The biology of Unionicola formosa (Dana and Whelpley): a water mite parasitic in the unionid bivalve, Anodonta cataracta (Say), in a New Brunswick lake

1979 ◽  
Vol 57 (9) ◽  
pp. 1748-1756 ◽  
Author(s):  
M. J. Gordon ◽  
B. K. Swan ◽  
C. G. Paterson
Keyword(s):  
Life Cycle ◽  
Sex Ratio ◽  
New Brunswick ◽  
Seasonal Variations ◽  
The Other ◽  
Warm Water ◽  
Host Size ◽  
Water Mite ◽  
Mantle Tissue ◽  
Host Sex

The eggs, teleiochrysalis, and adults of the water mite Unionicola formosa (Dana and Whelpley) occur in Anodonta cataracta whereas only the egg stage is found in the other three unionid bivalves in Morice Lake, New Brunswick. There is no selectivity for host sex. Female mites do not reside in smaller bivalves. The incidence of infection and host loading increases with bivalve length. No evidence was found for territoriality of females within the host or for seasonal variations in abundance of either males or females. Only one male mite resides in each infected host. Incidence of infection increases with host size up to 5 cm and then remains stable at about 52%. A positive male–female association occurs during the warm water period but not after the water cools. The sex ratio is 1.60 females: 1 male. The teleiochrysalis occurs in the siphons during July at a density approximately 2.5 times that of the adults. Eggs are laid from late May until early July in the mantle tissue of most available hosts. The eggs hatch the following June and the larvae leave. Nymphs are found periodically except when teleiochrysalises are present. The available data suggest a 3-year life cycle for U. formosa.

scholarly journals Siklus Hidup Spodoptera frugiperda Dengan Pemberian Pakan Kangkung dan Daun Bawang di Laboratorium

2021 ◽  
Vol 26 (3) ◽  
pp. 386-391
Author(s):  
Ichsan Luqmana Indra Putra ◽  
Nanda Dwi Martina
Keyword(s):  
Climate Change ◽  
Life Cycle ◽  
Sex Ratio ◽  
Spodoptera Frugiperda ◽  
The Other ◽  
Head Diameter ◽  
Corn Fields

  Spodoptera frugiperda was found to have entered Indonesia and damaged maize crops. There is a concern that climate change in Indonesia will cause these pests to migrate to other crops besides corn, such as kale and leeks. This research was conducted to observe the life cycle of S. frugiperda with feed treatment of kale leaves, leeks and corn leaves as a control. The larvae came from corn fields that were infested by S. frugiperda and were cultured in the laboratory. The variables observed were larva length, head diameter, pupa length, number of eggs, sex ratio, and time to complete one cycle. The life cycle of S. frugiperda varies between 37 and 47 days. Kale leaf feed is a good feed for the growth of S. frugiperda compared to the other two feeds, while corn leaf is good in fecundity.   Keywords: corn, fecundity, growth, life cycle, sex ratio

Variation in the sex ratio of Rhabdochona fortunatowi (Spirurida: Rhabdochonidae) in Capoeta capoeta gracilis (Cypriniformes: Cyprinidae), relative to levels of infection, host size and temperature

2011 ◽  
Vol 86 (1) ◽  
pp. 41-45 ◽  
Author(s):  
M. Golestaninasab ◽  
M. Malek ◽  
B. Jalali ◽  
I. Mobedi
Keyword(s):  
Sex Ratio ◽  
Drainage Basin ◽  
Parasite Burden ◽  
Host Size ◽  
Site Preference ◽  
Intensity Of Infection ◽  
Mean Intensity ◽  
Fish Intestine ◽  
Host Sex ◽  
Different Parts

AbstractIn the present study, 81 specimens of Capoeta capoeta gracilis (Keyserling, 1861) were collected from the Shiroud River, the Caspian drainage basin, Iran in June and October 2007. The fish were examined for infection with the nematode Rhabdochona fortunatowi (Dinnik, 1933). Nematodes were counted and sexed, then the sex ratio and intestinal site preference of the R. fortunatowi individuals and the intersexual interactions of the parasites were investigated. Significant differences were observed in the prevalence and intensity of infection in relation to host size and sampling season, but not host sex. Parasite burden (mean intensity) was higher in October than in June and the results revealed a decrease in female-to-male sex ratio (FMR) in the fish in October compared to the ones in June. In other words, as the mean intensity of infection of R. fortunatowi increases, the proportion of male worms increases, too. The female-biased sex ratio in June was replaced by a male-biased one in October. Nematode distribution rose to a significant peak in the mid-region of the fish intestine relative to the anterior and posterior parts. Some changes in the distribution of male and female worms in different parts of the host intestine were also observed during June and October. Density-dependent selection and intersexual competition seem to be the main factors driving such a shift in the sex ratio and its variation in different parts of the host intestine.

scholarly journals Infestation rates of the pedunculated barnacle Octolasmis lowei (Cirripedia: Poecilasmatidae) on the spider crab Libinia spinosa (Decapoda: Majoidea)

2009 ◽  
Vol 90 (2) ◽  
pp. 315-322 ◽  
Author(s):  
C.A.M.M. Cordeiro ◽  
T.M. Costa
Keyword(s):  
Life Cycle ◽  
Developmental Stage ◽  
Ovigerous Female ◽  
Host Size ◽  
Spider Crab ◽  
Density Dependent ◽  
The Real ◽  
Host Sex ◽  
Main Factor

The prevalence and infestation intensities of Octolasmis lowei in the branchial chambers of Libinia spinosa were evaluated according to the host's sex, size, and moult condition. Epibionts were classified as cyprid larvae, non-ovigerous or ovigerous according to their developmental stage. A median intensity of infestation of 21 epibionts/host was found (range = 1–644; Q3 = 81). Epibiont prevalence values (88%) were higher on ovigerous female hosts than on males (55%) or on non-ovigerous females (31%). Intensity of infestation was positively correlated with host size in both sexes for non-ovigerous and ovigerous epibionts. No preference between host sex by cyprid larvae was observed, nor any correlation between cyprid abundance and host size. Cyprid larvae abundance was positively correlated with settled epibionts on both host sexes. The duration of the intermoult phase was the main factor linked to the establishment of sessile epibionts. These observations are important in relation to crabs that have a terminal moult, because these animals cannot eliminate their epibionts in future moults, thus increasing the importance of density-dependent mechanisms on epibiont establishment; in that way, prevalence of infestation alone can underestimate the real impact of infestation on the host's life cycle.

scholarly journals SEX-RATIO MANIPULATION BY THE PARASITOID WASPMUSCIDIFURAX RAPTORIN RESPONSE TO HOST SIZE

Evolution ◽  
1993 ◽  
Vol 47 (6) ◽  
pp. 1876-1882 ◽  
Author(s):  
Sandra E. Seidl ◽  
Bethia King
Keyword(s):  
Sex Ratio ◽  
Host Size

The butterfly squid Stoloteuthis leucoptera in the Mediterranean

1991 ◽  
Vol 71 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Lidia Orsi Relini ◽  
Daniela Massi
Keyword(s):  
Life Cycle ◽  
Adult Male ◽  
The Other ◽  
Otter Trawl ◽  
Ligurian Sea ◽  
The Mediterranean ◽  
Unique Species ◽  
Recent Immigration

The presence of Stoloteuthis leucoptera in the Mediterranean is recorded on the basis of three specimens, including an adult male, caught by IKMT and by commercial otter-trawl in the Ligurian Sea. The hypothesis of a recent immigration is discussed.The list of Mediterranean cephalopods (Mangold Wirz, 1963; Torchio, 1968; Bello, 1986; Mangold & Boletzsky, 1987) includes the Sepiolidae of the subfamily Heteroteuthinae, whose members are supposed to be pelagic throughout their life cycle. Mangold Wirz (1963) recognizes in the Mediterranean fauna the unique species Heteroteuthis dispar, the other authors include H. atlantis Voss, which Voss himself (1955) reported at Messina. To this group may now be added Stoloteuthis leucoptera (Verrill, 1878) a species until now recorded in limited Atlantic areas. Verrill (1881) wrote “This species is an exceedingly beautiful one, when living, owing to the elegance and brilliancy of its colours and the gracefulness of its movements. In swimming it moves its fins in a manner analogous to the motion of the wings of a butterfly.”

Limnetic Zooplankton Assemblages in Atlantic Canada with Special Reference to Acidification

1986 ◽  
Vol 43 (2) ◽  
pp. 444-456 ◽  
Author(s):  
J. C. H. Carter ◽  
W. D. Taylor ◽  
R. Chengalath ◽  
D. A. Scruton
Keyword(s):  
Nova Scotia ◽  
New Brunswick ◽  
Fish Predation ◽  
Low Ph ◽  
Buffering Capacity ◽  
The Other ◽  
Bay Of Fundy ◽  
Factor Scores ◽  
Multiple Discriminant Analysis ◽  
Biological Factors

Crustacean and rotifer plankton assemblages of 93 lakes in Labrador, 107 in Newfoundland, and 142 in New Brunswick – Nova Scotia were investigated for evidence of correlations with lake morphometric, chemical, or biological factors. Labrador assemblages were almost completely lacking in identifiable structure. Newfoundland species clustered into two groups of different body size, suggesting the influence of fish predation. Only one species in Labrador and Newfoundland was significantly correlated with a derived factor related to lake water buffering capacity. New Brunswick – Nova Scotia species clustered into two groups, one featuring significant positive and the other significant negative correlations with the buffering factor. From this we conclude that acidification is having an impact on the limnetic zooplankton of these two provinces. Multiple discriminant analysis was used to demonstrate that New Brunswick – Nova Scotia lakes differing in their buffering capacity were also distinct in zooplankton composition. Lakes with low factor scores (low pH, alkalinity, and calcium) were mainly located in the Bay of Fundy region; this area has above average fog and precipitation, and lies within the summer air flow carrying pollutants from the south.

scholarly journals The density of females of Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) affects their reproductive performance on pupae of Bombyx mori L. (Lepidoptera: Bombycidae)

2010 ◽  
Vol 82 (2) ◽  
pp. 323-331 ◽  
Author(s):  
Fabricio F. Pereira ◽  
José C. Zanuncio ◽  
José E. Serrão ◽  
Teresinha V. Zanuncio ◽  
Dirceu Pratissoli ◽  
...  
Keyword(s):  
Life Cycle ◽  
Relative Humidity ◽  
Sex Ratio ◽  
Bombyx Mori ◽  
Reproductive Performance ◽  
Climatic Chamber ◽  
Glass Tubes ◽  
Bombyx Mori L

Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) is a gregarious and polyphagous parasitoid mainly of Lepidoptera pupae. The objective of this paper as to study the developent of parasitoid on Bombyx mori L. (Lepidoptera: Bombycidae) pupae exposed to one, nine, 18, 27, 36, 45 or 54 female P. elaeisis, respectively. The females of the parasitoid remained in contact with pupae for 24 hours in glass tubes (14.0 x 2.2 cm), packed in a climatic chamber regulated at 25 ± 2°C, 70 ± 10% relative humidity and photo phase of 12 hours. With the exception of density 1:1 (72.72%), in other densities parasitism was 100%. Adults of P. elaeisis did not emerge from pupae at densities of 1:1 and 9:1, but 100.0% of parasitoid emergence was observed at the density of 45:1 and 54.54% at 54:1. The duration of the life cycle of this parasitoid ranged from 20 to 28 days. P. elaeisis produced 49 to 589 descendants per pupa of B. mori. The sex ratio of P. elaeisis ranged from 0.93 ± 0.01 to 0.97 ± 0.01 without differences with 18, 27, 36, 45 and 54 females/host. This parasitoid should be reared with the density of 45 females per pupa of B. mori.

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