bluuebunny/crossref_metadata_2025_split huggingface dataset:
Why is one of the periodical cicadas (Magicicada septendecula) a comparatively rare species?
Authors: LLOYD MONTE , WHITE Jo ANN 
Published: March 2008

ABSTRACT.

The same woodland rarely supports two different broods of 17‐year cicadas, and never two that appear in successive years. Theoretically, this is because a build‐up of predators, generated by the leading brood, would eliminate the lagging one, or because nymphs of the lagging brood would suffer a competitive disadvantage, or both.
Nevertheless, substantial numbers of 17‐year cicadas of all three species (Magicicada septendecim, M.cassini and M.septendecula) did appear in Grant County, Kentucky, in 1974 (Brood XIV, expected) and 1975 (not expected). This is interpreted to mean that many individuals delayed their emergence until the eighteenth year.
Dissected eggnests show that the expected build‐up of hymenopterous egg parasitoids failed to occur, although there may have been a build‐up of dipteran parasitoids, which may leave no trace in the eggnest.
Excavated young nymphs show that establishment rate was poorer in 1975 than in 1974, which is attributed to nymphal competition.
Identification of eggnests from the two years shows that one of the species (M.septendecula, which is usually the rarest in mixed‐species populations) is much more susceptible to delaying its development by a year than are the other two species.
It is predicted that the 1975 emergence will produce no adult progeny, i.e. that there will be no emergence in 1992.
The sporadic occurrence of this phenomenon, other factors being equal, would be sufficient to explain the comparative rarity of M. septendecula, or even its local extinction.
Historical records from northern Illinois show frequent emergences one year behind schedule. These delayed individuals never produce progeny that survive to the next generation. M.septendecula is absent from northern Illinois and indeed absent from the northern areas of all periodical cicada broods in the northern part of the range.
The biogeography of herbivorous arthropods: species accrual on tropical crops
Authors: McCOY EARL D. , REY JORGE R. 
Published: March 2008

ABSTRACT.

The size of range of host plants and animals has been shown repeatedly to be the best single correlate of number of associated parasite species. For a single species of host distributed over many regions, there should exist two important additional correlates: the sizes of source pools of potential colonists within regions and the distribution of the host's close relatives among regions.
Certain tropical crops are useful in examining these ideas because they are widely‐cultivated and the relevant data are available. A comparison of the data for the herbivorous arthropods of cacao, citrus, coconuts, coffee, cotton, rice and sugar cane shows that regions in Amazonia, Southern Asia/Australia and sub‐Saharan Africa consistently fall above species‐area regression lines, whereas regions in North and South America (except Amazonia), Western Asia and Europe tend to fall below them.
The pattern implicates the importance of source pool size of potential colonists and taxonomic isolation of the host in influencing arthropod accrual.
Cultivation methods, sampling effects and latitude conceivably could also influence accrual, but their importance is questionable for the seven crop/parasite systems examined.
Flight duration of the brown planthopper, Nilaparvata lugens (Homoptera: Delphacidae)
Authors: ROSENBERG L. J. , MAGOR J. I. 
Published: March 2008

ABSTRACT.

The brown planthopper, Nilaparvata lugens (Stål), is a major pest of rice in Asia. It is known to make wind‐assisted migratory flights each year to colonize the summer rice growing areas of China, Japan and Korea.
Modelling windborne displacements between rice growing areas in Asia requires migratory behaviour and flight duration to be established for this insect.
Field and laboratory observations suggest that N. lugens take‐off at dusk and that some continue flying for up to 24–26 h if the temperature is ≥ 17°C.
Trajectories for 10 m above ground level and 1.5 km above mean sea level are used to identify possible sources and, hence, to estimate the flight times of N.lugens caught in nets on ships on the East China Sea in 1973 and 1981.
Estimated flight times between the sources and the ships ranged from about 9 to 30 h.
Results suggest that long‐distance migration can occur in surface winds, when they are strong, but that long‐distance migration is more likely at 1.5 km.
When simulating windborne displacements of N.lugens, it can be assumed that in areas and at heights where the temperature is ≥ 17°C, some migrants will fly downwind for up to 30 h after a dusk take‐off. Others will fly for shorter periods, giving the population as a whole the opportunity to colonize all the rice crops flown over.
Intraspecific variation in beech scale populations and in susceptibility of their host Fagus sylvatica
Authors: WAINHOUSE D. , HOWELL R. S. 
Published: March 2008

ABSTRACT.

Within a seed orchard in southern England, beech trees (Fagus sylvatica L.) belonging to three clones were artificially infested by introducing beech scale larvae (Cryptococcus fagisuga Lind. Homoptera: Coccidae) into small cages attached to the bark.
Some larvae developed to fecund adults on trees of two susceptible clones but all failed to develop on a third, resistant clone.
Within susceptible clones, survival of larvae on individual trees was positively related to their degree of natural infestation.
Larvae deriving from several separate trees differed significantly in their ability to survive when inoculated onto trees of susceptible clones.
Five forest trees which acted as both donors of larvae and as hosts for artificial inoculation were each inoculated with larvae from all five trees.
There was significant variation in survival of inoculated larvae both between the host trees and between sources of larvae on each host.
Survival of larvae reinoculated onto their original host was significantly higher than that of larvae originating from other trees.
Fecundity of adults on the forest trees was positively correlated with the probability of inoculated larvae surviving to the adult stage.
A comparative analysis of Chrysoperla carnea catches in light‐ and suction‐traps
Authors: PERRY J. N. , BOWDEN J. 
Published: March 2008

ABSTRACT.

The lacewing C.carnea was caught weekly at Rothamsted in six traps, in 1973 and between 1975 and 1980. The traps were in three pairs: two light‐traps in woodland, two light‐traps in open fields, and two suction‐traps, sampling at 12 m and 1.2 m above the ground.
Standardized trap phenologies were compared seasonally, for each year, using multivariate methods. Trap environments caused the greatest phenological difference, which was between the woodland and the other traps. The suctiontraps and the light‐traps in open fields also differed. The greatest similarity was between the woodland light‐traps, the next between the suction‐traps, but the two light‐traps in open fields were relatively dissimilar.
These results were supported by analysis of the sex‐ratio of catches in each trap. We suggest an overall phenology in which the wood is important as an overwintering site for adults in autumn and as a source in spring.
Assessment of consistency over years showed no year was typical, but 1979 was markedly dissimilar from other years; 1976 was particularly similar to 1975.
The use of generalized Procrustes analysis (Gower, 1975) is recommended for similar sets of ecological data.
Observations of the flight behaviour of the army worm moth, Spodoptera exempta, at an emergence site using radar and infra‐red optical techniques
Authors: RILEY J. R. , REYNOLDS D. R. , FARMERY M. J. 
Published: March 2008

ABSTRACT.

Studies were made in Kenya of the flight behaviour of African armyworm moths which had emerged from areas previously infested with‘gregarious’caterpillars. The use of radar and an infra‐red optical detector permitted quantitative, direct observations of the flying moths, over all of their flight altitudes, without disturbing their behaviour.
Almost all of the successfully emergent moths climbed to altitudes of several hundred metres above ground level and migrated from the emergence sites. Their migratory flights sometimes started on the night of emergence, but on other occasions the moths remained roosting in trees until dawn, then engaged in short dispersal flights, concealed themselves during the day. and commenced migration in mass flights at dusk the following night.
The onset of these‘dusk flights’occurred when the irradiance level fell on average to 2.7 × 10−5Wm−2 nm−1 in the 450–800 nm range (in the photometric units appropriate for human vision this corresponds approximately to 2 lux). The‘dawn flights’began with the first sustained increase in irradiance at dawn, and terminated at the end of dawn twilight.
Migratory flight in the strong, easterly winds which usually occurred during the first half of the night resulted in rapid, down‐wind displacement to the west. Observations of groups of flying moths passing successively over two radars demonstrated that these migrations could cover at least 20 km.
In the second half of the night, winds were usually weak and variable, and up‐wind or cross‐wind directions of displacement were sometimes observed.
Moths were observed to disperse rapidly during their migration, so that the mass influxes which lead to outbreaks must be a consequence of subsequent reconcentration. The importance of meso‐scale wind convergence zones in reconcentrating flying moths, and the role of rainfall in inducing descent, and possibly landing, are discussed.
Ecologically seIective coIoured traps
Authors: KIRK WILLIAM D. J. 
Published: March 2008

Abstract. 1. This paper analyses catches of flower thrips, grass thrips and predatory flies in water‐traps of seven colours.2. A correlation is demonstrated between type of host‐plant of thrips and the relative numbers caught by traps of different colours.3. The literature is reviewed and some general relationships with the effectiveness of different trap colours are hypothesized for: non‐grass foliage insects and their predators and parasites; grass foliage insects; flower‐dwelling insects; predators and parasites not associated with foliage; biting insects; and wood‐borers.4. This may permit trap colours to be chosen, in particular circumstances, that are ecologically selective for different types of insect.
Biology and bionomics in Scotland of Anthocoris gallarum‐ulmi
Authors: PARKER N. J. B. 
Published: March 2008

Abstract. 1. Observations were made on the biology of Anthocoris gallarumulmi De Geer (Hemiptera ‐ Heteroptera: Anthocoridae) in West Central Scotland from 1973 until 1975. The life cycle was intimately linked with those of its principal prey species Schizoneura ulmi and S.patchae, leaf roll‐gall aphids, and elm, their primary host (Ulmus sp.).2. Overwintered adults emerged in late April/May and could be found on a number of early flowering tree species, before congregating on elm in late May/June. This population was univoltine and exhibited obligatory female reproductive diapause.3. Overwintered females emerged already mated but the subsequent pre‐oviposition period was 25 days and oviposition period 27 days. Ova were deposited only in close association with galls of S.ulmi and Spatchae, and behavioural variations were shown between sites. Fecundity was c. 16 ova per female.4. The incubation period was c. 8 days with the subsequent period of larval development 38–53 days, during which time the diet was almost exclusively either S.ulmi or S.patchae. Intergall migration was characteristic of post second instar larvae, which resulted in the concentration of fifth instar larvae and adults in a limited number of galls. It was during this period of local high population density that mating occurred.5. Adults left elm within 14 days of imaginal ecdysis and thereafter, until overwintering, were recorded in only very low numbers from a range of tree, shrub and herb species.6. Overwintering adults selected as hibernacula the bark of four tree species but principally Acer pseudoplatanus and Quercus robor. Females required a period of at least 75 days of cold ‘shock’ to terminate reproductive diapause.7. Mortality among males surviving to spring emergence was 67%.
Fluctuations in the abundance of butterflies, 1976–82
Authors: POLLARD E. 
Published: March 2008

Abstract. 1. A scheme for monitoring the abundance of butterflies at about eighty sites in Britain is described.2. Indices of abundance are presented for twenty‐nine species for the years 1976–82.3. There are marked differences between species in the scale of annual fluctuations.4. Some species show correlations between successive index values; for example the summer generation index of Pieris brassicae is highly correlated with the spring generation index.5. The annual changes in the index values of many species are highly Correlated. The index values themselves also show positive correlations, but these are less strong.6. The drought of 1976 is believed to have severely depressed populations of many species in 1977.7. The data do not indicate any general fall in butterfly numbers over the period at the sites in the scheme.8. The sites are not representative of the countryside as a whole, but, for a number of species, it is considered that the index values reflect wider trends.
Burying beetles: intraspecific interactions and reproductive success in the field
Authors: WILSON DAVID SLOAN , FUDGE JULIE 
Published: March 2008

Abstract. 1. The discovery and utilization of small carcasses by burying beetles (Silphidae, Nicrophorus) was studied by placing dead mice at random points on large grids at two Iocations in Michigan, U.S.A.2. The majority of mice are found within 24 h by more beetles than ultimately will utilize the carcass. If a carcass is likely to be usurped by a larger species of beetle or by a vertebrate, then intraspecific competition may be postponed until the carcass is concealed and buried.3. Both males and females practice parental care. Maturing broods are tended by no adults, a single female, a single male, or a male—female pair. No differences in brood success were observed among these categories.4. The female lays a larger clutch than ultimately will survive. Brood size is regulated after the egg stage, such that offspring number varies, but individual offspring size does not.5. A large amount of unexplained variation exists in brood size, in both the laboratory and the field. This variation is probably caused by the environment, and not the reproductive physiology of the beetles. Competition with microbes is a likely candidate.6. Differences exist not only between Nicrophorus species, but also between localities for a single species, suggesting adaptation to local environments.
Host‐plant shifts and adult survival in the cactus breeding Drosophila mojavensis
Authors: BRAZNER JOHN , ABERDEEN VIRGINIA , STARMER WILLIAM T. 
Published: March 2008

Abstract. 1. In order to gain insight into how Drosophila mojavensis Patterson and Crow (which lives on the rotting tissue of cactus) successfully shifted host plants, from an Opuntia species to columnar cactus species, over evolutionary time, specific components of columnar cactus and Optunia tussue were examined for their effects on adult longevity.2. The availability of free sugars affects the survival of adult D.mojavensis. The addition of a sugar to columnar cactus tissue significantly increased the longevity of adults that fed on those tissues. This increase in adult longevity was equal to the longevity observed on unsupplemented Opuntia tissue, which has free sugars present.3. Live microorganisms added to Opuntia tissue had a slight detrimental effect on adult longevity (longevity was decreased by approximately 1 week).4. Low concentrations of atmospheric ethanol (independent of diet) increased the longevity of adult D.mojavensis to levels comparable in magnitude to that provided by the addition of free sugars to the diet.5. This information and the apparent lack of a year‐round supply of free sugars for D.mojavensis in nature suggests that the ethanol (produced by fermentation) rather than free sugars per se is the most important component of rotting cactus tissue for the survival of this species and may explain its successful host‐plant shift.
Honeydew: an arrestant stimulus for coccinellids
Authors: CARTER M. C. , DIXON A. F. G. 
Published: March 2008

Abstract. 1. The presence and quantity of honeydew, produced by the, cereal aphid, Sitobion aveme (Fab.), on the time Coccinella seprempunctara L. larvae spent searching ears of wheat and on the number of aphids eaten, was investigated.2. In the presence of honeydew larvae spent longer searching the ears, resulting in a greater exploitation of prey than in the absence of honeydew.3. Larvae did not respond to differences in the amount of honeydew, so that the arrestment response would not result in aggregation in areas of high prey density.
Phenology of weight, moisture and energy reserves of Australian monarch butterflies, Danaus plexippus
Authors: JAMES DAVID G. 
Published: March 2008

Abstract. 1. In the Sydney area of New South Wales, dry weights of reproductive monarch butterflies averaged 156 mg and were higher during winter than in other seasons. Dry weights of non‐reproductive monarchs ranged from 216 to 324 mg and declined by 15–25% during over wintering.2. Fat in reproductive butterflies ranged from 0.009 to 0.017g/0.1g dry weight and was lower during winter than in other seasons. Fat content of non‐reproductive monarchs was higher (0.019–0.037 g/0.1g) and declined by 24–51% during over wintering.3. Lean dry weights of reproductive monarchs were lower than those of non‐reproductive individuals. Lean dry weights of non‐reproductive butterflies increased rapidly at the beginning of over wintering and remained high throughout the winter. Analysis of protein content indicated the higher lean weight of non‐reproductive monarchs was due to greater protein levels.4. Moisture content of monarchs did not vary with season or reproductive status and appeared to be correlated with ambient humidity.5. Non‐reproductive monarch butterflies in New South Wales adjust bio chemically during over wintering. Energy reserve dynamics of these butterflies are comparable to those that occur in non‐reproductive monarchs in North America.
The probing behaviour of nymphs of Vanduzeea arquata and Enchenopa binotata (Homoptera: Membracidae) on host and non‐host plants
Authors: KISS AGNES , CHAU ROBERT 
Published: March 2008

Abstract. 1. Nymphs of Vanduzeea arquata Say have been found to be more host‐specific in nature and to show a higher degree of selectivity in host discrimination experiments than nymphs of Enchenopa binotata (Say), It was hypothesized that this differential selectivity would be reflected in the probing behaviour of individuals placed on twigs of host and non‐host plants. Probing behaviour was examined by direct observation of nymphs and by sectioning and staining the probed plant tissues.2. All nymphs probed readily and for extended periods on both host and non‐host twigs. E.binotuta nymphs showed no consistent differences in probing behaviour on hosts versus non‐hosts, but V.atquuta nymphs were more likely to withdraw their stylets within 60 s when on non‐host twigs and produced honeydew only when on their host species. V.urquatu nymphs reached the phloem sieve elements only when on host twigs and broke many cells in peripheral plant tissue layers while probing. E.binotata nymphs broke few cells and often reached the phloem of non‐host as well as host plants.3. Nymphs of V.arquata always reject non‐host plants, apparently in the course of probing and prior to encountering the phloem sap. Chemical compounds released from ruptured parenchyma cells may act as probing stimulants or inhibitors. E.binotura nymphs often feed on non‐host plants in a non‐choice situation; their preferential settling on host twigs in discrimination experiments may reflect a tendency to abandon non‐host twigs more readily than host twigs.
Alternative reproductive routines in a small fly, Puliciphora borinquenensis (Diptera: Phoridae)
Authors: MILLER P. L. 
Published: March 2008

Abstract. 1. Puliciphora borinquenensis (Wheeler), a very small phorid fly in which the female is apterous, breeds in small patches of decomposing organic matter such as dead insects.2. Females leave the shelter of oviposition sites during the afternoon and ‘parade’ in exposed places making vigorous abdominal pumping movements which probably help to disperse a pheromone.3. Males exhibit one of four reproductive routines. In the first they perform rapid sequences of stationary copulations with different parading females, achieving rates of 0.66 females min‐1 for periods of 30min (Al). In the second (A2) they wait on oviposition sites and grab non‐parading females which have recently arrived.4. In the third routine a male airlifts a parading female in copula to an oviposition site (Bl); in the final type of routine, females are airlifted and then deposited randomly when oviposition sites cannot be found (B2).5. Males are able to learn the location of oviposition sites and this enables them to transport large numbers of females (up to thirty‐three per male) to sites at a high rate (0.5 females min‐1).6. Immediately a female is released after a B routine, the male follows her closely for up to 10s. This is thought to represent a phase of non‐contact guarding, suggesting the occurrence of sperm competition.7. Individual males persist with either A or B routines for long periods (c. 30 min), but they are able to switch between routines.8. Young males (< 27 h after emergence) carry out A routines 18 times more commonly than B routines, whereas older males carry out A routines only 1.6 times more commonly than B routines. The choice between A and B routines in older flies does not depend on male or female density.9. Males benefit from B routines because the eggs they fertilize are likely to reach oviposition sites, but they pay a considerable energy cost. A routines, on the other hand, are energetically cheaper, but mated females are less likely to reach oviposition sites unless they are subsequently transported by B males. An A male can then benefit provided his sperm are not completely displaced by the second male.
Poly modal emergence of the tiger swallowtail, Papilio glaucus (Lepidoptera: Papilionidae): source of a false second generation in central New York State
Authors: HAGEN ROBERT H. , LEDERHOUSE ROBERT C. 
Published: March 2008

Abstract. 1. The tiger swallowtail butterfly, Papilio glaucus (L.) (Lepidoptera: Papilionidae), is commonly assumed to have a bivoltine life cycle in central New York State and other parts of the northeastern United States. The seasonal abundance of adults in Tompkins County, New York, shows a bimodal pattern in some years, and a skewed unimodal pattern in others. We studied the incidence of diapause, the potential for successful development of two generations in the field, and the dates of adult emergence from overwintering pupae to determine whether these seasonal patterns are the result of bivoltinism.2. Insects from Tompkins County, reared as larvae under 16L:8D photoperiod, uniformly enter pupal diapause.3. Comparison of the heat units required for successful development of two generations with the heat units available in the field during 11 years shows that emergence of non‐diapausing individuals would occur too late in the summer to contribute to the second peak of butterfly abundance. Offspring of non‐diapausing individuals could only rarely complete development before the end of the growth season.4. Diapausing offspring of butterflies collected in early June and late July differed sufficiently in dates of emergence to account for the field pattern of seasonal abundance.5. Electrophoretic studies revealed no evidence of genetic isolation between early and late emerging butterflies.6. These results suggest that polymodal emergence of diapausing insects can masquerade as a bivoltine life cycle.