Influence of the prey aphid Uroleucon nigrotuberculatum parasitizing Solidago canadensis on the larval and adult survivorship of the predatory ladybird beetle Harmonia axyridis

The ladybird beetle Harmonia axyridis is an aphidophagous natural enemy in Japan. The alien plant Solidago canadensis is widespread in Japanese agricultural landscapes, and the alien aphid Uroleucon nigrotuberculatum parasitizes the plant. We examined the quality of the aphid as food for all developmental stages of H. axyridis. First-instar larvae fed the aphid died within 2 days. Larvae at later developmental stages survived for significantly longer periods but died before pupation. Adults fed the aphid also died within 10 days. These results suggest that U. nigrotuberculatum parasitizing S. canadensis is unsuitable for H. axyridis during the beetle’s entire life cycle.     

Earwig preying on ambrosia beetle: Evaluating predatory process and prey preference

Earwigs (Dermaptera), such as Forficula auricularia L., are important euryphagous predators for a wide variety of prey and can markedly influence the populations of orchard pests. Most previous studies on earwig feeding behaviour have not used adult beetles of the prey species; few researchers have focused on prey preference in earwigs. Some fragments of beetle exoskeleton and an earwig adult, Anisolabella marginalis (Dohrn), were found in the same cage, where adults of ambrosia beetle, Euwallacea interjectus (Blandford), were emerging from the logs of a fig tree infected with Ceratocystis canker (fig wilt disease). Thus, A. marginalis was suspected of being a predator of E. interjectus. To shed light on this issue, in the laboratory, we set up a test arena and observed and recorded behavioural interactions between A. marginalis and E. interjectus. E. interjectus was collected from the logs of fig trees and reared on an artificial diet, along with six different ambrosia beetle species, which were collected from a trap (baited with ethanol) and a fallen maple tree. A series of laboratory experiments demonstrated that A. marginalis is actually a predator of E. interjectus and other species of ambrosia beetle, indicating its a potential for use in effective pest control in the field. The predators frequently consume and tend to select their prey depending on prey size, rather than sex and beetle species. Furthermore, earwigs have alternative predatory strategies for dealing with seven different species, although they use their forceps to cut the body of most tested beetles.     

Production and storage of mealworm beetle as prey for predatory stinkbug

Arthropod predators can be produced using alternative prey, but the availability of a constant supply of prey at low cost is necessary to support large-scale production. The use of stored prey can be advantageous for maintaining a constant food supply, but its quality may decline in storage. Thus, we tested the effect of using stored pupae of the alternative prey Tenebrio molitor L. at low temperature (mean of 3.6°C) on the performance of predatory stinkbug Podisus nigrispinus (Dallas). The treatment conditions we tested were: pupae stored for exactly 30 days before being used as prey (30-d pupae); pupae stored for either 20 or 35 days prior to the initiation of their use as prey, with continued storage during nymphal and adult stages (20-d+ or 35-d+ pupae); and 2-day-old newly moulted pupae as the control treatment. The duration of the nymphal stage of females and the weight of males were lower for nymphs fed 20-d+ and 35-d+ pupae, respectively. The pupal weight consumed and the rate of eggs and nymphs produced per gram of consumed pupae were also lower for adult females fed 35-d+ pupae compared to females that were fed 2-day-old pupae. These measures, however, were similar for females fed 30-d and 20-d+ pupae. The greatest consumption of pupae was observed for 20-d+ and 35-d+ treatments during nymphal and adult stages, respectively. The use of stored T. molitor pupae supported the development and reproduction of P. nigrispinus, regardless of the period of storage but with variable results among treatments. Therefore, among any of the tested treatments those pupae that were stored for exactly 30 days produced the highest fitness for P. nigrispinus.     

Effects of prey density, prey instar, and patch size on the development of the predatory mosquito, Toxorhynchites towadensis

Effects of prey density, prey instar, and patch size on the development of the predatory mosquito larva, Toxorhynchites towadensis, were investigated in the laboratory. Survivors of T. towadensis showed different developmental patterns in relation to prey age structure. All predatory larvae in containers with only second instar prey developed into the third instar. However, in several containers with fourth instar prey, mortality of predators was observed. During the third instar, no predatory larva died, but both prey density and prey instar significantly affected the survival of predators during their fourth instar. Large prey size promoted large predator adults, and predatory larvae which grew up in small surface containers responded by developing to large sizes than those in large containers. Larval developmental time of the predators differed in each treatment. During first and second instars, faster predator development was observed in containers with small surface areas and containing young prey individuals. However, when development was enhanced by the presence of old prey individuals, no surface effect was observed. The fastest predator development was observed with prey of mixed instars and high density. This study suggests that a small surface container containing prey of mixed instars and high density is suitable for development of predators.     

Effects of a larval antipredator response and larval diet on adult phenotype in an aposematic ladybird beetle

Many ladybird beetles respond to a potential predation event by `reflex bleeding' or secreting a noxious defensive chemical that is similar to hemolymph. Both adults and larvae show this response. Reflex bleeding is known to reduce predator attack rates and increase prey survival after an attack, especially when reflex bleeding is employed in combination with other cues such as odor and warning coloration. In this experiment, we examined how variability in the number of reflex bleeding events and food quality in the larval stage of the aposematic ladybird beetle Harmonia axyridis affected elytral color, development time, and terminal size in adults. Effects of reflex bleeding were subtle and may have been influenced by diet treatments. Adult color did not differ between bleed treatment groups but beetles that reflex bled tended to take longer to develop and grow to smaller sizes than control group beetles. There were clear and strong effects of larval diet on adult phenotype: an ad libitum pollen diet resulted in paler adult coloration, shorter development time, and larger adult size relative to a limited-availability aphid diet. Our results suggest that the best environment for producing bright-red coloration may not be the best environment for favorable expression of life history characters, especially under stressful conditions. Interactions between different life history stages of H. axyridis are also discussed. Received: 20 April 1997 / Accepted: 30 September 1997     

Effects of prey quantity and quality on predatory wasps

1. The simultaneous effects of prey quantity and prey quality on fitness correlates of the predatory wasp Polistes fuscatus were examined in a glasshouse study. Prey quantity was manipulated by providing prey in excess (high quantity) or one‐third of that (low quantity). Prey quality was manipulated by providing either palatable (Manduca sexta) caterpillars or unpalatable (Junonia coenia) caterpillars. 2. The effect of prey quality on wasp production depended on prey quantity. Nests given unpalatable prey produced few wasps whereas nests given palatable prey increased wasp production with increased prey. 3. The low production of nests given unpalatable prey reflected the low acceptability of those prey. The wasps preferred the palatable prey and learned to reject the unpalatable prey. With no choice of prey, they took only enough unpalatable prey to develop a small nest or colony. 4. A diet of unpalatable prey also resulted in smaller wasps and reduced the proportion of males produced, from about 40% to just 8–14%, depending on the year.     

Aphid and ladybird beetle abundance depend on the interaction of spatial effects and genotypic diversity

Intraspecific variation and genotypic diversity of host-plants can affect the structure of associated arthropod communities and the dynamics of populations. Similarly, neighboring plants can also affect interactions between host-plants and their associated arthropods. However, most studies on the effects of host-plant genotypes have largely ignored the potential effects of neighboring host-plants on arthropod communities. In this study, we used a common garden experiment to ask how spatial effects of neighboring patches, along with genotype identity and genotypic diversity in tall goldenrod (Solidago altissima), affect the abundances of a common goldenrod herbivore (Uroleucon nigrotuberculatum) and their dominant predator (Harmonia axyridis, a ladybird beetle). Aphid abundance varied 80-fold among genotypes, while ladybird beetle abundance was not affected by genotype identity. Additionally, there were strong effects of neighboring plots: aphid abundance in a focal plot was positively correlated to aphid abundance in nearby plots, suggesting strong spatial patterning in the abundance of aphids. Neither aphid nor ladybird beetle abundance was affected by genotypic diversity. However, focal plot genotypic diversity mediated the strength of the neighborhood effect (i.e., strong effects for genotype polyculture focal plots and weak effects for genotype monoculture focal plots). Our results show that aphids were directly influenced by host-plant genotype identity while ladybird beetles responded mainly to prey abundance, and suggest that genotypic diversity can influence the effects of spatial processes on the plant-herbivore interactions.     

Abundance and spatial distribution of aphids and scales select for different life histories in their ladybird beetle predators

Abstract:  Life history parameters tend to differ between aphidophagous and coccidophagous ladybird beetles. It seems that the nature of prey, in particular the abundance, number and size of the colonies and their spatial distribution, may have been selected for the evolution of the life histories in these two groups of coccinellids, leading the aphidophagous ladybird beetles to develop at a fast pace and the coccidophagous beetles at a slower pace. To study the abundance, number and size of the colonies and the spatial distribution of aphid and coccid species, 100 sampling plots regularly spaced along four parallel transects were surveyed in the summer of 2004. At each sampling plot, species abundance, and the number and size of colonies of aphid and coccid species were recorded. Iwao's patchiness regression was used to assess the spatial distribution of aphids and coccids. From this study, it was found that coccids are much rarer than aphids but formed more colonies. Whereas aphids display a stonger tendency to crowding, aphid colonies are randomly distributed in space while coccid groups are aggregated. So, it seems that the abundance and spatial distribution of prey distribution may be factors selecting for the evolution of different life histories among aphidophagous and coccidophagous ladybird beetles.     

Hunger, partial consumption of prey and prey size preference in a carabid beetle

ABSTRACT.

• 1 Partial consumption of prey and prey size preference were studied in females of the carabid Notiophilus biguttatus F., using different size-classes of the springtail Orchesella cincta (L.) as prey.
• 2 Time to ingest a prey increases disproportionately with prey size, mainly as a consequence of satiation.
• 3 During consumption of a prey the predator's rate of ingestion decreases, partly because of diminishing returns from the prey over feeding time.
• 4 The hypothesis that the diminishing returns from the prey induce partial consumption was refuted.
• 5 Partial consumption in the beetle is due to gut limitation; its occurrence depends on prey size.
• 6 Average weight of prey remains in four prey size classes were close to weights expected from average intercatch intervals and estimates of hunger.
• 7 Prey choice depends on level of food deprivation.
• 8 Partial consumption of prey, prey size preference and profitability of prey in relation to hunger of the beetle are discussed.

     

Influence of six aphid prey species on development and reproduction of a ladybird beetle, Coccinella septempunctata

Pre-imaginal development, immaturesurvival, and reproduction of a ladybird, Coccinella septempunctata Linnaeus, werestudied in response to six aphid species, Aphiscraccivora Koch, Aphis gossypii Glover,Aphis nerii Boyer de Fonscolombe,Lipaphis erysimi (Kaltenbach), Myzuspersicae (Sulzer) and Uroleuconcompositae (Theobald) to quantify theirrelative suitability as prey. Pre-adultdevelopment was shortest (13.93 ± 0.12 days)when fed on L. erysimi and longest(22.85 ± 0.10 days) on A. nerii. Immaturesurvival, adult emergence, growth index,relative growth rate, development rate, maleand female longevity, oviposition period,fecundity and hatching percent were maximal, i.e. 73.47 ± 0.89%, 90.07 ± 1.43%,8.62 ± 0.23, 1.52 ± 0.02, 0.07,81.10 ± 1.26 days, 85.70 ± 1.45 days,69.80 ± 1.32 days, 1764.10 ± 8.46,and 87.88 ± 1.05, respectively when C.septempunctata were fed on L. erysimi.The same parameters were minimal, i.e.43.86 ± 1.33%, 71.65 ± 2.75%,2.02 ± 0.08, 0.49 ± 0.02, 0.04,44.40 ± 1.39 days, 53.50 ± 1.00 days,16.40 ± 0.60 days, 203.20 ± 11.83, and48.68 ± 2.06, respectively on A. nerii. Theweights of different ladybird life stages weremaximal after feeding on L. erysimi and minimalon A. nerii. Regression analyses of thedata revealed linear relationships betweendevelopment rate and weight of adult; dailyprey consumption and relative growth rate; logweight of adult male and female; and longevityand fecundity of female. On the basis of thesefindings, the order of suitability of aphidspecies for C. septempunctata is L. erysimi >M. persicae > A. craccivora > A. gossypii >U. compositae > A. nerii. Thus, the presentinformation can be utilized for the massrearing of C. septempunctata by supplyingthe best food and can also help in theprediction of the relative abundance of theladybird on different aphid infestations in thefields.     

High rate of prey consumption in a small predatory fish on coral reefs

Coral Reefs - Small piscivores are regarded as important regulators of the composition of coral reef fish communities, but few studies have investigated their predatory ecology or impact on...     

Mechanisms of prey finding in the aphidophagous ladybird beetle,Harmonia axyridis [Coleoptera: Coccinellidae]

The mechanism of prey finding in adultHarmonia axyridis was investigated by presenting beetles with small gauze or polyethylene bags containing either aphidinfested leaves or healthy leaves alone together with empty control bags. Beetles were attracted to bags by olfactory and visual cues suggesting the presence of aphids, including the odor of aphid-infested leaves, the odor of aphids, the odor of healthy leaves, and the sight of leaves. Particularly effective in prolonging beetles's stay on bags visited was the odor of aphid-infested leaves. It is suggested that adults ofH. axyridis use olfactory and visual cues to detect prey before actual contact occurs. Use of such cues seems more advantageous than random searching, as has been reported in many previous studies of coccinellid foraging.

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Résumé Le mécanisme de découverte de la proie chez l'adulte d'Harmonia axyridis est étudié en donnant aux Coccinelles de petits sacs en gaze ou en polyéthylène contenant soit des feuilles infestées de pucerons, soit des feuilles saines seules, avec des sacs vides comme témoins. Les coccinelles sont attirées vers les sacs par des indicateurs olfactifs ou visuels suggérant la présence de pucerons, incluant l'odeur des feuilles infestées de pucerons, l'odeur des pucerons, l'odeur des feuilles saines et la vue des feuilles. L'odeur des feuilles infestées de pucerons est particulièrement efficace en prolongeant le séjour des Coccinelles sur le sac visité. Il est suggéré que les adultes d'H. axyridis utilisent des indicateurs olfactifs et visuels pour détecter leur proie avant que s'établisse le véritable contact. L'emploi de tels indicateurs semble plus avantageux que la recherche au hasard, comme cela a été indiqué dans de nombreuses études antérieures sur la quête alimentaire des Coccinelles.

     

Prey range of the predatory ladybird Cryptolaemus montrouzieri

The prey range of Cryptolaemus montrouzieri was studied in the laboratory to investigate whether the mealybug destroyer can contribute to the suppression of other pest insects besides mealybugs and to assess its potential impact on non-mealybug populations as part of an environmental risk assessment for its use in biological control. Prey tested in these experiments were: tobacco aphid Myzus persicae nicotianae (Sulzer)(Hemiptera: Aphididae), pea aphid Acyrthosiphon pisum (Harris)(Hemiptera: Aphididae), tobacco whitefly Bemisia tabaci (Gennadius)(Hemiptera: Aleyrodidae), southern green stinkbug Nezara viridula (L.)(Hemiptera: Pentatomidae) eggs, western flower thrips Frankliniella occidentalis (Pergande)(Thysanoptera: Thripidae), two-spotted ladybird Adalia bipunctata (L.)(Coleoptera: Coccinellidae) eggs and eggs of the greater wax moth Galleria mellonella L. (Lepidoptera: Pyralidae). Larval survival was high to moderate when C. montrouzieri was provided with hemipteran prey and poor to zero when the ladybirds were provided with non-hemipteran prey. Females reared on M. persicae and A. pisum produced similar numbers of eggs as their counterparts fed the citrus mealybug Planococcus citri (Risso)(Hemiptera: Pseudococcidae), but fecundity was significantly lower when the ladybirds were reared on B. tabaci nymphs or on A. bipunctata eggs. Prey species that were found to be less suitable for immature development of C. montrouzieri could still be an adequate food source for reproduction and survival of adult ladybirds. For example, only 8 % of the predator larvae reached the adult stage when provided with A. bipunctata eggs, but females that had developed on eggs of the Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) and that were supplied with A. bipunctata eggs from adult emergence on, were only 35 % less fecund than females provided with mealybugs in their adult life. The results are discussed in relation to the development of a suitable methodology for prey/host range testing in the framework of an environmental risk assessment for arthropod natural enemies.     

Effects of spatial distribution of light on prey ingestion of Atlantic halibut larvae

The hypothesis that light distribution affects prey distribution and in turn influences prey ingestion was tested on Atlantic halibut larvae Hippoglossus hippoglossus . Low intensity concentrated light produced swarms of Artemia sp., but did not affect the distribution of Brachionus plicatilis . Low intensity diffused light, however, did not create swarms with either prey. As a consequence, halibut larvae ingested more Brachionus than Artemia in concentrated light, but not in diffused light. Due to differences in dry weight between Artemia and Brachionus , ingested biomass values were indistinguishable under the two experimental regimes.The term' population ingestion value' is introduced as an expression for the ingestive capability of the population as a whole.     

Effects of plant and prey characteristics on the predatory behavior of Delphastus catalinae

Nymphal setosity of the whitefly Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) has been reported to be induced by mechanical stimuli such as leaf tomentosity, and related to the predatory performance of the coccinellid Delphastus catalinae (Horn) (Coleoptera: Coccinellidae). In this study, a possible adaptive value of this phenomenon for the whitefly is shown through the combined effects of leaf and prey characteristics on the walking and predatory behaviors of the beetle. Leaf tomentosity significantly affected the walking patterns of the beetle and therefore its searching abilities, thus indirectly increasing the influence of prey distribution upon predator's efficiency. Moreover, while searching on tomentose leaves, the beetles showed preference for the smooth prey phenotype. This behavior was found dependent on the experience of the beetle in previous encounters. These results are pertinent to intraspecific competition between the different nymphal phenotypes and to the predatory efficiency of this beetle, which is utilized in biological control of whiteflies.     

Consequences of adult size for survival and reproductive performance in a herbivorous ladybird beetle

Abstract.

• 1 A univoltine herbivorous ladybird beetle Epilachna niponica (Coleoptera: Coccinellidae) shows a large variation in adult size within a population.
• 2 Large adults had higher survival from emergence to the reproductive season, and the size-dependent adult survival was most apparent during hibernation. On the other hand, adult survival during pre-hibernation contributed little to size-dependent overall survival.
• 3 Neither reproductive lifespan nor lifetime fecundity were a function of adult size, though large females produced larger size of egg batches.
• 4 Size of adult beetles was significantly reduced by leaf damage to plants on which they grew up on larval stage. Since leaf herbivory increases through the season, late emerged adults that were subjected to food deterioration during the larval period were smaller than early-emerged individuals.

     

Habitat or prey specialization in predatory ladybird beetles: a case study of two closely related species

This study examines the niche and diet breadth of two closely related sympatric aphidophagous ladybirds: Adalia decempunctata and A. bipunctata. The degree of habitat specialization of these species is investigated, and its effect on life history traits of females is explored. The importance of prey quality in determining the diet breadth is also examined. The niches occupied by these species in three countries, the UK, Belgium and southern France, are similar: A. decempunctata is an arboreal habitat specialist with a narrower set of prey than A. bipunctata, which is commonly found on several types of vegetation. The niches of the two species overlap on trees. Experiments indicate that habitat specialization has resulted in A. decempunctata investing more in each of its offspring than A. bipunctata. A. decempunctata females lay, relative to their body size, heavier eggs than those of the more generalist A. bipunctata, which results in A. decempunctata having bigger larvae. In addition, A. decempunctata larvae are better at surviving starvation than A. bipunctata larvae. In contrast to the expected pattern in food specialization, our study failed to demonstrate a better efficiency of the specialist when fed its usual prey and a detrimental effect when fed on prey that it is unlikely to encounter in the field. The reproductive performance of the specialist ladybird was better when fed an aphid that it was unlikely to regularly feed on in the field. Therefore, the narrow diet of the specialist ladybird is most likely a consequence of it occupying a narrow habitat rather than the quality of the prey. Although further studies on specialization in predatory insects are needed, the results indicate that unlike the role of plant quality in host specialization in herbivorous insects, prey quality has not been the main determinant of ecological specialization in these predatory insects.     

杂拟谷盗体内 Wolbachia 感染密度的时间和空间分布状况

为搞清杂拟谷盗体内沃尔巴克氏体(Wolbachia)感染密度的时间和空间分布状况,本研究采用实时荧光定量PCR方法测定了杂拟谷盗不同发育阶段、不同日龄、不同性别和不同身体部位的Wolbachia感染密度。结果表明,杂拟谷盗在卵和成虫期Wolbachia感染密度高于其幼虫和蛹期,成虫腹部的Wolbachia感染密度高于其头部和胸部,而成虫不同日龄和雌雄之间的Wolbachia感染密度均没有显著性差异。本研究明确了Wolbachia在杂拟谷盗体内的时空分布和动态变化规律,这对于揭示寄主与共生菌之间的互作关系有着重要意义。     

The effect of prey density on the functional and numerical reponses of three species of predatory mites

Functional and numerical responses of the predators:Phytoseiulus persimilis Athias-Henriot,Metaseiulus occidentalis (Nesbitt), andAmblyseius chilenensis (Dosse) [Acarina, Phytoseiidae] were observed at prey (Tetranychus urticae Koch [Acarina, Tetranychidae]) densities up to 300 prey/6.45 cm². Neither functional nor numerical response curves revealed any prey-predator interference effects, i.e.: the dome-shaped response curves (Holling, 1961), did not occur.