ADULT-LARVAL INTRASPECIFIC COMPETITION IN AGROMYZA FRONTELLA (DIPTERA: AGROMYZIDAE)

1984 ◽  
Vol 116 (10) ◽  
pp. 1385-1391 ◽  
Author(s):  
Daniel T. Quiring ◽  
Jeremy N. McNeil
Keyword(s):  
Population Dynamics ◽  
Indirect Effect ◽  
Food Source ◽  
Developmental Time ◽  
Laboratory Studies ◽  
Larval Competition ◽  
Adult Females ◽  
Adult Feeding ◽  
Low Levels ◽  
Agromyza Frontella

AbstractBoth adult females and larvae of Agromyza frontella (Rondani) exploit the same food source, alfalfa leaflets. In laboratory studies, larval development in leaflets with many adult nutrition holes resulted in a higher incidence of mortality than in leaflets with low levels of adult feeding. Furthermore, in heavily attacked leaflets, survivors had a slightly longer larval developmental time and lower pupal weights. In heavily attacked alfalfa fields where adult nutrition holes are numerous, the above-mentioned adult–larval interaction could play a density-dependent role in the population dynamics of A. frontella. However, in most situations adult feeding probably has an indirect effect, accentuating intraspecific larval competition by decreasing the quantity of the available limiting resource.

scholarly journals Adult Feeding Preference and Fecundity in the Large Pine Weevil, Hylobius abietis (Coleoptera: Curculionidae)

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 473
Author(s):  
Petr Doležal ◽  
Lenka Kleinová ◽  
Markéta Davídková
Keyword(s):  
Betula Pendula ◽  
Food Source ◽  
Abies Alba ◽  
Feeding Preference ◽  
Hylobius Abietis ◽  
Feeding Preferences ◽  
Single Female ◽  
Coniferous Species ◽  
Adult Feeding ◽  
The Mean

Adult feeding preferences of Hylobius abietis on Picea abies, Larix decidua, Pinus sylvestris, Pseudotsuga menziesii, Abies alba and Betula pendula were tested in outdoor conditions. The preferred food source was P. menziesii, and the mean bark area consumed per seedling was 440.8 ± 147.9 mm2. The second most preferred host was P. abies. The coniferous species that suffered the least damage was A. alba (76.8 ± 62.56 mm2 per seedling). B. pendula was the least preferred source of food, and it caused mortality of 60% of weevils that fed on it. Weevils exhibited large differences in fecundity when fed with different tree species in a laboratory experiment. The largest number of eggs was laid by females fed with P. abies. Mean egg numbers reached 26.4 ± 24.89 eggs per experiment for P. abies. Similar fecundity was observed in weevils fed with twigs of P. sylvestris. Oviposition was approximately six times lower in females fed with L. decidua and P. menziesii. The maximum number of eggs laid by a single female during a one-month experiment was 90. The results are discussed in relation to management of H. abietis.

scholarly journals Population dynamics and net primary production of the aquatic macrophite Nymphaea rudgeana C. F. Mey in a lotic environment of the Itanhaém River basin (SP, Brazil)

2000 ◽  
Vol 60 (1) ◽  
pp. 83-92 ◽  
Author(s):  
A. F. M. CAMARGO ◽  
E. R. FLORENTINO
Keyword(s):  
Population Dynamics ◽  
Primary Production ◽  
Aquatic Macrophytes ◽  
Aquatic Macrophyte ◽  
Net Primary Production ◽  
Growth Period ◽  
Pistia Stratiotes ◽  
Annual Productivity ◽  
Lotic Environment ◽  
Low Levels

In this paper we evaluated the population dynamics and obtained estimates of the net primary production of the aquatic macrophyte Nymphaea rudgeana in an arm of the Itanhaém River (São Paulo State, Brazil). This species presents, in the studied area, a broad seasonal variation of biomass. As from November (13.1 g DW/m²) we observed a gradual increase of biomass that reached a maximum in February (163.1 g DW/m²). Then, the biomass decreased, maintaining low levels until a new growth period. The reduction of biomass is associated to the development of floating aquatic macrophytes (Pistia stratiotes and Salvinia molesta) and, subsequently to environmental factors (higher salinity values) that are unfavorable to their development. The net primary production of N. rudgeana was estimated from the biomass data, and the annual productivity value was estimated between 3.02 and 3.82 t/ha/year.

The curvilinear relationship between advice-giving and innovative capability: a knowledge exchange and combination explanation of the moderated relations

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Dao-Jin Wang ◽  
Hong-Jiang Lv ◽  
Ying-Tang Zhou
Keyword(s):  
Indirect Effect ◽  
Design Methodology ◽  
Knowledge Exchange ◽  
Curvilinear Relationship ◽  
Content Type ◽  
Advice Giving ◽  
Innovative Capability ◽  
Low Levels ◽  
Practical Implications

Purpose The purpose of this paper is to elucidate how the advice-giving affects innovative capability by involving knowledge exchange and combination as a mediator and contextual ambidexterity as an important contingency. Design/methodology/approach Based on a survey of 96 Chinese teams, a set of hypotheses was tested using regression analyzes. Findings The findings showed that contextual ambidexterity moderates the indirect effect of advice-giving on innovative capability through knowledge exchange and combination. When contextual ambidexterity is high, workers engage in more knowledge exchange and combination for the team at intermediate levels of advice-giving, the indirect effect of advice-giving at low levels and at high levels exist. When contextual ambidexterity is low, there is no indirect effect of advice-giving at any level. Practical implications Managers should be aware of the inverted U-shaped relationship between advice-giving and innovative capability and strengthen the construction of contextual ambidexterity. Originality/value This paper makes up for the theoretical gap between advice-giving and innovative capability. Furthermore, it provides a theoretical reference for practitioners to improve their innovative capability.

scholarly journals Larval Competition Extends Developmental Time and Decreases Adult Size of wMelPop Wolbachia-Infected Aedes aegypti

2014 ◽  
Vol 91 (1) ◽  
pp. 198-205 ◽  
Author(s):  
Perran A. Ross ◽  
Heng Lin Yeap ◽  
Ary A. Hoffmann ◽  
Nancy M. Endersby
Keyword(s):  
Aedes Aegypti ◽  
Developmental Time ◽  
Adult Size ◽  
Larval Competition

The relationship of Zonocerus variegatus (L.) (Acridoidea: Pyrgomorphidae) with cassava (Manihot esculenta)

1977 ◽  
Vol 67 (3) ◽  
pp. 391-404 ◽  
Author(s):  
E. A. Bernays ◽  
R. F. Chapman ◽  
E. M. Leather ◽  
A. R. McCaffery ◽  
W. W. D. Modder
Keyword(s):  
Hydrogen Cyanide ◽  
Manihot Esculenta ◽  
Normal Growth ◽  
The Other ◽  
Zonocerus Variegatus ◽  
Laboratory Studies ◽  
Low Levels ◽  
Relationship Of ◽  
The Relationship ◽  
Ibadan Nigeria

AbstractField and laboratory studies at Ibadan, Nigeria, showed that the young nymphs of Zonocerus variegatus (L.) normally reject cassava after biting it and die if they are confined on growing leaves. Later instars will eat cassava, especially when deprived of food for some time, but the adults progressively lose weight when restricted to feeding on growing cassava. On cut cassava, on the other hand, extensive feeding occurs and normal growth is maintained. The change from unpalatability to acceptability occurs within about an hour of cutting and is apparently associated with wilting. Cassava produces latex, but this was not distasteful to Zonocerus. The readiness to feed on growing cassava was associated with low levels of hydrogen cyanide production by the leaves; wilted leaves still produced hydrogen cyanide, but at a lower rate than turgid, growing leaves. In the area around Ibadan, Zonocerus regularly defoliates cassava in the latter part of the dry season, probably because a shortage of attractive foods forces the insect to eat cassava.

Population dynamics of Newfoundland beaver

1977 ◽  
Vol 55 (9) ◽  
pp. 1480-1492 ◽  
Author(s):  
Arthur T. Bergerud ◽  
Donald R. Miller
Keyword(s):  
Population Dynamics ◽  
Mortality Rate ◽  
Litter Size ◽  
Food Resources ◽  
Territorial Behaviour ◽  
Population Densities ◽  
Adult Females ◽  
Annual Mortality

The demography of beaver was studied in Newfoundland from 1956 to 1965. Population densities were low and seldom exceeded one colony per 2.6 km2 (1 mi2). About 80% of the adult females were fertile and the number of young per litter averaged 2.7. The annual mortality rate of beavers was about 30% in southeastern Newfoundland. A more detailed study was made of a population living in a 39-km2 (15-mi2) study area. This population had 20, 23, and 24 active colonies, 1958–1960. In 1961 it declined to 18 colonies. We removed the beavers in 1962. The replacement colonies, resulting initially from ingress, were 7 in 1962, 12 in 1963, 17 in 1964, and 15 in 1965. When the population was high in 1958–1960, the fertility of females was high (78%) but the litter size in 1960 appeared to be less than elsewhere. When the population declined in 1960–1961, productivity declined and some animals may have starved over winter. It was concluded that territorial behaviour spaces colonies, dispersing the population within the limits dictated by the availability of water and food resources. However, such a system did not prevent overutilization of food resources and decline of the population from reduced reproduction and increased mortality.

Size influences male mating success in the alfalfa blotch leafminer (Diptera: Agromyzidae)

2001 ◽  
Vol 133 (5) ◽  
pp. 717-719 ◽  
Author(s):  
Arild Andersen ◽  
Jeremy N. McNeil
Keyword(s):  
Reproductive Success ◽  
Male Mating ◽  
Female Size ◽  
Larval Competition ◽  
Female Reproduction ◽  
Male Size ◽  
Female Life History ◽  
Males And Females ◽  
Alfalfa Blotch Leafminer ◽  
Agromyza Frontella

Male size is an important parameter in mate choice for many species and has been associated with such female life-history parameters as increased fecundity or fertility and larger progeny (Phelan and Baker 1986; Savalli and Fox 1998, 1999; Brown 1999). In the alfalfa blotch leafminer, Agromyza frontella (Rondani), intraspecific larval competition may significantly influence the size of both males and females (Quiring and McNeil 1984a). The influence of female size on female reproductive success has been studied (Quiring and McNeil 1984b, 1984c), but to date, no attention has been given to the possible effects of male size. The objectives of this study were to determine if differences in male size, the result of intraspecific larval competition, affected male longevity and reproductive success, as well as various parameters of female reproduction.

Larval development of the parasitic copepod Salmincola edwardsii on brook trout (Salvelinus fontinalis)

1994 ◽  
Vol 72 (1) ◽  
pp. 154-159 ◽  
Author(s):  
David C. Conley ◽  
Mark A. Curtis
Keyword(s):  
Larval Development ◽  
Brook Trout ◽  
Laboratory Experiments ◽  
Salvelinus Fontinalis ◽  
Infection Intensity ◽  
Parasitic Copepod ◽  
Developmental Time ◽  
Adult Males ◽  
Pectoral Fins ◽  
Adult Females

We conducted laboratory experiments to determine the developmental time from larva to adult of the parasitic copepod Salmincola edwardsii on brook trout (Salvelinus fontinalis) at 13 °C. Healthy fingerlings were exposed to large doses of recently hatched copepodids for 12 h. Three infected fingerlings were sacrificed at 12-h intervals until day 6 and then at 24-h intervals until day 20 postexposure. The gills, opercula, and pectoral fins were the major sites of attachment. Adult males were detected as early as day 3 and as late as day 8 postexposure, with the greatest number occurring about day 5. Adult males may live for up to 3 days at 13 °C. Adult females were detected as early as day 11 postexposure but not consistently until day 13, indicating that permanent bulla attachment took place between 11 and 16 days postexposure. Infection intensity declined rapidly until day 9 postexposure then less quickly for the rest of the experiment.

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