AUTECOLOGY OF TWO AESHNA SPECIES (ODONATA) IN WESTERN VIRGINIA

1984 ◽  
Vol 116 (4) ◽  
pp. 567-578 ◽  
Author(s):  
Timothy G. Halverson
Keyword(s):  
Life Cycles ◽  
Growth Patterns ◽  
Juncus Effusus ◽  
Embryonic Diapause ◽  
Maturation Period ◽  
Larval Diapause ◽  
Early Evening ◽  
High Dispersal ◽  
Males And Females ◽  
Dead Plant

AbstractAeshna tuberculifera Walker and A. umbrosa Walker were studied in the Shenandoah Mountains, Rockingham County, Virginia for 5 years. Both species had 2-year life cycles. They passed the first winter in an embryonic diapause and the second in a larval diapause. Although A. umbrosa was slightly smaller and developed earlier in the year, growth patterns of the two species were similar. Adults emerged from mid-summer to mid-fall with a slight protandry. Sex ratio at emergence was equal in A. tuberculifera but slightly biased toward males in A. umbrosa. Individuals emerging later in the season tended to be smaller than those emerging earlier, and the decline in size was linear over time. The maturation period lasted 4–6 weeks. Poor recovery of marked teneral and breeding adults indicates either high mortality or high dispersal, but observed movement among ponds by marked breeding adults suggests high dispersal. Breeding males of both species defended entire ponds for short periods. Both males and females were present more frequently in the afternoon than during the morning or at mid-day. Females often oviposited in the late afternoon or early evening when males were usually absent from the ponds. A. tuberculifera used stems of Juncus effusus L. almost exclusively for oviposition, while A. umbrosa used a variety of dead plant or other material and rarely used J. effusus stems.

THE INTERACTIONS OF VERTEBRATES AND INVERTEBRATES IN PEATLANDS AND MARSHES

1987 ◽  
Vol 119 (S140) ◽  
pp. 15-30 ◽  
Author(s):  
Henry R. Murkin ◽  
Bruce D.J. Batt
Keyword(s):  
Current Knowledge ◽  
Life Cycles ◽  
Future Research ◽  
Aquatic Environments ◽  
Research Needs ◽  
Avian Community ◽  
Wide Range ◽  
Dead Plant ◽  
Living Organisms ◽  
And Function

AbstractThis paper reviews the interactions of vertebrates and invertebrates in peatlands and marshes to assess current knowledge and future research needs. Living organisms may interact through a number of direct trophic and nutrient pathways and a variety of non-trophic, habitat-dependent relationships. Freshwater marshes and peatlands are dynamic aquatic environments and organisms that occupy these areas must be adapted to a wide range of environmental conditions. The avian community illustrates the main interactions of invertebrates and vertebrates in peatlands and marshes. Waterfowl, along with fish and furbearers, are the most economically important vertebrates using these habitats. Each of these groups has important trophic and habitat links to the invertebrates within wetlands.The most common interaction between vertebrates and invertebrates is the use of invertebrates as food by vertebrates. Few studies, however, have dealt with trophic dynamics or secondary production within wetlands. Waterfowl, fish, and many other wetland vertebrates, during all or part of their life cycles, regularly feed on invertebrates. Some invertebrates are vectors of disease and parasites to vertebrates. Vertebrates can directly affect the structural substrate that invertebrates depend on as habitat through consumption of macrophytes or through the use of living and dead plant material in the construction of houses and nests. Conversely, herbivorous invertebrates may directly affect the survival and distribution of macrophytes in wetlands. Macrophyte distribution, in turn, is an important factor in determining vertebrate use of wetlands. The general lack of both taxonomic and ecological information on invertebrates in wetlands is the main hindrance to future elucidation of vertebrate–invertebrate interactions in these environments. Development of invertebrate sampling techniques suitable for wetland habitats also is necessary. More specific research needs must be met to develop a better understanding of the structure and function of these dynamic systems.

Growth and life histories in Nematoda with particular reference to environmental factors

Nematology ◽  
2003 ◽  
Vol 5 (5) ◽  
pp. 653-664 ◽  
Author(s):  
Brian Boag ◽  
Gregor Yeates
Keyword(s):  
Life Histories ◽  
Developmental Stages ◽  
Relative Size ◽  
Nematode Species ◽  
Life Cycles ◽  
Growth Patterns ◽  
Female Size ◽  
Lower Growth ◽  
Physical Support ◽  
Unifying Principles

AbstractTo seek unifying principles underlying growth patterns in the phylum Nematoda, the volume of successive developmental stages was determined from published measurements. Within some groups occupying fairly uniform, non-living habitats ( e.g. , Longidoridae, Mononchida, non-parasitic Rhabditida) growth patterns are similar, as are the sizes of both sexes. In aquatic Chromadorida and Monhysterida, females are commonly larger than males. Plant-parasitic groups vary in the relative size of the sexes; within Criconematoidea there is some reduction of males in Hemicyliophora but extreme reduction in Tylenchulus. Despite freeliving and parasitic cycles of Strongyloides showing differing growth in stages 2 to 4, females are similar in both cycles. The strongylid parasites of vertebrates studied have a bacterial-feeding external stage and have lower growth rates and achieve smaller female size than Ascardia with direct life cycles. In taxa for which data are available, the increase in volume between stages 1 and 2 was 0.4-53-fold; that between stages 2 and 3, typically, 1.8-2.9-fold but up to 8191-fold; between stages 3 to 4, 1.7-3.8-fold but up to 100-fold; and between stage 4 to female, typically, 1.1-42-fold but up to 918-fold. Complete data are available for few nematode species and there is no apparent consistent pattern in which taxa contain 'outliers' at particular stages. Many more data are required to assess the impacts of habitat texture, physical support, food supply and experienced temperature on nematode growth and size.

Mating Behaviour of the Oriental Fruit Moth, Grapholitha molesta (Busck) (Lepidoptera: Olethreutidae)

1964 ◽  
Vol 96 (8) ◽  
pp. 1087-1093 ◽  
Author(s):  
G. G. Dustan
Keyword(s):  
Mating Behaviour ◽  
Codling Moth ◽  
Egg Laying ◽  
Oriental Fruit Moth ◽  
Late Afternoon ◽  
Grapholitha Molesta ◽  
Early Evening ◽  
Males And Females ◽  
Bait Traps ◽  
Peach Orchard

AbstractExperiments and observations on Oriental fruit moths in cages and in a peach orchard showed that both males and females may mate more than once. The maximum recorded number of matings was 7 for males and 5 for females. Mating usually occurred in the late afternoon and early evening during the daily flight and egg-laying period. Males seldom mated oftener than once in 24 hours and they transferred only one spermatophore to the female per mating. In cages, males mated approximately 1.4 times each when confined with equal numbers of females. Of the females taken in bait traps in a peach orchard, an average of 2.9% had not mated, 78.8% had mated once, 14.6% twice, and 3.7% more than twice. The mating behaviour of the Oriental fruit moth was shown to be similar to that of the codling moth.

Growth ecology of the tree lizard Urosaurus bicarinatus (Squamata: Phrynosomatidae), in a tropical dry forest of the Chamela Region, Mexico

2016 ◽  
Vol 66 (2) ◽  
pp. 189-199 ◽  
Author(s):  
Aurelio Ramírez-Bautista ◽  
Uriel Hernández-Salinas ◽  
J. Gastón Zamora-Abrego
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Growth Rates ◽  
Average Rate ◽  
Growth Patterns ◽  
Dry Forest ◽  
Von Bertalanffy ◽  
Mexican Pacific ◽  
Males And Females ◽  
Tree Lizard

Determination of growth rate provides an important component of an organism’s life history, making estimations of size at maturity, survival rate, and longevity possible. Here, we report on growth rate of males and females of the tropical tree lizard Urosaurus bicarinatus, in a seasonal environment in the state of Jalisco on the Mexican Pacific Coast. We calculated body growth rates and fitted these to the Von Bertalanffy, the logistic-by-length, and the logistic-by-weight growth models. The Von Bertalanffy model provided the best fit, and we used it to analyze the growth pattern. Males and females did not differ in estimated asymptotic size and other characteristic growth parameters. Estimated growth curve predicted an age at maturity of 38 mm SVL on 120 days for males, and 40 mm SVL on 170 days for females. On the basis of the similarities in the growth rates between the sexes, comparisons were made between seasons, and we found that the average rate of growth was slightly, albeit insignificantly, higher in the rainy season than in the dry season. The similarities in the growth patterns for the sexes of this species might be indicative of variance in its life history traits (e.g., fecundity, egg size) compared to those of other populations of this species and other species of this genus; therefore, it is important to document interpopulation differences to understand the evolutionary changes that have led to optimal adaptation in a particular environment more accurately.

scholarly journals Sexual Allometric Monomorphism in Araucan Pig from Colombia: Preliminary Results

Animals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1763
Author(s):  
Arcesio Salamanca-Carreño ◽  
Jordi Jordana-Vidal ◽  
René Alejandro Crosby-Granados ◽  
José Norberto Arias-Landazábal ◽  
Pere M. Parés-Casanova
Keyword(s):  
Body Size ◽  
Quantitative Traits ◽  
Growth Patterns ◽  
Environmental Adaptation ◽  
Sexual Differences ◽  
Multivariate Approach ◽  
Allometric Growth ◽  
Preliminary Results ◽  
Face Width ◽  
Males And Females

This study aimed to evaluate the allometric growth of the Araucan pig breed, a creole breed from Arauca, East Colombia, locally known as “Sabaneros”, in relation to different quantitative traits and considering genders separately. To do this, a total of 31 male and 27 female Araucan pigs, ranging from 4 to 48 months of age, were studied in order to evaluate their growth patterns, using a multivariate approach. Animals belonged to different farms (“fincas”) of the Department of Arauca, Colombia. From each individual, 10 quantitative traits were obtained: face width, croup height, croup length, croup width, tail base height, hock height, loin height, cannon length, and length and width of ear. Our results, which must be interpreted as preliminary, showed that the Araucan pig is allometrically monomorphic as sexual differences do not increase with body size. We suggest that although males and females have evidently different reproductive roles, during growth they shift the allocation of energy to structures linked to environmental adaptation rather than those linked to reproduction.

scholarly journals Eupelmus messene Walker, 1839 and E. microzonus Förster, 1860 as parasitoids of Aulacidea hieracii (Bouché, 1834) (Hymenoptera, Eupelmidae, Cynipidae)

2021 ◽  
Vol 84 ◽  
pp. 87-102
Author(s):  
Vladimir E. Gokhman ◽  
Matvey I. Nikelshparg
Keyword(s):  
Life History ◽  
Host Species ◽  
European Russia ◽  
Life History Strategies ◽  
Parasitoid Species ◽  
Gall Wasp ◽  
Larval Diapause ◽  
Host Body ◽  
Subzero Temperatures ◽  
Males And Females

In the southeast of European Russia, the gall wasp Aulacidea hieracii (Bouché, 1834) is attacked by ten parasitoid species, including Eupelmus (Eupelmus) microzonus Förster, 1860 and E. (Macroneura) messene Walker, 1839. Although both members of the genus Eupelmus Dalman, 1820 are idiobiont ectoparasitoids, they demonstrate different life-history strategies in respect to many bionomic features. Specifically, E. messene is represented by brachypterous thelytokous females which lay single eggs directly onto the host body. This species can parasitize both concealed and exposed larvae and pupae of A. hieracii, but fails to attack its primary parasitoids. On the contrary, arrhenotokous males and females of E. microzonus are fully winged. These parasitoids usually lay several eggs per host which are placed onto the wall of the host chamber and covered with a particular fibrous substance. E. microzonus never parasitizes pupae or exposed larvae, although it can readily attack concealed larvae of A. hieracii and its primary parasitoids. In addition, hibernating individuals of E. messene undergo obligatory larval diapause, but those of E. microzonus are able to develop without exposure to subzero temperatures. All these data collectively suggest that the former species is highly specialized to exploit A. hieracii as a host, whereas the latter one mostly exhibits the so-called morphotypical specialization. These different strategies allow E. messene and E. microzonus to coexist on the same host species, as a local specialist and a more or less evenly distributed generalist, respectively.

Reproductive strategy of the Australian Sharpnose Shark, Rhizoprionodon taylori (Elasmobranchii: Carcharhinidae), from Cleveland Bay, Northern Queensland

1992 ◽  
Vol 43 (1) ◽  
pp. 67 ◽  
Author(s):  
CA Simpfendorfer
Keyword(s):  
Litter Size ◽  
Reproductive Strategy ◽  
Life Histories ◽  
Early Embryo ◽  
Northern Territory ◽  
Embryonic Diapause ◽  
Early Embryo Development ◽  
Males And Females ◽  
Developmental Traits ◽  
Size At Birth

Reproduction and early embryo development of Rhizoprionodon taylori from Cleveland Bay, Queensland, was studied on the basis of 455 specimens caught between May 1987 and February 1990. Males and females mature at sizes larger than those reported from northern Western Australia, the Northern Territory and far northern Queensland. Mating occurs annually in summer, and the gestation period is approximately 11.5 months. After development to a small blastodermic disc, the embryos enter a state of diapause that lasts approximately 7 months. R. taylori is the only species of shark that is known to have a period of embryonic diapause. The litter size ranges from 1 to 10 (mean 4.9, being markedly larger than that for other carcharhinid species of a similar size. The size at birth is 220- 260 mm. The reproductive and developmental traits are discussed in relation to the life histories of this species and other carcharhinids.

Larval growth and development of the stonefly Pteronarcys californica (Insecta: Plecoptera) in the Crowsnest River, Alberta

1998 ◽  
Vol 76 (12) ◽  
pp. 2274-2280 ◽  
Author(s):  
G D Townsend ◽  
G Pritchard
Keyword(s):  
Aquatic Insects ◽  
Larval Growth ◽  
Adult Emergence ◽  
Head Capsule ◽  
Life Cycles ◽  
Embryonic Diapause ◽  
Larval Recruitment ◽  
Summer Diapause ◽  
History Of ◽  
High Degree

We used head-capsule width, wing-pad length, larval recruitment, adult emergence, and MULTIFANTM analysis to determine the life history of the stonefly Pteronarcys californica in the Crowsnest River, Alberta. Embryonic development, incorporating an early diapause, accounts for approximately 1 year of the life cycle. Both sexes spend a further 4 years in the larval stage. Female larvae grow faster than males and so achieve a larger size at emergence. Extended larval recruitment leads to variation in the sizes of larvae of the same year class and probably to cohort splitting. There is a high degree of synchrony in adult emergence, perhaps as a result of a summer diapause in antepenultimate-instar larvae. These phenomena (embryonic diapause, extended larval recruitment, different growth rates of the sexes, cohort splitting, and larval diapause) are possibly typical of aquatic insects with long life cycles.

scholarly journals Growth characteristics of noiler chickens as determined by nonlinear algorithms

2021 ◽  
Vol 48 (5) ◽  
pp. 12-19
Author(s):  
J. Adamu ◽  
A. Y. Shuaibu ◽  
A. O. Raji
Keyword(s):  
Goodness Of Fit ◽  
Growth Models ◽  
Growth Patterns ◽  
Growth Characteristics ◽  
Coefficient Of Determination ◽  
Logistic Growth ◽  
Mathematical Function ◽  
Morphometric Traits ◽  
Male And Female ◽  
Males And Females

The assessment of growth characteristics of noilers chickens as determined by non- linear algorithms will provide the best mathematical function in the growth of male and female noilers chickens This study sought to determine the adequacy of two mathematical functions for modeling growth characteristics of male and female Noiler® chickens. Body weights and morphometric traits of 200 Noiler chickens were measured bimonthly for 20 weeks and the data obtained fitted to the Gompertz and Logistic growth models using the nonlinear regression. The results showed significant (P<0.05) difference between males and females only at 16, 18 and 20 weeks of age, with values of 2316.2 vs 2121.9 g, 2624.3 vs 2378.1 g, and 3002.7 vs 2718.7g, respectively. There were no discernable differences between males and females for most body measurements except body length which was longer in the latter than former from 14 weeks of age. The asymptomatic weight (A) of the models revealed that Gompertz model had higher values for both male and female Noilers than the Logistic for body weight and all morphometric traits. The reverse was observed with the scale parameter 2 (B) and relative growth rate (C) for all traits. The coefficient of determination (R ) values for both models (male and female) were generally high (>80%) indicating a good fit for the data. The other goodness of fit criteria; Akaike Information Criterion (AIC) and standard deviation (SD) were lower for the Gompertz compared to Logistic for both male and female. Thus, the study revealed that the Gompertz was the better model for explaining the growth patterns of both male and female Noiler chickens.     L'évaluation des caractéristiques de croissance des poulets de Noilers tels que déterminées par des algorithmes non linéaires fournira la meilleure fonction mathématique de la croissance des poulets de Noilers masculins et féminins. Cette étude a cherché à déterminer l'adéquation de deux fonctions mathématiques pour la modélisation des caractéristiques de croissance des poulets mâles et femelles Noiler. Les poids corporels et les traits morphométriques de 200 poulets nilaques ont été mesurés bimenshly pendant 20 semaines et les données obtenues dans les modèles de Gompertz et croissance logistiques utilisant la régression non linéaire. Les résultats ont montré une différence significative (p <0,05) entre les mâles et les femmes seulement à 16, 18 et 20 semaines, avec des valeurs de 2316,2 vs 2121,9 g, 2624.3 contre 2378,1 g et 3002,7 vs 2718.7g, respectivement. Il n'y avait pas de  différences discernables entre les hommes et les femmes pour la plupart des mesures du corps, à l'exception de la longueur du corps, ce qui était plus long que l'ancien de 14 semaines. Le poids asymptomatique (A) des modèles a révélé que le modèle de Gompertz avait des valeurs plus élevées pour les noilers mâles et femelles que la logistique pour le poids corporel et tous les traits morphométriques. L'inverse a été observé avec le paramètre d'échelle (B) et le taux de croissance relative (C) pour tous les traits. Le coefficient de valeurs de détermination (R ) pour les deux modèles (hommes et femmes) était généralement élevé (> 80%) indiquant un bon ajustement pour les données. L'autre bonté des critères d'ajustement; Le critère d'information Akaike (CIA) et l'écart type (ET) étaient plus bas pour le Gompertz par rapport à la logistique pour les hommes et les femmes. Ainsi, l'étude a révélé que le Gompertz était le meilleur modèle d'explication des schémas de croissance des poulets mâles et femelles Noilers. 

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