bluuebunny/crossref_metadata_2025 huggingface dataset:
The distribution and biology of Lonchopteridae (Diptera) in upland regions of northern England
Authors: COULSON J. C. , BUTTERFIELD JENNIFER
Published: March 2008

Abstract. 1. A survey was made of the distribution of Lonchopteridae over 2 years at forty sites in northern England. Material was collected by pitfall trapping.

2. Two species, Lonchoptera lutea and L.furcata, were taken in approximately similar numbers. No other species were recorded.

3. Considerable separation of the two species was found, with both species occurring at ten sites, whilst one species only was taken at twenty‐five sites. L.furcata occurred coinrnonly on upland mineral sods, shallow peat soils and on lowland bogs whilst L.lutea was numerically most abundant on upland blanket bog.

4. Almost 39% of the L.lutea specimens and 14% of the L.furcata captures were males.

5. The capture of numbers of males of L.furcata is unusual, since the species is regarded as being parthenogenetic and males occur only in a very small part of the species' range. Confirmation of the association between the males and females of L.furcata is given, whilst there is close agreement between the cliaetotaxy of British males and females, and British and continental European females. The suggestion that the males belong to an undescribed species is rejected.

6. The seasonal capture of L.lutea adults is similar at all altitudes. Captures of males of L.furcata show an abrupt seasonal change above and below about 420 m; captures being in mid‐summer in the higher altitude zone and between October and December at lower altitudes. The captures of females of L.furcata show the same trend, but this is partially obscured by the longer life‐span of the females. It is suggested that this difference represents a change in the lifecycle, possibly from an annual to a biannual one at the higher altitudes.

7. The biology and distribution of the Lonchopteridae at low altitudes requires investigation.
Intraspecific competition amongst larval Aedes aegypti: food exploitation or chemical interference?
Authors: DYE CHRISTOPHER
Published: March 2008

Abstract. 1. Competition within and between the larval instars of the yellow fever mosquito, Aedes aegypti, can be measured by its effect on stage duration. In a series of laboratory experiments the relative importance of chemical interference and food exploitation in mediating competition between first and fourth instar larvae was investigated.

2. In contrast to the results of three previous studies, I found no evidence that a chemical growth retardant played any part in greatly prolonging the stage durations of larvae in both age classes.

3. When competition between the two age classes became important, the relative increase in stage duration wasgreater for first instar larvae than for fourth instar larvae. This result can be reproduced with Gilpin & McClelland's (1979) model of competition by food exploitation alone, providing the range of available food particle size is assumed to be an increasing function of age. An additional, but less important, refinement makes the conversion efficiency of food into larval biomass a decreasing function of age.
Entomogenous fungi in tropical forest ecosystems: an appraisal
Authors: EVANS H. C.
Published: March 2008

Abstract. 1. Species of the genus Cordyceps (Ascomycotina; Clavicipitales) are the commonest fungi encountered on arthropods in tropical forests.

2. The asexual states of Cordyceps may occur in conjunction with or separately from the perfect state and are classified in the genera Hirsutella, Hymenostilbe, Nomuraea, Paecilomyces and Verticillium of the imperfect fungi (Deuteromycotina; Moniliales).

3. Most Cordyceps species have a restricted host range and this rigid host specificity, at the generic or tribal level, is especially evident in ant‐fungal associations.

4. Pathogenicity was not tested but circumstantial evidence is presented which supports the view that Cordyceps species are primary pathogens of arthropods.

5. Observations of living, infected ants suggest that behavioural patterns are radically altered, possibly altruistically orientated.

6. It is thought that entomogenous fungi are involved in the regulation of arthropod populations and may help to maintain stability in tropical forest ecosystems.

7. The value of these organisms to man may be in the metabolites they produce rather than in their direct usage as biological control agents of insect pests.
Interspecific competition between two field populations of grass‐feeding bugs
Authors: GIBSON CHARLIE , VISSER MAYKE
Published: March 2008

Abstract. 1. We tested the hypothesis that interspecific competition between two grass‐feeding stenodemine bug species (Notostira elongata Geoffroy and Megaloceraeu recticornis Geoffroy) was capable of causing population‐scale mortality in the field.

2. N.elongata nymphs were added to two field enclosures in which the M.recti‐cornis population was to hatch. In one of these enclosures the grass Arrhena‐therum elatius L., on which only M.recticornis can feed, was also added. Population changes of the bug species were then monitored. An unmanipulated enclosure and an unfenced plot of grassland were used as controls.

3. The results demonstrated that N.elongata lowered the survival of M.recticornis and that this effect was removed by the addition ofA.elatius. The results also suggested that N.elongata suffered less from the effects of competition with M.recticornis when the latter had access to the refuge foodplant.

4. Interspecific competition was rare among members of the grass‐feeding stenodemine guild in the area studied. Only one out of fifteen possible pairs competed, and this competition occurred only under special circumstances.
Normal and atypical nesting behaviour of Copris lunaris (L.): comparison with related species (Coleoptera, Scarabaeidae)
Authors: KLEMPERER H. G.
Published: March 2008

Abstract. 1. The lifecycle, mating and larval behaviour of Clunaris are described. Adults appeared in the autumn and nested in the following spring. The female beetle remained in the nest with the brood and could nest again the following year.

2. Nesting was initiated when virgin females were mated in the spring. Brood balls were formed by techniques sirnilar to those used by Scarabaeini. The female beetle left the nest soon after the first imagos broke out of the brood balls.

3. Nesting behaviour was readily modified by external conditions. Many parts of the sequence could be repeated or omitted. The female beetle left the nest if the brood was removed, but she remained for longer than usual if younger brood was substituted near the end of the normal nesting period.

4. Certain experimental conditions released behaviour patterns typical of other species. These were formation of superficial nests or of two‐chambered nests, oviposition before completing the brood ball, and coating of the brood balls with soil (all found in other Coprina), as well as ball rolling and ball burial (found in Scarabaeini). The results are discussed in relation to the evolution of Copris nesting behaviour.
Oviposition behaviour of the grasshopper Zonocerus variegatus
Authors: McCAFFERY A. R. , PAGE W. W.
Published: March 2008

Abstract. 1. Long‐term changes in the numbers of Zonocerus at oviposition sites reflect changes in the maturity of the general population.

2. Short‐term changes in the numbers of Zonocerus at oviposition sites are associated partly with normal diurnal behaviour in which roosting occurs at night.

3. Immigration of Zonucems, particularly females, into the oviposition site occurs prior to periods of oviposition activity. Emigration follows oviposition.

4. The majority of Zonocerus move upwind into the oviposition site suggesting an odour and/or sound attraction.

5. Periods of intense oviposition activity follow heavy rainfall.
Instar duration, adult consumption, oviposition and nitrogen utilization efficiencies of leafhoppers feeding on different quality food (Auchenorrhyncha: Homoptera)
Authors: PRESTIDGE R. A.
Published: March 2008

Abstract. 1. Plant material of Holcus lanatus L. removed from an artificially fertilized trial was used to rear leafhoppers of three feeding types: Dicrano‐tropis hamata Boheman and Ebmana sulphurella Zetterstedt, (phloem feeders), Eucelis incisus Kirschbaum (xylem feeder) and Zyginidia scutellaris Herrich‐Schaeffer (mesophyll feeder).

2. In the laboratory, leafhopper instar durations, adult consumption rate, oviposition rate, and nitrogen utilization efficiency were influenced by the quality of the food consumed. Adult longevity was unaffected by the level of food quality normally found in plants.

3. Z.scutellanis consumed mesophyll contents equivalent to 72% of its body weight each day but only digested about 30% of its intake. Eincicus had a low dry weight consumption rate (12% body weight/day) but digested its food more efficiently (60%) than the other feeding types. The two phloem feeders consumed mounts equivalent to 25% of their body weight each day and digested 40–50% of their intake.

4. Each species reached maximum nitrogen utilization efficiencies at different plant nitrogen levels. This suggests that leafhopper species may be associated with a particular nitrogen concentration in the grasses.
Sib‐mating and sex ratio strategies in scelionid wasps
Authors: WAAGE JEFFREY K.
Published: March 2008

Abstract. 1. Theoretical models by Hamilton and others predict that the optimal sex ratio (proportion males) for a species should decrease with increasing levels of sib‐mating. A test of this hypothesis is made for members of the parasitoid family Scelionidae.

2. Scelionid wasps differ in levels of sib‐mating as a consequence of differences in host egg mass size, male—male aggression and female—female aggression.

3. Sex ratios for thirty‐one species vary with inferred changes in sib‐mating as predicted by the models.

4. Interspecific differences in sex ratio may represent different fvted strategies or different manifestations of a single variable strategy (sex ratio game) in response to parasitoid‐produced stimuli.

5. Males and females are assigned non‐randomly to egg masses in a manner which ensures mixed broods in the proper proportions for a particular species.
Differential stratification, movement and parasitism of sexes of the bagworm, Thyridopteryx ephemeraeformis on redcedar
Authors: GROSS SCOTT W. , FRITZ ROBERT S.
Published: March 2008

Abstract. 1. Male and female bagworm larvae develop and pupate at different heights on redcedar trees.

2. Habitat segregation by height of male and female bagworms is apparent by the third instar, and results in part from differential movement of male and female larvae on redcedar foliage during their development. Females gradually ascend the crown, whereas males remain at the same height on the tree.

3. Parasitism of male bagworm pupae was greater than for female pupae. Pupal parasitism is heaviest in the bottom of redcedar trees, where most male bagworms pupate.

4. Several hypotheses are offered concerning the origin and maintenance of differential habitat utilization by male and female bagworms, despite apparently strong selection against males pupating low in the crowns of redcedar.
Parental behaviour in Copris lunaris (Coleoptera, Scarabaeidae): care and defence of brood balls and nest
Authors: KLEMPERER H. G.
Published: March 2008

Abstract. 1. Nesting female beetles righted brood balls (so as to replace the egg or larva in the uppermost position) and repaired damaged balls. This behaviour required the presence of an egg or larva in the ball, or of a short‐lasting material found just after oviposition. The shape of the ball was also a righting stimulus since artificial ellipsoids were stood on end.

2. Balls containing dichloromethane extracts of C.lunaris brood were righted and repaired. Eggs and larvae of several other Scarabaeidae did not release these responses but were destroyed.

3. Righting behaviour was released when brood was absent from the top of the ball. The beetle then crawled vertically downwards and, if it encountered the displaced apex, a novel rolling action followed which automatically turned the ball towards the correct position.

4. An opening made in the nest was repaired with soil excavated from the chamber floor. Clunaris adults and Aphodius fossor larvae were attacked if they were encountered in the nest.
Interference by the mantispid Mantispa uhleri with the development of the spider Lycosa rabida
Authors: REDBORG K. E.
Published: March 2008

Abstract. 1. The larvae of Mantispa uhleri Banks (Neuroptera: Mantispidae) board spiders to await the production of an egg sac containing their obligate developmental food. While aboard the spider, larvae maintain themselves by feeding on spider blood. This parasitic behaviour was investigated by allowing larvae to board sixth instar Lycosa rabida Walckenaer (Araneae: Lycosidae). Larval parasitism has a direct and indirect effect on the developmental physiology of the spider.

2. The direct effect, equal in both spider sexes, is an increase in development time and a decrease in adult size.

3. The indirect effect on development time and adult size is brought about by the loss of an instar in female spiders only. Parasitized females were mature at nine or ten instars; control females at ten or eleven. Male instar number was not affected; both control and parasitized males were mature at nine or ten instars.

4. The net result is that parasitized female spiders are even smaller than would be predicted from the direct effect alone, but actually mature faster than control females. In males there is only the direct effect. The adaptive significance of this sexually dimorphic response is discussed.
Observations on the biology and ecology of the chrysomelid beetle Gastrophysa polygoni in cereal fields
Authors: SOTHERTON N. W.
Published: March 2008

Abstract. 1. Observations were made on the biology of Gastrophysu polygoni (L.) (Coleoptera: Chrysomelidae) in cereal fields in southern England in 1977, 1978 and 1979. Adults of the overwintering generation emerged in late April/ May and there were usually two generations during the spring and summer months. In 1979 there was some evidence for at least a partial third generation.

2. In the field, the oviposition period was 44 days in the first generation and c. 25 days in the second. Fecundity varied from 586 to 1028 eggs per female and was higher in the first than in the second generation in both 1977 and 1979; in 1978 the reverse was true.

3. Every year there were Iarge losses in the numbers within a generation. However, only one parasite was bred from the developmental stages and a pathogen attacking the larvae was found only in 1977.

4. In some fields and in some years, harvesting and straw burning operations were carried out when eggs were present on the plants. Harvesting did not result in a significant reduction in the numbers of eggs. Burning reduced the numbers of egg batches. The effect was most severe when the straw was spread over the field prior to burning.

5. In the field, significantly more eggs were laid on plants of Polygonum aviculare than on P.convolvulus. In the laboratory, larval survival was higher and duration of development shorter on these two species than on other Polygonaceae found on the farm.
Bionomics of Prays citri (Lepidoptera: Yponomeutidae) and their use in a model of control by male mass trapping*
Authors: STERNLICHT M.
Published: March 2008

Abstract. 1. The paper describes the population dynamics of Prays citri (Milliere), relevant to the control of this pest by synthetic pheromone, as well as infestation of lemon trees in various areas and seasons.

2. The responses of males to natural and synthetic sex pheromones are compared, and ratios for the degree of attraction of traps compared with the degree of attraction of competing wild females are calculated.

3. The ratios obtained with various population densities over two seasons of the pest's activity are presented.

4. The data are used in a model simulating control of Prays citri by male mass trapping.
Potential interspecific competition and host specificity: hispine beetles on Heliconia
Authors: STRONG DONALD R.
Published: March 2008

Abstract. 1. Adults of rolled‐leaf hispine beetles (Chrysomelidae, Coleoptera) spend their lives in the scrolls formed by immature leaves of Heliconia (Heli‐coniaceae, Monocotyledonae) in Tropical America. As many as eight hispine species can intermingle in the host scrolls at a single site. Scrolls of single host species are invariably occupied by adults of more than one hispine species, and as many as five species can simultaneously occupy one scroll.

2. I made virgin scrolls, which had never contained any insects, by growing leaves under the cover of plastic bags.

3. Thirty‐seven combinations of single hispine and Heliconia species were experimentally created in the virgin scrolls, at two sites and in two seasons, in Costa Rica. Combinations included all abundant host species at the sites.

4. All beetles left all leaves of the twenty‐eight unnatural beetle—host combinations, within 24 h. On the other hand, none of the nine natural combinations was completely abandoned within the experimental period.

5. Thus, host specificity is not broader in the absence of similar hispine species that might be competitors, and interspecies competition does not affect this obvious aspect of resource utilization for these phytophagous insects.
Energy reserves and metabolic expenditures of monarch butterflies overwintering in southern California
Authors: CHAPLIN SUSAN B. , WELLS PATRICK H.
Published: March 2008

Abstract. 1. Energetic expenditure and predicted requirements for overwintering metabolism were determined for monarch butterflies (Danaus plexippus L.) in southern California.

2. Fat content of butterflies declined steadily from a maximum of 71% lean dry weight in late November to a minimum of 36% lean dry weight in late January. The energy expenditure measured by fat depletion over a 61 day period from 24 November to 25 January was 26.05 joules per day.

3. Butterflies were generally the same temperature as the air at any time they were inactive, whether they were part of a large cluster or roosting solitarily.

4. Oxygen consumption of butterflies increased in a curvilinear fashion with increasing air temperature. Thus, the predicted metabolic requirements for an inactive butterfly during their quiescent period from late November to late January was 30.32 joules per day.

5. In contrast to the steady depletion of fat reserves during their quiescent period in December and January, low and stable fat levels of butterflies in late February coincide with high levels of flight activity, mating and emigration of females from the colony.

6. Progressive tightening of the energy balance due to increasing nocturnal temperatures from northern to southern California coastal areas may limit the southern distribution and duration of overwintering aggregations.
The effects of host‐plant distribution and local abundance on the species richness of agromyzid flies attacking British umbellifers
Authors: FOWLER SIMON V. , LAWTON JOHN H.
Published: March 2008

Abstract. 1. The number of agromyzid species (Diptera: Agromyzidae) attacking British Umbelliferae generally increases with the size of the geographic range of the host, measured as occupied 10 km squares in the Atlas of the British Flora (Lawton & Price, 1979).

2. In the present study we tried to explain the large, residual variation in this species—area relationship using two new variables, namely the local abundance of the host plant, and the number of habitats within which it grows.

3. Local abundance was estimated from eight floras that map plant distributions within English countries by tetrads (2 times 2 km squares). Local abundance was defined as:

Total number of occupied tetrads

Total number of available tetrads within occupied 10 km squares

4. The number of habitats occupied by each host plant was taken from the only county flora to record plant habitats objectively, that for Warwickshire.

5. We expected to find a correlation between local abundance and the residuals from the national species—area relationship, with locally scarce plants having fewer agromyzids than expected from the sizes of their national ranges, and vice versa.

6. What we found was that size of geographic range and local abundance were highly correlated; hence their relative contributions to agromyzid species richness were difficult to disentangle. Residuals from the national species—area relationship were positively correlated with local abundance, but the relationship marginally failed to achieve statistical significance (P= 0.06).

7. In contrast, the number of habitats occupied by each species of umbellifer in Warwickshire had a marked effect upon agrornyzid species richness, with plants that grow in more habitats supporting more species of insects. Not surprisingly, local abundance and number of habitats occupied were highly correlated.

8. Lawton & Price's observation that aquatic umbellifers are faunally impoverished now emerges as part of the general effect of number of habitats occupied by the host plants on agromyzid species richness.

9. Once the number of habitats occupied by each host plant in Warwickshire was entered into a multiple regression, the effect of size of host geographic range on agromyzid species richness was no longer statistically significant.

10. A combination of the number of habitats occupied, and leaf‐form of the host (the latter taken from Lawton & Price, 1979), explains 61% of the variation in agromyzid species richness on British Umbelliferae.
Nest construction and larval behaviour of Onitis belial and Onitis ion (Coleoptera, Scarabaeidae)
Authors: KLEMPERER H. G.
Published: March 2008

Abstract. 1. Female beetles working alone or in cooperation with a male buried dung to make brood masses. O.belial brood masses were packed close together in clusters; each mass was constructed as a horizontal thick‐walled tube of dung which was filled with a dung sausage containing two to six eggs. O.ion made vertical sausage‐shaped brood masses with one to four eggs.

2. The larvae of both species were able to survive in artificial brood balls as well as in multi‐egg brood masses because of their ability to repair larval chambers with their own excrement.

3. The multi‐egg brood mass of Onitis has probably evolved from a simple one‐egg brood mass. It does not resemble the underground dung mass from which brood balls are made by certain Coprini.
Diurnal periodicity of fight in some Delphacidae and Cicadellidae associated with rice
Authors: PERFECT T. J. , COOK A. G.
Published: March 2008

Abstract. 1. The diurnal periodicity of flight of delphacids and cicadellids associated with rice was assessed by suction trapping.

2. All the delphacids examined and most cicadellids showed a bimodal, crepuscular pattern of flight, the major peak occurring in the evening.

3. Some cicadellids showed a unimodal crepuscular pattern of flight activity with the peak occurring in the evening, whereas flight activity of Cofana spectra and Cunimaculata continued throughout the night.

4. Changes in the periodicity of flight activity of Nilaparvata lugens, Sogatella furcifera, Recilia dorsalis and Macrosteles striifrons were observed in relation to phases of the moon and the nature of the habitat.

5. Periodicity of take‐off for N.lugens, Sfurcifera and R.dorsalis assessed by canopy net traps also showed a bimodal, crepuscular pattern with the major peak occurring in the evening.

6. The significance of diurnal periodicity is discussed in relation to the flight behaviour of the insects studied.
The assessment of arboreal insect fauna: comparisons of knockdown sampling and faunal lists
Authors: SOUTHWOOD T. R. E. , MOW V. C. , KENNEDY C. E. J.
Published: March 2008

Abstract. 1. A comparison is made between the fauna of six British tree species sampled by pyrethrum knockdown and the faunal lists in the literature for the same tree species.

2. Conspecific trees vary both in abundance of arthropods and their proportional distribution across taxa, but there are important overriding differences between tree species.

3. The percentage similarity in faunal composition between tree species reflects the ecological specificity of the arthropod groups used for the comparison.

4. The similarity in species composition between tree species is least for phytophages, the guild most closely associated with particular tree species, The two species of Salix are most similar in their fauna for most guilds.

5. About 40% of the entirely phytophagous species in the faunal lists for native trees were found in the knockdown samples.

6. The proportion of individuals of predominantly phytophagous taxa collected that belong to the relevant faunal lists ranges from 0.39 to 0.99.

7. Those species found in the knockdown samples which are not included in faunal lists none the less contribute to the trophic web of the tree.

8. The relative species richness of arboreal faunas assessed from knockdown samples parallels that derived from faunal lists.

9. The two approaches to the categorization of arboreal faunas, knockdown sampling and faunal lists, provide comparable data.
Factors affecting equal catchability in two swallowtail butterflies, Papilio polyxenes and P.glaucus
Authors: LEDERHOUSE ROBERT C.
Published: March 2008

Abstract. 1. Recapture probabilities were analysed for individually marked black swallowtails, Papilio polyxenes F., and tiger swallowtails, P.glaucus L. (Lepidoptera: Papilionidae).

2. Recapture rates differed with sex and behaviour at time of capture for P.polyxenes, but not with age. For P.glaucus, only differences related to behaviour at time of capture were significant.

3. Black swallowtail males that were not physically restrained in identification had a recapture probability (73%) that was significantly higher than the 45% for males that were captured and handled. The higher rate was also exhibited by released, laboratory‐reared males.

4. The capture effect was due to increased dispersal out of the areas and not to avoidance of capture or the capture site.
Host selection and egg allocation behaviour by Aphytis melinus and A.lingnanensis: comparison of two facultatively gregarious parasitoids
Authors: LUCK ROBERT F. , PODOLER HAGGAI , KFIR RAMI
Published: March 2008

Abstract. 1. The ovipositional and egg allocation behaviour of individual females of Aphytis melinus DeBach and A.lingnunensis Compere were compared.

2. Both Aphytis species exhibit the same behavioural sequence during oviposition.

3. Aphytis melinus laid most of its female eggs on the dorsum of a scale‐insect beneath its cover, and most of its male eggs under the scale‐insect's body. Aphytis lingnanensis also oviposited both dorsally and ventrally on scale‐insect hosts, but female and male progeny arose with equal frequency from eggs laid in both locations.

4. Both A.melinus and A. lingnanensis are facultatively gregarious parasitoids. The degree of gregariousness depends on host size, i.e. the larger the host, the more the Iikelihood that several eggs will be deposited at each visit by the parasitoid.

5. When two eggs were laid during the same host visit, both A.melinus and A.lingnanensis laid one female and one male egg more often than would be expected under an assumption of random allocation of sexes.

6. Because A.melinus successfulIy utilize smaller hosts than A.lingnanensis to produce progeny, these parasitoids should not be considered ecological homo‐logues, as suggested by DeBach & Sundby (1963).
Foliar nitrogen and larval parasitism as determinants of leafminer distribution patterns on Spartina alterniflora
Authors: STILING PETER D. , BRODBECK BRENT V. , STRONG DONALD R.
Published: March 2008

ABSTRACT, 1. In northwest Florida, Hydrellia valida hew (Diptera: Ephydridae) frequently mines the leaves of salt marsh cord, grass, Spartina alterniflora. Larvae and pupae are more commonly found in shoreline plants within 3 m of the sea than in inland plants.

2. Shoreline plants contain over twice as much total foliar nitrogen as inland plants. In transects from inland to shoreline plants, leafminer density is positively correlated with total leaf nitrogen content.

3. We experimentally increased foliar nitrogen content on inland Spartina patches to levels above those of shoreline plants. Leafminer densities on experimental centres remained far below those on control edges.

4. Larval parasitism by Opius sp. (Hymenoptera: Braconidae) and Pteromalus sp. (Hymenoptera: Pteromalidae) reaches over 90%, with parasitism increasing from shoreline to inland plants. We suggest that gradients in leafminer densities are caused by differences in parasitoid abundance.
Phenotypic variability in nesting success among Osmia lignaria propinqua females in a glasshouse environment: (Hymenoptera: Megachilidae)
Authors: TEPEDINO V. J. , TORCHIO P. F.
Published: March 2008

Abstract. 1. The phenotypic variability of several estimates of fitness among seventeen nesting female O.lignaria Cresson was examined in a glasshouse provided with abundant resources.

2. Females exhibited wide variation in: (a) number of nests and cells made and in their rate of construction, (b) the incidence of mortality of offspring, and (c) the percentage of male offspring produced (52–100%).

3. In confirmation of earlier field studies: (a) more offspring of both sexes were produced during the first half of the nesting season, (b) most female offspring were produced early in the nesting season, (c) most parental investment during the last half of the flight season was made in male offspring, (d) there was a decrease in offspring size with season, with females decreasing more than males, and (e) the ratio of female/male body weight was = 1.8. These results appear to be due to ageing rather than to a reduction in resource availability.

4. No relation between female size and fecundity was evident.

5. There was no evidence that small females tended to produce a greater proportion of the smaller sex (males) than did large females.

6. Smaller offspring of both sexes had a much greater probability of dying overwinter than did large offspring. However, where the sexes overlapped in size (large males, small females), almost all females died and almost all males survived. We hypothesize that as size of offspring produced declines with season, a greater proportion of males are produced because they have a much greater probability of surviving at small body sizes.
Further evidence for windborne movement of armyworm moths, Spodoptera exempta, in East Africa
Authors: TUCKER M. R. , MWANDOTO S. , PEDGLEY D. E.
Published: March 2008

Abstract. 1. Comparison of dominant wind directions with seasonal redistribution of Spodoptera exempta caterpillar outbreaks in East Africa provides further circumstantial evidence to support the hypothesis of downwind migration by adult moths.

2. Calculated backward and forward tracks for sixty‐nine nights during the 1973–74 and 1974–75 seasons, when there were sudden increases in numbers of moths caught at six light traps, illustrate the variability of downwind movement due to the effects of temporary atmospheric disturbances.

3. Comparison of calculated tracks with known outbreaks before and after the nights of increased moth catch suggests that some outbreaks are derived from unreported sources, especially eariy in the season, and it is therefore unwise to link new outbreaks only with known earlier ones.
Role of two phoretic mites in transmission of bluestain fungus, Ceratocystis minor
Authors: BRIDGES J. ROBERT , MOSER JOHN C.
Published: March 2008

ABSTRACT.

Tarsonemus mites phoretic on southern pine beetles were shown to be hypervectors of bluestain fungus, Ceratocystis minor (Hedgcock 1906).

Beetles with phoretic mites had significantly more C.minor than did mite‐free beetles.

Over 90% of tarsonemid mites collected from beetle‐infested inner bark and 59% of mites phoretic on emerging beetles carried C.minor spores.

This association is an interesting example of a three‐way mutualism among insects, mites and fungi.
The effect of larval photoperiod on pupal colour and diapause in swallowtail butterflies
Authors: HAZEL WADE N. , WEST DAVID A.
Published: March 2008

ABSTRACT.

There are significant differences in the effects of larval photo‐period on diapause and pupal colour among the speciesPapilio polyxenesFabr.,P.troilusL.,Battus philenor(L.) andEurytides marcellus(Cramer).

Diapause and pupal colour inP.polyxenesandP.troilusare strongly influenced by larval photoperiod, short photophase eliciting brown diapausing pupae. Photoperiods of 15L:9D permit the expression of the green and brown pupal colour alternatives.

Pupal colour inB.philenorandE.marcellusis not affected by larval photoperiod, but short photophase induces diapause in these species.

All species exceptB.philenorshow an association between brown pupal colour and diapause:Emarcelluswhen reared on long (midsummer) photophase,P.polyxenesandP.troiluswhen reared on short (autumnal) photophase.

InP.polyxenes, short photophase can affect pupal colour responses directly, whether the individual enters diapause or not.

Differences among the species are related to differences in the ecology of their natural pupation sites.
Brood ball construction by the non‐brooding CopriniSulcophanaeus carnifexandDichotomius torulosus(Coleoptera, Scarabaeidae)
Authors: KLEMPERER H. G.
Published: March 2008

ABSTRACT.

Feeding burrows made byS.carnifexandD.torulosusadults consisted of tunnels filled with sausage‐shaped masses of dung. Brood balls were made by taking fragments of dung from an adjacent feeding burrow and aggregating them into a small sphere which was gradually enlarged and then coated with soil.

S.carnifexadult females showed no response to their own eggs (unlikeCopris lunaris:Klemperer, H.G. (1982)Ecological Erltonzology, 7, 155–167).S.carnifexlarvae made and maintained an air channel to the upper pole of the ball and they are in this respect preadapted to receive parental care.

Compared with a brood mass, a brood ball was less likely to be attacked by Meptoparasitic larvae. The soil coat retarded drying of the brood ball by increasing the total mass of moisturecontaining material.
Ecophysiological aspects of bruchid reproduction. I. The influence of pod maturity and seeds of Phaseolus vulgaris and the influence of insemination on the reproductive activity ofZabrotes subfasciatus
Authors: PIMBERT MICHEL P. , PIERRE DOMINIQUE
Published: March 2008

ABSTRACT.

Economically important bruchid beetles like Zabrotes sub‐fasciatus (Boh.) are able to reproduce both in the field before the legume crop harvest – whilst the seeds are still enclosed within pods – and on seeds in storage sites.

To take into account this reproductive feature, the influence of pods at different stages of maturity and seeds of Phaseolus vulgaris (Lin.) together with the influence of insemination on the reproductive activity of Zabrotes subfasciatus were examined.

Female fecundity, insemination and ovarian production were studied under laboratory conditions approximating as closely as possible to the thermal and photoperiodic regimes of the Costa Rican region from which the experimental strain originated.

The three stages of pod maturity used in experiments (fresh green, fresh yellow and dry yellow pods, all non‐dehiscent) induced copulations and significantly stimulated oogenesis. Fecundities of females in the presence of pods were low and did not differ from controls.

The influence of bean seeds on female reproductive activity was more pronounced than that of pods. Contact with seeds led to a marked increase in the number of sexual meetings, ovarian production and egg‐laying activity. Under these conditions, eggs are laid directly on the larvae's food.

Insemination alone stimulated oogenesis but did not induce egg‐laying.

Possible additive or synergistic interactions between host plant information perceived by females, the effects of egg‐laying and insemination are suggested to explain the observed results.

The adaptive value of this form of reproductive regulation by host plant seeds and pods is discussed in terms of the natural history and oviposition behaviour of Zabrotes subfasciatus.
Pupal colour dimorphism in California Battus philenor: pupation sites, environmental control, and diapause linkage
Authors: SIMS S. R. , SHAPIRO A. M.
Published: March 2008

ABSTRACT.

Natural pupation sites and corresponding pupal colour (green or brown) were determined for samples of Battus philenor (L.) from two Californian populations.

Larvae pupate off the ground on trees, shrubs and man‐made objects.

The vertical distribution of pupation sites and relative frequencies of pupae formed on narrow twigs and broad substrates show interpopulation variability, and seem to be determined by habitat‐specific and possibly behavioural differences among populations.

The percentage of‘mismatched’pupae in green leafy environments (brown) is greater than that on wide substrates (green). Heterogeneity in samples of the latter suggest strong but sporadic predation pressure on non‐cryptic pupae in exposed areas.

Green and brown substrates generally promoted formation of cryptic green and brown pupae although rearing conditions modified pupal colour response to substrate colour and larval pupation site choice.

Warm temperatures and long days increased the production of brown pupae. Short photoperiods increased the tendency of larvae to pupate on narrow twig‐like substrates and to form green pupae.

Green pupae show less tendency to diapause than brown pupae. The difference between percentage diapause in the two colour forms increases under conditions favouring progressively more continuous development.
Arthropod accumulation on tea in young and old habitats
Authors: BANERJEE BARUNDEB
Published: March 2008

ABSTRACT.

A comparison is made of the number of species of arthropods that inhabit tea plants in young and old habitats. Tea plants of comparable age harbour more species in old habitats than in young habitats.

In both young and old habitats, there is an initial rise in the number of arthropod species on young tea upto 11 years: in the intermediate phase, i.e. between 12 and 21 years, a sharp decline in species numbers occurs followed by a rapid increase between 22 and 36 years, and a final drop after 36 years. These phases are characterized by sap‐feeding mites and insects; leaf eaters and defoliators; stem and root borers; and termites and wood‐eating insects respectively.

Attracting abilities of the plants of different age‐groups vary according to their morphological, and physiological attributes depending on their locations in young and old habitats.

Diverse species of arthropods coexist on tea by developing their own niches in different parts of plants; they apparently avoid interspecific competition by maintaining their numbers at low density.
Cyanide as a feeding stimulant for the southern army worm, Spodoptera eridania
Authors: BRATTSTEN L. B. , SAMUELIAN J. H. , LONG K. Y. , KINCAID S. A. , EVANS C. K.
Published: March 2008

ABSTRACT.

All instars of Spodoptera eridania larvae grow as well or better when cyanide is present in their diet as when it is absent. Concentrations up to 0.05% stimulate feeding in first to fourth instar larvae. Concentrations from 0.1% to 1.0% stimulate feeding in fifth and sixth instar larvae.

Three‐day‐old sixth instar larvae pre‐exposed to cyanide are completely resistant to its acutely toxic effects, but previously unexposed larvae suffer reversible symptoms of poisoning when feeding on a diet containing 1.0% KCN.

A 1.0% dietary KCN exposure during the sixth instar reduces ecdysis to 17% adult emergence and completely inhibits oviposition.

Cyanide concentrations from 0.5% to 1.0% in the diet, although effecting increased growth rates, induce necrotic lesions in larval mid‐gut epithelial cells.

Thiocyanate, one of the in vivo cyanide metabolites, at 0.5% in the diet reduces pupation to 23%, delays and reduces adult emergence to 20% and inhibits oviposition.

The preferred host plant of S.eridania is the lima bean, Phaseolus lunatus, probably due to its content of the cyanogenic glycoside linamarin. Dietary valine has no effect on the southern armyworm feeding and growth behaviour (Long & Brattsten, 1982) but dietary cyanide does. The lima bean is known to contain up to 31 ppm cyanide in some varieties.
Orientation behaviour in the Grayling butterfly: thermoregulation or crypsis?
Authors: FINDLAY ROBIN , YOUNG MARK R. , FINDLAY JOHN A.
Published: March 2008

ABSTRACT.

Body orientation and wing tilting in Hipparchia semele (L.) have been explained previously both by the need for shadow‐minimization (crypsis hypothesis) and by the need to regulate body temperature (thermoregulation hypothesis).

This study tests the thermoregulation hypothesis by quantifying butterfly orientation in relation to sun position, using vector analysis, and correlating the data with ambient temperature and time of day.

During sunshine, Graylings tend to present a maximal wing area to the sun's rays when the ambient temperature is relatively low, and a minimal area when it is high ('sunning’and‘heat‐avoiding’positions respectively).

On cool sunny days, butterflies adopt sunning positions throughout the day, whereas on warm sunny days they adopt sunning positions during the outlying periods and heat‐avoiding positions in the middle period of the day. Correlations between wing exposure and both ambient temperature and time of day are statistically significant for warm sunny days.

During overcast weather, butterfly orientation is very variable and possibly random.

Analysis of sunny day data supports the thermoregulation hypothesis. This is discussed in relation to other known types of thermoregulatory behaviour observed in this species: stilting, shade‐seeking, ground‐hugging and shivering.

Conversely, the results do not support the crypsis hypothesis.
Estimating the susceptibility of tree species to attack by the gypsy moth, Lymantria dispar
Authors: LECHOWICZ MARTIN J. , JOBIN LUC
Published: March 2008

ABSTRACT.

Numbers of gypsy moth larvae feeding on each of 922 randomly sampled trees in a Quercus—Acer—Fraxinus forest in southwestern Quebec, Canada were counted in 1979 and in 1980 to quantify the larval feeding preferences as observed in the field for eighteen deciduous and one coniferous tree species at the northern range limit of the gypsy moth.

Both the diameter at breast height (dbh) and the estimated foliage biomass of the sampled trees were used to calculate the relative proportions of foliage represented by each of the nineteen tree species in the forest canopy. With these data on availability and utilization of the tree species by the gypsy moth larvae an Ivlev‐type electivity index was used to quantify the larval feeding preferences. These preferences observed in the field define the susceptibility of a tree species to attack by the gypsy moth.

The feeding preferences calculated using estimated foliage biomass were comparable to the simpler calculation based on dbh (Spearman's rho = 0.79; P= 0.0001). The dbh‐based feeding preferences remained almost unchanged in 1979 and 1980 (Spearman's rho = 0.83; P= 0.0001).

The composite 1979—80, dbh‐based feeding preferences show Quercus rubra, Populus grandidentata, Ostrya virginiana, Amelanchier spp. and Acer saccharum were preferentially attacked by gypsy moth. Prunus serotina, Betula lutea, Acer rubrum, A. pensylvanicum, Fraxinus americana, Ulmus rubra, P. pensylvanicum and B. papyrifera were avoided. All nineteen tree species were, however, utilized to at least some degree by gypsy moth larvae.

These results quantitatively affirm and clarify earlier reports of gypsy moth feeding preferences in North America and Eurasia. The advantages and limitations of using an electivity index to estimate the susceptibility of different tree species to attack by folivores like the gypsy moth are discussed.
Asymmetrical competition and amensalism through soil dumping by the ant, Myrmicaria natalensis
Authors: SAMWAYS M. J.
Published: March 2008

ABSTRACT.

Myrmicaria natalensis (Smith) (Hym: Formicidae) is a large, predaceous ant that excavates large amounts of soil during nest construction.

During the winter, 25% of its nests went extinct through resistance and aggression from allospecific ants. The remaining 75% thrived, although one nest was forced to move, but did not go extinct, through intense competition.

The surviving fifteen M.natalensis nests obliterated forty‐one allospecific nests by covering them with excavated soil.

During spring, M.natalensis nests expanded rapidly and none went extinct, so there was no longer asymmetrical competition but total amensalism in favour of M.natalensis.

Implications for ant management are that control by trunk banding of honeydew‐seeking ants will increase asymmetry towards M.natalensis through positive feedback. This is desirable in that M.natalensis is a highly predaceous ant of pests such as lepidopteran larvae.
Influence of environmental factors on daily flight activity of the filbertworm,Melissopus latiferreanus(Lepidoptera, Olethreutidae)
Authors: ALINIAZEE M. T.
Published: March 2008

ABSTRACT.

Flight ofMelissopus latiferreanus (Walsinghzm), the filbertworm, was influenced by a number of environmental factors including temperature, wind, and rainfall.

FewM. latiferreanusmoths were trapped in light or suction traps or found in sweep nets samples when air temperatures were above 31°C or below 15°C. Moth captures were optimum when prevailing temperature was between 21 and 26°C.

Typically moth flights began at about sunset and continued throughout the night with a peak at 22.00 hours, about an hour after sunset.

Very few moths were trapped under showery and gusty conditions when wind velocity was over 16km h−1.

More moths were captured in light traps during dark nights than on full moon nights. The pattern of captures indicated that females flew earlier than males.
Divergence in larval responses to food plants between temperate and tropical populations of the black swallowtail butterfly
Authors: BLAU WILLIAM S. , FEENY PAUL
Published: March 2008

ABSTRACT.

Larvae of the black swallowtail butterfly, Papilio polyxenes Fabr., from New York and Costa Rica were reared under the same environmental conditions on Daucus carota L. and Spananthe paniculata Jacq. (Umbelliferae), which are the host plants most commonly used by the two populations, respectively. Feeding rates, growth rates and feeding efficiencies of the fifth instar larvae were measured by standard techniques.

Larvae from each population grew faster on the host‐plant species from their region of origin than did larvae from the other population, though differences on S.paniculata were not significant. On D.carota the faster growth by New York larvae was attributable to greater efficiency. On S.paniculata, by contrast, the somewhat faster growth by Costa Rican larvae seemed to have resulted chiefly from faster feeding. The two populations have thus come to differ in metabolic and, probably, behavioural responses to host plants.

S.paniculata was a superior host plant for larvae of both populations, even though the total energy, nitrogen and water content of its foliage was similar to that of D.carota.

These results are consistent with the hypothesis that insects in the two populations have diverged in adaptation to their host plants following curtailment of gene flow between them as the species colonized Central America from the north.