Latitudinal variation in Dendroctonus ponderosae (Coleoptera: Scolytidae) development time and adult size

2001 ◽  
Vol 133 (3) ◽  
pp. 375-387 ◽  
Author(s):  
B.J. Bentz ◽  
J.A. Logan ◽  
J.C. Vandygriff
Keyword(s):  
Pinus Ponderosa ◽  
Native Species ◽  
Development Time ◽  
Second Generation ◽  
Dendroctonus Ponderosae ◽  
Offspring Size ◽  
Adult Size ◽  
Southern Population ◽  
Northern Population ◽  
Generation Offspring

AbstractDendroctonus ponderosae (Hopkins) is widely distributed across western North America, feeding in at least 12 native species of Pinus L. (Pinaceae). We investigated the existence of heritable differences in two life-history parameters (adult size and development time) of D. ponderosae from a northern population (central Idaho, Pinus contorta Douglas ex Loudon) and a southern population (southern Utah, Pinus ponderosa Douglas ex P. and C. Lawson). We attempted to separate heritable from environmental effects by rearing individuals from both populations through two generations (F1 and F2) in a common standardized laboratory environment with a constant temperature. Two treatment effects were tested for in the F2 generation: (1) geographic location (source host) for F0D. ponderosae; and (2) the F2 brood host. We hypothesized that, if differences were observed and the F0 source host and region had a greater effect on F2 brood development time and adult size than did the host in which F2 brood were reared, a heritable factor related to the F0 parents was responsible. Time to emergence was significantly shorter for second-generation offspring of the northern population than for second-generation offspring of the southern population, regardless of the F2 brood host. Although both the F2 brood host and F0 source parents were significant in explaining differences observed in the developmental-time distribution of F2 brood, the F0 source effect was found to be much greater. Also, F2 males and females from southern source parents were significantly larger than F2 brood from northern source parents when reared in both F2 brood hosts. Geographic region and original host of F0 source parents had a significant effect on F2 offspring size, whereas the immediate food for F2 brood was not significant in explaining differences. These results suggest genetically based regional differences in D. ponderosae populations.

scholarly journals Dietary analysis of an uncharacteristic population of the Mountain Pygmy-possum(Burramys parvus)in the Kosciuszko National Park, New South Wales, Australia

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6307 ◽  
Author(s):  
Tahneal Hawke ◽  
Hayley Bates ◽  
Suzanne Hand ◽  
Michael Archer ◽  
Linda Broome
Keyword(s):  
Seasonal Variation ◽  
National Park ◽  
Climatic Variability ◽  
Critically Endangered ◽  
Conservation Strategies ◽  
Dietary Composition ◽  
Southern Population ◽  
Northern Population ◽  
Dietary Analysis ◽  
Critically Endangered Species

BackgroundThe Mountain Pygmy-possum (Burramys parvus) is a critically endangered marsupial, endemic to alpine regions of southern Australia. We investigated the diet of a recently discovered population of the possum in northern Kosciuszko National Park, NSW, Australia. This new population occurs at elevations well below the once-presumed lower elevation limit of 1,600 m.Goals and MethodsFaecal material was analysed to determine if dietary composition differed between individuals in the newly discovered northern population and those in the higher elevation southern population, and to examine how diet was influenced by rainfall in the southern population and seasonal changes in resource availability in the northern population.Results and DiscussionThe diet ofB. parvusin the northern population comprised of arthropods, fruits and seeds. Results indicate the diet of both populations shares most of the same invertebrate orders and plant species. However, in the absence of preferred food types available to the southern population, individuals of the northern population opportunistically consumed different species that were similar to those preferred by individuals in higher altitude populations. Differing rainfall amounts had a significant effect on diet, with years of below average rainfall having a greater percentage composition and diversity of invertebrates. Seasonal variation was also recorded, with the northern population increasing the diversity of invertebrates in their diet during the Autumn months when Bogong Moths (Agrotis infusa) were absent from those sites, raising questions about the possum’s dependence on the speciesConclusionsMeasurable effects of rainfall amount and seasonal variation on the dietary composition suggest that predicted climatic variability will have a significant impact on its diet, potentially impacting its future survival. Findings suggest that it is likely thatB. parvusis not restricted by dietary requirements to its current pattern of distribution. This new understanding needs to be considered when formulating future conservation strategies for this critically endangered species.

scholarly journals Male parental investment reflects the level of partner contributions and brood value in tree swallows

2017 ◽  
Author(s):  
Ádám Z. Lendvai ◽  
Çağlar Akçay ◽  
Mark Stanback ◽  
Mark F. Haussmann ◽  
Ignacio T. Moore ◽  
...  
Keyword(s):  
Parental Care ◽  
Interesting Case ◽  
Temporary Increase ◽  
Southern Population ◽  
Tree Swallows ◽  
Parental Effort ◽  
Northern Population ◽  
Nestling Begging ◽  
Two Populations ◽  
Partial Compensation

AbstractBiparental care presents an interesting case of cooperation and conflict between unrelated individuals. Several models have been proposed to explain how parents should respond to changes in each other’s parental care to maximize their own fitness, predicting no change, partial compensation, or matching effort as a response. Here, we present an experiment in tree swallows (Tachycineta bicolor) in which we increased the parental care of females by presenting them, but not their mates, with additional nestling begging calls using automated playbacks. We performed this experiment in two populations differing in future breeding opportunities and thus the intensity of conflict over current parental care. We found that in response to a temporary increase in female parental effort, males in the northern population with lower sexual conflict matched the increased effort, whereas males in the southern population did not. We also found that increases in parental care during playbacks were driven by the females (i.e., females initiated the increased effort and their mates followed them) in the northern population but not the southern population. These results support the idea that with incomplete information about the brood value and need, cues or signals from the partner might become important in coordinating parental care.

INSECT AND HOST ODORS IN THE AGGREGATION OF THE WESTERN PINE BEETLE

1969 ◽  
Vol 101 (2) ◽  
pp. 113-117 ◽  
Author(s):  
J. P. Vité ◽  
G. B. Pitman
Keyword(s):  
Sex Ratio ◽  
Pinus Ponderosa ◽  
Dendroctonus Ponderosae ◽  
Insect Pheromone ◽  
Dendroctonus Brevicomis ◽  
Western Pine Beetle ◽  
Pine Beetle ◽  
Host Odor ◽  
Host Odors ◽  
Per Se

AbstractDendroctonus brevicomis Lec. responded in flight to combinations of insect- and host-produced volatiles. Emergent female beetles crushed at −70 °C, as well as synthetic exo-7-ethyl-5-methyl-6, 8-dioxabicyclo [3.2.1] octane (“brevicomin”) attracted both sexes of the western pine beetle when offered with oleoresin freshly tapped from the host, Pinus ponderosa Laws. Offered separately, these materials were inactive. Crushed emergent Dendroctonus ponderosae Hopk. males per se, however, attracted flying D. brevicomis in appreciable numbers. Dominance of either host odor or insect pheromone appeared to govern the sex ratio of the responding insects.

scholarly journals Hunter-gatherer adaptions during the Early Holocene in Northern Sweden

The Holocene ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 83-94
Author(s):  
Therese Ekholm
Keyword(s):  
Ice Sheet ◽  
The Other ◽  
Early Holocene ◽  
Taiga Zone ◽  
Southern Population ◽  
Northern Sweden ◽  
The West ◽  
Northern Population ◽  
Long Time ◽  
Sea Mammals

This paper deals with the study of the ecology of early Holocene, 9000-4000 cal BC, specifically human and faunal dispersal into the Norrland and Dalarna areas of northern Sweden. It has been hypothesised that this region of Sweden was settled by hunter-gatherer groups of Butovo/Veretye ancestry moving in from the eastern taiga zone and at the same time groups from the West Scandinavian coast were moving north following the melting Weichselian ice sheet. Due to the speed of the melting ice these two groups must have encountered each other in the central part of northern Sweden. This article discusses the environment of these two separate groups and the possible consequences of their encounter, informed by results from the zooarchaeological analysis of burnt, radiocarbon dated bones from sites spanning much of Norrland and Dalarna. A compilation of previously dated sites are presented, and also new 14C dates from excavated sites. The northern population preferred to hunt forest game and held on to it for a long time even if sea mammals were available. The southern population, on the other hand, hunted sea mammals and forest game through the whole period.

Population Biology of Orangestriped Oakworm (Lepidoptera: Saturniidae) in Southeastern Virginia

1993 ◽  
Vol 28 (2) ◽  
pp. 218-229
Author(s):  
Mark A. Coffelt ◽  
Peter B. Schultz
Keyword(s):  
Population Biology ◽  
Development Time ◽  
First Generation ◽  
Second Generation ◽  
Egg Mass ◽  
Mass Size ◽  
Quercus Palustris ◽  
The Mean ◽  
Pupal Mortality ◽  
Egg Mass Size

Population biology of orangestriped oakworm, Anisota senatoria (J. E. Smith), was studied in southeastern Virginia. Egg mass size was larger on Quercus palustris Muench., pin oak, compared with Q. phellos L., willow oak. Females produced a sex pheromone that attracted male moths. Blacklight traps were not effective for monitoring A. senatoria adults. Peak male emergence occurred on 2 July, 4 days earlier than female. The mean life span was 33.5 days in the laboratory. Pupal mortality was high and only 1.2% of the pupae produced moths in 1989 and 1990. Pupae were capable of overwintering for two years in the field. The first report of a second generation from September - November was documented. Second generation A. senatoria oviposited more egg masses, infested more trees and had a longer development time compared with first generation. Large egg mass size, pupae that were capable of overwintering for two years and the presence of a second generation may partially explain the consistent A. senatoria populations that have occurred in southeastern Virginia.

scholarly journals Bigger mothers are better mothers: disentangling size-related prenatal and postnatal maternal effects

2013 ◽  
Vol 280 (1766) ◽  
pp. 20131225 ◽  
Author(s):  
Sandra Steiger
Keyword(s):  
Body Size ◽  
Maternal Effects ◽  
Maternal Care ◽  
Genetic Effects ◽  
Offspring Size ◽  
Adult Size ◽  
Burying Beetle ◽  
Maternal Body ◽  
Maternal Size

Despite a vast literature on the factors controlling adult size, few studies have investigated how maternal size affects offspring size independent of direct genetic effects, thereby separating prenatal from postnatal influences. I used a novel experimental design that combined a cross-fostering approach with phenotypic manipulation of maternal body size that allowed me to disentangle prenatal and postnatal maternal effects. Using the burying beetle Nicrophorus vespilloides as model organism, I found that a mother's body size affected egg size as well as the quality of postnatal maternal care, with larger mothers producing larger eggs and raising larger offspring than smaller females. However, with respect to the relative importance of prenatal and postnatal maternal effects on offspring growth, only the postnatal effects were important in determining offspring body size. Thus, prenatal effects can be offset by the quality of postnatal maternal care. This finding has implications for the coevolution of prenatal and postnatal maternal effects as they arise as a consequence of maternal body size. In general, my study provides evidence that there can be transgenerational phenotypic plasticity, with maternal size determining offspring size leading to a resemblance between mothers and their offspring above and beyond any direct genetic effects.

scholarly journals The ecological genetics of growth in Drosophila 3. Growth and competitive ability of strains selected on different diets

1960 ◽  
Vol 1 (3) ◽  
pp. 333-350 ◽  
Author(s):  
Forbes W. Robertson
Keyword(s):  
Body Size ◽  
Development Time ◽  
Competitive Ability ◽  
Variable Degree ◽  
Adult Size ◽  
Adverse Conditions ◽  
Low Protein ◽  
Unselected Population ◽  
Selection For ◽  
Live Yeast

1. The growth of strains of Drosophila melanogaster selected for large size under different nutritional conditions has been recorded on a variety of different media and compared with that of the unselected population. The experiments were designed to test the inference from earlier work that selection for the same ‘character’, body size, on different diets leads to more or less different changes in growth and metabolism. The inference has been amply confirmed.2. When compared on a number of deficient synthetic diets, the strains which had been selected either on a low-protein diet or on one in which all the essential nutrients had been reduced, suffered a much smaller reduction in body size than either the unselected population or, especially, a large strain selected on the favourable live yeast medium. Some diets which drastically reduced the body size of the unselected population lead to no change in the size of strains selected on the synthetic media, although development time was prolonged. Hence selection had extended the capacity for maintaining a characteristic adult body size to diets which normally would lead to a decline. This is taken as evidence of improved adaptation to such conditions. There is also some evidence that selection on the synthetic diets had lowered the level of adaptation to the usual live yeast diet, since body size tended to be lower on this medium than on some of the normally sub-optimal diets.3. To provide comparisons in adverse conditions which are probably more closely related to those commonly encountered by populations in nature or the laboratory, the performance of the strains has been compared in a graded series of competitive conditions on the live yeast medium. By using genetically marked files of the foundation population, which were shown to react in the same way as unmarked flies—in terms of survival, body size and development time—the competitive ability of the different strains has been tested against that of unselected individuals. The latter are generally superior to the selected strains, which differ among themselves, however, in a way which can be related to the conditions in which they were selected.4. Under such competitive conditions, the strains selected on the synthetic diets suffer a much greater decline in body size than do the unselected individuals. For the strain selected on live yeast, the proportional reduction of body size is about the same for the unselected flies at lower levels of crowding, but is clearly greater under more severe conditions of competition.5. The low-protein strain has been backcrossed to the unselected stock. When reared on a variety of synthetic diets, the performance of the F1 was generally intermediate between that of the parents.6. Nutritional variation may be responsible for either a high environmental correlation between the two measures of growth, body size and duration of larval period, or no apparent correlation. Provided the diet is not too unfavourable, body size remains constant although development time may be lengthened to a variable degree. With more adverse conditions, body size is reduced and development time is lengthened more or less proportionately. Such differences in reaction probably depend on the particular stage of larval growth and development primarily affected by the treatment; this problem is being examined further. The inverse relations between body size and development time may represent the operation of a kind of safety mechanism which ensures that the adult reproductive state is attained sooner than would be so if the capacity for maintaining a characteristic body size were more effective in relation to deficient diets. Populations and species adapted to different conditions are likely to differ as to where the balance is struck between effective maintenance of a characteristic adult size, with maximum potential egg production, and the alternative response, according to their ecology. This possibility must be borne in mind when the response to selection for, say, body size is compared in different species.

A General Model for the Scaling of Offspring Size and Adult Size

2008 ◽  
Vol 172 (3) ◽  
pp. 299-317 ◽  
Author(s):  
Daniel S. Falster ◽  
Angela T. Moles ◽  
Mark Westoby
Keyword(s):  
General Model ◽  
Offspring Size ◽  
Adult Size

scholarly journals No impact of biocontrol predator on development time or size of surviving Aedes albopictus under optimal nutritional availability

2021 ◽  
Author(s):  
Marie C. Russell ◽  
Lauren J. Cator
Keyword(s):  
Aedes Albopictus ◽  
Development Time ◽  
Wing Length ◽  
Sublethal Effects ◽  
Cyclopoid Copepod ◽  
Adult Size ◽  
Fish Food ◽  
Predator Treatment ◽  
Copepod Predation ◽  
Significant Difference

AbstractBackgroundCyclopoid copepods have been applied successfully to limit populations of highly invasive Aedes albopictus mosquitoes that can vector diseases, including chikungunya, dengue, yellow fever, and Zika, to humans. However, there is concern that changes in certain vector traits, induced by exposure to copepod predation, might increase the risk of disease transmission. In this study, we tested whether cyclopoid copepod predation has sublethal effects on the development time or adult size of Ae. albopictus under the scenario of an invasion in southeast England, which lies at the northern edge of the vector’s expanding global range.MethodsThird instar Ae. albopictus larvae, hereafter referred to as “focal individuals”, were placed in individual Petri dishes, each containing four newly-hatched Ae. albopictus larvae, which were counted, removed, and replaced daily. All focal individuals were provided with fish food ad libitum, and half were exposed to Megacyclops viridis copepod predators. The day of pupation was recorded for each focal individual, and the wing length of each focal adult was also measured.ResultsExposing late instar Ae. albopictus to predation decreased their chances of surviving to adulthood. Mortality of the focal individuals was 12.9% in the predator treatment, and 2.9% in the controls. Three focal larvae that died in the predator treatment showed signs of melanization, indicative of wounding. Among surviving Ae. albopictus, no significant difference in either pupation day or wing length was observed due to copepod predation.ConclusionsWe found that M. viridis predation on smaller Ae. albopictus larvae does not significantly affect the pupation day or adult size of surrounding larger larvae that are less vulnerable to copepod attacks. This study controlled for density effects on size by maintaining a constant number of newly-hatched prey larvae surrounding each focal larva. Those working to control Ae. albopictus populations in the field should be made aware that increased adult body size can occur if copepod biocontrol agents are applied at lower than necessary levels. The absence of a significant sublethal impact from M. viridis copepod predation on surviving later-stage larvae in this analysis supports the use of M. viridis as a biocontrol agent.Graphical abstract

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