Migrations of dragonflies (Odonata) in the south of the West Siberian plain

The paper presents a summary of mass dragonfly migrations observed previously in Russia, in particular in West Siberia. From 1969 to 2009, the authors studied the dynamics of dragonfly population, their spatial distribution and movements in the West Siberian forest-steppe. The main studies were conducted in the Lake Chany basin (the Biological Station of the Institute of Animal Systematics and Ecology, Siberian Division, Russian Academy of Sciences). The spatial redistribution of dragonflies is regarded as a balance of homing and wandering behavior. Homing results in a relative stability of local dragonfly populations and assemblages, while wandering leads to dispersal of dragonflies from their emergence sites and colonization of new habitats; the latter is especially important due to the ephemeral nature of many shallow reservoirs where the nymphs develop. The formation of more or less constant migration routes is a peculiar variant of wandering activities. A special type of dragonfly migrations is mass exodus from native habitats, triggered by excessive population growth and leading to elimination of all or most individuals. Such migrations not only optimize the size of dragonfly populations but also facilitate removal of nutrients and organic matter from eutrophic water bodies. An original generalized classification of dragonfly migrations is proposed.     

Mind wandering in chinese daily lives - an experience sampling study

MIND WANDERING HAS RECENTLY RECEIVED EXTENSIVE RESEARCH BECAUSE IT REVEALS AN IMPORTANT CHARACTERISTIC OF OUR CONSCIOUSNESS: conscious experience can arise internally and involuntarily. As the first attempt to examine mind wandering in a non-western population, the present study used experience-sampling method to collect the daily momentary mind wandering episodes in a Chinese sample. The results showed that mind wandering was also a ubiquitous experience among the Chinese population, and, instead of emerging out of nowhere, it was often elicited by external or internal cues. Furthermore, most of the mind wandering episodes involved prospective thinking and were closely related to one's personal life. Finally, the frequency of mind wandering was influenced by some contextual factors. These results taken together suggest that mind wandering plays an important role in helping people to maintain a continuous feeling of "self" and to prepare them to cope with the upcoming events.     

Courtship Activity of Wandering and Burrow-holding Male Uca arcuata

The male of Uca (Deltuca) arcuata, a vertical claw-waving fiddler in the Indo-Pacific, is used to court females by approaching them from his burrow or while wandering. Differences in the rate of encounters with females between burrow-holding males and burrowless wandering males are found not to be significant. Burrow-holding males less often cause displacement of wandering by females than wandering males do. Wandering of females caused by wandering males occurs as often as wandering of males caused by other males. Thus, burrow-holding males tend not to reduce the number of their potential mates in the neighborhood. Burrow dwelling males are apt to start wandering after decreased encounters with females. Wandering males experience more interactions with other males than burrow-holding males do. Most wandering males that displace burrow owners descend the burrows one or more times after displacing the owners. The extra fighting for temporary burrows is responsible for no increase of the encounter rate with females during wandering.     

Dissociation of subjectively reported and behaviorally indexed mind wandering by EEG rhythmic activity

Inattention to current activity is ubiquitous in everyday situations. Mind wandering is an example of such a state, and its related brain areas have been examined in the literature. However, there is no clear evidence regarding neural rhythmic activities linked to mind wandering. Using a vigilance task with thought sampling and electroencephalography recording, the current study simultaneously examined neural oscillatory activities related to subjectively reported and behaviorally indexed mind wandering. By implementing time-frequency analysis, we found that subjectively reported mind wandering, relative to behaviorally indexed, showed increased gamma band activity at bilateral frontal-central areas. By means of beamformer source imaging, we found subjectively reported mind wandering within the gamma band to be characterized by increased activation in bilateral frontal cortices, supplemental motor area, paracentral cortex and right inferior temporal cortex in comparison to behaviorally indexed mind wandering. These findings dissociate subjectively reported and behaviorally indexed mind wandering and suggest that a higher degree of executive control processes are engaged in subjectively reported mind wandering.     

Differences in venom composition between orb-weaving and wandering Hawaiian Tetragnatha (Araneae)

Spider venoms are complex mixtures of toxins that are used primarily for immobilizing prey. There is evidence of chemical variation in spider venoms among close relatives, yet few studies have analysed their evolution within an ecological and phylogenetic framework. On the Hawaiian archipelago, Tetragnatha, a cosmopolitan orb-weaving genus, has undergone a radiation in which a monophyletic lineage has abandoned web-building and become obligately wandering foragers. This study compares venom composition and details of feeding behaviour between orb-weaving and wandering Hawaiian Tetragnatha. Protein gel electrophoresis patterns indicated that relative to orb-weavers, wandering species had a reduced concentration of low molecular weight (<14kDa) components. Both orb-weaving and wandering Tetragnatha captured flying prey (adult lepidopterans, dipterans), but wandering spiders also captured non-flying prey (insect larvae, spiders). There were no distinct differences between orb-weavers and wanderers in prey capture and immobilization sequences, or in the paralytic effects of bites on prey. However, prey bitten by wanderers took longer to be permanently immobilized than prey bitten by orb-weavers. Contrary to predictions, there was no indication that web-loss in this group was associated with an increase in venom potency.     

Origin, age, sex and breeding status of wandering albatrosses (Diomedea exulans), northern (Macronectes halli) and southern giant petrels (Macronectes giganteus) attending demersal longliners in Falkland Islands and Scotia Ridge waters, 2001–2005

A total of 547 sightings of 291 banded wandering albatrosses Diomedea exulans and 21 sightings of 14 banded giant petrels Macronectes spp. were made from toothfish longliners operating on the southern Patagonian Shelf during 2001–2005. This included 25% of the wandering albatrosses with Darvic bands that bred at Bird Island (South Georgia) during this period. Thirteen of the northern Macronectes halli and southern giant petrels Macronectes giganteus had been banded at South Georgia, and there was one sighting of a southern giant petrel from Argentina. Male and female wandering albatrosses of all age classes except young birds (<15 years old) were equally likely to attend longline vessels. Most sightings of all age classes were made during the incubation period and fewest during the brood period. Eighty-six percent of birds sighted had bred at least once before, with half currently breeding and half on sabbatical (i.e. between breeding attempts). Almost half of the wandering albatrosses were sighted on more than one occasion. The data confirms that the southern Patagonian shelf is an important foraging area for wandering albatrosses and northern and southern giant petrels, and that some individuals show consistent associations in multiple years with longline vessels fishing in the region.     

Upregulation of the immune protein gene hemolin in the epidermis during the wandering larval stage of the Indian meal moth, Plodia interpunctella

Expression of hemolin, which generates an immune protein, was up-regulated in wandering fifth instar larval stage of Plodia interpunctella. The mRNA level peaked in the middle of the wandering stage. Major expression was in the epidermis, rather than in the fat body or gut. To test a possible ecdysteroid effect on hemolin induction we treated with RH-5992, an ecdysteroid agonist, and KK-42, which inhibits ecdysteroid biosynthesis in both feeding and wandering fifth instar larvae. When feeding larvae were treated with RH-5992 the hemolin mRNA level was increased. When wandering larvae were treated with KK-42 its level was reduced. In addition, when KK-42-treated larvae were subsequently treated with RH-5992 the hemolin mRNA level was recovered. These results strongly suggest that ecdysteroid up-regulates the expression of hemolin mRNA. Hormonal and bacterial effects on hemolin induction were further analyzed at the tissue level. Major induction of hemolin mRNA was detected following both RH-5992 treatment and bacterial injection in the epidermis of both feeding and wandering larvae. Minor induction of hemolin was detected in the fat body following a bacterial injection, but not RH-5992 treatment. We infer that in P. interpunctella larvae, the epidermis is the major tissue for hemolin induction in na?ve insects and in insects manipulated with bacterial and hormonal treatments.     

Changes in the chemical composition of fat body during the last larval instar of Manduca sexta.

The fat body increases in weight throughout the last larval instar in spite of the loss in total body weight during the wandering and prepupal stages. The protein content of fat body increases dramatically and is greatly responsible for the increase in fat body weight in the wandering and prepupal stages. Lipids do not contribute significantly to the fat body weight gain except during the feeding stage. The amount of total fat body RNA increases until wandering then drops abruptly in the prepupal stage. The total amount of fat body DNA peaks before the onset of wandering and prepupal stages.     

Alternative male reproductive tactics in a natural population of prairie voles <Emphasis Type="Italic">Microtus ochrogaster</Emphasis>

Alternative reproductive tactics have been described in male mammals, but little information exists regarding fitness benefits and whether males change tactics. Adult male prairie voles Microtus ochrogaster (Wagner, 1842) display alternative tactics described as resident and wanderer. Enclosure studies provide conflicting data concerning the relative success of each tactic and whether males display one tactic throughout adulthood. To characterize further residents and wanderers in this species, we examined data collected during 5 years of monitoring a natural population in Illinois, USA. We found that during the breeding period, wandering males survived longer, moved longer distances, and were more likely than residents to have scrotal testes. During the nonbreeding period, wandering and resident males differed only in whether or not they established residency. Data on sources and fates of resident and wandering males revealed that a substantial proportion of males switched tactics. Our estimate of the reproductive contribution of wandering males to the population, which is based on the premise that wandering males typically mate with single females, suggests that wanderers contribute 34–38% of young recruited during March through October and 4–12% in November, when single females are less common. Parentage studies in natural populations are necessary to test our estimates.     

Effect of an ecdysone agonist,RH-5849, on wandering behaviour in Spodoptera littoralis

1. Wandering behaviour of the fall armyworm, Spodoptera littoralis has been examined using a video-digitizing computer system. 2. Ecdysteroid titers prior to and during wandering have been determined using an enzyme immunoassay. 3. RH 5849, an agonist of 20-hydroxyecdysone (20E) applied at various times before wandering to last instar larvae of S. littoralis caused a delay in the onset of wandering, varying from 0.5 to 4.5 hr. This delay was dose dependent. 4. We suggest that wandering in S. littoralis may be induced by a decrease in ecdysteroid titers.     

应用RAPD技术对蜘蛛系统演化的初步研究

利用随机扩增多态ＤＮＡ 技术检测了３ 类不同蜘蛛的系统发生关系．用１２ 个随机引物对各实验蜘蛛的基因组ＤＮＡ 进行扩增,选择其中扩增谱带清晰的８ 个引物进行分析并计算不同类蜘蛛间的遗传距离．结果表明：所有８ 个引物获得的ＲＡＰＤ谱带均表现为不同程度的多态性;地穴型蜘蛛与结网型蜘蛛间的遗传距离及结网型与游猎型之间的遗传距离,均比地穴型与游猎型之间的遗传距离近,体现了蜘蛛由地穴→结网→游猎的系统演化进程．这一结论与根据古生物学、胚胎学、形态学及生态学等得出的结论一致,从而进一步从ＤＮＡ 分子水平上为蜘蛛系统演化提供了新的证据．     

Extrapair paternities in black-browed Thalassarche melanophris, grey-headed T. chrysostoma and wandering albatrosses Diomedea exulans at South Georgia

Extrapair paternities (EPP) are relatively common in passerines, but rare in seabirds. Like most seabirds, albatrosses are long lived, form long-term pair bonds and require biparental care for chick-rearing. Microsatellite analyses of 327 chicks from black-browed Thalassarche melanophris , grey-headed T. chrysostoma and wandering albatrosses Diomedea exulans over two breeding seasons revealed the presence of EPP in all three species. Though EPP rates varied between species and years, up to 21% of offspring were the result of extrapair matings. Rates were highest in wandering albatrosses (6–21%) followed by grey-headed (3–10%) and black-browed (0–9%) albatrosses. EPP rates were lower in 1998 compared to 1999 in both black-browed and grey-headed albatrosses, whereas the reverse was true for wandering albatrosses. Interspecific differences in EPP rates may reflect differences in breeding phenology and sexual size dimorphism. Differences in timing and frequency of breeding may promote different opportunities for interactions with birds other than their normal partner. The different breeding habitat, dispersion and mate-attraction rituals in wandering albatross, together with the disparity in size between the sexes may also offer more scope for higher rates of EPP. Despite extensive sampling within each colony, we were unable to identify sires for many of the extrapair young; however males from other colonies were involved, raising interesting questions regarding the timing and nature of such events.     

Memory for Lectures: How Lecture Format Impacts the Learning Experience

The present study investigated what impact the presentation style of a classroom lecture has on memory, mind wandering, and the subjective factors of interest and motivation. We examined if having a professor lecturing live versus on video alters the learning experience of the students in the classroom. During the lectures, students were asked to report mind wandering and later complete a memory test. The lecture format was manipulated such that all the students received two lectures, one live and one a pre-recorded video. Results indicate that lecture format affected memory performance but not mind wandering, with enhanced memory in the live lectures. Additionally, students reported greater interest and motivation in the live lectures. Given that a single change to the classroom environment, professor presence, impacted memory performance, as well as motivation and interest, the present results have several key implications for technology-based integrations into higher education classrooms.     

Status and distribution of wandering, black-browed and grey-headed albatrosses breeding at South Georgia

Long-term studies at Bird Island, South Georgia, show that numbers of wandering, black-browed and grey-headed albatrosses have been decreasing since the late 1970s. To determine the status of the total South Georgia population, all known colonies were censused in 2003/2004 using a combination of yacht-based digital photography and ground counts. The breeding population estimates from this census are 1,553 pairs of wandering albatross, 74,296 pairs of black-browed albatross and 47,674 pairs of grey-headed albatross. A 30% decline since 1984 was recorded for wandering albatross, and comparison of a sample of black-browed and grey-headed albatross colonies on the mainland of South Georgia photo-censused in both 1985/1986 and 2003/2004 indicates similarly substantial population declines. Unless these decreases can be halted or reversed, doubt will exist as to the long-term viability of these species of albatross at South Georgia.     

Host plant exodus and larval wandering behaviour in a butterfly: diapause generation larvae wander for longer periods than do non‐diapause generation larvae

1. Prior to pupation, lepidopteran larvae enter a wandering phase lasting up to 30 h before choosing a pupation site. Because stillness is important for concealment, this behaviour calls for an adaptive explanation. 2. The explanation most likely relates to the need to find a suitable pupation substrate, especially in terms of shelter from predation, and given that many predators and parasitoids use host plants as prey‐location cues, mortality probably decreases with distance from the host plant. Hence, remaining on the host includes a long‐term risk, while moving away from the host introduces an increased risk during locomotion. 3. Bivoltine species that overwinter in the pupal stage produce two kinds of pupae; non‐diapausing pupae from which adults emerge after 1–2 weeks, or diapausing pupae that overwinter with adults emerging after 8–10 months. 4. Given the hypothesis of distance‐from‐host‐plant‐related predation, this should select for phenotypic plasticity with larvae in the diapausing generation having a longer wandering phase than larvae under direct development, if there is a trade‐off between mortality during the wandering phase and accumulated mortality during winter. 5. Here this prediction is tested by studying the duration of the wandering period in larvae of the partially bivoltine swallowtail butterfly, Papilio machaon, under both developmental pathways. 6. The results are in agreement with the predictions and show that the larval wandering phase is approximately twice as long under diapause development. The authors suggest that the longer duration of the wandering phase in the diapause generation is a general phenomenon in Lepidoptera.     

Influence of environmental factors on the wandering phase and pupariation in stable fly, Stomoxys calcitrans, larvae

Abstract. Components of the wandering phase of mature stable fly ( Stomoxys calcitrans L. (Diptera: Muscidae)) larvae were examined. The mean length of the wandering phase was estimated to be 10.6 ± 3.5 h. In a factorial experiment in which wandering larvae were allowed to pupate in media with three levels each of moisture, temperature and light, the mean time to 50% pupariation was delayed and the rate of pupariation was lowest at high moisture levels, but this latter effect was seen only at the moderate light level. Pupae in media with higher moisture contents had significantly higher fresh weights. However, none of the three factors affected dry weight of pupae. A significant interaction was observed between the effects of moisture and temperature on survival; only at highest moisture content and at the highest temperature did a significant decrease in survival occur. In a separate experiment, density was found to have no effect on mean time to 50% pupariation or the rate of pupariation. Puparium formation appeared to be random under a LD 169 h photocycle, showing no apparent circadian rhythm.     

Annual energy budget and food requirements of breeding wandering albatrosses (<Emphasis Type="Italic">Diomedea exulans</Emphasis>)

Energy budgets form an integral part of our understanding of animal energetics, particularly when presented in the context of reproduction. In this paper, I created a time-energy budget for a breeding pair of wandering albatrosses (Diomedea exulans) to estimate the annual breeding costs and food requirements of the population at Possession Island, Crozet Archipelago. For a breeding cycle that lasts 356 days on average, a pair uses 2,733 MJ to raise a single chick to fledging. This estimate is 1.21 times higher than previously calculated for wandering albatrosses breeding at Marion Island. Unlike the current analysis, the previous study assumed that foraging costs were constant across all stages of the breeding cycle. Recent evidence shows that foraging costs vary during breeding for wandering albatrosses at Crozet and this is probably true for all populations. Incubation costs have also been shown to be substantially lower than previously determined. Therefore, if a wandering albatross pair at Crozet uses a total of 2,733 MJ to breed, they would need to consume at least 1.7 kg bird^–1 day^–1 of fresh food, on average, to balance their own energy requirements and to provision a single chick for approximately 278 days. At this rate of food consumption, the breeding population at Crozet would consume approximately 340 tonnes of fresh food per breeding season.     

Identification of a gene, Desiccate, contributing to desiccation resistance in Drosophila melanogaster

Suitable alterations in gene expression are believed to allow animals to survive drastic changes in environmental conditions. Drosophila melanogaster larvae cease eating and exit moist food to search for dry pupation sites after the foraging stage in what is known as the wandering stage. Although the behavioral change from foraging to wandering causes desiccation stress, the mechanism by which Drosophila larvae protect themselves from desiccation remains obscure. Here, we identified a gene, CG14686 (designated as Desiccate (Desi)), whose expression was elevated during the wandering stage. The Desi expression level was reversibly decreased by transferring wandering larvae to wet conditions and increased again by transferring them to dry conditions. Elevation of Desi expression was also observed in foraging larvae when they were placed in dry conditions. Desi encoded a 261-amino acid single-pass transmembrane protein with notable motifs, such as SH2 and PDZ domain-binding motifs and a cAMP-dependent protein kinase phosphorylation motif, in the cytoplasmic region, and its expression was observed mainly in the epidermal cells of the larval integuments. Overexpression of Desi slightly increased the larval resistance to desiccation stress during the second instar. Furthermore, Desi RNAi larvae lost more weight under dry conditions, and subsequently, their mortalities significantly increased compared with control larvae. Under dry conditions, consumption of carbohydrate was much higher in Desi RNAi larvae than control larvae. Based on these results, it is reasonable to conclude that Desi contributes to the resistance of Drosophila larvae to desiccation stress.     

Symbiont acquisition alters behaviour of stinkbug nymphs

In parasitic associations, the evolutionary interest of a symbiont contradicts that of a host, which sometimes causes the phenomena so-called 'parasite manipulation' wherein symbiont infection alters host behaviour to facilitate its vertical/horizontal transmission. In mutualistic associations, meanwhile, symbiont-induced alteration of host behaviour that enhances its transmission has been little described. Here we report such a case in the stinkbug Megacopta punctatissima associated with an obligate gut bacterium. When female stinkbugs lay eggs, small particles called 'symbiont capsules' are deposited underside of the egg mass. Newborn nymphs immediately acquire the symbiont from the capsule, and then aggregate and become quiescent. By manipulating the levels of symbiont supply to newborn nymphs experimentally, we demonstrated that (i) experimental depletion of the symbiont resulted in the occurrence of wandering nymphs, (ii) the less symbiont supply, the more wandering nymphs, and (iii) almost all wandering nymphs were either symbiont-free or symbiont-depleted, whereas the majority of resting nymphs were infected with sufficient titres of the symbiont. These results strongly suggest that the nymphal behaviour is strongly influenced by the success/failure of the symbiont acquisition, thereby ensuring transmission of the essential symbiont and minimizing the energy and time spent for the activity.