the female when the egg is deposited. Upon exposure to air it hardens and glues the egg to the twig or leaf. It also serves as an insulation against evaporation of the embryonic fluid. Among some species the external adhesive covering is very sticky and dries slowly. This is the case with the eggs of Longistigma caryae (Harris). It is not unusual to find eggs of this species covered with numerous grey or brown dust particles, especially if the host plant is adjacent to a dusty field or road.

The cabbage aphid, Brevicoryne brassicae (L.), turnip aphid, Rhopalosiphum pseudobrassicace (Davis), green peach aphid, Myzuts persicae (Sulzer), potato aphid, Macrosiphum euphorbiae (Thomas), poplar petiole gall aphid, Pemphigus populitransversus (Riley), known locally as the cabbage root aphid, cabbage looper, Trichoplusia ni (Hubn.), and the leaf miner, Liriomyza munda Frick, are pests of cabbages, tomatoes, and turnips in the Lower Rio Grande Valley. Insecticides and combinations of insecticides with oils and surfactants were evaluated as foliar and soil applications on these crops for control of these insects during the 1962-1964 seasons. The objectives were to (1) determine if oils and surfactants increase control when added to chemical and biological insecticides and (2) evaluate various systemic and nonsystemic phosphate and chlorinated hydrocarbon insecticides for control of the above insect pest species. Littleford and Ditman (1963) found Bayer 44646 to be an effective material for cabbage looper control. Shorey (1963) found Bayer 44646, Monsanto 40294, and Zectran to be effective against the cabbage looper. Shorey and Hall (1963) found DDT to be ineffective for leaf miner and potato aphid control. Shorey (1963) found parathion and mevinphos to be effective for cabbage aphid control on cabbage. He also found that Bayer 44646 was not effective for cabbage aphid control. Various phosphate insecticides were shown to be effective for leaf miner control (Wolfenbarger and Getzin 1963b). These included dimethoate, Bayer 25141, Bidrin, GC 4072, and Delnav. Carbaryl effectively controlled corn earworm populations on lettuce (Wolfenbarger and Getzin 1962). Endrin, toxaphene, mevinphos, naled, parathion, a toxaphene + parathion combination, and Kepone effectively controlled the cabbage looper (Wolfenbarger and Getzin 1962). Dimethoate, demeton, mevinphos, endrin, Telodrin, and mevinphos-oil combinations were shown to be effective for green peach and cabbage aphid control on peppers and cabbage (Wolfenbarger and Getzin 1963). METHODS AND MATERIALS