The Ecology of Aphis craccivora Koch and Subterranean Clover Stunt Virus. I. The Phenology of Aphid Populations and the Epidemiology of Virus in Pastures in South-East Australia

1971 ◽  
Vol 8 (3) ◽  
pp. 699 ◽  
Author(s):  
A. P. Gutierrez ◽  
D. J. Morgan ◽  
D. E. Havenstein
1966 ◽  
Vol 17 (6) ◽  
pp. 875 ◽  
Author(s):  
PR Smith

A disease causing serious crop losses in early-sown French beans in the East Gippsland area of Victoria has been shown to be caused by subterranean clover stunt virus. The virus infected a wide range of leguminous plants and persisted through a moult of its principal vector, Aphis craccivora Koch. It was not seed-borne, nor was it mechanically transmissible. The field symptoms of the disease on French beans consisted of chlorosis and epinasty of leaves, the whole plant being markedly stunted with a reduction in the length of the internodes. These symptoms were reproduced in the glasshouse by aphid inoculation of the virus to French beans. However, the virus was recovered from both naturally infected and artificially inoculated beans with difficulty. In field tests, no cultivar of French bean tested was immune to the virus, although a high degree of tolerance was observed in the cultivars Red Mexican U.I.3, U.I.34, and U.I.37, and Pinto U.I.72 and U.I.78.


1981 ◽  
Vol 8 (2) ◽  
pp. 99-102 ◽  
Author(s):  
H. B. Highland ◽  
J. W. Demski ◽  
J. H. Chalkley

Abstract Higher percentages of peanuts than soybeans or cowpeas become infected when these crops are growing equal distances from a source of peanut mottle virus (PMV). The total number of aphids trapped in these crops are about equal and cannot explain this differential percentage infection. Known vectors of PMV such as Aphis craccivora Koch and Myzus persicae (Sulzer) comprised 31% of the aphid population in peanuts compared to 14% in soybeans and 17% in cowpeas and could be responsible for the higher number of peanut infections. In addition, trapping of live aphids in peanut fields showed that viruliferous Rhopalosiphum maidis (Fitch) were present. Laboratory studies confirmed R. maidis could transmit PMV from peanut to peanut. This is the first report of R. maidis as a vector of PMV.


2021 ◽  
Vol 19 (1) ◽  
pp. 139-154
Author(s):  
MA Hossain ◽  
MS Yasmin ◽  
MAA Bachchu ◽  
MA Alim

Botanicals are promising and attractive alternatives for pest management. In the present study, three botanical oils namely neem (Azadirachta indica), karanja (Pongamia pinnata) and mehogony (Swietenia mahagoni) were tested against the nymphs of Aphis craccivora Koch to evaluate the toxic and repellent effects under laboratory conditions (25 ± 5oC, 65-75% RH). Four concentrations (0.5, 1.0, 1.5, and 2.0%) along with control were maintained with distilled water and tween-20 was used as emulsifier. Leaf dipped method were used for insect bioassay. Insect mortality was recorded at 24, 48 and 72 hours after intervals while repellency was carried out at 2 hours after intervals upto 10th hours and the collected data were analyzed through MSTAT-C program. Results indicated that all the tested oils had toxic and repellent effects against the A. craccivora nymphs. Among the tested botanical oils, no significant difference was observed in terms of mortality over treatment time. But significant difference was noticed over level of concentrations exerted by the botanical oils. The average highest mortality (28.62%) was recorded by the application of mehogony oil whereas neem oil showed the lowest mortality (27.21%) against the A. craccivora and the mortality was directly proportional to the level of concentrations and hour after treatment (HAT). Probit analysis showed the lowest LD50 values of mehogony oil which revealed the highest toxic effect against the nymph of bean aphid. The highest repellent effect (77.33%) was found in mehogony oil (repellent class IV) among all the botanical oils applied. On the contrary, neem (57.33%) and karanja (55.00%) oils belonged to the same repellent class that is repellent class II. Although all the tested botanical oils evaluated showed toxic and repellent effects but mehogony oil performed as the best potent oil against the nymphs. We therefore suggested using the mehogony oil for the management of bean aphid. SAARC J. Agric., 19(1): 139-154 (2021)


1976 ◽  
Vol 66 (2) ◽  
pp. 331-333 ◽  
Author(s):  
J. A. K. Farrell

AbstractIn two trials, at Chitedze, Malawi, in 1966–1967, the spread of rosette virus disease in groundnuts (Arachis hypogaea) intersown with field beans (Phaseolus vulgaris) was less than the spread in groundnut monocultures comprising plant populations equivalent to the number of groundnut plants and to the total number of plants in the intersown crop. In one trial, numbers of early rosette transmissions were related to numbers of alate Aphis craccivora Koch, the vector of the virus, found on groundnut plants. Immigrant alate A. craccivora settling on the intersown crop were trapped by the hooked epidermal hairs of the bean plants and the observed reduction of rosette infection in the intersown crop was attributed to this effect. Inter-sowing with beans is considered less effective than early-sown, high-density monoculture as a method of reducing groundnut rosette infections and yields of groundnuts from inter-sown crops may be lower than those obtained from high-density monoculture.


2019 ◽  
Vol 143 (6) ◽  
pp. 659-669
Author(s):  
Seydou Diabate ◽  
Emilie Deletre ◽  
Lucy Kananu Murungi ◽  
Komi K.M. Fiaboe ◽  
John Wesonga ◽  
...  

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