Field studies of growth, reproduction, and mortality in the burrowing wolf spider Geolycosa domifex (Hancock)

1978 ◽  
Vol 56 (9) ◽  
pp. 2037-2049 ◽  
Author(s):  
Donald J. McQueen

A population of burrowing wolf spiders (Geolycosa domifex (Hancock)) was studied near Toronto, Canada, from 1974 to 1977. By following the life history of individuals in marked burrows, it was found that females produce one brood when they are 3 years old. Juveniles leave their mothers during July and August, after which they search for suitable burrow sites, establish burrows, and overwinter. During this period approximately 85% of the juveniles die and the average burrow diameter increases from 1 mm in August to 2–3 mm in October. In the second summer approximately 9% of the original cohort die and the average burrow diameter is 7 mm when the remaining individuals overwinter. In the third summer 4–5% of the original cohort die and burrow diameters average 13 mm when the remaining individuals overwinter. In the fourth summer the remaining 1 or 2% of the original cohort reproduce and more than 99% of these are killed by acrocerid flies (Pterodontia flavipes Grey) and pompilid wasps (Anoplius relativus (Fox)). Because < 0.008% of the original cohort survive to reproduce in their 4th year of life, three separate cohorts occupy the same habitat with little (< 1%) gene flow between them.

2012 ◽  
Vol 90 (6) ◽  
pp. 714-721 ◽  
Author(s):  
J.J. Bowden ◽  
C.M. Buddle

We studied populations of three tundra-dwelling wolf spider (Lycosidae) species to determine reproductive trait relationships and developmental timing in the Arctic. We collected 451 Pardosa lapponica (Thorell, 1872), 176 Pardosa sodalis Holm, 1970, and 117 Pardosa moesta Banks, 1892 during summer 2008. We used log-likelihood ratio tests and multiple linear regressions to determine the best predictors of fecundity and relative reproductive effort. Female body size best explained the variation in fecundity and body condition was the best predictor for relative reproductive effort. We tested for a trade-off between the allocation of resources to individual eggs and the number of eggs produced (fecundity) within each species using linear regression. There was variation in detectable egg size and number trade-offs among sites and these may be related to local variation in resource allocation linked to density-related biotic or abiotic factors. These findings contribute to knowledge about the fitness of arctic wolf spiders in the region of study and are particularly relevant in light of the effects that climate changes are predicted to have on the arctic fauna.


1985 ◽  
Vol 63 (5) ◽  
pp. 938-945 ◽  
Author(s):  
Patricia S. Muir ◽  
James E. Lotan

Mature serotinous and nonserotinous trees of Pinus contorta Dougl. var. latifolia Engelm. in the Bitterroot Watershed of western Montana do not differ in most life-history characteristics (reproductive or vegetative). No differences between trees of the two cone types were found in height, basal area, basal area growth rates over the lives of the trees, or crown ratio. Cone number, weights of individual cones and seeds, and estimates of reproductive effort were similar in serotinous and non-serotinous trees. Reproductive characteristics were either independent of tree age, or related similarly in trees of the two cone types. Nonserotinous trees may, however, have more seeds per cone than serotinous trees. This difference in seed numbers may be adaptive if serotinous trees invest relatively heavily in cone materials to protect seeds (which are retained in cones for many years), while nonserotinous trees (which shed seeds each year) invest relatively heavily in seeds. Trees of the two cone types differ mainly in the particular types of disturbance favoring their regeneration, but they often grow in the same stands where there are similar selective pressures on most aspects of their biology. Gene flow between them probably homogenizes all but those differences maintained by strong selective pressures.


2017 ◽  
Vol 1 (5) ◽  
Author(s):  
Geir H. Bolstad ◽  
Kjetil Hindar ◽  
Grethe Robertsen ◽  
Bror Jonsson ◽  
Harald Sægrov ◽  
...  

1967 ◽  
Vol 15 (4) ◽  
pp. 739 ◽  
Author(s):  
RK Keith

Observations are reported on the morphology of the egg and infective larva, and on the development in calves of the parasitic stages of Cooperia pectinata Ransom. The third and fourth moults occurred 2 and 8 days, respectively, after infection. The pre-patent period was 13-14 days.


2019 ◽  
Vol 81 (8) ◽  
pp. 561-567
Author(s):  
Kathryn S. Craven ◽  
Alex Collier ◽  
Jay Y. S. Hodgson

Field investigations represent an excellent opportunity to integrate the Next Generation Science Standards to complement and enhance both classroom and laboratory instruction. This inquiry-based exercise is designed to introduce students to the basic anatomy, ecology, and natural history of a common backyard denizen, the wolf spider (Lycosidae). Students are charged with developing one or more testable hypotheses regarding wolf spiders in their own backyards. Wolf spiders are an ideal subject for field investigation because their secondary eyes possess a highly reflective layer called the tapetum lucidum. At night, this layer produces an unmistakable “eyeshine” when viewed with the beam of a flashlight. Playing the role of students, we tested the hypothesis that wolf spiders should occur at higher density in an undeveloped field than in a typical backyard. To test this, we utilized random quadrat sampling in both habitats using flashlights to detect nocturnal eyeshine. Students obtaining similar results would likely have concluded that wolf spiders were more abundant in natural habitats.


Nematology ◽  
2001 ◽  
Vol 3 (5) ◽  
pp. 455-461 ◽  
Author(s):  
Noritoshi Maehara ◽  
Kazuyoshi Futai

AbstractAlthough fourth-stage dispersal juveniles (JIV) of Bursaphelenchus xylophilus, the pinewood nematode (PWN), developed in the presence of both Monochamus alternatus and Psacothea hilaris, the numbers and the percentage of JIV were far higher in the presence of the former than of the latter. JIV first appeared 7 days after pupation of M. alternatus and the number increased from the day of beetle eclosion to the third day thereafter, then remained stable. We conclude that the presence of specific vectors affects both the life history of the PWN and the numbers of nematodes carried by vectors emerging from killed pine trees.


Parasitology ◽  
1930 ◽  
Vol 22 (2) ◽  
pp. 242-259 ◽  
Author(s):  
Enid K. Sikes

A short historical account is given of the writings on flea larvae since the seventeenth century. The larvae have been known since Leeuwenhoek tried to breed them in 1683.The life-history of Ceratophyllus wickhami is described. The fleas were bred in the laboratory on a grey squirrel. Three larval instars occur, and the life-history occupies, on an average, 6 weeks under experimental conditions.The external anatomy of the third instar larva of C. wickhami is described. The mouth parts are generalised and suggest the condition of a primitive insect. The tracheal system is composed of a double longitudinal trunk on each side, with spiracles on the prothorax, metathorax and first eight abdominal segments.The first and second instar of C. wickhami are similar to the third instar larvae, except in size and the presence of a hatching spine in the first stage.The larva of Ceratophyllus fasciatus is mentioned. The importance of the species lies in the presence of completely separated galea and lacinia.Larvae of Xenopsylla cheopis and X. astia are briefly described. The larvae of the two species are practically identical except for the shape of the mandibles.


1957 ◽  
Vol 5 (2) ◽  
pp. 188 ◽  
Author(s):  
MJ Mackerras

First-stage larvae of Aelurostrongylus abstrusus (Railliet) developed readily in the garden slug, Agriolimax laevis (Muller), two moults occurring in this host. When infected slugs were eaten by a cat, the third-stage larvae migrated at once to the lungs, where they underwent the third and fourth moults. The prepatent period in the cat was about 39 days. When infected slugs were fed to laboratory-bred mice, the third-stage larvae were not digested, but congregated in great numbers in the gastro-splenic ligament, forming minute yellowish cysts. They were also recovered in small numbers from other parts of the body. Third-stage larvae survived unchanged in mice for 12 weeks, and probably would survive for longer periods. Mice were regarded as important auxillary hosts. The minute adult worms were found in the bronchioles of the cat. They were always very difficult to locate. The eggs were laid in the alveoli, forming a characteristic pattern of small, solid nodules scattered throughout the lung tissue.


2003 ◽  
Vol 81 (8) ◽  
pp. 1293-1297 ◽  
Author(s):  
Christopher M Buddle ◽  
Sean E Walker ◽  
Ann L Rypstra

Cannibalism is an important regulating mechanism in many terrestrial and aquatic arthropod communities. Spider ecologists have suggested that cannibalism with wolf spiders (Araneae: Lycosidae) in the genera Schizocosa and Pardosa is common and can act in population regulation. This hypothesis was tested with the species Pardosa milvina (Hentz), a small wolf spider that shows high densities in disturbance-driven ecosystems, including agricultural fields, throughout eastern North America. Under laboratory conditions, cannibalism was more common between pairs of P. milvina with the greatest differences in both mass and size. Field studies, in which we stocked natural densities, 2× natural densities, and 4× natural densities of P. milvina in enclosures placed in soybean fields, revealed that survival was lowest when conspecific density was highest, and larger individuals prevailed under high-density conditions. Thus, cannibalism likely plays an important role in governing populations of P. milvina, and the generality about the prevalence and importance of cannibalism with wolf spiders is supported.


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