« Previous |
1 - 10 of 44
|
Next »
Number of results to display per page
Search Results
2. Adaptations of Coccinella magnifica, a myrmecophilous coccinellid to aggression by wood ants (Formica rufa group). II.. Larval behaviour, and ladybird oviposition location1
- Creator:
- Sloggett, John J. and Majerus, Michael E.N.
- Type:
- article, model:article, and TEXT
- Subject:
- occinella magnifica, Coccinella septempunctata, Formica rufa, ant-tended aphids, myrmecophily, and oviposition
- Language:
- English
- Description:
- Like adults, larvae of the myrmecophilous ladybird Coccinella magnifica are rarely attacked by Formica rufa ants on foraging trails, but more often attacked on ant-tended aphid colonies. Larvae of the non-myrmecophile Coccinella septempunctata, to which C. magnifica was compared, were more readily attacked by ants in both situations. To avoid or counter ant aggression when foraging for aphids, C. magnifica larvae exhibit three main tactics: they may feed on un- or non-tended aphids; when feeding on tended colonies they often carry prey away, minimising time spent there; and if attacked, they use limited chemical defence. No novel behaviours were found in C. magnifica larvae, not occurring to some extent in C. septempunctata. Coccinella magnifica eggs were laid distant to ant-tended aphids, although closer to un- or non-tended aphids.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
3. Adaptive preferential selection of female coccinellid hosts by the parasitoid wasp Dinocampus coccinellae (Hymenoptera: Braconidae)
- Creator:
- Davis, Dexter S., Stewart, Sarah L. , Manica, Andrea, and Majerus, Michael E.N.
- Type:
- article, model:article, and TEXT
- Subject:
- Parasitoidism, host discrimination, host sex, Dinocampus coccinellae, Braconidae, Coccinella septempunctata, and Coccinellidae
- Language:
- English
- Description:
- Females of the parasitoid wasp Dinocampus coccinellae are known to parasitise both male and female coccinellid hosts. It is suggested that female hosts provide more resources for developing wasp larvae because they tend to be larger than male hosts, and female coccinellids have a much greater food intake than males. Thus the wasp's lifetime reproductive success should be increased by ovipositing preferentially in female rather than male hosts when given a choice. Laboratory experiments, using Coccinella septempunctata as a host, show that such a preference does exist. Wasps preferentially oviposit in females, and this preference is not simply a result of the larger mean size of females compared to males. These results corroborate higher rates of prevalence in female compared to male hosts reported previously.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4. Adaptive preferential selection of young coccinellid hosts by the parasitoid wasp Dinocampus coccinellae (Hymenoptera: Braconidae)
- Creator:
- Majerus, Michael E. N., Geoghegan, Irene E., and Majerus, Tamsin M. O.
- Type:
- article, model:article, and TEXT
- Subject:
- parasitoid, host selection, host discrimination, Dinocampus coccinellae, Braconidae, Coccinella septempunctata, and Coccinellidae
- Language:
- English
- Description:
- Dinocampus coccinellae females which eclose in mid-summer have the opportunity to oviposit in overwintered or in newly eclosed coccinellid hosts. Given the short further longevity of overwintered hosts, offspring fitness would be increased by ovipositing preferentially in young hosts. Laboratory choice tests show that female D. coccinellae do exhibit such a preference.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5. Aggregation characteristics of three species of Coccinellidae (Coleoptera) at hibernation sites
- Creator:
- Honěk, Alois, Martinková, Zdeňka, and Pekár, Stano
- Type:
- article, model:article, and TEXT
- Subject:
- Coleoptera, Coccinellidae, Coccinella septempunctata, Ceratomegilla undecimnotata, Hippodamia variegata, overwintering, distribution, and hibernaculum
- Language:
- English
- Description:
- Adults of some coccinellid species overwinter in aggregations consisting of many individuals. They may clump because adults are attracted to particular environmental stimuli and/or of an innate tendency to join conspecific individuals. Aggregation behaviour was studied in Coccinella septempunctata L., which forms small clumps, and Ceratomegilla undecimnotata (Schneider) and Hippodamia variegata (Goeze), which form large clumps. Adults were recorded at five hilltop hibernacula (400-1500 m altitude) in central Europe (50-51°N, 14-16°E) for periods up to 27 years. The hibernacula occur in areas sparsely covered with isolated grass tussocks or completely with stones. Numbers of adults recorded under each of 300-900 stones or among the stems of the grass tussocks were counted every year at each hibernaculum. The degree of aggregation was determined using Taylor's power law. The coccinellid distributions became more aggregated and the size of the aggregations increased as their abundance increased, less in C. septempunctata than in the other two species. Aggregations formed even in the absence of prominent structures, which may attract immigrants, and even when unoccupied stones or tussocks suitable for overwintering were available. Aggregations may be established and their size limited by the strength of the intrinsic preference to join conspecifics. The supposed advantage of aggregated overwintering must be greater than the risk associated with the easy spread of diseases.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
6. Ant-aphid interactions in multispecies ant communities: Some ecological and ethological aspects
- Creator:
- Novgorodova, Tatiana A:
- Type:
- article, model:article, and TEXT
- Subject:
- Ants-aphids interaction, Formicinae, Myrmicinae, Coccinella septempunctata, multispecies communities, symbiosis, aphid diversity, behaviour, trophobionts, and foragers
- Language:
- English
- Description:
- Investigations of the interactions between aphids and ants in multispecies ant communities and an experimental investigation of some ethological aspects of ant-aphid interactions were carried out in mixed forests at Novosibirsk Academic Centre, from 1998-2002. The eight species of ants investigated were characterized by different levels of territorial organization and interaction with aphids, which were associated with different degrees of specialization of the worker ants. The most myrmecophilous species of aphids (24 out of 33 species identified) were associated with the red wood ants. By placing Coccinella septempunctata Linnaeus (Coleoptera: Coccinellidae) in aphid colonies it was shown that only ants with large protected territories attacked the adults and larvae of the predator. Other species of ants either protected aphids only from adult ladybirds or did not guard them at all. Moreover, only individuals of Formica s. str., which has specialized workers, did not switch to collecting protein food. However, aphids make up a considerable part of the prey of ants, in which non-myrmecophilous aphids predominate (about 60-100% of the aphid prey). Moreover, ants only killed unattended or damaged myrmecophilous aphids. Formica s. str., which has the highest level of social and territorial organization, provides aphids with the most services and is the dominant species forming symbiotic relationships with aphids in the communities studied.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
7. Body size and the temporal sequence in the reproductive activity of two species of aphidophagous coccinellids exploiting the same resource
- Creator:
- Honěk, Alois, Dixon, Anthony F.G., and Martinková, Zdeňka
- Type:
- article, model:article, and TEXT
- Subject:
- Coccinella septempunctata, Propylea quatuordecimpunctata, Coccinellidae, Coleoptera, Dinocampus coccinellae, Braconidae, Hymenoptera, body size, reproduction, oviposition, and prey abundance
- Language:
- English
- Description:
- The hypothesis that small species of aphidophagous coccinellids need lower aphid population densities for reproduction than large species (Dixon, 2007) was tested in the field. In 2006 we compared seasonal changes in the oviposition behaviour of two coccinellid species regularly found in cereal stands in central Europe, the large Coccinella septempunctata L. and the small Propylea quatuordecimpunctata (L.). Adults of both species were collected at 2-3 day intervals from stands of winter wheat and spring barley, females were allowed to deposit eggs for 24 h following collection and the percentage that laid eggs and the number of eggs were recorded. Both species colonized the cereal crop simultaneously in the middle of May. After colonization of the crop, while the aphid density was still low, few females of C. septempunctata oviposited and laid only a few eggs. Oviposition increased up to a maximum c. 1 month later and was closely associated with prey abundance. Of the females of P. quatuordecimpunctata, whose mass is about one quarter of that of the former species, the percentage ovipositing and number of eggs laid varied less in time and was less associated with prey abundance than in C. septempunctata. As predicted by theory, the small P. quatuordecimpunctata was more effective at exploiting the lower prey densities as it produced proportionally more of its eggs during the early stages of the aphid infestation than the larger C. septempunctata.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
8. Coccinellidae captured in blacklight traps: seasonal and diel pattern of the dominant species Harmonia axyridis (Coleoptera: Coccinellidae)
- Creator:
- Christine A. Nalepa
- Type:
- article, model:article, and TEXT
- Subject:
- Zoologie, zoologie, entomologie, Coleoptera, Coccinellidae, Harmonia axyridis, Coleomegilla maculata, Hippodamia convergens, Coccinella septempunctata, blacklight trap, ultraviolet, migration, phototaxis, flight-oogenesis, nocturnal, 2, and 59
- Language:
- English
- Description:
- Two blacklight traps were operated in a non-agricultural setting in Cary, North Carolina, USA, from spring through fall in 2004 and 2005 and all Coccinellidae collected and identified. More than 1300 lady beetles were collected in each of the two years, with Harmonia axyridis dominant (> 98%) and collected consistently over the course of the trapping period. Although other coccinellid species were observed in the vicinity of the traps during photophase, their appearance in blacklight traps was negligible. Harmonia axyridis exhibited a distinct diel periodicity in appearance at the traps, beginning approximately an hour after sunset and ending about midnight. Sunrise and sunset collections from flight interference and sticky traps in a local alfalfa field suggest that H. axyridis may be more flight active during the scotophase than Coleomegilla maculata, Hippodamia convergens, and Coccinella septempunctata. This study supports the suggestion that blacklight traps give a biased depiction of coccinellid species composition in a given area, and indicates that seasonal and circadian thresholds for flight activity, phototaxis, or both in H. axyridis may diverge from those in most other Coccinellidae., Christine A. Nalepa., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
9. Defence, oviposition and sex: semiochemical parsimony in two species of ladybird beetles (Coleoptera, Coccinellidae)? A short review
- Creator:
- Hemptinne, Jean-Louis and Dixon, F. G.
- Type:
- article, model:article, and TEXT
- Subject:
- semiochemical parsimony, alkanes, oviposition deterring pheromone, mate recognition, defensive allomone, Coccinellidae, Adalia bipunctata, and Coccinella septempunctata
- Language:
- English
- Description:
- Certain alkanes or their mixture present on the surface of ladybird elytra is important in the recognition of potential mates. Similar chemicals are present in the tracks of larvae, which deter conspecific female ladybirds from laying eggs in aphid colonies already being attacked by larvae. Finally, the shell of ladybird eggs is covered with alkanes that deter other species of ladybirds from eating the eggs. In each case the alkanes are similar although they fulfil different functions. There are, therefore, indications that ladybirds exploit their natural product with parsimonious versatility.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
10. Differential parasitisation of adult and pre-imaginal Coccinella septempunctata (Coleoptera: Coccinellidae) by Dinocampus coccinellae (Hymenoptera: Braconidae)
- Creator:
- Geoghegan, Irene E., Majerus, Tamsin M. O., and Majerus, Michael E. N.
- Type:
- article, model:article, and TEXT
- Subject:
- Braconidae, Coccinellidae, Dinocampus coccinellae, Coccinella septempunctata, host suitability, host recognition, and host instar choice
- Language:
- English
- Description:
- The parasitoid wasp Dinocampus coccinellae has been reported to parasitise adult, pupal and larval coccinellids. Field samples of larvae and pupae of Coccinella septempunctata, collected over 13 years in Britain, have failed to reveal any infected pre-imaginal individuals. The parasitisation rates of D. coccinellae into pre-imaginal and adult C. septempunctata were assessed in both choice and no-choice tests. Observations and test results revealed that British D. coccinellae have a strong preference to oviposit in adult coccinellids rather than larvae or pupae. This preference decreases as wasps age if denied oviposition opportunities.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public