Impacts of Larval Diet on Pre-imaginal Development, Survival and Adult Size of Six Species of Coccinellidae (Coleoptera)

2021 ◽  
Vol 93 (3) ◽  
Author(s):  
Nathan H Mercer ◽  
John J Obrycki
Keyword(s):  
2019 ◽  
Author(s):  
Gonçalo M. Poças ◽  
Alexander E. Crosbie ◽  
Christen K. Mirth

ABSTRACTAdult body size is determined by the quality and quantity of nutrients available to animals. In insects, nutrition affects adult size primarily during the nymphal or larval stages. However, measures of adult size like body weight are likely to also change with adult nutrition. In this study, we sought to the roles of nutrition throughout the life cycle on adult body weight and the size of two appendages, the wing and the femur, in the fruit fly Drosophila melanogaster. We manipulated nutrition in two ways: by varying the protein to carbohydrate content of the diet, called macronutrient restriction, and by changing the caloric density of the diet, termed caloric restriction. We employed a fully factorial design to manipulate both the larval and adult diets for both diet types. We found that manipulating the larval diet had greater impacts on all measures of adult size. Further, macronutrient restriction was more detrimental to adult size than caloric restriction. For adult body weight, a rich adult diet mitigated the negative effects of poor larval nutrition for both types of diets. In contrast, small wing and femur size caused by poor larval diet could not be increased with the adult diet. Taken together, these results suggest that appendage size is fixed by the larval diet, while those related to body composition remain sensitive to adult diet. Further, our studies provide a foundation for understanding how the nutritional environment of juveniles affects how adults respond to diet.


Author(s):  
Débora Aline Souza Nascimento ◽  
Frances Tatiane Tavares Trindade ◽  
Alexandre de Almeida e Silva

Abstract Several experiments with Anopheles darlingi Root, an important malaria vector in the Amazon region, were carried out in the laboratory, depending on the large-scale production of viable larvae and adults. Certainly, improvements in rearing conditions, including dietary requirements, can strongly affect mosquito production. In order to increase the production of this species in the laboratory, we first supplemented the regular larval diet (TetraMin Tropical Flakes) with different concentrations of vitamins and minerals and recorded several biological variables: survival and larval development time, emergence ratio, and adult longevity under a small-scale rearing condition. Second, we established an experimental design under regular lab-rearing conditions based on the concentration of vitamins and minerals that best contributed to the development of these anophelines, and evaluated the biological parameters already mentioned. Moreover, under regular rearing conditions, we recorded sex ratio, adult size, and longevity of adults fed with supplemented sucrose. The lowest concentration of vitamins (V5) and the average concentration of minerals (M3) increased larval survival and decreased larval development time compared with the control. Under regular rearing conditions, minerals provided higher larval survival and increased the longevity of adults fed with supplemented sucrose. Supplementing the regular larval diet and sucrose solutions with vitamins and minerals increased the production of immatures and the longevity of An. darlingi adults.


2019 ◽  
Author(s):  
Zac Wylde ◽  
Foteini Spagopoulou ◽  
Amy K Hooper ◽  
Alexei A Maklakov ◽  
Russell Bonduriansky

Individuals within populations vary enormously in mortality risk and longevity, but the causes of this variation remain poorly understood. A potentially important and phylogenetically widespread source of such variation is maternal age at breeding, which typically has negative effects on offspring longevity. Here, we show that paternal age can affect offspring longevity as strongly as maternal age does, and that breeding age effects can interact over two generations in both matrilines and patrilines. We manipulated maternal and paternal ages at breeding over two generations in the neriid fly Telostylinus angusticollis. To determine whether breeding age effects can be modulated by the environment, we also manipulated larval diet and male competitive environment in the first generation. We found separate and interactive effects of parental and grandparental ages at breeding on descendants’ mortality rate and lifespan in both matrilines and patrilines. These breeding age effects were not modulated by grandparental larval diet quality or competitive environment. Our findings suggest that variation in maternal and paternal ages at breeding could contribute substantially to intra-population variation in mortality and longevity.


2020 ◽  
Vol 646 ◽  
pp. 79-92
Author(s):  
RE Scheibling ◽  
R Black

Population dynamics and life history traits of the ‘giant’ limpet Scutellastra laticostata on intertidal limestone platforms at Rottnest Island, Western Australia, were recorded by interannual (January/February) monitoring of limpet density and size structure, and relocation of marked individuals, at 3 locations over periods of 13-16 yr between 1993 and 2020. Limpet densities ranged from 4 to 9 ind. m-2 on wave-swept seaward margins of platforms at 2 locations and on a rocky notch at the landward margin of the platform at a third. Juvenile recruits (25-55 mm shell length) were present each year, usually at low densities (<1 m-2), but localized pulses of recruitment occurred in some years. Annual survival rates of marked limpets varied among sites and cohorts, ranging from 0.42 yr-1 at the notch to 0.79 and 0.87 yr-1 on the platforms. A mass mortality of limpets on the platforms occurred in 2003, likely mediated by thermal stress during daytime low tides, coincident with high air temperatures and calm seas. Juveniles grew rapidly to adult size within 2 yr. Asymptotic size (L∞, von Bertalanffy growth model) ranged from 89 to 97 mm, and maximum size from 100 to 113 mm, on platforms. Growth rate and maximum size were lower on the notch. Our empirical observations and simulation models suggest that these populations are relatively stable on a decadal time scale. The frequency and magnitude of recruitment pulses and high rate of adult survival provide considerable inertia, enabling persistence of these populations in the face of sporadic climatic extremes.


2020 ◽  
Vol 31 (8) ◽  
pp. 803-816
Author(s):  
Umberto di Porzio

AbstractThe environment increased complexity required more neural functions to develop in the hominin brains, and the hominins adapted to the complexity by developing a bigger brain with a greater interconnection between its parts. Thus, complex environments drove the growth of the brain. In about two million years during hominin evolution, the brain increased three folds in size, one of the largest and most complex amongst mammals, relative to body size. The size increase has led to anatomical reorganization and complex neuronal interactions in a relatively small skull. At birth, the human brain is only about 20% of its adult size. That facilitates the passage through the birth canal. Therefore, the human brain, especially cortex, develops postnatally in a rich stimulating environment with continuous brain wiring and rewiring and insertion of billions of new neurons. One of the consequence is that in the newborn brain, neuroplasticity is always turned “on” and it remains active throughout life, which gave humans the ability to adapt to complex and often hostile environments, integrate external experiences, solve problems, elaborate abstract ideas and innovative technologies, store a lot of information. Besides, hominins acquired unique abilities as music, language, and intense social cooperation. Overwhelming ecological, social, and cultural challenges have made the human brain so unique. From these events, as well as the molecular genetic changes that took place in those million years, under the pressure of natural selection, derive the distinctive cognitive abilities that have led us to complex social organizations and made our species successful.


2021 ◽  
Vol 87 (1) ◽  
Author(s):  
G A Rivera-Figueroa ◽  
J A Büchner-Miranda ◽  
L P Salas-Yanquin ◽  
J A Montory ◽  
V M Cubillos ◽  
...  

ABSTRACT Free-living, planktonic larvae can be vulnerable to capture and ingestion by adult suspension-feeders. This is particularly the case for larvae that settle gregariously in benthic environments where suspension-feeders occur at high densities. Larvae of gregarious suspension-feeding species are at particularly high risk, as adults of their own species often serve as cues for metamorphosis. We conducted laboratory experiments to assess the extent to which adults of the suspension-feeding caenogastropod Crepipatella peruviana would capture and ingest their own larvae. Experiments were conducted with adults of different sizes, with larvae of different ages and sizes, and in the presence or absence of phytoplankton. Adults captured larvae in all experiments. The presence of microalgae in the water did not influence the extent of larval capture. On average, 39% of larvae were captured during the 3-h feeding periods, regardless of adult size. However, up to 34% of the larvae that were captured on the gill were later discarded as pseudofaeces; the other 64% were ingested. The extent of capture by adults was not related to adult size, or to larval size and, thus, to larval age. Our results suggest that the filtration of congeneric larvae by adult C. peruviana is a result of accidental capture rather than a deliberate feeding preference. Such ingestion could, however, still be an important source of larval mortality, especially when the advanced larvae of this species are searching for a suitable substrate for metamorphosis.


Parasitology ◽  
1973 ◽  
Vol 66 (2) ◽  
pp. 355-365 ◽  
Author(s):  
C. A. Hopkins ◽  
P. M. Grant ◽  
Helen Stallard

The effect of oxyclozanide (2,2′-dihydroxy-3,3′,5,5′,6-pentachlorobenzanilide) on Hymenolepis microstoma in the bile duct of mice, and H. diminuta in the small intestine of mice and rats was measured. Oxyclozanide at doses as low as 4mg/kg removed 13-day-old H. diminuta and caused no obvious harmful effect to the rat host up to the maximum level (256 mg/kg) tested. Worms were displaced and degenerating within 1 h. Results in mice were more difficult to assess because of the immune response, but similar total amounts of oxyclozanide caused destrobilation and loss of 7-day-old H. diminuta. Oxyclozanide was less effective against 21-day-old H. microstoma attached in the bile duct. Approximately half the strobila was lost following dosing at 5 mg/kg and progressively greater amounts as the dose level was increased. At 50 mg/kg worm loss commenced but even at 150 mg/kg 25 % of worms survived. The time taken to regrow to the original adult size varied but was complete within 7–9 days at levels up to 25 mg/kg. Double dosing at 5-day intervals did not enhance the effect of a single dose. The apparent existence of a sensitivity gradient down the strobila in H. microstoma is discussed.


1991 ◽  
Vol 48 (6) ◽  
pp. 1015-1021 ◽  
Author(s):  
Jan Henning L'Abée-Lund

I compared adult size and sea age at sexual maturity among nine populations of anadromous brown trout, Salmo trutta, in two Norwegian rivers to determine the extent of inter- and intrariverine variations. Variation in the mean length of spawners and in the mean sea age at sexual maturity were mainly dependent on the variations found within rather than between rivers. Mean lengths and mean age at maturity of males increased significantly with increasing altitude of the spawning area and with migration distance in freshwater. In females, positive significant correlations were found with mean lengths and altitude of the spawning area and with mean sea age at maturity and both spawning site altitude and migration distance. Mean lengths and ages of males and females were not significantly correlated with the rate of water discharge in the streams during spawning. The size of gravel substrate for spawning was of minor importance in explaining interpopulation variation in mean female size. The increase noted in mean length and in mean sea age at maturity of both males and females is probably an adaptation to greater energy expenditure to reach the uppermost natal spawning areas.


Sign in / Sign up

Export Citation Format

Share Document