Daily Prey Consumption Research Articles

Functional response and predation rate of Cryptolaemus montrouzieri (Coleoptera: Coccinellidae) to Paracoccus marginatus (Hemiptera: Pseudococcidae) at different temperatures.

The ladybug, Cryptolaemus montrouzieri (Mulsant) (Coleoptera: Cocccinellidae)(Mulsant)(Coleoptera: Cocccinellidae), is a highly efficient predator in controlling mealybug populations and is considered an effective agent for controlling the papaya mealybugs (Paracoccus marginatus) (Williams & Granara de Willink) (Hemiptera: Pseudococcidae). Various criteria have been proposed for evaluating predator effectiveness, with the consumption rate of prey by individual predators, specifically the functional response, emerging as a common and crucial metric. This study evaluated the functional responses of third- and fourth-instar larvae, as well as male and female adults (<48 h old) of C. montrouzieri to adult females of P. marginatus at 3 different temperatures (22 °C, 28 °C, and 35 °C) with 70% ± 5% RH and a 12L:12D h photoperiod. Prey densities were 2, 4, 8, 16, 32, 45, or 60 papaya mealybugs per predator for all tests. The response to prey density by third- and fourth-instar larvae or both sexes of adult C. montrouzieri was a type II at all temperatures. The highest attack rate and lowest handling time were estimated at 28 °C in males and 35 °C in females, respectively. The highest daily prey consumption rate occurred at 35 °C in both the immature and adult stages of C. montrouzieri. These findings support the potential of C. montrouzieri in controlling the papaya mealybug, especially in tropical and subtropical regions, given its search efficiency at high temperatures tested in this study. However, additional field investigations are needed to ascertain the control efficacy of C. montrouzieri for this mealybug in biocontrol programs.

The effect of water temperature, prey availability and presence of conspecifics on prey consumption of pikeperch (Sander lucioperca)

In this study, the effect of water temperature, predator’s sex, prey density, and the presence of conspecifics on prey consumption of pikeperch (Sander lucioperca) was experimentally tested. In Experiment 1, predators of both sexes [males: total length (TL) = 473 ± 22 mm and body weight (BW) = 1 070 ± 100 g and females: TL = 464 ± 12 mm and BW = 1 060 ± 100 g] were kept in separate tanks and exposed to different densities of prey (Pseudorasbora parva; 3, 6, 12, 24 and 48 prey fishes per tank) under fixed water temperatures of 4.5 °C, 8.5 °C, and 12.5 °C. After 63 days of this experiment, it was found that pikeperch predation was significantly affected by increasing water temperature. The effect of prey density was significant at all tested temperatures. Pikeperch females tended to have the higher prey consumption than males, although that trend was statistically insignificant. Results suggest that increased feeding demands at temperatures above 4.5 °C can lead to predator starvation in conditions of low prey availability. Due to the higher prey consumption, pikeperch females could be more vulnerable to low prey availability during their culture. In Experiment 2, pikeperch were kept at different densities of 1, 2, 4, and 8 individuals per tank supplied with a prey rate of 50 individuals per predator, ensuring ad libitum feeding rate. The average daily prey consumption was significantly higher in the tanks with multiple predators, accounting for 17.6 ± 3.57 prey fishes/day compared to 11.6 ± 2.33 prey fishes/day in the tank with a single predator. These results indicate that pikeperch predation activity and prey consumption can be significantly affected by the water temperature, prey availability, and the presence of conspecifics. The findings contribute to understanding the predatory function, natural feeding request of pikeperch and its potential importance for broodstock culture and broodstock final maturation for a successful spawning season. Also, this information can be used for better management of pikeperch pond aquaculture or bio-melioration process in open water bodies and ecosystems.

Functional Response and Predation Potential of Carabus elysii Adults against the Terrestrial Slug Agriolimax agrestis.

Simple SummaryAgriolimax agrestis is one of the most important cash crop pests in China, widely affecting tobacco, vegetables, edible mushrooms, and other crops. Not only does it cause direct damage to plants but it also spreads bacteria that are harmful to plants and humans. Currently, the control of A. agrestis relies mainly on chemical agents; however, the heavy application of chemicals often leads to ecological damage. In this study, using Carabus elysii as a natural enemy, the predatory ability of adult C. elysii on A. agrestis was assessed under indoor conditions for the first time. The results show that C. elysii adults have a strong predatory ability on different sizes of slugs, especially juvenile slugs, and the female adults have a better predatory ability than the male adults. In general, C. elysii has strong potential to control A. agrestis and can be used as an effective control measure.Terrestrial slugs are a prominent agricultural pest worldwide. To mitigate the negative effects of chemical pest control, biological control involves the use of natural enemies to reduce the impact of target pests. Numerous insects are natural predators of slugs. This study evaluated potential of the predatory species, Carabus elysii Thomson (Coleoptera: Carabidae) to biologically control the terrestrial slug, Agriolimax agrestis. Laboratory experiments were conducted to investigate the functional response, searching efficiency, and interference effect of female and male C. elysii adults regarding adult, immature, and juvenile A. agrestis individuals. The results show that both female and male ground beetle adults are functionally capable of preying on different sizes of terrestrial slugs. C. elysii exhibited Holling type II functional responses when preying on A. agrestis. The maximum daily prey consumption was 35.5 juveniles, 25.1 immatures, and 17.1 adults for adult females and 26.9 juveniles, 20.3 immatures, and 11.6 adults for adult males. The searching efficiency of female C. elysii adults regarding A. agrestis was always higher than that of male adults for identical ages and densities of A. agrestis. Moreover, the predation of C. elysii on slugs was affected by predator density. The disturbance coefficient of male C. elysii were the highest on adult A. agrestis. The results of this study suggest that female C. elysii exhibit a high potential for the biological control of A. agrestis.

Feeding potential of phytoseiid predator, Neoseiulus baraki Athias-Henriot on Coconut eriophyid mite, Aceria guerreronis Keifer

Experimental results showed that the overall daily prey consumption rate of individual larva, protonymph and deutonymphal stage of N. baraki were consumed 6.33 ± 0.50, 11.00 ± 0.75 and 13.45 ± 0.89 prey mites, respectively. Whereas, the consumption rate of adult male and female were 14.07 ± 0.56 and 15.91 ± 0.45 preys, respectively. The total prey consumption rate of larval, protonymph and deutonymphal stage of N. baraki were 12.65 ± 1.00, 22.00 ± 1.50 and 40.35 ± 2.69 preys, respectively. However, total consumption rate for adult male and female were 219.40 ± 5.86 and 477.97 ± 5.51 prey mites, respectively. The prey consumption rate during entire life period of male was 294.40 ± 14.09 preys, while female of 552.97 ± 14.09 prey mites. Thus, the present finding clearly suggest that N.baraki could be a highly efficient biological control agent of A. guerreronis.

Developmental biology and prey preference of Diomus notescens Blackburn (Coleoptera: Coccinellidae): A predator of Aphis gossypii Glover (Hemiptera: Aphididae)

The minute two-spotted ladybeetle, Diomus notescens Blackburn is a common predator of aphids and other pests in Australian agricultural crops, however little is known about the biology of D. notescens. The aim of this study was to provide information on the life cycle of this predator and improve our understanding of its biological control potential, particularly against one of the major pests of cotton, Aphis gossypii Glover. In laboratory experiments, juvenile development, prey consumption, as well as adult lifespan and fecundity were studied. Results from this study revealed that D. notescens could successfully complete development on A. gossypii, which at 25°C required 21days and during this period they each consume 129±5.2 aphids. At 25°C adult lifespan was 77±9.6days, with a mean daily prey consumption of 28±1.8 aphids and a mean daily fecundity of 8±0.5 eggs. Net reproductive rate was estimated as 187±25.1 females and the intrinsic rate of increase was estimated as 0.14. Juvenile development was recorded at four constant temperatures (15, 21, 26 and 27°C) and using a linear model, the lower threshold for D. notescens development was estimated to be 10±0.6°C with 285±4.7 degree days required to complete development. A prey choice experiment studying predation rates revealed a strong preference for A. gossypii nymphs compared to Bemisia tabaci Gennadius eggs.

&lt;p class="Body"&gt;&lt;strong&gt;Prey&lt;/strong&gt;&lt;strong&gt; diet quality affects predation, oviposition and conversion rate of the predatory mite &lt;em&gt;Neoseiulus barkeri&lt;/em&gt; (Acari: Phytoseiidae)&lt;/strong&gt;&lt;/p&gt;

Biological characteristics of a predator can be affected by the nutritional history of its prey, e.g., change in the nutritional components of prey may influence the development and reproduction of its predator. In this study, the predation, reproduction and conversion rate of a native predatory mite, Neoseiulus barkeri were compared when fed with two colonies of the flour mite Tyrophagus putrescentiae, the one reared on common wheat bran (TPA) and the other on a mixture of wheat bran and yeast (TPB). The experiments were conducted under laboratory condition at 25°C, 80% relative humidity, and 16:8 light:dark photoperiod. The daily consumption of unmated and mated N. barkeri females fed with TPB was 1.30 and 1.93 times higher than those fed with TPA. The daily and cumulative fecundity of mated predator females fed with TPB were 1.55 and 2.47 times, and their eggs being 1.20 times as those of females fed with TPA. The daily consumption of unmated females gradually decreased with age. For both mated and unmated females fed with TPA or TPB, we observed a wave pattern curve of daily prey consumption. The mean difference between two wave peaks was 3.55±0.23 days. It seems a periodic trend instead of random vibration due to the relative consist differences between wave peaks and similar sizes of the peaks. About 82% and 74% overall consumption of mated females offered TPA and TPB were allocated to reproduction, with corresponding conversion rate being 0.39 and 0.28, respectively. Overall, adding yeast to the diet of T. putrescentiae led to increased fecundity of N. barkeri mainly through stimulating its predation.

&lt;p class="Body"&gt;&lt;strong&gt;Life history traits of predatory mite &lt;em&gt;Typhlodromus &lt;/em&gt;(&lt;em&gt;Anthoseius&lt;/em&gt;)&lt;em&gt; bagdasarjani&lt;/em&gt; (Phytoseiidae) fed on &lt;em&gt;Cenopalpus irani &lt;/em&gt;(Tenuipalpidae) under laboratory conditions &lt;/strong&gt;&lt;/p&gt;

Biological traits of Typhlodromus (Anthoseius) bagdasarjani Wainstein &amp; Arutunjan when exposed to the false spider mite, Cenopalpus irani Dosse (Tenuipalpidae), as a food source were determined at 27±1°C, with 16:8 h L: D, at an average daily relative air humidity of 60±10%. The developmental durations of egg, larva, protonymph, deutonymph stages and of all the juvenile phase (egg–adult) being 1.9±0.14, 0.9±0.05, 2.2±0.12, 2.5±0.12 and 7.6±0.18 days, respectively. Survivorship of the juvenile phase was 87%. Fecundity and daily oviposition rate was 33.8±2.60 eggs/female and 1.8 eggs/female/day, respectively. Oviposition period, adult longevity and total life span of females were 19.1±1.76, 36.8±1.88 and 44.3±1.84 days, respectively. The mean generation time (T), net reproductive rate (R0) and intrinsic rate of increase (rm) were 15.32±0.69 days, 14.38±1.11 female offspring and 0.174±0.005 day-1, respectively. Daily prey consumption rates by T. bagdasarjani protonymphs and deutonymphs were 6.0±0.21 and 5.1±0.17 prey individuals/day, respectively. Protonymphs and deutonymphs of T. bagdasarjani preferred the larval stages of C. irani to feed. The results of this study suggested that C. irani is a suitable prey for T. bagdasarjani, and that the predator might play a significant role in preventing that prey from reaching even higher population levels than it does on apple in western Iran.

Mercury and selenium ingestion rates of Atlantic leatherback sea turtles (Dermochelys coriacea): A cause for concern in this species?

Bodily accumulation of certain toxic elements can cause physiologic harm to marine organisms and be detrimental to their health and survival. The leatherback sea turtle (Dermochelys coriacea) is a broadly distributed marine reptile capable of consuming hundreds of kilograms of gelatinous zooplankton each day. Little is known about toxicants present in these prey items. Specifically, mercury is a known neurotoxin with no known essential function, while selenium detoxifies bodily mercury, but can be toxic at elevated concentrations. I collected 121 leatherback prey items (i.e., gelatinous zooplankton) from known leatherback foraging grounds and sampled the esophagus and stomach contents of stranded turtles. All samples were analyzed for total mercury and selenium. Additionally, two prey items and three liver samples were analyzed for methylmercury, the most toxic form of the element. Total mercury concentrations in prey items ranged from 0.2 to 17 ppb, while selenium concentrations ranged from <10 to 616 ppb; methylmercury concentrations in liver ranged from 25 to 236 ppb. Prey items had methylmercury concentrations below the limits of detection (<0.4 ppb). Hazard quotients and exposure rates indicate that leatherbacks of all life stages may be at risk for selenium toxicity. For endangered species like the leatherback, continued anthropogenic deposition of mercury and selenium into the environment is concerning, especially since bodily mercury and selenium concentrations increase as organisms age. Because leatherbacks are long-lived and have large daily prey consumption rates, mercury and selenium loads may increase to physiologically harmful levels in this imperiled species.

Effect of temperature on prey consumption of Typhlodromus bagdasarjani (Acari: Phytoseiidae) on Tetranychus urticae (Acari: Tetranychidae)

ABSTRACT Typhlodromus bagdasarjani Wainstein and Arutunjan (Acari: Phytoseiidae) is a generalist predator frequently reported in plants infested by phytophagous mites or insects. In this study, we determined the daily and total prey consumption of different life stages of Ty. bagdasarjani on Tetranychus urticae Koch nymphs at constant temperatures of 15, 20, 25, 30 and 35°C, relative humidity of 60 ± 10% and a photoperiod of 16: 8 h (light : dark). The results showed a significant effect of temperature on food consumption by Ty. bagdasarjani. The number of prey consumed daily by protonymphs increased with increasing temperature from 15 (0.8 preys) to 25°C (3.5 preys), and then decreased at 30 (2.8 preys) and 35°C (3.1 preys). The daily predation of the other life stages of Ty. bagdasarjani followed a similar trend as that which occurred in protonymphs, with the exception of post-oviposition period, in which the highest values for the mean prey consumption were observed at 30°C (6.6 preys/day). The highest means for the daily and total prey consumption of females were observed during oviposition, when they devoured an average of 2.7, 5.3, 10.1, 10.9, and 11.0 prey/day and 173.7, 255.9, 244.8, 259.0, and 185.8 prey in their entire period of oviposition at 15, 20, 25, 30, and 35°C, respectively. During adult life, the maximum number of prey was consumed at 20°C (432.7), which may be because of the longer period of adulthood at lower temperatures. Therefore, the efficiency of this predator in control of T. urticae populations could be higher at temperatures of above 20°C.

Predation of the apefly, Spalgis epius (Lepidoptera: Lycaenidae) on citrus mealybug, Planococcus citri (Hemiptera: Pseudococcidae)

The citrus mealybug, Planococcus citri (Risso) (Hemiptera: Pseudococcidae) is a serious pest of economically important crops worldwide. The apefly, Spalgis epius (Westwood) (Lepidoptera: Lycaenidae) is a potential predator of various species of mealybugs. Earlier investigation on its daily preying capacity and preference for prey stages on P. citri is incomplete. Hence, a study was conducted to find out the daily prey consumption ability and preference for prey stages by different larval instars of S. epius reared on P. citri in the laboratory. Through the 8-day developmental period with four larval instars, the daily prey consumption of S. epius increased from the first to the seventh day and decreased on the eighth day prior to the prepupal stage. Generally, there was a significant difference in the prey consumption on different days. When the prey stages were offered separately, the first to fourth instar larva of S. epius consumed, respectively, a mean of 199.6, 722.6, 1908.8, and 4625.6 eggs or 21.5, 77.0, 168.5, and 670.5 nymphs or 3.2, 7.2, 16.0, and 35.1 adults of P. citri. When an S. epius larva was fed on P. citri eggs, nymphs and adults separately, it consumed a mean of 7456.7 eggs, 937.6 nymphs, or 62.3 adults during its entire development. When the prey stages were offered all together, a single S. epius larva consumed 2618.4 eggs, 170.4 nymphs, and 39.7 adults of P. citri throughout its entire development. The study revealed that S. epius is a voracious predator of P. citri and thus could be utilized as a major biological control agent.

Functional response of Phytoseiulus macropilis under different Tetranychus urticae (Acari: Phytoseiidae, Tetranychidae) population density in laboratory

We tested the functional response of the phytoseiid predator Phytoseiulus macropilis (Banks, 1904) to different population densities of Tetranychus urticae Koch, 1836 (the two-spotted spider mite - TSSM) in the laboratory. We evaluated the curve that best fits the data obtained, based on the reduced X2. The predators were obtained from leaves of Oso Grande strawberries at the municipality of Bom Principio, state of Rio Grande do Sul, Brazil. Fifteen seemingly healthy females of P. macropilis were randomly chosen and individualized in each of the arenas with different TSSM densities. The following prey densities were tested: 1, 2, 3, 5, 10, 20, 30, 35, 45, 55, 70 and 125 females. The tests were performed in a germination chamber with photoperiod of 12 hours at 28 ± 1oC per day and 22 ± 1oC at night and 80 ± 5% relative humidity. In all tests with up to three prey items, P. macropilis showed low functional response, whereas higher rates were observed when more prey items were offered. There was a strong positive correlation between increased prey numbers and daily prey consumption (r = 0.84 and p = 0.0006). A significant correlation was found between prey consumption and total oviposition (r = 0.70, p = 0.01). The daily oviposition rate was lower when few prey items were offered, increasing significantly with increased prey availability. The results showed a positive correlation between the number of prey items offered to the predator and its oviposition rate (r = 0.66, p = 0.01). Nevertheless, a strong correlation was observed between the daily consumption of prey and eggs/female/day (r = 0.92, p < 0.0001). A shorter oviposition period was reported when up to three prey items were offered. The oviposition period and the increase in prey numbers were positively correlated (r = 0.30, p = 0.34), but the difference was not statistically significant. Nevertheless, the longer the egg-laying period, the greater the oviposition rate (r = 0.90, p < 0.0001). The curve that best fits the data obtained in each case was also calculated, based on the least square method.

Prey consumption and functional response of a phytoseiid predator, Neoseiulus womersleyi, feeding on spider mite, Tetranychus macfarlanei

The spider mite, Tetranychus macfarlanei (Baker and Pritchard) (Acari: Tetranychidae) is a pest of various crops and trees with a cosmopolitan geographic range that includes the country of Bangladesh. This study was conducted to evaluate the biological control potential of the predacious mite, Neoseiulus womersleyi (Schicha) (Acari: Phytoseiidae), against T. macfarlanei . The consumption rate (when offered egg, larvae, protonymph, and deutonymph as prey) and functional responses (over different prey densities) of N. womersleyi were investigated in laboratory experiments. Experimental results showed that the predator consumed significantly more larvae than other stages of T. macfarlanei . Logistic regression indicated that the predator exhibited a Type II functional response on all immature stages of prey; the number of prey consumed increased with prey density up to a maximum after which it slowly decreased. The attack rate ( a ) and handling time ( T h) coefficients of a Type II response were estimated by fitting Holling’s disc equation to the data. The lowest estimated value of a and the highest value of T h were obtained for the predator feeding on deutonymphs. The lowest value of T h was obtained for the predator feeding on larvae. However, the attack rate on larvae was not significantly different than the attack rate obtained on eggs and protonymphs. The predicted maximum daily prey consumption was 212.8 eggs, 238.1 larvae, 53.5 protonymphs, and 29.6 deutonymphs. Thus, our results suggest that N. womersleyi could be a highly efficient biological control agent of T. macfarlanei at least at low prey densities, although field studies are needed to draw firm conclusions.

Prey consumption by the mealybug predator Spalgis epius on pink hibiscus mealybug (Maconellicoccus hirsutus)

The pink hibiscus mealybug Maconellicoccus hirsutus (Green) (Hemiptera: Pseudococcidae) is a major pest of economically important crops. The apefly Spalgis epius (Westwood) (Lepidoptera: Lycaenidae) is a potential predator of various species of mealybugs. Studies of its preying potential and preference for prey stages on M. hirsutus are incomplete. An investigation was undertaken to determine the daily prey consumption and preference for prey stages by different larval instars of S. epius reared on M. hirsutus in the laboratory. During the 8-day larval development period with four larval instars of S. epius, the daily prey consumption increased from the first to the seventh day and decreased on the eighth day prior to the prepupal stage. Generally, there was a significant difference in the prey consumption on different days. The 1st to 4th instar larvae of S. epius consumed, respectively, a mean of 181.3, 679.1, 1770.4 and 4333.0 eggs or 19.1, 67.7, 153.0 and 639.0 nymphs or 2.72, 6.26, 13.8 and 32.1 adults of M. hirsutus. When an S. epius larva was fed on M. hirsutus eggs, nymphs and adults separately, it consumed a mean of 6952.6 eggs, 878.8 nymphs or 53.9 adults during its entire development. A single larva of S. epius consumed 2358.3 eggs, 151.2 nymphs and 34.3 adults of M. hirsutus during its entire development when the prey stages were offered all together. The study revealed that S. epius is a voracious predator of M. hirsutus and thus could be utilized as a potential biological control agent.

Development and Evaluation of a Bioenergetics Model for Saugeye

AbstractWe parameterized and evaluated a bioenergetics model for saugeye (walleye Sander vitreus × sauger S. canadensis) by using laboratory experiments in an effort to improve predictions of prey consumption. First, we measured daily prey consumption rate and growth of age‐0 and age‐1 saugeyes fed two daily rations (ad libitum and 50% of maximum) at five temperatures ranging from 10°C to 28°C. Additional experiments quantified routine respiration rates and waste losses for three ages of saugeye (ages 0, 1, and 2) at five temperatures ranging from 10°C to 28°C. Mean daily rates of prey consumption (g·g−1·d−1) by saugeyes increased from 10°C to 25°C, declining at 28°C. Respiration rates (g O2·g−1·d−1) increased over the entire range of water temperatures. Waste losses were minor for saugeyes as egestion averaged 3.5% of consumed energy and energy lost via excretion was 4.5% of assimilated energy. We evaluated the accuracy of bioenergetics model predictions of saugeye prey consumption using daily prey consumption and corresponding growth data from our first set of experiments. Model estimates of prey consumption rates (g·g−1·d−1) closely followed observed trends, providing reasonable estimates of cumulative prey consumption across temperature and fish size. The saugeye model provided improved estimates of consumption compared with a model published for walleyes (Kitchell et al. 1977), especially when water temperatures were in excess of 25°C. The differences we observed in predictive performance between the two models resulted from higher thermal optima for saugeyes compared with walleyes, and waste constants for saugeyes were two to three times lower than those calculated from the walleye model. These differences may largely be responsible for the walleye model's overestimation of consumption. Saugeye thermal optima are warmer than those of either parent species, and saugeye is better suited for warm, productive midwestern U.S. reservoirs. The saugeye model developed herein will improve the ability of managers to more accurately predict the consumptive demand of in situ saugeye populations and better tailor stocking rates to match available prey biomass.

Diet and prey consumption of breeding Common Kestrel ( Falco tinnunculus) in Northeast China

The diet of Common Kestrels Falco tinnunculus was studied during the breeding seasons from 2004 to 2008 in Northeast China. Diet was determined by direct observation of the prey brought to nests, and analysis of prey remains collected from nests. Fifteen vertebrate species from three classes, and two groups of insects were identified as prey items. Rodents were the main prey items, comprising 93.9% of the total prey items (TPI) and 97.0% of total prey biomass (TPB). Birds, frogs and insects were also eaten. The kestrels preferred to prey on small rodents (mean weight 20–40 g) and displayed density-dependent prey selection. Daily prey consumption of an adult and a nestling was 2.6 individual rodents or 87.6 g, and 1.7 individual vertebrates or 48.2 g, respectively. The estimated prey consumption of a breeding pair (adults and nestlings) during the breeding season was 520.1 individual vertebrates or 19.7 kg.

Evaluating the prudence of parents: daily energy expenditure throughout the annual cycle of a free‐ranging bird, the macaroni penguin Eudyptes chrysolophus

We measured daily energy expenditure (DEE) continuously for a whole year in a free ranging bird, the macaroni penguin Eudyptes chrysolophus. We combined these measurements with concurrently recorded foraging behaviour, and literature information on body mass and dietary factors to estimate prey consumption rates and foraging success. DEE was at a maximum during late chick‐rearing but was equally high during all other active phases of the breeding season. DEE was approximately 4×resting metabolic rate, which accords with established theory and suggests a common ‘energetic ceiling’ throughout the summer period. However, whether this represents a maximum in physiological capacity, or a rate which optimises fitness is still unclear. Rates of prey consumption and foraging success followed different patterns from daily energy expenditure. Daily prey consumption was high as the penguins prepared for long fasts associated with moulting and incubation but relatively low during chick‐rearing, when foraging areas were restricted and foraging success lower. It appears that the energy intake of macaroni penguins is subject to extrinisic or environmental constraints rather than to intrinsic physiological limits.

Feeding Habits and Prey Consumption of Antarctic Minke Whale (Balaenoptera bonaerensis) in the Southern Ocean

The Antarctic minke whale (Balaenoptera bonaerensis) is the most abundant baleen whale species in the Southern Ocean. Quantitative information on prey consumption of whales is useful to understand their feeding ecology and role in the ecosystem. The purposes of this study are 1) to investigate the feeding habit of Antarctic minke whales based on information on prey species, freshness and diurnal change in stomach contents, and 2) to estimate the amount of prey consumed by whales. Estimates are made for whales of different sexual maturity classes as it is expected that the energy requirements vary among them. The analysis is based on the data from whales taken by JARPA (Japanese Whale Research Program under Special Permit in the Antarctic) in a longitudinal sector between 35o E and 145o W, and south of 60o S. Sampling was conducted in the austral summer seasons from 1987/1988 to 2004/2005, mainly in the months from December to March. Daily prey consumption by the whales in each sexual maturity class was estimated using energy-requirement and energy deposition. The whales feed mainly before 05:00 h, which suggest that they cease to feed early in the day. Daily prey consumptions were estimated to be 83.7–325.5 kg, equivalent to 2.7–4.0% of body weight. The mean prey consumptions per capita during feeding season were 7.5 and 16.4 t for immature and mature male, 12.5 and 39.1 t for immature and mature female, respectively. In Area IV (70°–130°E), total prey consumptions of krill by Antarctic minke whales in 1999/2000 and 2001/2002 seasons were estimated to be 0.9 and 1.1 million t, respectively. In Area V (130° E–170° W including the Ross Sea), these estimates in 2000/2001 and 2002/2003 seasons were 3.9 and 4.1 million t, respectively. The estimations of feeding impact on krill resources by Antarctic minke whales in Areas IV and V were from 2.7 to 3.2%, and from 18.2 to 18.9% of krill biomasses, respectively. These results on prey consumption are important input data for the development of ecosystem modeling in the Southern Ocean.

Prey consumption ofOrius similisZheng (Het., Anthocoridae) with different aphid species as prey

The laboratory experiments showed that the predatory bug Orius similis Zheng, originally from China, is able to prey on different aphid species. It consumed significantly higher Aphis gossypii Glover and Aphis pomi (De Geer) than other aphid species during its entire nymphal development and adult stage as females (mated and unmated) and males. There were no significant differences in the mean daily and total prey consumption of females and males during the nymphal development. The mean daily prey consumption of adult O. similis was significantly higher by mated females than unmated females and males. No significant differences in the mean daily prey consumption of unmated females and males were detected. When A. gossypii and A. pomi were offered, the mean total prey consumption was significantly higher by females (mated and unmated) than by males. It was significantly higher by mated females than unmated females and males with Acyrthosiphon pisum (Harris) and Myzus persicae (Sulzer) as prey. O. similis ad...

총채벌레 천적 으뜸애꽃노린재(Orius strigicollis)와 미끌애꽃노린재(Orius laevigatus)의 생물학적 특성 비교

With the comparison of native Orius strigicollis (Poppius) to European O. laevigatus (Fieber), we investigated biological characteristics such as developmental period, fecundity, life span, predation ability, and augmentation after release. Experiments were carried out at five temperature condition, , and . In the case of O. strigicollis, egg period was days (hatchability: ), and developmental period of nymphs was days (survival rate: ). Fecundity at each temperature was 28.1, 107.9, 123.6, 127.3, and 18.1, respectively. Life span of adults was 63.4, 40.1, 22.1, 18.3, and 11.0 days, respectively. In the case of O. laevigatus, egg period was days (hatchability: ), and developmental period of nymphs was (survival rate: ) days. Fecundity at each temperature was 101.8, 218.6, 224.5, 219.5, and 15.7. Life span of adults was 70.6, 66.4, 32.6, 34.5, and 7.3 days, respectively. In long-day condition (16L:8D), fecundity of O. strigicollis and O. laevigatus was 105.8 and 109.5 , respectively. In short-day condition (10L:14D), fecundity of them was 1.0 and 63.0 , respectively. Daily prey consumption of second instar Frankliniella occidentalis was 14.3 and 10.9, respectively. In greenhouse, density of O. strigicollis begins to increase from mid May and peaked about early July (1.8 individual/flower), while that of O. laevigatus begins to increase from mid March and peaked about early June (6.6 individual/flower).

Development, feeding and reproduction responses of Adalia fasciatopunctata revelierei(Mulsant) (Coleoptera: Coccinellidae) to Hyalopterus pruni(Geoffroy) (Homoptera: Aphididae)

This study was carried out to determine the development, survival and reproduction responses of Adalia fasciatopunctata revelierei (Mulsant) (Coleoptera: Coccinellidae) feeding on Hyalopterus pruni (Geoffroy) (Homoptera: Aphididae), using 20, 40, 80, 160 and 250 prey densities. All experiments were conducted at 25±1°C, 60±5% relative humidity, 16:8 light:dark under laboratory conditions. The average daily prey consumption of A. fasciatopunctata revelierei immatures and adults increased with increasing prey densities. Predation was not different for the larval stages at 80, 160 and 250 prey densities. The longevities of adult females were 35.67, 35.33, 49.00, 58.33 and 57.16 days when 20, 40, 80, 160 and 250 H. pruni were provided, respectively. The mean daily and total fecundity of A. fasciatopunctata revelierei increased with increasing prey densities. Females of A. fasciatopunctata revelierei feeding on H. pruni laid 89 eggs at 20 prey density and 301.67 eggs at 160 prey density. The search rate of females was higher than that of all larval instars; and the search rate of the fourth-instar larvae was higher than that of younger instars. Handling time decreased with development from larval stages to adult.