scholarly journals Studies on the Intraspecific Competition in Dung-Breeding Flies III. Pupal Size and Mortality in Immature Stages under Various Larval Density Conditions in Musca hervei VILLENEUVE (Diptera : Muscidae)

1987 ◽  
Vol 22 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Kazuhiro AMANO
Keyword(s):  
Intraspecific Competition ◽  
Larval Density ◽  
Immature Stages ◽  
Pupal Size

The effects of food and density on growth and metamorphosis in larval wood frogs (Rana sylvatica) from central Labrador

1990 ◽  
Vol 68 (6) ◽  
pp. 1221-1226 ◽  
Author(s):  
Dennis L. Murray
Keyword(s):  
Growth Rate ◽  
Larval Stage ◽  
Larval Density ◽  
Life History Strategy ◽  
Rana Sylvatica ◽  
Food Density ◽  
Immature Stages ◽  
Growth Inhibitors ◽  
Wood Frogs ◽  
Positive Effects

Two experiments were performed on Rana sylvatica tadpoles from central Labrador to test for effects of food and density on growth and metamorphosis. In an experiment examining for the presence of diffusible growth inhibitors, one group of tadpoles was given water treated by adding a high density of sibling tadpoles, and another group was given filtered lake water. No diffusible growth inhibitors existed in this population, as body weight measured weekly, weight at metamorphosis, and duration of larval stage did not differ between control and treated groups. In a food-density experiment, effects of food and larval density were examined by subjecting tadpoles at four different densities to four food levels, creating a 4 × 4 food–density matrix. Food and density both affected growth rate, weight at metamorphosis, and duration of larval stage. Socially governed negative density-dependent interactions are either nonexistent in northern populations, or were completely masked by slight positive effects of grouping. Results suggest that northern larvae differ in life-history strategy from southern populations, and the possibility of overwintering in immature stages of high-latitude populations is discussed.

DESCRIPTION OF THE IMMATURE STAGES OF LEUCOPIS SP. NR. ALBIPUNCTA (DIPTERA: CHAMAEMYIIDAE) AND THEIR ROLE AS PREDATORS OF THE APPLE APHID, APHIS POMI (HOMOPTERA: APHIDIDAE)

1983 ◽  
Vol 115 (7) ◽  
pp. 735-742 ◽  
Author(s):  
Kevin T. Tracewski
Keyword(s):  
New Hampshire ◽  
Larval Density ◽  
The State ◽  
Immature Stages ◽  
Larval Instars ◽  
Aphis Pomi ◽  
Growing Region ◽  
Aphid Populations

AbstractThe role of Leucopis sp. nr. albipuncta larvae in controlling outbreaks of the apple aphid, Aphis pomi De Geer, was studied in five New Hampshire orchards. There was significant correlation of larval density with changes in the density of apple aphid populations, and larvae were widely distributed throughout the apple growing region of the state. The egg, three larval instars, and puparium are described and illustrated.

The biology of Cryptolestes capensis (Waltl) (Coleoptera, Cucujidae)

1962 ◽  
Vol 53 (3) ◽  
pp. 529-535 ◽  
Author(s):  
L. P. Lefkovitch
Keyword(s):  
Larval Density ◽  
Total Duration ◽  
Immature Stages ◽  
Adult Males ◽  
Optimal Conditions ◽  
Innate Capacity ◽  
Harmful Effects ◽  
Capacity For Increase

Cryptolestes capensis (Waltl) has been reared successfully upon wheatfeed at constant temperatures of 15 to 32·5°C., at intervals of 2·5°C., and 90 per cent. R.H., and at 30°C. and 10 to 70 per cent. R.H. Newly formed adult males were found to weigh more than females bred under the same conditions. Oviposition was investigated at 90 per cent. R.H. and 17·5, 20, 30 and 32·5°C.; the highest rate was at 30°C. It was concluded that 30°C., 90 per cent. R.H. were the optimal conditions of those observed. Comparison with C. turcicus (Grouv.) which occurs in the same habitat as C. capensis, shows that the temperature limits of the former are higher, but that at those temperatures at which both species can breed, there is little, if any, difference between the total duration of the immature stages. At the observed optimum for the two species, C. capensis has a higher innate capacity for increase than C. turcicus. These observations do not account for the rarity of C. capensis in comparison with C. turcicus, and it is postulated that C. capensis is, like C. ferrugineus (Steph.), more susceptible to the harmful effects of high larval density than is C. turcicus.

AN INTRASPECIFIC COMPETITION MODEL FOR THE LEAFMINER, AGROMYZA FRONTELLA (RONDANI)

1988 ◽  
Vol 120 (8-9) ◽  
pp. 779-786 ◽  
Author(s):  
Lothar A. Dohse ◽  
Jeremy N. McNeil
Keyword(s):  
Mathematical Model ◽  
Intraspecific Competition ◽  
Laboratory Experiments ◽  
Larval Density ◽  
Instar Larva ◽  
Larval Competition ◽  
The Third ◽  
Field Samples ◽  
Agromyza Frontella ◽  
Third Instar Larva

AbstractA mathematical model was constructed to simulate the effect of intraspecific larval competition on the survival of Agromyza frontella (Rondani). It was shown that the probabilities of cannibalism and starvation can be expressed as functions of larval density and food availability (leaflet surface area), and that expected pupal weights can be determined from the amount of food available to the third-instar larva. Predictions were compared with data from laboratory experiments and field samples with excellent results.

scholarly journals 3D imaging reveals potential anticipatory responses to increasing intraspecific competition in the Drosophila male reproductive system

2021 ◽  
Author(s):  
Juliano Morimoto ◽  
Renan Barcellos ◽  
Todd Andrew Schoborg ◽  
Liebert Parreiras Nogueira ◽  
Marcos Vinicius Colaco
Keyword(s):  
Intraspecific Competition ◽  
Larval Density ◽  
Micro Ct ◽  
Accessory Glands ◽  
Sexually Selected Traits ◽  
Sexual Selection Theory ◽  
History Of ◽  
Selected Traits ◽  
Access To Food ◽  
Ejaculatory Bulb

Selection favour males that anticipate intraspecific competition levels and develop appropriate competitive traits. In holometabolous insects, larval density can act as an ecological cue of males future intraspecific competition levels while also limiting access to food allocated to sexually selected traits (e.g., testes). To date, however, most studies have been conducted in larval densities that may have little or no relevance to species ecology. Here, we manipulated Drosophila melanogaster larval density based on the natural history of the species and used 3D micro-CT imaging to show a strong modulation of testes volume based on larval density: males from high larval densities generally had larger testes. Conversely, males from high densities tended (albeit not statistically significantly) to have the smallest accessory glands and ejaculatory bulb. Overall, we used micro-CT to measure male reproductive morphology in an ecologically relevant design for which the findings broadly support predictions from sexual selection theory.

Larval performance and oviposition habitat selection of the tree frog, Hyla savignyi, in response to conspecific larval density

2015 ◽  
Vol 61 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Meital Stein ◽  
Leon Blaustein
Keyword(s):  
Habitat Selection ◽  
Intraspecific Competition ◽  
Larval Density ◽  
Breeding Habitat ◽  
Larval Performance ◽  
Tree Frog ◽  
Larval Competition ◽  
Anuran Species ◽  
Size At Metamorphosis ◽  
Hyla Savignyi

Amphibians breeding in temporary pools may experience strong intraspecific density-dependent effects in the form of larval competition and oviposition site selection. These potential effects are untested for the tree frog, Hyla savignyi, an anuran species of conservation concern in Israel. We conducted an outdoor mesocosm experiment to examine how intraspecific larval density may affect larval performance and oviposition habitat selection in H. savignyi. We added ecologically relevant densities of 0, 10, or 40 early-stage tadpoles into mesocosms (plastic tubs) containing 20 L of water. Each density was replicated with four tubs. Time to and size at metamorphosis were not significantly affected by initial H. savignyi density. However, strong intraspecific competitive effects were observed in the form of reduced size at metamorphosis at the high density. We also found that gravid H. savignyi females reduce future intraspecific competition for their progeny by choosing to oviposit in mesocosms with no, or low, densities of H. savignyi tadpoles. Thus, intraspecific competition in this anuran species appears to be an important factor at ecologically relevant densities; larval competition increases with increasing densities and may be avoided by gravid females assessing breeding habitat quality in the form of conspecific tadpole density or mass.

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