Density and Spatial Relationships Between a Wasp Parasite and Its Housefly Host

1965 ◽  
Vol 97 (10) ◽  
pp. 1031-1037 ◽  
Author(s):  
John L. Madden ◽  
David Pimentel
Keyword(s):  
Musca Domestica ◽  
Parasite Density ◽  
Spatial Relationship ◽  
Spatial Relationships ◽  
Nasonia Vitripennis ◽  
The Mean

AbstractThe density and spatial relationship between the wasp parasite, Nasonia vitripennis, and the housefly host, Musca domestica, were investigated. As parasite dispersion decreased in a defined space, parasitism increased from 30 to 76% and host survival decreased from an average of 65.0 to 18.9%. The number of host pupae producing parasite progeny and the survival of host pupae decreased as the proportion of small host pupae increased. With host numbers increasing and parasite numbers constant, the mean number of eggs deposited per host increased significantly from 31.25 to 87.25 and the number of stings increased from 2.25 to 8.00. As parasite density increased and host number remained constant, the number of hosts which were nor attacked declined from a mean of 2.2 with 1 parasite to none with 32 parasites. Host survival declined from about 50% at the 1:8 ratio of female parasites to hosts to no survival at the 2:1 ratio.

Effects of Superparasitism on Nasonia vitripennis (Walk.) (Hymenoptera: Pteromalidae)

1965 ◽  
Vol 97 (3) ◽  
pp. 326-331 ◽  
Author(s):  
H. G. Wylie
Keyword(s):  
Musca Domestica ◽  
House Fly ◽  
Food Shortage ◽  
Nasonia Vitripennis ◽  
Rate Of Development

AbstractSuperparasitism created a food shortage and thereby reduced survival and size of adult Nasonia vitripennis (Walk.) (Hymenoptera: Pteromalidae) reared on pupae of the house fly, Musca domestica L. Superparasitism also reduced the percentage of females in the adult progeny but had no effect on rate of development, ability to emerge, or incidence of diapause in N. vitripennis.

OVIPOSITION RESTRAINT OF SPALANGIA CAMERONI (HYMENOPTERA: PTEROMALIDAE) ON PARASITIZED HOUSEFLY PUPAE

1972 ◽  
Vol 104 (2) ◽  
pp. 209-214 ◽  
Author(s):  
H. G. Wylie
Keyword(s):  
Musca Domestica ◽  
Nasonia Vitripennis

AbstractFemales of Spalangia cameroni Perk, use the ovipositor to differentiate between unparasitized and parasitized housefly (Musca domestica L.) pupae; and prefer to lay on unparasitized hosts instead of those attacked by S. cameroni, Nasonia vitripennis (Walk.), or Muscidifurax zaraptor K. & L. (Hymenoptera: Pteromalidae). The intensities of oviposition restraint on the three kinds of attacked hosts are similar. Changes in parasitized pupae to which the female parasites react probably involve "venoms" injected by each species during oviposition.

CONTROL OF EGG FERTILIZATION BY NASONIA VITRIPENNIS (HYMENOPTERA: PTEROMALIDAE) WHEN LAYING ON PARASITIZED HOUSE FLY PUPAE

1973 ◽  
Vol 105 (5) ◽  
pp. 709-718 ◽  
Author(s):  
H. G. Wylie
Keyword(s):  
Musca Domestica ◽  
House Fly ◽  
Nasonia Vitripennis ◽  
House Flies

AbstractFemales of Nasonia vitripennis (Walk.) lay a smaller percentage of fertilized (i.e. female) eggs on house fly, Musca domestica L., pupae previously parasitized by their own species, by Muscidifurax zaraptor K. & L., or by Spalangia cameroni Perk. (Hymenoptera: Pteromalidae) than on unparasitized hosts. They respond to changes in the fly pupae associated with death, and in the case of house flies attacked by N. vitripennis, to "venoms" injected at that time or to changes unrelated to death. By not fertilizing eggs that they lay on attacked hosts, the females also conserve sperm, for immature N. vitripennis on previously-attacked fly pupae are usually killed by parasite larvae already present.

Effect of Host (Musca domestica Linnaeus) Age on the Pteromalid Parasite Nasonia vitripennis (Walker)

1966 ◽  
Vol 98 (11) ◽  
pp. 1226-1231 ◽  
Author(s):  
Peter C. Chabora ◽  
David Pimentel
Keyword(s):  
Musca Domestica ◽  
Oviposition Behavior ◽  
Age Groups ◽  
Pupal Stage ◽  
Nasonia Vitripennis

AbstractAn investigation was made of the influence of age of the host (Musca domestica Linn.) in the pupal stage on the oviposition behavior and development of the pteromalid parasite Nasonia vitripennis (Walk.). Five age groups of hosts were employed in 10 pair combinations with an excess of hosts available for selection. Except for the 1-day-old hosts, more of the younger hosts of the combinations produced parasite progeny while the older hosts had a high percentage yielding neither fly nor parasite. Parasite production per pupa was 6.25 on the youngest hosts, with the number decreasing to 4.85 per host at 5 days. Hosts 2, 3, and 4 days old combined with 1-day-old hosts had higher rates of parasitism than when combined with hosts of other ages. The ranking for successful parasitization of hosts, by age of pupae, was 2, 3, 1, 4, and 5 days old.

On-Line Chinese Character Recognition Via a Representation of Spatial Relationships Between Strokes

1997 ◽  
Vol 11 (03) ◽  
pp. 329-357 ◽  
Author(s):  
Ju-Wei Chen ◽  
Suh-Yin Lee
Keyword(s):  
Character Recognition ◽  
Chinese Character ◽  
Spatial Relationship ◽  
Spatial Relations ◽  
Chinese Characters ◽  
Spatial Relationships ◽  
Matching Problem ◽  
Structural Rules ◽  
Chinese Character Recognition ◽  
On Line

Chinese characters are constructed by basic strokes based on structural rules. In handwritten characters, the shapes of the strokes may vary to some extent, but the spatial relations and geometric configurations of the strokes are usually maintained. Therefore these spatial relations and configurations could be regarded as invariant features and could be used in the recognition of handwritten Chinese characters. In this paper, we investigate the structural knowledge in Chinese characters and propose the stroke spatial relationship representation (SSRR) to describe Chinese characters. An On-Line Chinese Character Recognition (OLCCR) method using the SSRR is also presented. With SSRR, each character is processed and is represented by an attribute graph. The process of character recognition is thereby transformed into a graph matching problem. After careful analysis, the basic spatial relationship between strokes can be characterized into five classes. A bitwise representation is adopted in the design of the data structure to reduce storage requirements and to speed up character matching. The strategy of hierarchical search in the preclassification improves the recognition speed. Basically, the attribute graph model is a generalized character representation that provides a useful and convenient representation for newly added characters in an OLCCR system with automatic learning capability. The significance of the structural approach of character recognition using spatial relationships is analyzed and is proved by experiments. Realistic testing is provided to show the effectiveness of the proposed method.

scholarly journals Relationship between biomass and parasite density of Mediorhynchus emberizae (Acanthocephala: Gigantorhynchidae) parasites of Paroaria dominicana (Passeriformes: Emberizidae) of the State of Bahia, Brazil

2008 ◽  
Vol 17 (2) ◽  
pp. 118-121
Author(s):  
Adriano R. Carvalho ◽  
Sueli Souza-Lima ◽  
Luiz E. R. Tavares ◽  
José L. Luque
Keyword(s):  
Small Intestine ◽  
Parasite Density ◽  
The State ◽  
Metazoan Parasites ◽  
Density Dependent ◽  
Parasite Intensity ◽  
The Mean

During the study of the metazoan parasites of Paroaria dominicana (Linnaeus, 1758), eight infrapopulations of Mediorhynchus emberizae (Rudolphi, 1819), were collected in the medium third of the small intestine, with parasite intensities ranging from one to ten specimens. Differences among the average values of the biomass, volume of the eggs, volume of the testicles and the parasite density of the infrapopulations were statistically tested in order to detect variations of these parameters in function of parasite density. Was observed that the acanthocephalans biomass increased with the volume of the intestine and also that the parasite density increased with the parasite intensity in the infrapopulations. It was verified that the increase of the parasite intensity was accompanied by the decrease of the mean biomass of the parasites. Decrease of the volume of the eggs was verified with the increase of the density and of the parasite intensity. The results of the present work could suggested the occurrence of density-dependent factors and the decrease of testicles volume and the biomass of the males with the increase of the parasite density in the infrapopulations of M. emberizae in the intestine of P dominicana.

scholarly journals Parasitóides de dípteros muscóides coletados no matadouro Alvorada em Itumbiara, sul de Goiás, Brasil

2007 ◽  
Vol 16 (4) ◽  
pp. 235-237 ◽  
Author(s):  
Carlos H. Marchiori ◽  
Alexandre S Leles ◽  
Selma A. De Carvalho ◽  
Renata F. Rodrigues
Keyword(s):  
Musca Domestica ◽  
Nasonia Vitripennis ◽  
Chrysomya Albiceps

Espécies de parasitóides associados com moscas sinantrópicas foram coletadas com auxílio de iscas de fígado bovino no matadouro Alvorada em Itumbiara, Estado de Goiás, de março a dezembro de 2005. As pupas foram removidas da areia, após usar iscas de fígado como substrato para atrair as moscas. Elas foram individualizadas em cápsulas de gelatina até a emergência dos adultos de moscas ou de seus parasitóides. A prevalência total de parasitismo foi 15,3%. A freqüência absoluta, porcentagem e espécies de parasitóides coletados foram: 205 exemplares (2,3%) de Aphaereta sp., 173 (80,0%) de Brachymeria podagrica, 578 (15,7%) Nasonia vitripennis, um (0,5%) de Pachycrepoideus vindemmiae, dois (0,9%) de Spalangia sp. e um (0,5%) de Trybliographa sp. A porcentagem de parasitismo apresentada pelos parasitóides de Aphaereta sp., B. podagrica, N. vitripennis, P. vindemmiae, Spalangia sp., e Trybliographa sp. foi de 0,4%, 12,3%, 2,4%, 0,1%, 0,1% e 0,1%, respectivamente. As espécies de dípteros parasitados foram: Chrysomya albiceps, C. megacephala, Musca domestica, Oxysarcodexia thornax, Peckia chrysostoma e Sarcodexia lambens.

OVIPOSITION RESTRAINT OF MUSCIDIFURAX ZARAPTOR (HYMENOPTERA: PTEROMALIDAE) ON PARASITIZED HOUSEFLY PUPAE

1971 ◽  
Vol 103 (11) ◽  
pp. 1537-1544 ◽  
Author(s):  
H. G. Wylie
Keyword(s):  
Musca Domestica ◽  
Nasonia Vitripennis ◽  
Drilling Site

AbstractFemales of Muscidifurax zaraptor K. & L. oviposit on unparasitized housefly (Musca domestica L.) pupae in preference to those attacked by M. zaraptor, Nasonia vitripennis (Walk.), or Spalangia cameroni Perk. (Hymenoptera: Pteromalidae). The discrimination against parasitized houseflies is greatest in the case of those attacked by M. zaraptor and least for those parasitized by S. cameroni. Discrimination is based on differences between unparasitized and parasitized pupae that the female parasites detect after they pierce the pupae with the ovipositor. Death of parasitized hosts, or a change resulting directly therefrom, is not responsible for the differences. The fact that hosts pierced at or near the original drilling site are more likely to be rejected than those attacked elsewhere supports the hypothesis that a ’venom’ injected by the female parasites during oviposition diffuses throughout the host and is responsible for oviposition restraint.

Spatial component position in total hip arthroplasty: Accuracy and repeatability with a new CT method

2003 ◽  
Vol 44 (1) ◽  
pp. 84-91
Author(s):  
H. Olivecrona ◽  
L. Weidenhielm ◽  
L. Olivecrona ◽  
M. E. Noz ◽  
G. Q. Maguire ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Spherical Surface ◽  
Spatial Relationship ◽  
Component Position ◽  
Total Hip ◽  
Percent Difference ◽  
Prosthetic Head ◽  
The Mean ◽  
Accuracy And Repeatability

Purpose: 3D detection of centerpoints of prosthetic cup and head after total hip arthroplasty (THA) using CT. Material and Methods: Two CT examinations, 10 min apart, were obtained from each of 10 patients after THA. Two independent examiners placed landmarks in images of the prosthetic cup and head. All landmarking was repeated after 1 week. Centerpoints were calculated and compared. Results: Within volumes, all measurements of centerpoints of cup and head fell, with a 95% confidence, within one CT-voxel of any other measurement of the same object. Across two volumes, the mean error of distance between center of cup and prosthetic head was 1.4 mm (SD 0.73). Intra- and interobserver 95% accuracy limit was below 2 mm within and below 3 mm across volumes. No difference between intra- and interobserver measurements occurred. A formula for converting finite sets of point landmarks in the radiolucent tread of the cup to a centerpoint was stable. The percent difference of the landmark distances from a calculated spherical surface was within one CT-voxel. This data was normally distributed and not dependent on observer or trial. Conclusion: The true 3D position of the centers of cup and prosthetic head can be detected using CT. Spatial relationship between the components can be analyzed visually and numerically.

Visualization and Measurement of the Cortical Surface

2000 ◽  
Vol 12 (5) ◽  
pp. 739-752 ◽  
Author(s):  
Brian A. Wandell ◽  
Suelika Chial ◽  
Benjamin T. Backus
Keyword(s):  
Magnetic Resonance ◽  
Human Brain ◽  
Source Code ◽  
Spatial Relationship ◽  
Complex Pattern ◽  
The Internet ◽  
Cortical Surface ◽  
Spatial Relationships

Much of the human cortical surface is obscured from view by the complex pattern of folds, making the spatial relationship between different surface locations hard to interpret. Methods for viewing large portions of the brain's surface in a single flattened representation are described. The flattened representation preserves several key spatial relationships between regions on the cortical surface. The principles used in the implementations and evaluations of these implementations using artificial test surfaces are provided. Results of applying the methods to structural magnetic resonance measurements of the human brain are also shown. The implementation details are available in the source code, which is freely available on the Internet.

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