Assessment of cues potentially mediating host selection of Leptoglossus occidentalis on Pinus contorta

2016 ◽  
Vol 19 (3) ◽  
pp. 245-256 ◽  
Author(s):  
Tamara A. Richardson ◽  
Ward B. Strong ◽  
Brian H. Aukema ◽  
Stephen Takàcs ◽  
Tracy Zahradnik ◽  
...  
Parasitology ◽  
1995 ◽  
Vol 111 (4) ◽  
pp. 531-536 ◽  
Author(s):  
A. Saul

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.


1962 ◽  
Vol 53 (2) ◽  
pp. 241-256 ◽  
Author(s):  
E. S. Brown

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.


2006 ◽  
Vol 138 (6) ◽  
pp. 888-896 ◽  
Author(s):  
Ward B. Strong

AbstractManagement of Leptoglossus occidentalis Heidemann in lodgepole pine (Pinus contorta var. latifolia Engelm.) seed orchards of British Columbia, Canada, would be improved with knowledge of its damage potential at different times of the growing season. Mesh insect-exclusion bags were placed over cones, and adults or nymphs of L. occidentalis were enclosed in different bags for 9 periods of 10 to 38 days between 6 May and 17 September 2004. Feeding by adult females between 6 May and 28 May reduced total extractable seeds, a result of ovule damage before fertilization. Reduction in the number of filled seeds per cone was highest between 6 May and 29 June, with each adult female reducing yield by approximately 1.7 seeds per day. Between 29 June and 10 August, each adult female reduced the number of filled seeds per cone (seed set) by 1.0 to 1.25 per day. Seed set reduction declined to approximately 0.25 filled seeds per adult female per day after 10 August. Third to fifth instars caused seed set reduction between 0.6 and 1.2 filled seeds per cone per nymph feeding day from 29 June to 10 August. Utilizing these findings would improve management of L. occidentalis in a commercial seed orchard setting.


2001 ◽  
Vol 79 (11) ◽  
pp. 1349-1357 ◽  
Author(s):  
Cameron G Lait ◽  
Sarah L Bates ◽  
Karen K Morrissette ◽  
John H Borden ◽  
Allison R Kermode

Radiography is a valuable tool for assessing quality of conifer seeds, but it cannot differentiate between aborted seeds and seeds that have been emptied by western conifer seed bug (Leptoglossus occidentalis Heidemann) feeding. We tested three biochemical marker-based assays that were developed to identify L. occidentalis damage to seeds of Douglas-fir, Pseudostuga menziesii (Mirb.) Franco, for their use in lodgepole pine, Pinus contorta var. latifolia Engelmann. The three assays included measurement of storage protein reserve depletion, immunodetection of fragments of insoluble (crystalloid) storage proteins, and immunodetection of L. occidentalis salivary proteins. Aborted seeds contained significantly less soluble and insoluble protein than seeds that were fed on by L. occidentalis. Polyclonal antibodies raised against 11S globulin crystalloid proteins or L. occidentalis salivary gland extracts only immunoreacted with proteins in seeds exposed to L. occidentalis feeding. In a single-blind test, antibody raised against salivary-gland extracts correctly distinguished between undamaged full seeds, unfilled aborted seeds, and seeds fed on by L. occidentalis. Immunodetection of L. occidentalis salivary proteins was also performed on seeds of Abies amabilis Dougl. ex J. Forbes, Tsuga heterophylla (Raf.) Sarg., Picea sitchensis Bong (Carr.), Pinus ponderosa Lawson, and Pinus monticola Dougl. ex D. Don. For all species, immunoreactive polypeptides were only detected in seeds fed on by L. occidentalis. These biochemical marker-based techniques could help researchers and seed orchard managers estimate seed losses caused by L. occidentalis in commercial seed orchards and natural forest stands.Key words: Leptoglossus occidentalis, saliva, biochemical markers, polyclonal antibody, immunodetection, Pinus contorta.


1962 ◽  
Vol 94 (12) ◽  
pp. 1309-1325 ◽  
Author(s):  
L. H. McMullen ◽  
M. D. Atkins

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.


1999 ◽  
Vol 6 (4) ◽  
pp. 370-377 ◽  
Author(s):  
Xianguo Guo ◽  
Zhengda Gong ◽  
Tijun Qian ◽  
Xiguang Feng ◽  
Xingde Duan ◽  
...  

PLoS ONE ◽  
2016 ◽  
Vol 11 (7) ◽  
pp. e0158768 ◽  
Author(s):  
Chunlei Yang ◽  
Lan Mi ◽  
Xialu Hu ◽  
Jianxin Liu ◽  
Jiakun Wang
Keyword(s):  

2006 ◽  
Vol 92 (4) ◽  
pp. 725-729 ◽  
Author(s):  
Hiroshi Yokoyama ◽  
Jeong-Ho Kim ◽  
Shigehiko Urawa
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document