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Start Over Creator Růžička, Zdeněk

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