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2. Behavioural evidence for a putative oviposition-deterring pheromone in the butterfly, Phengaris (Maculinea) teleius (Lepidoptera: Lycaenidae)
- Creator:
- Sielezniew, Marcin and Stankiewicz-Fiedurek, Anna M.
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, zoologie, entomologie, host plant marking behaviour, host plant selection, Maculinea teleius, myrmecophily, oviposition, oviposition-deterring pheromone, Phengaris teleius, Sanguisorba officinalis, social parasite, 2, and 59
- Language:
- English
- Description:
- Larvae of the endangered Scarce Large Blue butterfly, Phengaris (Maculinea) teleius, are initially endophytic, feeding upon developing seeds of Sanguisorba officinalis, but complete their development as social parasites preying on the brood of Myrmica ants. Females show very specific preferences, laying eggs exclusively in young flower heads of the food plant. In the present contribution we report the results of a detailed study of female behaviour at three sites differing in size and abundance of S. officinalis. Tracked individuals switched between feeding on nectar (nectaring), flight and oviposition. They fed exclusively on flowers of reddish, pink or violet colouration, favouring Viccia cracca and S. officinalis. However, females spent about one fifth of the time they were active ovipositing and laid about 20 eggs per hour. Oviposition visits to flower heads were highly stereotyped and followed a specific ritual. Examination of accepted, rejected and randomly sampled flower heads showed that females avoided those containing conspecific eggs and at a site where this was difficult due to a shortage of suitable flower heads, they tended to distribute their eggs evenly among the available flower heads. Our results indirectly indicate the existence of an oviposition-deterring pheromone (ODP) in P. teleius. This hypothetical marking ensures a more even distribution of eggs and possibly increases the chances of survival of caterpillars by reducing competition during both the phytophagous and myrmecophagous stages of development. There are few reports of butterflies producing ODPs and to our knowledge this is the first evidence of their presence in the family Lycaenidae., Marcin Sielezniew, Anna M. Stankiewicz-Fiedurek., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
3. Biological and ecological studies on Scymnus syriacus and Scymnus levaillanti (Coleoptera: Coccinellidae)
- Creator:
- Allawi, Thabet
- Type:
- article, model:article, and TEXT
- Subject:
- Scymnus syriacus, Scymnus levaillanti, aphidophagous coccinellids, oviposition, developmental time, longevity, and food consumption
- Language:
- English
- Description:
- Both Scymnus syriacus Mars. and Scymnus levaillanti Muls. are aphidophagous coccinellids. In the laboratory they consumed and successfully reproduced on several species of aphids. Larvae suck the prey contents from aphid appendages, while adults consume the whole aphid, except for parts of the appendages. Extra-oral digestion is practiced during feeding. The mean number of aphids consumed by the larval stage of S. syriacus when reared at 25°C was 95, and 130 aphids at 30°C. For S. levaillanti it was 125 and 139 aphids at 25°C and 30°C, respectively. The mean number of eggs deposited daily by S. syriacus for the first three weeks of adult life was 19.5, with a range of 3-30 eggs at 25°C. Longevity of adults ranged from 3 to 4 months at 25°C and 2.5-3 months at 30°C.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4. 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
5. Changes in the volatile profile of Brassica oleracea due to feeding and oviposition by Murgantia histrionica (Heteroptera: Pentatomidae)
- Creator:
- Conti, Eric, Zadra, Claudia, Salerno, Gianandrea, Leombruni, Benedetta, Volpe, Daniela, Frati, Francesca, marucchini , Cesare, and Bin, Ferdinando
- Type:
- article, model:article, and TEXT
- Subject:
- Heteroptera, Pentatomidae, Murgantia histrionica, herbivore-induced plant volatiles, feeding, oviposition, and Brassicaceae
- Language:
- English
- Description:
- The mixture of volatile compounds emitted by Brassica oleracea var. sabauda changed significantly in response to feeding and/or oviposition by Murgantia histrionica (Heteroptera: Pentatomidae). Volatiles were collected from (1) healthy plants and those with (2) feeding punctures, (3) a combination of feeding punctures and oviposition, (4) feeding punctures and one hatched egg mass and (5) plants bearing only an egg mass. In the case of plants with feeding punctures or feeding punctures plus an egg mass, the volatiles were also collected at different time intervals after plants were subjected to these two treatments (0-24 h, 24-48 h and 48-72 h). Gas chromatographic and gas chromatograph-mass spectrometric analysis showed that the percent emission of several compounds changed significantly from plants subjected to the feeding and oviposition or just oviposition. Percentage of terpenes generally decreased after feeding and oviposition, although the percentage emission of (E)-β-caryophyllene from these plants and those with just feeding punctures significantly increased. Plants with just an egg mass emitted linalool de novo but not (E)-β-ocimene. The emission of jasmonates, mainly methyl jasmonate, increased from plants with feeding punctures plus an egg mass compared to those with only an egg mass. Higher percentages of the volatile glucosinolate derivatives (VGSs), mainly 4-methoxy-3-indolylacetonitrile, were emitted by plants with feeding punctures and an egg mass. The percentage emission of most of these compounds increased during the first 24 h after the treatment and then decreased over the next 24 h, except for methyl jasmonate, which remained high also 48-72 h later. The possible ecological roles of such volatiles in plant interactions with the second and third trophic levels are discussed.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
6. Cold hardiness of Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae) from central and southern Europe
- Creator:
- Kalushkov, Plamen and Nedvěd, Oldřich
- Type:
- article, model:article, and TEXT
- Subject:
- Heteroptera, Pyrrhocoris apterus, survival, mortality, supercooling, low temperature, diapause, overwintering, oviposition, Bulgaria, and Bohemia
- Language:
- English
- Description:
- The cold hardiness of individuals from overwintering populations of a freeze susceptible bug Pyrrhocoris apterus from central and southern Europe differed significantly. Supercooling point (SCP) correlated well with both lethal temperature (LT50) and lethal time (Lt50), and is agood index of cold hardiness of adults during and after diapause. In January, diapause terminated, but cold hardiness was similar to that recorded in November; cold hardiness decreased slightly in March and markedly in May. Short exposure (less than a week) to higher temperatures before termination of diapause did not reduce the cold hardiness. Cold hardiness did not closely follow air temperatures.The Bulgarian bugs retained lower cold hardiness regardless of acclimation to harsh field conditions in the Czech Republic. The interpopulation difference is therefore a heritable character representing an adjustment to local climates.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
7. Comparative behavioral and EAG responses of female obliquebanded and redbanded leafroller moths (Lepidoptera: Tortricidae) to their sex pheromone components
- Creator:
- Gökce, Ayhan, Stelinski, Lukasz L., Gut, Larry J., and Whalon, Mark E.
- Type:
- article, model:article, and TEXT
- Subject:
- Tortricidae, obliquebanded leafroller, Choristoneura rosaceana, redbanded leafroller, Argyrotaenia velutinana, electroantennogram recording, sex-attractant pheromone, female response, autodetection, calling behaviour, oviposition, and mating disruption
- Language:
- English
- Description:
- Studies were conducted investigating the responses of female obliquebanded leafrollers, Choristoneura rosaceana (Harris) and redbanded leafrollers, Argyrotaenia velutinana (Walker) (Lepidoptera: Tortricidae), to components of their sex pheromone. Electroantennogram (EAG) recordings revealed significant responses from antennae of female moths of both species to the major pheromone component, (Z)-11-tetradecenyl acetate, at dosages ranging from 2 µg - 2 mg. However, tested individually, the minor pheromone components of the obliquebanded leafroller, (E)-11-tetradecenyl acetate and (Z)-11-tetradecenol, elicited little or no antennal response from conspecific females. This result was consistent for redbanded leafroller females, which showed only weak responses to the minor component (E)-11-tetradecenyl acetate at a 2 mg dosage. For both species, species-specific blend ratios of the Z and E isomers of tetradecenyl acetate did not elicit a greater antennal response than the Z isomer alone. Virgin females of each species (2-4 d old) were placed into 1-liter plastic assay chambers with constant throughput of carbon-filtered air passed through 1-liter flasks containing rubber septa loaded with (Z)- and (E)-11-tetradecenyl acetates and (Z)-11-tetradecenol for trials with female obliquebanded leafrollers or with (Z)- and (E)-11-tetradecenyl acetates and dodecyl acetate for trials with female redbanded leafrollers. Exposure to pheromone-permeated air delayed the onset of calling by 1 h and terminated the calling period 1 h earlier for both species compared with solvent-control exposed females. Furthermore, the total proportion of calling females was reduced by half in chambers receiving constant throughput of pheromone-permeated air compared with solvent controls. Exposure to pheromone-permeated air also significantly reduced egg-laying in both species compared with clean-air controls. Furthermore, application of the major pheromone component, (Z)-11-tetradecenyl acetate, at dosages ranging from 2 µg - 2 mg to wax-paper ovipositional substrates, deterred oviposition by females of both species. Our data suggest that application of synthetic sex-attractant pheromones for mating disruption of leafroller species may have deleterious effects on female moth behavior, which may contribute to pest control. Field investigations will need to be conducted to test this hypothesis.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
8. Comparison of the severity of selection among beech leaves prior to egg-laying between a leaf-mining and two gall-inducing insects
- Creator:
- Béguinot, Jean
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, entomologie, behaviour, oviposition, egg-laying, selectivity, host acceptance, clutch size, insect, mine, gall, inference, Lepidoptera, Gracillariidae, Diptera, Cecidomyiidae, Mikiola fagi, Hartigiola annulipes, Phyllonorycter maestingella, 2, and 59
- Language:
- English
- Description:
- a1_Quantitative behavioural traits associated with egg-laying, such as the level of selectivity for host-supports and the size of egg clutches, are generally thought to be of great importance for the subsequent survival and development of offspring. These quantitative traits, however, are often difficult to assess reliably by direct observation in the field. This is particularly the case when the insects are very tiny, which is the case for most galling and leaf mining insects. However, a new approach, the "Melba" procedure, allows the indirect inference of these quantitative traits, using easily recorded field-data only. Application of this diagnostic procedure to a large series of samples of beech leaves (Fagus silvatica), harbouring either a leaf miner, Phyllonorycter maestingella (Lepidoptera: Gracillariidae) or one or the other of two galling insects, Mikiola fagi or Hartigiola annulipes (Diptera: Cecidomyiidae) indicates that the leaf miner differs significantly from the two species of galling insect in term of combined values of host-acceptance ratio and average clutch-size, while the two gall-inducing species remain substantially undistinguishable from each other according to these traits. Thus, the galling insects (i) show stronger selectivity for a host than does the miner at any given average clutch-size and (ii) show larger average clutch-size at any given level of selectivity. That is, for at least these three species, the galling insects show a greater level of selectivity when choosing leaves to oviposit on but, then, tend to lay larger egg-clutches. These differences may be due (i) to the gall-inducing process requiring far more of leaf tissues than being simply palatable, which makes it likely that galling species will be more selective in their choice of leaves than leaf miners and (ii) to the capacity of galls to become nutrient sinks, which may help explain why the galling insects laid larger, a2_egg clutches. However, whether these trends can be regarded as general rather specific to this particular case, depends on the outcome of future studies on other groups of insects with similar life histories., and Jean BÉGUINOT.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
9. Drosophila species (Diptera: Drosophilidae) oviposition patterns on fungi: The effect of allospecifics, substrate toughness, ovipositor structure and degree of specialisation
- Creator:
- Rouquette, Jennifer and Davis, Andrew John
- Type:
- article, model:article, and TEXT
- Subject:
- Drosophila, fungi, oviposition, ovipositor structure, and resource partitioning
- Language:
- English
- Description:
- To determine if small-scale resource partitioning aids coexistence in fungal breeding Diptera we investigated the avoidance of interspecific larval competition by micro-resource partitioning of the host substrate in several species of Drosophila ovipositing on fungal fruiting bodies. No avoidance was detected and oviposition patterns were unaffected by the presence of allospecifics. There was a general tendency for all species to oviposit preferentially on the cap but no significant differences between species. Egg distribution was not strongly related to the sporophore's resistance to penetration measured by penetrometer and was also uncorrelated with ovipositor structure even though species had concordant suites of ovipositor characteristics with apparent specialists typified by hard and sharp ovipositors. We discuss the significance to species coexistence of the absence of micro-resource partitioning of the host.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
10. Effect of photoperiod on parasitization by Trichogramma principium (Hymenoptera: Trichogrammatidae)
- Creator:
- Reznik, Sergey Ya. and Vaghina, Nina P.
- Type:
- article, model:article, and TEXT
- Subject:
- Photoperiod, egg parasitoids, Trichogramma, oviposition, pre-oviposition period, oogenesis, egg retention, and fecundity
- Language:
- English
- Description:
- The effect of photoperiod on parasitization of the eggs of the Angoumois grain moth, Sitotroga cerealella (Olivier, 1789) by Trichogramma principium Sugonyaev & Sorokina, 1976 was investigated under several photoperiodic regimes of L : D = 3 : 21, 6 : 18, 9 : 15, 12 : 12, 15 : 9, 18 : 6 and 21 : 3. In all regimes, certain wasps delayed ovipositing in this non-preferred host. Potential fecundity of T. principium females (the number of mature ovarial eggs at emergence) and subsequent oogenesis (estimated by the number of mature ovarial eggs in non-ovipositing females) was independent of photoperiod. However, the percentage of females that oviposited was higher for females that developed and were kept under 6-12 h long photophase than for those that developed and were kept under ultra short (3L : 21D) and under long (18L : 6D and 21L : 3D) photophases. The average duration of the pre-oviposition (egg retention) period showed the opposite pattern to the photoperiodic response. A possible explanation of this reaction is that the delay in oviposition is adaptive if the probability of finding a better host is high. In autumn, when the last Trichogramma females are still active but their lepidopteran hosts are already much less abundant, then parasitization of any suitable host is the best strategy.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
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