Host Selection of Potomida semirugata (Unionidae: Bivalvia) in Reproduction Strategy

SUMMARYA stochastic simulation model of the transmission and maintenance of genetic heterogeneity in the absence and presence of external selection pressures is presented for polygamous intestinal helminths such as Ascaris. The model assumes that the density distribution of the adult parasites is highly aggregated and that density-dependent effects on fecundity are important. The model gives rise to stable infection rates in the host. Where the parasite population contains genetic heterogeneity, with the exception of stochastic fluctuations which models genetic drift, the ratio of the different alleles remained constant over extended periods of time. This result contrasts with that of an earlier analytical model (Anderson, R. M., May, M. R. & Gutpa S. (1989) Parasitology 99, S59–S79), in which uneven mating probabilities for the different combinations of worm possible in a host was postulated to inevitably lead to fixation of the most abundant allele. New results suggest that in spite of the restricted choice of mating available to a worm in the confines of a host, selection pressure always leads to enrichment of the parasites carrying resistant alleles.

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The Role of Experience in the Host Selection of Phytophagous Insects

Proceedings in Life Sciences - Perspectives in Chemoreception and Behavior ◽

10.1007/978-1-4612-4644-2_9 ◽

1987 ◽

pp. 143-157 ◽

Cited By ~ 70

Author(s):

Tibor Jermy

Keyword(s):

Host Selection ◽

Phytophagous Insects ◽

Selection Of

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Notes on parasites of Pentatomidae and Scutelleridae (Hemiptera-Heteroptera) in Middle East countries, with observations on biological control

Bulletin of Entomological Research ◽

10.1017/s0007485300048100 ◽

1962 ◽

Vol 53 (2) ◽

pp. 241-256 ◽

Cited By ~ 14

Author(s):

E. S. Brown

Keyword(s):

Biological Control ◽

Middle East ◽

Host Selection ◽

Biological Control Agent ◽

Control Agent ◽

Sunn Pest ◽

Eurygaster Integriceps ◽

Middle East Countries ◽

Central Turkey ◽

Selection Of

A number of observations were made on parasites of certain Pentatomoids (sunn pest) attacking wheat in Middle East countries, during the course of other work on these pests. The principal host species studied were Eurygaster integriceps Put., E. maura (L.) and Aelia rostrata Boh. The data concern both Dipterous (Tachinid) endoparasites of the adult bugs, and also Hymenopterous (Scelionid) egg-parasites; the observations were made principally in central Turkey, and in the Varamine district of Iran. A few observations on predators were made also.The data concerning Tachinids consist of host records for six species of parasites. In no case observed by the author did these parasites appear to be of great importance in reducing the numbers of sunn pest; the same is true of the few instances of predators recorded.Observations were made on six species of Scelionid egg-parasites (five species of Asolcus and one of Hadronotus), five of which were bred from eggs of four species of Pentatomoid hosts collected in the field. The species concerning which the most comprehensive data were obtained were Asolcus rufiventris (Mayr), A. semistriatus (Nees) and A. vassilievi (Mayr). Egg-parasites are well known to be more efficacious in reducing sunn-pest populations, and A. semistriatus has been extensively used in Iran as a biological control agent. The data obtained enabled some ideas which are of importance for the use of egg-parasites in biological control to be formed and discussed. These concern principally (a) the susceptibilities of different hosts to parasitisation; (b) host selection by parasites; (c) the selection of a species of parasite most suitable for biological control in a particular area.

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On the Flight and Host Selection of the Douglas-fir Beetle, Dendroctonus pseudotsugae Hopk. (Coleoptera: Scolytidae)

The Canadian Entomologist ◽

10.4039/ent941309-12 ◽

1962 ◽

Vol 94 (12) ◽

pp. 1309-1325 ◽

Cited By ~ 66

Author(s):

L. H. McMullen ◽

M. D. Atkins

Keyword(s):

Experimental Data ◽

Life Cycle ◽

Host Selection ◽

Bark Beetles ◽

Time Of Flight ◽

Field Studies ◽

Douglas Fir ◽

Major Portion ◽

Dendroctonus Pseudotsugae ◽

Selection Of

The flight of bark beetles covers a short but important period of their life cycle, during which they are exposed to conditions not encountered during the major portion of their life under the bark. The time of flight and the factors which affect it are important, not only to the dispersal and survival of the insect, but also in the interpretation of experimental data dependent upon the beetle's flight activity.Chapman (1954), Rudinsky and Vité (1956), and Atkins (1959, 1960, 1961) studied the flight of the Douglas-fir beetle under laboratory conditions, but there is scant reference to field studies on the flight of this insect. Chapman and Kinghorn (1958) recorded the number caught in window flight traps near Cowichan Lake, B.C., and unpublished reports describe emergence records obtained from cage studies conducted near Lumby, B.C.

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