转sck+cry1Ac基因水稻对二化螟及二化螟绒茧蜂存活和生长发育的影响

在实验室研究了转sck+cry1Ac基因水稻（MSB）对二化螟Chilo suppressalis (Walker)生长、存活以及经寄主对二化螟绒茧蜂Apanteles chilonis (Munakata)生物学特性的影响。连续取食转sck+cry1Ac基因水稻的二化螟, 体重下降、死亡率上升,从第2天开始,其体重显著低于取食明恢86的对照组;从第6天开始,死亡率极显著高于对照组。二化螟取食MSB 36 h后移至对照水稻上继续取食3、6、9、12天后,死亡率与对照差异都不显著;但体重均低于对照,其中第3天的体重差异达显著水平。二化螟绒茧蜂分别以取食MSB一定时间的3、4、5龄二化螟幼虫为寄主时,寄生率均低于以对照组,其中对4龄幼虫的寄生率差异显著;结茧率与对照差异均不显著;寄生在取食MSB的5龄二化螟幼虫体内的蜂、蛹期显著长于对照,而所结茧的茧长显著短于对照;但卵 幼虫历期、每茧块茧数、羽化率、雌性率、成蜂寿命和前翅长与对照无显著差异。结果表明转sck+cry1Ac基因水稻不仅对二化螟生长和存活有显著影响, 而且可经寄主二化螟影响到二化螟绒茧蜂的一些生物学特性。     

The feeding behaviour of the sand crab Scopimera inflata (Decapoda, Ocypodidae)

A sequence of activities all related to the feeding of Scopimera inflata H. Milne-Edwards, 1873 can be distinguished during the daytime periods of low tide. Emergence begins one to two hours after a feeding area is uncovered, reaches a peak after a further three hours but some crabs are still emerging after the tide has turned. Before feeding commences the burrow is cleared of waste sand down to the water-table. While feeding S. inflata forms a feeding trench which acts as an escape route back to the hole and is defended against other crabs of the same species. Agonistic behaviour becomes evident as feeding progresses. Threat displays, fighting, displacement feeding, and agitation feeding are recognizable behaviour patterns which have been observed.     

Preference of temperate Chinese elms (Ulmus spp.) for the adult Japanese beetle (Coleoptera: Scarabaeidae)

Trees of newly acquired Ulmus species originating from the temperate regions of China and growing at The Morton Arboretum, Lisle, IL, were evaluated in no-choice and multiple-choice laboratory bioassays and cage-studies for feeding preference for adults of the Japanese beetle, Popillia japonica Newman. Ulmus lanceaefolia, U. prunifolia, U. pseudopropinqua, and U. taihangshanensis were less preferred for feeding by adult Japanese beetles. No-choice, multiple-choice, and cage feeding studies revealed that Ulmus wallichiana was moderately preferred, and U. procera and U. americana were highly preferred for feeding. Dry fecal pellet weights were strongly correlated with the percent of leaf tissue removed. Feeding preference in the multiple-choice study was strongly correlated with feeding preference in the cage study and in the no-choice study. Likewise, adult feeding preference in the cage study was strongly correlated with preference in the multiple-choice and no-choice studies. The less preferred species of U. lanceafolia, U. prunifolia, U. pseudopropinqua, and U. taihangshanensis show promise for future elm breeding programs.     

Factors restricting the feeding of the cabbage stem flea beetle (Psylliodes chrysocephala)

The feeding acceptability of 40 different plants to Psylliodes chrysocephala L. (Coleoptera: Chrysomelidae) was determined using leaf disc consumption tests for the adult, and stem or petiole penetration tests for the larvae. Only plants that contained glucosinolates were accepted as food, but addition of the glucosinolate sinigrin to rejected food plants did not make them acceptable to adults. Of the 34 plants that contained glucosinolates, nine were either totally or mostly rejected. Solvent extracts of the rejected plants applied to oilseed rape inhibited feeding by adults. The feeding of P. chrysocephala within the group of plants tested is influenced by the presence or absence of glucosinolates, which may act as feeding stimulants, and other, unidentified chemicals which act as feeding inhibitors.     

DC electrical stimulation of the pretectal thalamus and its effects on the feeding behavior of the toad (Bufo bufo)

The feeding motivation of the common European common toad (Bufo bufo) can be quantified by the feeding sequence of arousal-orientation-approach-fixate-snap. Previous work has found that the optic tectum is an important structure responsible for the mediation of feeding behaviors, and combined electrical and visual stimulation of the optic tectum was found to increase the animals feeding behaviors. However, the pretectal thalamus has an inhibitory influence upon the optic tectum and its lesion results in disinhibited feeding behaviors. This suggests that feeding behavior of anurans is also subject to influence from the pretectal thalamus. Previous studies involving the application of DC stimulation to brain tissue has generated slow potential shifts and these shifts have been implicated in the modulation of the neural mechanisms associated with behavior. The current study investigated the application of DC stimulation to the diencephalon surface dorsal to the lateral posterodorsal pretectal thalamic nucleus in Bufo bufo, in order to assess effects on feeding motivation. The application of DC stimulation increased the incidence of avoidance behaviors to a visual prey stimulus while reducing the prey catching behavior component of approach, suggesting that the DC current applied to the pretectum increased the inhibition upon the feeding elements of the optic tectum. This can be explained by the generation of slow potential shifts.     

Feeding behaviour of the grass grub Costelytra zealandica (White) (Coleoptera: Melolonthinae)

The feeding response of 3rd‐instar Costelytra zealandica larvae to 20 amino acids tested individually at 2 concentrations was assessed. Six of these compounds had a phagostimulatory effect; in particular, the ubiquitous amino acids L‐aspartic acid, L‐glutamic acid, and L‐serine induced considerable feeding by the grubs. Ascorbic acid was also a strong feeding stimulant and, in combination with sucrose, evoked an intense behavioural response. A synergistic effect of ‘Salt Mix W on the larval response to sucrose was demonstrated.     

Diet and Feeding Behavior in Adults of the Apteropanorpidae (Mecoptera)

The Apteropanorpidae is a small family of scorpionflies endemic to Tasmania. The biology of the family is almost completely unknown. Here we present results of laboratory and field studies of the diet and feeding behavior of adult Apteropanorpidae. We describe the morphology of the alimentary canal and mouthparts and discuss the relationship between diet, feeding behavior and morphology. We compare these results to the feeding ecology of other extant Mecoptera, and speculate on the feeding strategies of fossil Mecoptera, placing all data in a phylogenetic context. Results show that adult Apteropanorpidae are most likely saprophagous in nature, predominantly on dead and decaying invertebrates.     

Feeding strategy of the megamouth shark Megachasma pelagios (Lamniformes: Megachasmidae)

The feeding biology of the planktivorous megamouth shark Megachasma pelagios was investigated. Morphological examination disclosed that the megamouth has a suite of unique characteristics among sharks, such as large mouth, large bucco-pharyngeal cavity, elongate jaw cartilages, long palatoquadrate levator and preorbital muscles, long ethmopalatine ligament and elastic skin around the pharynx. The combination of these characters suggests that the megamouth shark performs engulfment feeding that is typically seen in the rorqual and humpback whales. Engulfment is a new feeding method for sharks, and the detailed mechanism of the engulfment feeding is discussed.     

Seasonal variation in the feeding ecology of the grey-cheeked mangabey (Lophocebus albigena) in Cameroon

Seasonal fluctuations in resource abundance often cause primates to change their feeding behavior and ecology. The objective of this study was to examine the response of a largely frugivorous monkey, the grey-cheeked mangabey (Lophocebus albigena), to seasonal variations in fruit abundance. We used 15-min scan sampling to quantify feeding, activity, and habitat use by monkeys between February and December 1998 in the Dja Reserve, Cameroon. L. albigena were found to have omnivorous feeding habits, consuming the fruits, seeds, leaves, and flowers of 132 plant species. Although monkeys fed from many plant species, only five plant species accounted for 45% of all feeding records. The number of feeding observations on a plant species was significantly correlated with its fruit production. L. albigena responded to fruit-lean periods by shifting from a diet dominated by fruit to one dominated by seeds, flowers, and young leaves. This diet shift coincided with greater use of swamp habitat and higher dietary diversity. L. albigena spent the greatest percentage of scan samples feeding and traveling, but activities varied significantly over the day. Individuals spent a significantly higher percentage of scan samples feeding during the fruit-rich season than in the fruit-lean season. Comparing our results to those of studies in Gabon and Uganda, we found that L. albigena differ across regions in the number of plant species they consume and time spent feeding. These differences may be a result of variations in tree diversity or the strength of seasonal fluctuations in resource abundance among sites.     

Interspecific feeding associations of groupers (Teleostei: Serranidae) with octopuses and moray eels in the Gulf of Eilat (Agaba)

Synopsis Temporary interspecific feeding associations between groupers (Serranidae) and moray eels or octopuses in the Red Sea were observed 41 times during over 400 scuba dives. Such behavior is a feeding tactic adopted by groupers in which small organisms, escaping the primary (= nuclear) predators (eel or octopus), are caught by the groupers. Eels and octopuses, due to their body structure or shape, gain access to crevices that most fishes cannot enter. This feeding tactic increases the diversity of food resources used by their associates by making normally inaccessible food items available to them. Serranids from many parts of the world exploit normally unavailable food resources in this fashion. It appears that this is a learned behavior which increases food diversity and feeding efficiency.     

Functional morphology of the feeding system in the ruff — Gymnocephalus cernua (L. 1758) — (Teleostei,Percidae)

The ruff, Gymnocephalus cernua, is a European freshwater fish that feeds by sucking up small invertebrates from the bottom of ponds and slow flowing rivers. The feeding movements have been studied by simultaneous electromyography of seventeen muscles of the head and cinematographic techniques. A theoretical model of movements imposes the functional demands of suction upon an abstraction of the form of a teleost head. Three phases in the feeding act, a preparatory phase, a suction phase and a transport phase, could be correlated with the observed movements and EMGs. Differences between the predicted and the actual movement are discussed. Two different types of feeding occur. The direction, magnitude and duration of the suction forces during feeding are modified, according to the position of the prey. A mechanism preventing early mandibular depression allows sudden and strong suction. Retardation of the suspensorial abduction during the overall expansion of the buccal cavity is ascribed to kinetic interrelations with the hyoid arch. Protrusion of the upper jaws also permits an earlier closure of the mouth and directs the food-containing waterflow posteriorly. When the fish is feeding on sinking prey, protrusion occurs later in the sequence of movements than when it is feeding from the bottom. As the protruded jaws produce a downwardly pointed mouth this retardation aims the suction force.     

Evidence for an endogenous circadian rhythm of feeding in the trout (Oncorhynchus mykiss)

Abstract

The possible endogenous circadian rhythm in the feeding activity of rainbow trout (Oncorhynchus mykiss) was investigated using individual fish previously trained for self‐feeding. Under LD 12:12 conditions, the fish showed a diurnal behaviour, in many cases with a feeding rhythm with two main peaks of food demand at dawn and dusk, with an 8h interval of low feeding activity, and the actograms showed an expected 24 h rhythm. Fish kept under constant conditions (L : L, 15°±0.5°C), showed free‐running feeding activity for about 12 days. Food demands were concentrated at dawn, with a periodogram of 25.3 hour, under continuous environmental conditions. Results showed evidence for the endogenous origin of the circadian rhythm of feeding in this species.     

Laboratory experiments on the schooling and feeding behaviour of Trichogaster fasciatus (Pisces: Perciformes)

Laboratory experiments were performed on the schooling and feeding behaviour of Trichogaster fasciatus . There was a tendency on the part of individuals of similar size to school together; the instinct being stronger in younger specimens. Unavailability of similar-sized individuals led to schooling by members of different size-groups. Column feeding was exhibited by the fish. While feeding at the bottom, the fishes formed angles varying from 30°90°. Larger individuals formed a right angle more often than younger members of the species. Optimum degree of crowding seemed necessary for active feeding as confinement of single individual, or overcrowded condition, both resulted in a decline of feeding activity.     

Age class differences in the feeding behavior of captive Japanese macaques (Macaca fuscataia) in the forested and nonvegetated enclosure groups

Age class differences in feeding behavior of primates are affected by many factors, including feeding competition, foraging skills, habitat type, food abundance and distribution, body mass, and food types. Two captive groups of Japanese macaques (Macaca fuscata), one housed in a forested enclosure and the other in a nonvegetated enclosure, were studied to examine the effect of environmental enrichment on age class differences in feeding behavior. Although there was no significant age class difference in time spent feeding on provisioned foods in either enclosure, the feeding rate (intake of unit food/minute) of adults consuming provisioned monkey chow was significantly higher than that of immatures in both enclosures, and was faster for both age groups in the nonvegetated than in the forested enclosure. Overall, feeding time was greatly extended for individuals of both age classes in the forested enclosure compared with their counterparts in the nonvegetated enclosure. Immatures in the forested enclosure utilized a significantly greater number of plant species and food items, exploiting many food items available among the terminal branches, and spent significantly more time feeding than adults. Perhaps constrained by larger body size, adults fed more often on the ground or middle height of the trees, likely reducing competition over plant food resources between adults and immatures. The natural vegetation played an important role in extending feeding time and segregating substrate use during feeding by adults and immatures. This study revealed the benefits concerning environmental enrichment of a naturally forested enclosure, which provides captive primates the opportunity to exhibit age class and species-typical feeding behaviors of importance for their dietary maintenance and general health.     

Mixed-stock analysis reveals the migrations of juvenile hawksbill turtles (Eretmochelys imbricata) in the Caribbean Sea

Hawksbill turtles (Eretmochelys imbricata) migrate between nesting beaches and feeding habitats that are often associated with tropical reefs, but it is uncertain which nesting colonies supply which feeding habitats. To address this gap in hawksbill biology, we compile previously published and new mitochondrial DNA (mtDNA) haplotype data for 10 nesting colonies (N = 347) in the western Atlantic and compare these profiles to four feeding populations and four previously published feeding samples (N = 626). Nesting colonies differ significantly in mtDNA haplotype frequencies (Phi(ST) = 0.588, P < 0.001), corroborating earlier conclusions of nesting site fidelity and setting the stage for mixed-stock analysis. Feeding aggregations show lower but significant structure (Phi(ST) = 0.089, P < 0.001), indicating that foraging populations are not homogenous across the Caribbean Sea. Bayesian mixed-stock estimates of the origins of juveniles in foraging areas show a highly significant, but shallow, correlation with nesting population size (r = 0.378, P = 0.004), supporting the premise that larger rookeries contribute more juveniles to feeding areas. A significant correlation between the estimated contribution and geographical distance from nesting areas (r = -0.394, P = 0.003) demonstrates the influence of proximity on recruitment to feeding areas. The influence of oceanic currents is illustrated by pelagic stage juveniles stranded in Texas, which are assigned primarily (93%) to the upstream rookery in Yucatan. One juvenile had a haplotype previously identified only in the eastern Atlantic, invoking rare trans-oceanic migrations. The mixed-stock analysis demonstrates that harvests in feeding habitats will impact nesting colonies throughout the region, with the greatest detriment to nearby nesting populations.     

Morphofunctional changes in the midgut of the Ixodes females (Acari: Ixodidae) during the immunizing feedings

The changes of the midgut in the females of the tick species Ixodes persulcatus and I. ricinus during the second and third immunizing feeding on rabbits were studied by the histological technics. The alternation of one generation of the digestive cells of nymphal stage and two generations of the digestive cells of adult stage was observed. The generation of secretory cells is absent. The tick completes feeding and drop off when the last generation of the digestive cells is on the initial activity stages. The amount of the blood consumed is not enough for the rhythmical functioning of the midgut. The feeding of tick is broken on the second phase and full satiation does not take place. It is apparently an effect of the interruption of the blood entrance into the midgut cavity of feeding tick as a probable result of anti-ticks resistance of unnatural hosts.     

Improving slug baits: the effects of some phagostimulants and molluscicides on ingestion by the slug, Deroceras reticulatum (Miiller) (Pulmonata: Limacidae)

The effects of seven potential phagostimulants and of four molluscicidal compounds on feeding were examined by confining slugs with agar gels containing the chemicals in varying concentrations. Sugars generally increased the amount of gel ingested; sucrose more than glucose, lactose and fructose. Feeding increased with increasing sucrose concentration to a maximum and then fell progressively: the optimum concentration lay between 2.5% and 5%. The sweeteners saccharin and aspartame at concentrations up to 2.5% did not increase feeding. Addition of the molluscicides metaldehyde, methiocarb and ferric acetylacetonate to gels containing 2.5% sucrose progressively reduced feeding at concentrations of 0.001% and above. Metaldehyde reduced ingestion more than methiocarb and ferric acetylacetonate was intermediate. The molluscicidal herbicide Ioxynil deterred feeding completely at concentrations of 0.001%. The implications for slug bait development are discussed.     

Feeding behaviour of the Japanese loach,Misgurnus anguillicaudatus (Cobitididae)

The feeding behaviour of a Japanese loach,Misgurnus anguillicaudatus was experimentally analyzed. From observations the behaviour patterns were described. The adult fish responded to a piece of thread soaked with filteredTubifex homogenate (Tubifex solution) and showed feeding behaviour. But they ignored an unsoaked piece of thread. LivingTubifex kept in a glass cell failed to elicit feeding behaviour in the fish. A gauze-covered vessel withTubifex solution buried in the sand substrate released feeding behaviour in fish in its vicinity. It follows that the feeding behaviour of this fish is induced by some chemical stimuli. WhenTubifex solution was introduced at the central area of the plastic vessel with a fish, the fish suddenly started the Feeding-crawl and showed Gulp which was composed of Dig and Twist. Using sand particles, it was shown that intake of materials into the digestive tract occurs only at the moment of Twist and not any other time. The standard feeding patterns ofMisgurnus anguillicaudatus are thus quick inhalation of organic matter together with substrate, occurring at the moment of Twist, which is released at the place where the fish received the appropriate chemical stimuli.Misgurnus anguillicaudatus is regarded as a typical “detritus feeder”.     

Modelling the effect of feeding-related mortality on the feeding strategy of tsetse (Diptera: Glossinidae)

Abstract. Free-living haematophagous insects risk death through host grooming responses or through increased susceptibility to predation whenever they take a bloodmeal. In this paper we investigate the effects of these risks on the feeding strategy of tsetse. A model is presented that allows for death of tsetse by starvation if they do not succeed in feeding within a fixed time (set at 6 days in the first instance) and for mortality specifically associated with feeding. In addition there is background mortality that applies to all flies at all times.
The model is used to compute the individual life-time fertility (number of female puparia per female) as a function of the probability of obtaining a meal (indicated by field data to be very high, usually > 0.85 per day) and the day on which flies start to search for a meal. We suggest that the feeding strategy that would be selected for is that which allows the maximum reproductive output. The model shows that this strategy involves making no attempts to feed for 3–4 days after the previous meal and then attempting to feed with the greatest possible probability until a meal is obtained. The predicted feeding interval, obtained independently of any trapping data, agrees closely with all previous estimates from field studies using a variety of methods. Preliminary results from a laboratory experiment reveal an increased risk of predation of recently fed as compared with hungry tsetse. The lower the actual feeding mortality the more frequently will flies be able to feed should conditions so demand. It is adaptive, however, for tsetse to delay attempting to feed for as long as they can, which is made possible by the near certainty of locating and feeding on a host within 1 day, using their sophisticated sensory systems.