bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oviposition on host plants by a tropical forest grasshopper (Microtylopteryx hebardi: Acrididae)
Authors: BRAKER H. ELIZABETH 
Published: March 2008

Abstract. 1. The tropical forest grasshopper Microtylopteryx hebardi Rehn (Orthoptera, Acrididae, Ommatolampinae) oviposits inside leaves or stems of its host plants. This is the first known instance of oviposition inside living plant tissue (rather than in the ground, on top of leaves, or in detritus) for a tropical forest acridid.2. In understorey secondary forest at La Selva, Costa Rica, M.hebardi females fed on fifteen species of host plants, but oviposited in only four of these.3. In laboratory choice tests, females showed selectivity for oviposition host plants similar to that inferred from field observations.4. Plant volume was a better predictor of the number of eggs laid per stem than variables that indicated leaf or stem characteristics of individual plants.5. Unlike the ovipositor of acridids laying eggs in the ground, that of M.hebardi is equipped with toothed, sclerotized edges, probably used to bore into plant tissue.6. Endophytic oviposition in M.hebardi may be related to finding host plants in a habitat that is complex, heterogeneous, and rich in plant species.
Microhabitat specialization and similarity of scale‐insect assemblages on different fruit trees and in different countries
Authors: KOZÁR FERENC 
Published: March 2008

Abstract. 1. Assemblages of scale‐insects on deciduous fruit trees were compared in a wide geographic range of Palaearctic subregions.2. The parts of all host plant species in the whole geographic region were unsaturated with scale species. There was no clear niche expansion, nor any niche segregation between scale‐insect species.3. These results show that even plants such as deciduous trees, rich in coccoid species, are not fully utilized by scale insects.4. The similarity of the scale‐insect faunas on different plant species could be explained partly by the distribution patterns of the insects, and partly by phylogenetic connection between host plants.
The diversity of Hymenoptera in the tropics with special reference to Parasitica in Sulawesi
Authors: NOYES JOHN S. 
Published: March 2008

Abstract. 1. The results of a recent faunistic survey of the Hymenoptera of northern Sulawesi, Indonesia, are compared with the known British fauna.2. All families of Hymenoptera are probably more species rich in Sulawesi than in Britain, with the possible exception of Symphyta and gall‐forming Cynipidae.3. The diversities of the samples obtained from Sulawesi are compared with those published from previous studies on the relationship between latitude, altitude and the diversity of parasitic Hymenoptera in tropical and temperate regions.4. Despite its possibly greater species richness, the Ichneumonidae as a whole was no more diverse in the Sulawesi samples than in samples taken in temperate areas, including Britain.5. The diversity of Parasitica as a whole appears to have been greater in the Sulawesi samples than those from either Britain or Michigan but lower than those from Costa Rica.6. Parasitica as a whole was probably not more diverse inside the forest than at its edge, but the Aculeata was more diverse at its edge.7. Both Parasitica and Aculeata were less diverse at 1765 m than at 220 m altitude.
Mating prior to overwintering in the imported willow leaf beetle, Plagiodera versicolora (Coleoptera: Chrysomelidae)
Authors: STEVENS LORI , McCAULEY DAVID E. 
Published: March 2008

Abstract. 1. We report on the mating status of overwintering adults of the imported leaf beetle, Plagiodera versicolora Laicharting. This species overwinters as adults, under the bark of willow trees.2. Individuals were collected both in the autumn, just after initiation of diapause, and in the spring, just before natural termination of diapause. From the autumn sample, we discovered that diapause can be terminated by husbanding the adults at 4°C for 4 weeks.3. Most females lay fertile eggs upon the termination of diapause; however, a significant number of females lay non‐fertile eggs after overwintering in the field.4. Many females mate with more than one male before entering diapause. Progeny analysis using allozyme genetic markers shows that, on average, females who are fertile upon termination of diapause utilize sperm from 1.2 males to fertilize their eggs.
The growth and survival of Panolis flammea larvae in the absence of predators on Scots pine and lodgepole pine
Authors: WATT A. D. 
Published: March 2008

Abstract. 1. The survival, growth and development of larvae of the pine beauty moth, Panolis flammea (D & S) (Lepidoptera: Noctuidae) were examined as part of a study to determine (i) why damaging outbreaks of this insect in Scotland are frequent on lodgepole pine but do not occur on Scots pine, and (ii) why outbreaks are associated with areas of deep un‐flushed peat.2. Larvae were studied inside predator exclusion cages on mature pine trees in Elchies forest where a major infestation occurred in 1978–79.3. Surprisingly, larval survival was generally greatest on Scots pine and lowest on lodgepole growing in deep peat. Also, larval growth and development were greater on Scots than lodgepole pine and were unaffected by the type of soil in which the lodgepole pine was growing.4. Larval performance was generally better on lodgepole pine that had been thinned and received fertilizer.5. Larval survival was affected by pine shoot stage during egg hatch in one of the two years in which this was examined.6. Observations on P.flammea pupae were confused by disease, parasitism and probably by differences in weight loss caused by differences in larval development. Parasitism by ichneumonid parasitoids was recorded on Scots pine but not on lodgepole pine.7. It was concluded that (i) the absence of pine beauty moth outbreaks on Scots pine, and (ii) the occurrence of outbreaks on lodgepole pine growing in deep unflushed peat were not the result of lodgepole pine growing in deep peat being a more suitable host plant than lodgepole pine and Scots pine growing elsewhere. It seems more likely that the observed outbreak behaviour of P.flammea in Scotland is associated with differences in predation and parasitism in plantations of difference host plants and in plantations of lodgepole pine growing in different soils.
Regional diversity, local community structure and vacant niches: the herbivorous arthropods of bracken in South Africa
Authors: COMPTON S. G. , LAWTON J. H. , RASHBROOK V. K. 
Published: March 2008

Abstract. 1. Seventeen species of phytophagous arthropods (sixteen insects and one gall‐forming eryiophyid mite) were found feeding on the above‐ground parts of bracken (Pteridium aquilinum (L.) Khun.) in surveys throughout the geographic range of the plant in South Africa. A further thirteen species of insects may possibly feed on the plant in this region.2. Given the area over which bracken grows in South Africa, this is very close to the number of species expected on the plant, based on species‐area calculations and comparisons with bracken in other geographic regions.3. The species‐richness of bracken‐feeding arthropods in local communities reflects the size of the regional pool of species in different geographic areas. Local richness in South Africa is intermediate between that in south‐western U.S.A. and Britain.4. In both Britain and South Africa there is a weak tendency (0.05 < P < 0.07) for larger local patches of bracken to support more species of phytophages than small patches, with similar very shallow slopes (0.083 and 0.086) in plots of log species versus log area on both continents.5. The taxonomic composition of bracken‐feeding arthropods in South Africa is markedly different from that in other pants of the world, suggesting very different and largely independent evolutionary histories in different regions.6. There is no sign of convergence in the feeding niches of communities of bracken‐feeding arthropods in different parts of the world, and the pattern of feeding relationships is very different in South Africa to patterns observed elsewhere. Conspicuous vacant niches (ways of exploiting the plant that are observed in other geographic regions) are easily identified in the South African communities.
Patterns of locomotion of polyphagous arctiid caterpillars in relation to foraging
Authors: DETHIER V. G. 
Published: March 2008

Abstract. 1. Patterns of locomotion of three species of arctiid caterpillars, Diacrisia virginica, Fabr., Pyrrharctia Isabella (J. E. Smith) and Estigmene congrua Walk, were studied in the field and laboratory in an attempt to understand factors determining foraging behaviour.2. Tracks were recorded on artificial substrates indoors, in the open, and in the normal habitat under the following conditions: in darkness, in bright sunlight, under heavy overcast, under blue sky with the substrate intermittently rotated, with an overhead sheet of polaroid rotated, on a substrate with asperities, in natural field conditions with a variety of forbs in dispersed and clumped distributions.3. Tortuosity and general directions of paths were analysed.4. The effects of various levels of deprivation were also analysed.5. In the absence of photic and chemical stimulation paths on smooth surfaces are straight and direction is random.6. Obstacles perturb the paths and impart a meandering pattern. Patterns of locomotion induced by obstacles on a smooth substrate are indistinguishable from patterns of locomotion in the field. Unless food plants are closer than 1cm they have no effect on locomotion. Patterns of locomotion in dispersed and clumped foodplants are the same.7. What appears to be food‐related search behaviour is primarily the result of physical features of the environment perturbing a central neuronal pattern of locomotion. Stimuli from foodplants appear to be irrelevant unless actually enountered.
Oviposition site selection by Mansonia mosquitoes on water lettuce
Authors: LOUNIBOS L. P. , DEWALD L. B. 
Published: March 2008

Abstract. 1. Viable Mansonia egg masses occur in nature on both the upper and under surfaces of Pistia stratiotes (L.) leaves. Upper‐surface masses were from Mansonia dyari Belkin, Heinemann & Page, but lower‐surface oviposition was attributable to both M. dyari and M. titillans Walker.2. Upper‐surface egg masses were often out of water but were concentrated near a wet‐dry stain line on the leaf. Lower‐surface masses were laid underwater within 3 mm of the leaf edge, except for those oviposited through fenestrations caused by insect damage.3. Oviposition varied seasonally and masses were most numerous between August and December when water lettuce plants were large and crowded. Egg masses were clumped on plants and leaves and concentrated on mature or mature‐old leaves that subtended mean angles of 28–34° from the horizontal.4. On intact plants in cages, M. dyari laid egg masses on both leaf surfaces in approximately the same proportions as observed in nature. On detached leaves floating flat on the water, M. dyari laid all masses on under surfaces.5. At 20 and 25°C, egg development of M. dyari required 17.4 and 8.8 days (means), these being significantly longer than the mean times for M. titillans. Some larvae from eggs that hatched in the absence of water survived 72 h in the eggshell.6. Upper‐surface oviposition by M. dyari may be an adaptation to the crowded growth of water lettuce, the mosquito's favoured host plant, whose leaves are largely out of water. Leaf ageing and subsidence cause submergence of most upper‐surface eggs by the time of hatching.
Foraging behaviour of a leafminer parasitoid in the field
Authors: CASAS J. 
Published: March 2008

Abstract. 1. The searching behaviour of the parasitoid Sympiesis sericeicornis Nees (Hymenoptera, Eulophidae) is analysed under field conditions.2. Females were tracked when flying around the canopy of apple trees infested with the tentiform leafminer Phyllonorycter cydoniella (D. & S.)(Lepidoptera, Gracillariidae) and their behaviour studied at the level of a single mine and at the level of several mines on the same leaf (patch level).3. The presence of mines is detected during flight. The foraging behaviour at the patch level is efficient: the female is able to distinguish the suitable from the unsuitable hosts and handle the suitable hosts first. Not all mines are visited before departure from the leaf and those left unvisited are exclusively mines without suitable hosts. The patch leaving rule is discussed.4. An ethogram of the behaviour on the mine is constructed. Selected behavioural categories are analysed for different combinations of mine content and outcome of the visit to the mine. The assessment of the mine content is done in a differential way, quickly and without mistakes.5. The results are discussed in the context of two environmental factors, wind speed and temperature, which reduce the available time for searching. They are also related to the growing percentage of unsuitable hosts during each host generation. Tentiform mines remain attractive for a long period of time, even after parasitism or emergence of the adult, and their examination reduces the rate of host discovery.
The effects of temperature and body size on the mating pattern of a gregariously nesting bee, Colletes cunicularius (Hymenoptera: Colletidae)
Authors: LARSSON FOLKE K. , TENGÖ JAN 
Published: March 2008

Abstract. 1. In a 3‐year study of the solitary bee Colletes cunicularius L. in Sweden, average body size and population density fluctuated greatly between years.2. In this protandrous population, females mated just once and the sex ratio was slightly male biased. Males were smaller than females.3. Size assortative mating (homogamy), associated with an increase in population density during the central days of female emergence and mating, was observed in two out of three years. Homogamy was also observed in pairs with remating males.4. Most of the mating males had emerged the day they mated, but 42% were older. We found no support for a general large‐male mating advantage.5. Weight of emerging females and mating males were negatively correlated with ground temperature, indicating thermoregulatory influence on the process of sexual selection in this species.
Size variation and reproductive success of female Aedes punctor (Diptera: Culicidae)
Authors: PACKER M. J. , CORBET PHILIP S. 
Published: March 2008

Abstract. 1. Variation in size (wing length) of females and males within a population of Aedes punctor (Kirby) at emergence was recorded in northern Britain during 1984 and 1985.2. Wing length correlated well with body dry weight, confirming its usefulness as a measure of body size. In 1984, but not in 1985, mean size decreased significantly as emergence progressed.3. The size of host‐seeking females caught at human bait varied seasonally. This was partly accounted for by size variation during emergence.4. Of females which fed to repletion, the largest spent least time in contact with the host.5. In the laboratory, wing length correlated well with potential fecundity (number of ovarioles) and less well with actual fecundity (number of matured follicles) after feeding on human blood.6. In the field, larger females were more successful at locating hosts, developed more egg clutches in a lifetime and generally lived longer than did smaller ones. Larger females appear to enjoy greater reproductive success than do smaller females.
Onset and spread of an African army worm upsurge
Authors: PEDGLEY D. E. , PAGE W. W. , MUSHI A. , ODIYO P. , AMISI J. , DEWHURST C. F. , DUNSTAN W. R. , FISHPOOL L. D. C. , HARVEY A. W. , MEGENASA T. , ROSE D. J. W. 
Published: March 2008

Abstract. 1. Onset and spread of the severe outbreaks of African armyworm, Spodoptera exempta (Walk.), over Ethiopa, Kenya, Tanzania and Burundi in late 1984 have been analysed in relation to trap and weather records.2. Although first outbreaks in each country appeared progressively further south, winds on the best estimated dates of moth concentration and egg laying blew from directions precluding moth movements between them.3. Such independently developing outbreaks are called ‘primary’ to distinguish them from any ‘secondary’ outbreaks that may develop from them.4. Parent moths giving rise to all seven areas of primary outbreaks were derived from low‐density populations that had persisted through the dry season, probably near the coast of East Africa.5. Primary outbreaks developed on the south‐eastern sides of individual rainstorms over the highlands, most likely because windborne moths were concentrated there by convergent winds.6. Of the secondary outbreaks within Kenya, Tanzania and Burundi, most were derived from only one area of primary outbreaks in Kenya, which were therefore critical for effective control of spread; the paucity of other secondaries was presumably due to a lack of timely rainstorms or other concentrating mechanisms.
Life‐history responses of larviparous Boettcherisca formosensis (Diptera: Sarcophagidae) to larval competition for food, including comparisons with oviparous Hemipyrellia ligurriens (Calliphoridae)
Authors: SO PING‐MAN , DUDGEON DAVID 
Published: March 2008

Abstract. 1 The effect of larval rearing density on life‐history parameters of Boettcherisca formosensis Kirner & Lopes (Sarcophagidae) was investigated. Increases in rearing density resulted in lowered larval survivorship, shortened larval development time and production of smaller, shorter‐lived adults with reduced fecundity.2. B. formosensis is larviparous. Average brood size was 17.5±1.0 (mean±M) larvae, which was much less than the average number of mature larvae inside gravid females. Females apparently produced a series of small broods, distributing their offspring over a number of carcasses.3. Compared with the oviparous species Hemipyrellia ligurriens (Wiedemann) (Calliphoridae), B. formosensis adults were larger and longer‐lived, with a longer larval development time but shorter larval feeding period. However, females had a shorter pre‐reproductive period, were less fecund, and had a lower life time reproductive investment.4. B. formosensis had lower relative performance (measured by the composite index of performance, r') than H. ligurriens over the larval rearing density range, and was more sensitive to increases in density. Although the r' values suggest that the sarcophagid may be a competitively inferior species, other features which are not included in the index (such as larvipary, short larval feeding period and spreading of offspring from a single brood among carcasses) may be of significant adaptive value to B. formosensis.
Oviposition and host‐feeding patterns in Aphelinus asychis (Hymenoptera: Aphelinidae) at different aphid densities
Authors: BAI B. , MACKAUER M. 
Published: March 2008

Abstract. 1. The patterns of host‐feeding and oviposition were examined in Aphelinus asychis Walker, which had been provided with second‐instar pea aphids as hosts.2. Female wasps responded to increasing host density (between one and forty aphids for 24 h) with an increasing tendency to oviposit rather than to feed. Superparasitism occurred at all aphid densities, even when unparasitized aphids were available.3. Aphids intended for feeding were paralysed and died. Wasps did not feed on and oviposit in the same aphid.4. Feeding to satiation lasted between 4 min and 42 min. Females that had starved for ≰18 h generally deposited one or more eggs before feeding again, while the reverse was true in wasps that had starved for 21 h.5. The host‐feeding behaviour of A. asychis is determined by a female's nutritional status. At low rates of host encounter, the anhydropic eggs may be resorbed. This reproductive strategy conforms to the destructive non‐concurrent type among the Hymenoptera.
Choice of host plant as a factor in reproductive isolation of the aphid genus Cryptomyzus (Homoptera, Aphididae)
Authors: GULDEMOND J. A. 
Published: March 2008

Abstract. 1. Host plant preference experiments were conducted with closely related taxa of the aphid genus Cryptomyzus. Males, and presexual morphs (sexuparae and gynoparae), were used to determine the impact of host plant choice on reproductive isolation. In the case of host‐alternating species these morphs are migratory and so will select the host plant.2. Host plant preference of two closely related taxa of C. alboapicalis (Theobald) was found to promote their reproductive isolation. The preference of sexuparae of these monoecious taxa was more pronounced than that of the males.3. Host plant preference and subsequent production of oviparae showed that C. galeopsidis (Kaltenbach) consists of two host races restricted to Ribes rubrum L. and R. nigrum L., respectively. The existence of clones, intermediate in their preference and reproductive performance on these plants, suggests that hybridization occurs.
Mechanisms of predator accumulation in a mixed crop system
Authors: LETOURNEAU D. K. 
Published: March 2008

Abstract. 1. In a previous study, Orius tristicolor (White), a generalist predator of soft‐bodied insects and mites, invaded patches with a mixed plant assemblage at a faster rate than it did single‐species stands. This study was designed to determine experimentally the underlying mechanisms of predator movement patterns that cause more intense colonization of crop mixtures.2. Plots were established in a randomized complete block design. Treatments reflected different components of mixed crop patches: species richness, plant density, colour contrast, structural complexity, and volatile plant compounds.3. O. tristicolor colonists were more abundant on squash intercropped with corn and cowpea than in squash monocultures even though early season prey densities were similar. Initial accumulation of the generalist predator was also higher in densely planted monocultures and in monocultures with artificially enhanced structural complexity than in normally‐spaced squash monocultures.4. Therefore, mechanisms underlying rates of predator colonization in a stand initially depended upon aspects of plant architecture and density and were independent of prey density and plant diversity. O. tristicolor densities at the end of the colonization period, however, were greater on squash (Cucurbita pepo L.) in polyculture than in any other treatment.5. These results suggest that attributes of the vegetation can influence the colonization rates of interacting organisms on different trophic levels and thus can alter predator‐prey interactions and the development of community structure.
Intraspecific aggression, colony identity and foraging distances in Sudanese Microtermes spp. (Isoptera: Termitidae: Macrotermitinae)
Authors: PEARCE MICHAEL J. , COWIE ROBERT H. , PACK ANGELA S. , REAVEY DUNCAN 
Published: March 2008

Abstract. 1. Intraspecific aggression between termite major workers was used to obtain estimates of foraging distances for three Microtermes species in Sudan.2. Maximum foraging distance recorded for M. sp. nr albopartitus (Sjöstedt) in Khartoum was 11.3 m, giving an estimated minimum colony area of 100 m2. This is probably an underestimate. In the Tokar Delta, individuals from single colonies of M. najdensis Harris were encountered up to 42 m apart, giving a colony area of 1390 m2.3. Intraspecific aggression could not be used reliably to distinguish members of different colonies of M. lepidus Sjöstedt. Soil barrier formation between groups of workers in petri dishes may be of use as a supplementary technique, especially for species showing no clear aggression.4. Experiments on isolated laboratory colonics of M. sp. Nr lepidus Sjöstedt, established from alates collected in Khartoum, further confirmed the value of inter‐colony aggression for indicating colony identity.5. The complications introduced into estimation of subterranean termite foraging areas by overlap and interdigitation of colonies are discussed.