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32. Ecology of a relict population of the vulnerable butterfly Pyrgus sidae on the Iberian Peninsula (Lepidoptera: Hesperiidae)
- Creator:
- Hernández-Roldán, Juan L., Munguira, Muguel L., and Martín, José
- Type:
- article, model:article, and TEXT
- Subject:
- Conservation, Hesperiidae, Lepidoptera, mark-release-recapture, population parameters, Pyrgus sidae, relict population, resource use, spatial distribution, Iberian Peninsula, and Potentilla recta
- Language:
- English
- Description:
- There are isolated populations of the endangered butterfly, Pyrgus sidae, on the Iberian Peninsula. The mark-release-recapture method was used to study the population parameters, the use of resources and the spatial distribution of a population in the centre of Spain. The estimated number of males and females within the population were similar and did not differ significantly from a ratio of 1 : 1. Total population size was estimated to be 569 ± 83 individuals. Potentilla recta is the principal adult nectar source and larval food plant, and its abundance is correlated with the number of marked and recaptured butterflies. The average total distance moved between capture and recapture was significantly greater for males than females, but the average daily distances moved were similar for both sexes. The spatial distribution of the movements of males and females was of a uniform type and lacked a predominant flight direction, which is typical of sedentary species. Continuing the traditional land use (cattle grazing or hay mowing) of the habitat of the species keeps the habitat open, which is necessary if the butterfly is to survive at this locality. These management practices favour P. recta, which would otherwise succumb to competition from invasive shrubs. Taking into account the habitat requirements of this species, it is important to conserve the mosaic of meadows already present in the area.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
33. Effect of host species on larval growth differs between instars: The case of a geometrid moth (Lepidoptera: Geometridae)
- Creator:
- Vellau, Helen, Sandre, Siiri-Lii, and Tammaru, Toomas
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, entomologie, entomology, Lepidoptera, Geometridae, Ematurga atomaria, larval performance, body size, reaction norm, host plant quality, Calluna, Vaccinium, 2, and 59
- Language:
- English
- Description:
- Although the effects of host plant quality on the performance of polyphagous herbivores are largely uniform across insect taxa, there are various exceptions to this rule. In particular, there are scattered reports of cases in which the relative quality of different hosts differs among larval instars of a single insect species. Such cases are explained either in terms of differences in the susceptibility of different aged larvae to plant defences or, alternatively, age-specific nutritional demands. Here we report the results of experiments that show that young larvae of the polyphagous common heath moth Ematurga atomaria (Lepidoptera: Geometridae) consistently attain higher weights on common heather Calluna vulgaris than bilberry Vaccinium myrtillus, whereas the rank order of these host plants is reversed in the final larval instar. Phytochemical analyses showed that differences in nutrient content of these plants are not likely to explain the observed pattern. Instead, the results are more consistent with the idea that the greater chemical defence of bilberry has a relatively stronger influence on young than old larvae., Helen Vellau, Siiri-Lii Sandre, Toomas Tammaru., and Seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
34. Effect of insect-resistant transgenic maize on growth and development, utilization of nutrients and in vivo activity of the detoxification enzymes of the Asian corn borer, Ostrinia furnacalis (Lepidoptera: Pyralidae)
- Creator:
- Shi, Min Juan, Lu, Pei Ling, Shi, Xiao Li, and Yang, Yi Zhong
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, entomologie, Lepidoptera, Pyralidae, Ostrinia furnacalis, detoxification enzyme, growth and development, insect-resistant transgenic maize, nutritional indicators, 2, and 59
- Language:
- English
- Description:
- a1_There is little systematic research on the effect of transgenic maize expressing Bacillus thuringiensis (Bt) toxins on insect survival and the response in vivo of their detoxification enzymes. Results of laboratory bioassays indicate that the whorl leaves of transgenic maize lines G03-2396 and G03-2739 significantly affected the survival of neonate and third instar larvae of the Asian corn borer, Ostrinia furnacalis (Güenée). Neonate mortality two days after being fed on G03-2739 was 72.5% and exceeded 92.5% four days later. The percentage mortality of third instar larvae six days after being fed whorl leaves from G03-2396 exceeded 65%. The resistance of whorl leaves to insect attack was greater than that of maize-ears, but less effective against attacks by third instar larvae. Neonate development was more prolonged when they were fed on whorl leaves of both the transgenic maize lines. In contrast, low pupation (<80% of that recorded in the controls), ecolosion and fecundity were recorded following ingestion of maize-ears, with pupal weights 10-14 mg lower than that of controls. The growth rates of third instar larvae recorded three and six days after feeding on whorl leaves were lower, but food utilization, conversion and relative metabolism were not significantly affected. Relative food ingestion, relative growth rate and other nutritional indicators of third instar larvae were significantly lower six days after the ingestion of ears and that of fifth instar larvae after three days. In vivo activity of carboxylesterase was decreased to a greater degree after three days when the larvae were fed on whorl leaves than ears, with no significant effect on fifth instar larvae. Furthermore, in vivo activity of glutathione S-transferase (GST) of third instar larvae was significantly affected following the ingestion of whorl leaves. These results are discussed in the context of the literature on the resistance, a2_of transgenic plants and of improving the resistance of plants to attack by the different larval stages of insects., and Min Juan Shi, Pei Ling Lu, Xiao Li Shi, Yi Zhong Yang.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
35. Effect of larval crowding on the life history traits of Sesamia nonagrioides (Lepidoptera: Noctuidae)
- Creator:
- Fantinou, Argyro, Perdikis, Dionyssios C., and Stamogiannis, Nikolaos
- Type:
- article, model:article, and TEXT
- Subject:
- Lepidoptera, Noctuidae, Sesamia nonagriodes, density, competition, development, fecundity, and pink stalk borer
- Language:
- English
- Description:
- This study determined the effect of larval density-dependent competition for food on development and adult fitness in Sesamia nonagriodes Lef. (Lepidoptera: Noctuidae). Different numbers (5, 10, 15, 20 and 30 individuals) of larvae of the pink stalk borer were reared on a constant amount of food. Although crowding during the immature stages did not significantly increase mortality, it prolonged the larval developmental period and resulted in reduced pupal weight. Females were more adversely affected by high density than males, resulting in lighter females, indicating that female growth is more sensitive to density. The fecundity of the adults reared in the various larval crowding treatments was analysed. Total female fecundity was correlated negatively with increasing larval density. The effects of crowding on fecundity were not caused by the reduced pupal weight, indicating that food shortage during larval development may affect adult traits. Female longevity was negatively affected by density and positively related to pupal weight. Thus, larval density may affect the allocation of food resources and adult fitness. We conclude that crowding related changes during larval development directly affect larval life and reduce female fitness.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
36. Effect of photoperiod on the duration of summer and winter diapause in the cabbage butterfly, Pieris melete (Lepidoptera: Pieridae)
- Creator:
- Xiao, Hai-Jun, Yang, Dong, and Xue, Fang-Sen
- Type:
- article, model:article, and TEXT
- Subject:
- Lepidoptera, Pieridae, Pieris melete, photoperiod, pupal diapause, diapause termination, aestivation, and hibernation
- Language:
- English
- Description:
- Effect of photoperiod on the duration of summer and winter diapause was investigated in the cabbage butterfly, Pieris melete. By keeping naturally induced aestivating and hibernating pupae under various photoperiods, it was shown that diapause duration of aestivating pupae was significantly longer at long than at short daylengths, whereas diapause duration of hibernating pupae was significantly shorter at long than at short daylengths, suggesting both aestivating and hibernating pupae require opposite photoperiodic signals to promote diapause development. By transferring diapausing pupae, induced under various photoperiods, to 20°C with a naturally changing summer daylength, the diapause induced by short daylengths was easier to terminate than diapause induced by long daylengths. When naturally induced aestivating and hibernating pupae were kept under natural conditions, aestivating pupae had a long diapause (mean 155 days) and wide range of emergence (90 days), whereas hibernating pupae had a short diapause (mean 105 days) and a relatively synchronized emergence (lasted 30 days). Finally, the ecological significance of photoperiodic regulation of diapause duration is discussed.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
37. Effects of larval diapause and the juvenile hormone analog, fenoxycarb, on testis development and spermatogenesis in the wax moth, Galleria mellonella (Lepidoptera: Pyralidae)
- Creator:
- Bebas, Piotr, Bronisław Cymborowski, Kazek, Michalina, and Polanska, Marta Anna
- Format:
- print, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- motýli, zavíječovití, zavíječ voskový, spermatogeneze, butterflies, Pyralidae, Galleria mellonella, spermatogenesis, Lepidoptera, wax moth, juvenile hormone analogs, larval diapause, larval testes, vas deferens, 2, and 59
- Language:
- English
- Description:
- Facultative diapause in the wax moth, Galleria mellonella, occurs in the final larval instar. Application of juvenile hormone analogs (JHAs) to the larvae of this species has similar effects to diapause, in terms of prolonged development of the larval stages and the arrest in the metamorphosis of internal organs. Here, we focus on testes development and spermatogenesis at the end of larval development in G. mellonella, how they are affected by diapause induced by an environmental decrease in temperature to 18°C and the application of a JHA (fenoxycarb) to larvae. Because neither testis development nor spermatogenesis are described in detail for this species, we examined them in individuals not in diapause during the period from the last larval instar to the newly emerged adult and present a timetable of changes that occur in the development of testes in this species. These observations have increased the very limited data on the course of spermatogenesis in pyralid insects. We then used these data for comparative analysis of testes in larvae from two experimental groups: individuals in diapause and those treated with fenoxycarb. The results on the general morphology testes revealed obvious degenerative changes caused by fenoxycarb (but not by diapause), including testicular wall hypertrophy and disarrangement of testicular follicles. Moreover, treatment with fenoxycarb finally resulted in the disintegration of nearly all testicular cyst-containing germ cells at different stages of spermatogenesis, a situation never previously described in the literature. In contrast, the main effect of diapause on testes was merely the degeneration of spermatocytes in the proximal regions of the testicular follicles. Finally, the TUNEL analyses, revealed that the degenerative changes in germ cells were apoptotic in character in the testes of both individuals in diapause and fenoxycarb-treated males., Piotr Bebas, Bronislaw Cymborowski, Michalina Kazek, Marta Anna Polanska., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
38. Effects on lepidopteran herbivores of feeding on leaves of transgenic birch (Betula pendula) expressing the sugar beet chitinase IV gene
- Creator:
- Vihervuori, Liisa, Lyytikäinen-Saarenmaa, Päivi, Lu, Jinrong, and Pasonen, Hanna-Leena
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, zoologie, entomologie, Lepidoptera, Lymantriidae, Orgyia antiqua, Notodontidae, Phalera bucephala, Betula pendula, silver birch, chitinase, herbivory simulation by leaf wounding, insect herbivore, nutritional indices, transgenic tree, 2, and 59
- Language:
- English
- Description:
- Transgenic lines of silver birch (Betula pendula) carrying the sugar beet chitinase IV gene were used to study the effects of the heterologous expression of a transgenic chitinase on the performance of lepidopteran herbivores. The effect of wounding the leaves of birch on the performance of lepidopteran larvae and the growth of trees was also studied. Larvae of Orgyia antiqua L., Lymantriidae, and Phalera bucephala L., Notodontidae, were separately fed on the leaves of transgenic and wild-type birch, and their performance measured using nutritional indices. The relative growth rate (RGR) of O. antiqua larvae fed transgenic leaves was significantly lower than that of larvae fed wild-type leaves. Furthermore, there is little evidence that transgenic chitinase affects survival but it was lowest for the group of larvae fed leaves with the highest expression of chitinase IV. Wounding did not have a significant effect on the performance of the larvae or on the growth of the branches of the trees. The growth of branches of particular transgenic lines, however, was significantly associated with tree line. The performance of P. bucephala larvae fed leaves of transgenic and wild-type birches did not differ. The leaves used in both experiments from transgenic trees were shorter than those from wild-type trees. Using transgenic birch expressing sugar beet chitinase IV to improve the resistance of birch to fungal diseases can have negative effects on O. antiqua larvae feeding on the leaves of these birches. P. bucephala, however, was not similarly affected, which indicates that these two ecologically similar lepidopteran species may differ in their response to transgenic chitinase., Liisa Vihervuori ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
39. Egg distribution in the large copper butterfly Lycanea dispar batavus (Lepidoptera: Lycaenidae): Host plant versus habitat mediated effects
- Creator:
- Webb, Mark R. and Pullin, Andrew S.
- Type:
- article, model:article, and TEXT
- Subject:
- Lepidoptera, Lycaenidae, Lycaena dispar batavus, oviposition, insect-plant relationships, Rumex hydrolapathum, herbivory, consumer and host, butterfly, conservation biology, and wetlands
- Language:
- English
- Description:
- The large copper butterfly, Lycaena dispar batavus, a subspecies of much conservation interest, is host-specific to the great water dock, Rumex hydrolapathum, but little is known of the relationship between herbivore and host in wild populations. This study investigated the distribution of both R. hydrolapathum plants and L. d. batavus eggs in four different habitat types within the Weerribben National Park, The Netherlands, during the summer of 1993. As expected, host plant distribution strongly influenced that of its herbivore. Further, both species had significantly aggregated distributions, and that of R. hydrolapathum was in agreement with the negative binomial model. Host plant selection for oviposition showed no significant relationship with physical plant characteristics, such as plant height and the number of leaves, and at the scale studied, habitat type was of only limited influence. The possible influence of the vegetational architecture surrounding host plants is discussed.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
40. Endogenous 20-hydroxyecdysone levels in the haemolymph of non-diapause-destined and diapause-destined generations of tasar silkworm, Antheraea mylitta (Lepidoptera: Saturniidae) and associated developmental changes
- Creator:
- Kumar, Dinesh, Subrahmanyam, Bhattiprolu, Sharan, Shashi K., Mishra, Pradeep K., Singh, Bishwa M.K., and Suryanarayana, Nagabathula
- Type:
- article, model:article, and TEXT
- Subject:
- Lepidoptera, Saturniidae, Antheraea mylitta, tasar silkworm, pupal diapause, endocrine events, PTTH, and 20-HE titer
- Language:
- English
- Description:
- A complete profile of the 20-hydroxyecdysone (20-HE) titer, development and endocrine events from 1st instar to pupation of the larvae of non-diapause-destined (NDD) and diapause-destined (DD) tasar silkworm, Antheraea mylitta Drury (Lepidoptera: Saturniidae) was studied. Diapause is induced by short days of 11 hr photophase coupled with <= 24°C prevailing in September-November. Diapausing pupae produce adults in July (>= 12h light, >= 26°C) and one generation is completed by August. The growth rate during the course of development of larval instars decreases and instar durations are inversely related to the body weight at the time of initiation of a larval instar. A growth compensation mechanism operates during the development of the larval instars. The growth rate was higher in early instars (1st to 4th) in both generations. The DD larvae complete the final instar in 16 days followed by a spinning stage of 13 days. The NDD larvae complete the final larval instar in 9 days followed by spinning stage of 6 days and spend 14 days in the pupal stage. The signal to release the prothoracicotropic hormone (PTTH) is related to critical body weight of larvae. From 1st to 4th instar, pre-ecdysial peaks of 20-HE were recorded in both NDD and DD generations. The programme for undergoing diapause was initiated during 3rd instar and induced by a sudden decrease in the level of 20-HE in the DD generation. Two peaks of 20-HE are required for the larval-pupal transformation, first at the wandering stage and the second at cuticle formation.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public