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33. Behavioural and toxicological responses of Blattella germanica (Dictyoptera: Blattellidae) to monoterpenes

Creator:
Alzogaray, Raúl A., Sfara, Valeria, Moretti, Ariadna N., and Zerba, Eduardo N.
Type:
article, články, model:article, and TEXT
Subject:
Zoologie, zoologie, entomologie, Dictyoptera, Blattellidae, Blattella germanica, German cockroach, locomotor activity, monoterpenes, repellency, knock-down, 2, and 59
Language:
English
Description:
1_Certain monoterpenes produced by aromatic plants are known to have lethal and sublethal effects on insects. As there is a need to replace conventional pesticides (organophosphates, carbamates, pyrethroids) with biorational pesticides, we evaluated the behavioural and toxicological responses of the German cockroach, Blattella germanica, exposed to the following monoterpenes, namely (+)-a-pinene, (–)-a-pinene, limonene, menthone, linalool, menthyl acetate and geraniol. Locomotor activity and repellency were quantified using a video tracking system. To study the effect on locomotor activity, larvae were exposed to filter papers treated with concentrations of monoterpenes ranging between 1.4 and 1,400 µg/cm2. Only menthyl acetate applied at a concentration of 14 µg/cm2 or higher increased the locomotor activity of the larvae. Repellency was evaluated by exposing larvae to circles of filter paper divided in two equal zones: one zone was treated with a solution of a monoterpene in acetone (14 or 140 µg/cm2) and the other with only acetone. Larvae were repelled by all the monoterpenes tested. The two concentrations of geraniol and the highest concentration of menthyl acetate and linalool were as repellent as DEET (positive control). The fumigant effect was evaluated by exposing larvae to vapour from 100 µl of pure monoterpene in a sealed container., 2_The values of the 50% Knock-down Times (KT50), expressed in minutes, were: (+)-a-pinene: 11.8, (–)-a-pinene: 14.6, limonene: 81.0, menthone: 141.0, and linalool: 238.6. (+)-a-Pinene was as good a fumigant as dichlorvos (positive control, KT50 = 9.7 min). The least effective compounds were menthyl acetate and geraniol (both affected less than 50% of larvae after 490 min of exposure). In conclusion, (+)-a-pinene (for its fumigant effect), menthyl acetate (for its hyperactivant effect) and menthone and geraniol (for their repellent properties) could potentially be used for controlling B. germanica., Raúl A. Alzogaray ... [et al.]., and Obsahuje seznam literatury
Rights:
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34. 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:
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35. Bioinformatics analysis on structural features of microRNA precursors in insects

Creator:
Li, Jisheng, Fan, Wei, You, Zhengying, and Zhong, Boxiong
Type:
article, články, model:article, and TEXT
Subject:
Zoologie, zoologie, entomologie, structural features, bioinformatics, insects, microRNA precursors, 2, and 59
Language:
English
Description:
To date, thousands of microRNAs (miRNAs) and their precursors (pre-miRNAs) have been identified in insects and their nucleotide sequences deposited in the miRBase database. In the present work, we have systematically analyzed, utilizing bioinformatics tools, the featural differences between human and insect pre-miRNAs, as well as differences across 24 insect species. Results showed that the nucleotide composition, sequence length, nucleotides preference and secondary structure features between human and insects were different. Subsequently, with the aid of three available SVM-based prediction programs, pre-miRNA sequences were evaluated and given corresponding scores. Thus it was found that of 2633 sequences from the 24 chosen insect species, 2229 (84.7%) were successfully recognized by the Mirident classifier, higher than Triplet-SVM (72.5%) and PMirP (72.6%). In contrast, four species, including the domesticated silkworm, Bombyx mori L., the fruit fly, Drosophila melanogaster Meigen, the honeybee, Apis mellifera L. and the red flour beetle, Tribolium castaneum (Herbst), were found to be largely responsible for the poor performance of some sequence matching. Compared with other species, B. mori especially showed the worst performance with the lowest average MFE index (0.73). Collectively these results pave the way for understanding specificity and diversity of miRNA precursors in insects, and lay the foundation for the further development of more suitable algorisms for insects., Li, Jisheng ... [et al.]., and Obsahuje seznam literatury
Rights:
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36. Biological and distributional overview of the genus Eledonoprius (Coleoptera: Tenebrionidae): rare fungus-feeding beetles of European old-growth forests

Creator:
Carpani, Alberto, Chiari, Stefano, Audisio, Paolo A., Leo, Piero, Liberto, Andrea, Jansson, Nicklas, and Zauli, Agnese
Type:
article, články, model:article, and TEXT
Subject:
Zoologie, zoologie, entomologie, Tenebrionidae, Eledonoprius, saproxylic fauna, mycophagy, bracket fungi, forest ecosystems, old trees, cork oaks, 2, and 59
Language:
English
Description:
All the information on the genus Eledonoprius was gathered to provide an up to-date overview of the geographical distribution and ecology of its species, and to assess their association with old-growth forests. Based on recent samples collected in deciduous forests and woodlands of Italy, the authors outline the habitats of these rare species and give an account of their trophic relations with bracket fungi. E. armatus is recorded in Central Italy and Sardinia for the first time; E. serrifrons is new to Basilicata (Southern Italy) and Syria., Giuseppe M. Carpaneto ... [et al.]., and Obsahuje seznam literatury
Rights:
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38. Bumblebee (Hymenoptera: Apidae) sample storage for a posteriori molecular studies: interactions between sample storage and DNA-extraction techniques

Creator:
Moreira, António S., Horgan, Finbarr G., Murray, Tomás E., and Kakouli-Duarte, Thomas
Type:
article, články, model:article, and TEXT
Subject:
Zoologie, zoologie, entomologie, Hymenoptera, Apidae, Bombus terrestris, acetone, commercial kit, DNA quality, entomological pins, freezing, phenol-extraction, 2, and 59
Language:
English
Description:
A global decline in pollinator abundance and diversity has demanded increased research attention to the ecology and genetics of bumblebees. However, as progressively more restrictions are placed on sampling for insects, researchers are increasingly obliged to use archival specimens collected for purposes other than genetic analyses. In this study we assessed the suitability, for population genetic studies, of popular, low-cost methods for preservation and storage of bumblebee specimens. Specimens of Bombus terrestris L. were held under six storage regimes for up to two years. DNA was extracted from the samples using three extraction protocols and the quality of the DNA was examined using PCR amplification of a mitochondrial and a nuclear gene. All extraction and storage methods provided sufficient DNA for successful PCR amplification. However, samples preserved in acetone or at freezing temperatures yielded the highest DNA concentrations. DNA yields from pinned specimens at room temperature declined over time, particularly when using standard extraction techniques. DNA concentrations were significantly lower from specimens preserved in 70% ethanol compared to all other extraction techniques and declined linearly over the two years of storage. These results indicate that two of the most popular insect storage methods (pinning and storage in ethanol) should be avoided for the long-term preservation of genetic material for future studies. We suggest that optimal insect preservation methods should be incorporated into research protocols in order to best capitalise on limited collection opportunities., António S. Moreira ... []., and Obsahuje seznam literatury
Rights:
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40. Changes in the calling behaviour of female Spodoptera littoralis (Lepidoptera: Noctuidae) as a function of body weight and adult feeding

Creator:
Sadek, Medhat M.
Type:
article, články, model:article, and TEXT
Subject:
Zoologie, zoologie, entomologie, Lepidoptera, Noctuidae, Spodoptera littoralis, body weight, calling behaviour, adult food, 2, and 59
Language:
English
Description:
Because nutrients accrued during larval stages represent the major limiting factor for egg production, the use of adult feeding to enhance the reproductive output in moths is considered to be largely weight-dependent. It is hypothesized, however, that feeding by adults could be adaptive and an effective means of increasing their reproductive success. In order to test this, the calling behaviour of Spodoptera littoralis females that differed in body weight and whether they had fed or not were recorded. Two experiments were carried out. In the first, the calling behaviour of food-deprived females of different body weights was recorded. A strong positive correlation was found between body weight at emergence and the total duration of calling of females on the second to the fifth night after emergence. In the second experiment, groups of female moths that varied in body weight were given access to water or sucrose. Feeding on sucrose significantly reduced the pre-calling period and increased the total time spent calling on the six nights after emergence. The increase in time spent calling associated with ingesting sucrose were proportionately similar for both small and large females, implying that feeding by adults can result in an increase in the time spent calling by moths irrespective of larval nutritional status. Female longevity was also correlated with moth weight at emergence and/or sucrose availability. It is concluded that it is advantageous for female S. littoralis to be large and/or have access to sucrose-rich food in the adult stage as they can spend more time attracting a mate, which increases their chances of mating in early adult life, and their longer adult life may indirectly result in an increase in fecundity., Medhat M. Sadek., and Obsahuje seznam literatury
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public