scholarly journals Occurrence of entomopathogenic fungi in populations of Rhopalosiphum padi (L.) aphids feeding on primary and secondary host plants

2018 ◽  
Vol 58 (1) ◽  
Author(s):  
E.S. Gandrabur ◽  
◽  
A.B. Vereschagina ◽  

For example of the bird cherry-oat aphid, the analysis of the timing of development in the “plant-phytophage” system in heterocyclic aphids with alternation of the primary (winter, arboreal) host plant to the secondary (summer, herbaceous) ones was done. The similarity in the phenology of colonization by aphids of primary and secondary hosts was shown. The features of the stages of plant organogenesis and the formation of the number of aphids in connection with their harmfulness are noted. Modeling shifts in the synchronization of the work of this trophic system contributes to its destabilization.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Belén Cotes ◽  
Gunda Thöming ◽  
Carol V. Amaya-Gómez ◽  
Ondřej Novák ◽  
Christian Nansen

AbstractRoot-associated entomopathogenic fungi (R-AEF) indirectly influence herbivorous insect performance. However, host plant-R-AEF interactions and R-AEF as biological control agents have been studied independently and without much attention to the potential synergy between these functional traits. In this study, we evaluated behavioral responses of cabbage root flies [Delia radicum L. (Diptera: Anthomyiidae)] to a host plant (white cabbage cabbage Brassica oleracea var. capitata f. alba cv. Castello L.) with and without the R-AEF Metarhizium brunneum (Petch). We performed experiments on leaf reflectance, phytohormonal composition and host plant location behavior (behavioral processes that contribute to locating and selecting an adequate host plant in the environment). Compared to control host plants, R-AEF inoculation caused, on one hand, a decrease in reflectance of host plant leaves in the near-infrared portion of the radiometric spectrum and, on the other, an increase in the production of jasmonic, (+)-7-iso-jasmonoyl-l-isoleucine and salicylic acid in certain parts of the host plant. Under both greenhouse and field settings, landing and oviposition by cabbage root fly females were positively affected by R-AEF inoculation of host plants. The fungal-induced change in leaf reflectance may have altered visual cues used by the cabbage root flies in their host plant selection. This is the first study providing evidence for the hypothesis that R-AEF manipulate the suitability of their host plant to attract herbivorous insects.


1982 ◽  
Vol 72 (1) ◽  
pp. 157-163 ◽  
Author(s):  
S. Wiktelius

AbstractAlate exules of Rhopalosiphum padi (L.) were flown in a flight chamber for three different flight times: 1 min, 5 min and 25 min. The rate of climb was recorded continuously during flight. Afterwards, the aphids were forced to land on either wheat or potato and settling behaviour was recorded. The settling response was strengthened with increasing flight time on both plants. The aphids spent more time walking and made more probes on potato than on wheat after 25 min of flight. The rate of climb was the same immediately before landing as immediately after a spontaneous re-take-off, except after a 25-min flight and landing on potato when the rate of climb was significantly higher after re-take-off. Comparison with Aphis fabae Scop. from other investigations showed that the change in settling response with flight time was similar for the two species. R. padi seemed less able to discriminate rapidly between host and non-host plants than A. fabae. It is concluded that its behaviour does not hinder R. padi from being a vector of stylet-borne potato viruses.


2010 ◽  
Vol 142 (5) ◽  
pp. 481-488 ◽  
Author(s):  
Fabio Molinari ◽  
Gianfranco Anfora ◽  
Silvia Schmidt ◽  
Michela Villa ◽  
Claudio Ioriatti ◽  
...  

AbstractWe investigated whether or not pear ester (ethyl (E,Z)-2,4-decadienoate) attracted adult oriental fruit moths, Cydia molesta (Busck) (Lepidoptera: Tortricidae). The electroantennographic responses of C. molesta to pear ester were recorded and dose–response curves calculated. In laboratory bioassays, the attractiveness of different dosages was assessed in a dual-choice olfactometric arena. The responses of virgin males and females to pear ester in the presence and absence of pear (Pyrus communis L.), peach (Prunus persica (L.) Batsch.), and apple (Malus ×domestica Borkh.) (Rosaceae) shoots were evaluated. Electroantennographic recordings demonstrated that both male and female C. molesta were able to detect the pear ester. In our bioassay, however, pear ester readily attracted males but attracted very few females. The response of males was dose-dependent and they preferred pear ester over apple- and pear-shoot volatiles, whereas no apparent preference between pear ester and peach-shoot volatiles was observed. Therefore, this kairomonal compound could be more effective in attracting C. molesta when applied in orchards of secondary host plants, like apple or pear, than in peach orchards.


1967 ◽  
Vol 57 (3) ◽  
pp. 381-386
Author(s):  
J. Strangways-Dixon

Alarodia nana (Möschler) (Lepidoptera, Limacodidae) is a major pest of Citrus in Jamaica. An outbreak of the larvae, the ‘ slug caterpillar ’, may result in severe defoliation. All stages are found on the foliage and are present throughtout the year; the adults are inactive by day and appear to be weak fliers.Earlier attempts to breed the insect in the laboratory had been unsuccessful, and, whereas attempts at control had indicated that malathion was effective against the larvae, reingestation had invariably taken place, well-grown larvae being found five weeks after treatment.In the present work, done in 1963–4, adults that emerged from field-collected cocoons held in wire-mesh cages over Citrus plants in the laboratory mated on the night of emergence and the females oviposited readily on the following night. A technique for rearing individual larvae and for measuring their head capsules is described. In the laboratory at a mean midday temperature of about 27°C., the incubation period of the eggs was 6–8 days, and the durations of the larval and pupal phases 25–42 and 14–19 days, respectively.Results of a search for secondary host-plants from which reinfestation might take place were negative. Observations of emergence in the laboratory of adults from cocoons collected just before and just after the application to an orchard of a low-volume malathion spray derived from a 57 per cent. emulsifiable concentrate by dilution at the rate of 1: 80 in water showed that many pupae had survived the application, and suggested that reinfestation might arise from moths emerging from such pupae.A field trial comprising two application of the low-volume spray of malathion was carried out; the second application, designed to destroy larvae derived from pupae that had survived the first application, was made after an interval of 312; weeks and was completely successcful.


Author(s):  

Abstract A new distribution map is provided for Rhopalosiphum padi (L.) (R. prunifoliae (Fitch), R. fitchii auct.) (Hemipt., Aphididae) (Oat-Bird Cherry Aphis, Apple-Grain Aphis). Host Plants: Wheat, rice, other cereals, Manila hemp, apple, cherry. Information is given on the geographical distribution in EUROPE (excl. USSR), Albania, Austria, Azores, Belgium, Britain, Bulgaria, Czechoslovakia, Denmark, Faeroe Islands, Finland, France, Germany, Greece, Hungary, Iceland, Italy, Netherlands, Norway, Poland, Portugal, Spain, Sweden, Switzerland, Yugoslavia, ASIA (excl. USSR), China, Hong Kong, India, Indonesia, Iraq, Israel, Japan, Jordan, Korea, Peninsular Malaysia, Mongolia, Nepal, Pakistan, Philippines, Ryukyu Islands, Syria, Taiwan, Turkey, Vietnam, USSR, AFRICA, Cameroon, Crozet Islands, Egypt, Ethiopia, Kenya, Libya, Madeira, Morocco, Rhodesia, St. Helena, South Africa, AUSTRALASIA AND PACIFIC ISLANDS, Australia, Hawaii, Macquarie Island, New Zealand, NORTH AMERICA, Canada, U.S.A., SOUTH AMERICA, Argentina, Brazil, Chile, Falkland Islands Dependencies, Peru.


1987 ◽  
Vol 77 (1) ◽  
pp. 35-43 ◽  
Author(s):  
C. T. Williams

AbstractThe mid-winter development, reproduction and survival of field-acclimatized viviparae of Sitobion avenae (F.) and Rhopalosiphum padi (L.) on leaves of tillering wheat and perennial ryegrass (Lolium perenne) plants at similar growth stages were compared by monitoring batches of aphids in clip-cages in field plots in southern England. For both aphid species, survival, total fecundity and reproductive rate were much higher on wheat than on L. perenne, and on both host-plants they were much higher for S. avenae than for R. padi. Development times (in day-degrees) were longer on L. perenne than on wheat, and on both host-plants were longer for R. padi than for S. avenae, though these differences were less marked. Comparison of the results with those of earlier studies suggests that large changes in cereal aphid performance occur between summer and winter and that these are both aphid-specific and host-plant-specific.


Sign in / Sign up

Export Citation Format

Share Document