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1. Contribution to the biochemical characterization of the silk and structure characterization of the cocoons of the horse chestnut leaf miner Cameraria ohridella (Lepidoptera: Gracillariidae)

Creator:
Hněvsová, Veronika, Dalibor Kodrík, and František Weyda
Type:
article, články, model:article, and TEXT
Subject:
Zoologie, entomologie, silk, cocoon, pupal chamber, tissue of leaf mine, Cameraria ohridella, Gracillariidae, protease inhibitor, glycoprotein, electron microscopy, 2, and 59
Language:
English
Description:
This study of the proteins in the silk of the summer and winter cocoons of the horse chestnut leaf miner Cameraria ohridella revealed they can inhibit protease activity. The inhibitory activity of the summer silk was higher against both the fungal proteinase K and bacterial subtilisin than that of the winter silk. Also, the winter silk was more effective in inhibiting proteinase K than subtilisin. Further, it was demonstrated that some of the silk proteins are glycosylated probably by mannose carbohydrates. An electron microscopy study of the cocoons revealed the presence of silk fibres with different diameters in some pupal chambers. and Veronika Hněvsová, Dalibor Kodrík, František Weyda.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

2. Investment in cocoon-silk and structure of the clusters of cocoons produced by gregarious microgastrine wasps (Hymenoptera: Braconidae)

Creator:
Tagawa, Jun and Sato, Yoshibumi
Type:
article, model:article, and TEXT
Subject:
Braconidae, Microgastrinae, Glyptapanteles liparidis, Cotesia glomerata, Cotesia kariyai, cocoon, cocoon cluster, body size, silk investment, and aggregation
Language:
English
Description:
After leaving their hosts, the larvae of endoparasitic braconid wasps pupate in cocoons. To determine their investment in cocoon silk, the dry weight of newly emerged wasps and that of the empty cocoons were measured for three gregarious braconid species of slightly different sizes: Glyptapanteles liparidis (Bouché), Cotesia glomerata (L.) and Cotesia kariyai (Watanabe) (Hymenoptera: Braconidae, Microgastrinae). These braconids form clusters of cocoons of different types. Glyptapanteles liparidis is significantly larger than either of the Cotesia species, and C. kariyai is the smallest. The ratio of the weight of cocoon silk to the total weight of cocoon silk, wasp body, cast cuticle and meconium is smaller for small species than large species. Small species economise on their use of silk by aggregating cocoons and can therefore invest a larger fraction of their resources in adult body mass. Moreover, the larvae of the smallest species, C. kariyai, additionally reduce their use of silk by constructing a communal airy silk layer beneath which the individual cocoons are formed.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

3. Pupal traits and adult emergence in the pine processionary moth Thaumetopoea pityocampa (Lepidoptera: Notodontidae) are affected by pupal density

Creator:
Bonsignore, Carmelo P., Manti, Francesco , Castiglione, Elvira , and Battisti, Andrea
Format:
počítač and online zdroj
Type:
model:article and TEXT
Subject:
Lepidoptera, Notodontidae, Thaumetopoea pityocampa, cocoon, gregariousness, pupal density, pupal size, emergence, and Pinus
Language:
English
Description:
The expectation is that the phenology of an herbivore is influenced by abiotic factors and its own population density during development. In this study, we investigated how the pupal density affected the pupal traits and emergence of Thaumetopoea pityocampa moths over a period of 3 years in two clearings in a pine forest. The pupae were larger in years when the pupal density was high and in the clearing exposed to less solar radiation. There was no relationship between the time of pupation and pupal size. Large pupae were positively correlated with an early emergence of adult moths and a longer period of adult emergence. Up to 13.9% of the pupae developed without cocoons, especially in years when they were abundant, but this did not affect the emergence of the moths. Incidence of pupal diapause was density-dependent and only occurred at a low level in dense populations. Overall, our results indicate that gregariousness confers important fitness-related advantages in this species.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

4. White plant shoots, wax-producing insects and other white structures made by arthropods: a mimicry complex?

Creator:
Yamazaki, Kazuo
Format:
print, počítač, and online zdroj
Type:
article, články, journal articles, model:article, and TEXT
Subject:
Zoologie, vosky, pavouci, waxes, spiders, plant mimicry, anti-herbivore defence, cocoon, entomopathogenic fungus, spider egg sac, spittlebug froth, trichome, 2, and 59
Language:
English
Description:
Many insects masquerade as parts of plants, such as bark or leaves, or mimic poisonous organisms in order to defend themselves against predators. However, recent studies indicate that plants may mimic insects and other arthropods to deter herbivores. Here, I report visually similar white structures of plants and arthropods in Japan and suggest they are part of a mimicry complex. Young shoots covered with white trichomes or waxy substances may mimic wax-producing insects, such as woolly aphids, coccids and caterpillars, potentially resulting in reduced herbivory. Since wax-producing insects would reduce plant quality and quantity, be distasteful and attract natural enemies, herbivorous insects and mammals may avoid such white shoots. Furthermore, fungus-infected insects, gregarious braconid cocoons, spider egg sacs and froth made by froghopper nymphs or blasticotomid sawfly larvae are also conspicuously white and impose risks for herbivorous insects. Thus, these white structures may be mimicry models for white shoots and are likely to be part of a defensive mimicry complex. Although this study focuses on defence against herbivores, there are simultaneous physiological roles for white colouration that will not be discussed in depth here., Kazuo Yamazaki., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public