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2. Oviposition-deterring effects of conspecific and heterospecific larval tracks on Cheilomenes sexmaculata (Coleoptera: Coccinellidae)
- Creator:
- Růžička, Zdeněk
- Type:
- article, model:article, and TEXT
- Subject:
- Coccinellids, Ceratomegilla undecimnotata, Cheilomenes sexmaculata, Cycloneda limbifer, Harmonia dimidiata, aphids, predators, larval tracks, semiochemicals, oviposition-deterrence, site selection, intraspecific effects, intraguild competition, and clutch size
- Language:
- English
- Description:
- The oviposition deterring effects of fresh larval tracks of Cheilomenes sexmaculata (F.), Ceratomegilla undecimnotata (Schneider), Cycloneda limbifer Casey, and Harmonia dimidiata (F.) on C. sexmaculata females were compared in standard laboratory choice tests. Moreover, the persistence of intraspecific effects of C. sexmaculata larval tracks were investigated. Fresh tracks of C. sexmaculata, C. limbifer and C. undecimnotata larvae effectively deterred C. sexmaculata females from ovipositing. The effect of fresh larval tracks of H. dimidiata was not statistically significant. The oviposition-deterring effects of 10 d-old conspecific larval tracks were considerably lower than those of fresh tracks, but remained significant. Clutch sizes were smaller in the blank test without larval tracks than in choice tests with fresh tracks of conspecific, C. limbifer, C. undecimnotata, H. dimidiata larvae and with 10 d-old tracks of conspecific larvae. The study indicates that semiochemicals in the tracks of conspecific and heterospecific coccinellid larvae can contribute considerably to the spacing of C. sexmaculata offspring among prey resources of differing quality and that conspecific as well as heterospecific larval tracks can influence clutch size.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
3. Perception of oviposition-deterring larval tracks in aphidophagous coccinellids Cycloneda limbifer and Ceratomegilla undecimnotata (Coleoptera: Coccinellidae)
- Creator:
- Růžička, Zdeněk
- Type:
- article, model:article, and TEXT
- Subject:
- Oviposition-deterring semiochemicals, pheromone, larval tracks, aphidophagous coccinellids, Cycloneda limbifer, Ceratomegilla undecimnotata, Leis dimidiata, sense organs, perception, chemoreceptors, antennae, maxillary palpi, egg clusters, batches, and oviposition strategy
- Language:
- English
- Description:
- The ability of the aphidophagous coccinellids Cycloneda limbifer Casey and Ceratomegilla undecimnotata (Schneider) to discriminate between simultaneously provided clean paper strips and paper strips with oviposition-deterring larval tracks was studied after the ablation of different sense organs. Females oviposited similar numbers of eggs on paper strips with conspecific tracks and on clean paper strips only when deprived of both maxillary palpi. C. undecimnotata without maxillary palpi also did not differentiate between clean paper strips and paper strips with tracks of the coccinellid Leis dimidiata (F.). If both antennae and one maxillary palpus were simultaneously ablated, females of both species laid significantly more eggs on clean than contaminated paper strips. The results of this study indicate that females use contact chemoreceptors on maxillary palpi exclusively to detect oviposition deterring tracks of conspecific larvae. Intact females of C. limbifer laid significantly larger batches of eggs on paper strips with conspecific larval tracks, than on clean paper strips in blank test. In contrast, intact females of C. undecimnotata laid significantly smaller batches on paper strips with conspecific tracks than on clean paper strips in blank test. This is the first evidence of an opposite effect of conspecific oviposition deterring larval tracks on egg clustering in aphidophagous coccinellids.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4. Persistence of deterrent larval tracks in Coccinella septempunctata, Cycloneda limbifer and Semiadalia undecimnotata (Coleoptera: Coccinellidae)
- Creator:
- Růžička, Zdeněk
- Type:
- article, model:article, and TEXT
- Subject:
- Coccinellidae, Coccinella septempunctata, Cycloneda limbifer, Semiadalia undecimnotata, Chrysopidae, Chrysopa oculata, Chrysopa perla, aphid predators, larval tracks, deterrent secretion, pheromones, semiochemicals, persistence, oviposition, intraspecific effects, and interspecific effects
- Language:
- English
- Description:
- The persistence of oviposition-deterring effects of coccinellid and chrysopid larval tracks on females of three aphidophagous coccinellid species was compared. One month old tracks of first instars of the coccinellid Cycloneda limbifer Casey deterred conspecific females from oviposition in choice tests with clean and contaminated substrates. Intraspecific effect of larval tracks in Semiadalia undecimnotata Schneider was statistically significant after 10 days. Although fresh tracks of conspecific first instars effectively deterred females in both tested populations of Coccinella septempunctata L., deterrent effects disappeared when tracks of larvae were only one day old. However, females of C. septempunctata laid fewer eggs on sites with 10 days old tracks of Chrysopa oculata Say or sites with one month old tracks of Chrysopa perla (L.) first instars than on clean sites. In contrast to females of C. septempunctata and S. undecimnotata, C. limbifer females left significantly more faecal spots on clean sites than on sites with 5-30 days old tracks of conspecific first instars. This indicates that sites with tracks of larvae can also effectively repel conspecific females of some coccinellid species from searching.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5. Response of chrysopids (Neuroptera) to larval tracks of aphidophagous coccinellids (Coleoptera)
- Creator:
- Růžička, Zdeněk
- Type:
- article, model:article, and TEXT
- Subject:
- Chrysopidae, Coccinellidae, Chrysopa oculata, hrysopa perla, Coccinella septempunctata, Cycloneda limbifer, Leis dimidiata, Semiadalia undecimnotata, predators, aphidophagous insects, larval tracks, oviposition-deterring semiochemicals, allomones, and interspecific effects
- Language:
- English
- Description:
- Choice tests showed that tracks left by coccinellid larvae have generally little effect on oviposition site selection by chrysopid females. Fresh tracks of first instar larvae of the coccinellid species Coccinella septempunctata, Cycloneda limbifer, Leis dimidiata and Semiadalia undecimnotata, did not deter females of the chrysopid Chrysopa oculata from laying eggs. Females of Chrysopa perla avoided ovipositing only on substrates with tracks of L. dimidiata larvae.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public