Phylogeography, historical factors and host-parasite specificity: comparative study of the communities of acorn feeding insects (Curculio spp.) in the Iberian peninsula and California

Abstract Epistyliasis has been characterized as an emergent disease which has a great impact on fish farms, especially on Oreochromis niloticus production systems. Although epidemiological important, information about the dispersion of these parasites and their mechanical vectors is scarce. The present study reported the cooccurrence of Epistylis sp. as an epibiont of Dolops carvalhoi, a parasitic crustacean of cultivated/wild specimens (from accidental release) of O. niloticus from a cage fish farm area in the Ilha Solteira Reservoir, Grande River, SP, Brazil. The co-occurrence of Epistylis sp. and D. carvalhoi, and their epibiont relationship registered in this study suppose that the Epistylis may use the crustaceans for dispersion and as mechanical vectors for the dissemination of diseases in wild and cultivated hosts. Moreover, exchange of parasites between wild and cultivated hosts is possible, considering both organisms (protozoan and argulid). Furthermore, the results of the present study demonstrate the need to monitor the areas adjacent to cage fish farms as a preventive measure for the dispersion of pathogens. This is the first report of epibiosis between Epistylis sp. and argulid parasites of cultivated and wild O. niloticus, contributing to knowledge about host-parasite specificity, geographical distribution, dispersion of etiological agents and epidemiology in aquaculture.

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Parasitism of oospores of Pythium spp. by strains of Actinoplanes spp.

Canadian Journal of Microbiology ◽

10.1139/m93-145 ◽

1993 ◽

Vol 39 (10) ◽

pp. 964-972 ◽

Cited By ~ 9

Author(s):

N. I. Khan ◽

A. B. Filonow ◽

L. L. Singleton ◽

M. E. Payton

Keyword(s):

Biological Control ◽

Host Specificity ◽

Pythium Ultimum ◽

Pythium Myriotylum ◽

Pythium Irregulare ◽

Pythium Arrhenomanes ◽

Parasite Specificity ◽

Host Parasite ◽

First Time

Strains of Actinoplanes spp. were evaluated for their in vitro parasitism of oospores of Pythium aphanidermatum, Pythium arrhenomanes, Pythium irregulare, Pythium myriotylum, and Pythium ultimum. Oospores of Pythium arrhenomanes, Pythium irregulare, and Pythium myriotylum were identified for the first time as hosts of Actinoplanes spp. Newly recorded parasites of oospores of Pythium spp. were Actinoplanes azureus, Actinoplanes brasiliensis, Actinoplanes caeruleus, Actinoplanes ferrugineus, Actinoplanes ianthinogenes, Actinoplanes italicus, Actinoplanes minutisporangius, Actinoplanes rectilineatus, Actinoplanes teichomyceticus, Actinoplanes utahensis, Actinoplanes violaceous, Actinoplanes yunnahenis, plus 15 strains of Actinoplanes yet to be speciated. Parasitized oospores had disorganized cytoplasms and hyphae of Actinoplanes sp. emerging from them. Infection of oospores in vitro varied from 0 to > 90%. Strains also were very active parasites of oospores in sterile soils. When added to nonsterile soils, several strains increased (p = 0.05) the level of oospore parasitism compared with nonsupplemented soils. Strains of Actinoplanes spp. exhibited a host specificity for species of Pythium in vitro and in soil. Sporulation of Actinoplanes sp. from infected oospores incubated on soil was frequent and more abundant than that observed in vitro.Key words: Pythium spp., Actinoplanes spp., actinomycetes, biological control, host–parasite specificity.

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Injury-related phaseollin accumulation in Phaseolus vulgaris and its implications with regard to specificity of host–parasite interaction

Canadian Journal of Botany ◽

10.1139/b75-109 ◽

1975 ◽

Vol 53 (9) ◽

pp. 921-928 ◽

Cited By ~ 30

Author(s):

James E. Rahe ◽

Robert M. Arnold

Keyword(s):

Phaseolus Vulgaris ◽

Colletotrichum Lindemuthianum ◽

Living Tissue ◽

Cotyledonary Nodes ◽

Etiolated Seedlings ◽

Parasite Specificity ◽

Per Se ◽

Freezing Injuries ◽

Host Parasite ◽

Time Point

Phaseollin accumulated locally at point-freezing injuries on hypocotyls of intact etiolated seedlings of Phaseolus vulgaris. Maximum amounts occurred within 24 to 30 h after injury. Smaller amounts accumulated at similar sites on hypocotyls excised at the time point-freezing injuries were made, and the accumulation was less localized. Increasing amounts of phaseollin occurred at sites increasingly distant from the cotyledonary nodes in both intact and excised hypocotyls. Much higher levels of phaseollin were elicited by excision per se than by point-freezing. Phaseollin was not detected after freezing of whole hypocotyls, indicating that living tissue adjacent to injuries is required for accumulation. The data are discussed in relation to host–parasite specificity, with particular reference to the interaction between P. vulgaris and Colletotrichum lindemuthianum.

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