bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trapping as a means of controlling tsetse, Glossina spp. (Diptera: Glossinidae): the relative merits of killing and of sterilization
Authors: Langley P. A. , Weidhaas D. 
Published: July 2009

AbstractA deterministic simulation model for Glossina spp. based upon a simple life-history analysis was used to test a variety of effects designed to cause a decline in population numbers. Average daily survival values for pupae were varied to make populations grow at different rates. All age classes were then updated for all life stages each day for a 12-month period. As expected, the population remained stable when Ro = 1·0, and the population doubled in 105 days when Ro = 2·0. Sub-routines were added to test the effects of trapping 0·5 to 2·5% of the population per day and killing both sexes, sterilizing and releasing both sexes or sterilizing and releasing males only, the females not being trapped. Results suggest that killing or sterilizing both sexes is always superior to sterilizing males only and leaving the females unharmed but that this superiority is diminished when either population growth rates are low (<1·0) or trapping rates are high (>2·0% per day). As population growth rate increases or trapping rates decline, there is a proportionately greater advantage to be gained by sterilizing both sexes than by adopting either of the other two strategies. A situation is illustrated where for a trapping rate of 1% per day within a population that is doubling at close to its optimal rate (Ro = 2·0) sterilization of both sexes is the only strategy which will cause a population decline. Results are discussed in terms of development of low technology, cost-effective methods of tsetse control which are non-polluting and therefore environmentally acceptable.
A revision of the west Palaearctic pear psyllids (Hemiptera: Psyllidae)
Authors: Burckhardt D. , Hodkinson I. D. 
Published: July 2009

AbstractThe status and taxonomy of the west Palaearctic Pyrus-feeding psyllids are reviewed, and keys for the identification of adults and larvae are given. The species, now referred to the genus Cacopsylla, have been much confused. They are shown to comprise seven distinct species: C. pyrisuga (Förster), C. pyri (L.) (summer form pyrarboris, winter form pyri), C. pyricola (Förster) (summer form pyricola, winter form simulans), C. bidens (Šulc) (summer form vasilevi syn. n., winter form bidens), C. notata (Flor) sp. rev., C. permixta sp. n. (= simulans sensu Loginova and Gegechkori nec Förster) and C. fera (Baeva). Psylla horvathii Šulc and P. vicina Šulc are synonymized with C. pyricola; P. picta is regarded as a nomen dubium. Information is given on the host-plants and distribution of each species.
The breeding requirements of three members of the Anopheles gambiae Giles complex (Diptera: Culicidae) in the endemic malaria area of Natal, South Africa
Authors: Sueur David le , Sharp Brian L. 
Published: July 2009

AbstractThe breeding sites used by three species of the Anopheles gambiae Giles complex were investigated in northern Natal, South Africa. Those used by the two freshwater species, A. arabiensis Patton and A. quadriannulatus (Theobald) were similar, immature stages of both being collected from the same pool at five out of seven localities from which A. arabiensis was recorded. A. quadriannulatus was the most extensively distributed species of the complex and was found in association with A. arabiensis at only five of 49 localities. The difficulty in locating the breeding sites of A. arabiensis is a product of their low density, presumably as a result of the intra-domiciliary, residual insecticide spray programme. A. merus Dönitz larvae and pupae were recorded only in water with a salinity greater than 5 p.p.t. The pH, dissolved oxygen, pool size, turbidity, shade and association with vegetation of water bodies containing A. gambiae s.l. were also recorded and showed no difference between the three species. The importance of distinguishing between winter and summer breeding sites is discussed, as well as the need for entomological consultation prior to agricultural development in endemic malarious areas.
Models for combining methods of pest control: food-baited and pheromone-baited traps containing either insecticide or chemosterilant
Authors: Barclay Hugh J. 
Published: July 2009

AbstractFour models are presented which represent the four combinations of two trap types (food-baited or pheromone-baited), each containing either insecticide or chemosterilant. These were then modelled in combination to determine which combinations might be useful for controlling arthropod pest species in which the virgin females produce sex pheromone which attracts males. The most promising results occurred in combinations involving different trap baits but the same pesticide type, i.e. where one trap contains food bait while the other contains sex pheromone, and both contain either insecticide or chemosterilant. This conforms to the principle of complementarity of control methods and at the same time avoids the interference which would occur if insecticide was used in one trap type and sterilant in the other.
Development, oviposition, host feeding and sex determination inEpidinocarsis lopezi(De Santis) (Hymenoptera: Encyrtidae)
Authors: Umeh Ethel-Doris N. 
Published: July 2009

AbstractEpidinocarsis lopezi(De Santis) was found to parasitize and complete development in all developmental instars of its host,Phenacoccus manihotiMatile-Ferrero. However, parasitoid mortality was high (15·8%) when development took place in the first nymphal instar of the host. Complete development from egg to adult emergence was prolonged in smaller hosts, and developmental periods recorded were 18·8, 17·4, 16·1 and 14·9 days for the first, second, third and fourth nymphal instars, respectively. Irrespective of the age of the host parasitized (with which size is strongly correlated),E. lopezicompleted only one life-cycle during one life-cycle ofP. manihoti. Oviposition commenced within 24 h of emergence and lasted effectively for six days, during which 95% of its eggs were laid and 10·8 large hosts were killed through host feeding. Unmated females ofE. lopeziare arrhenotokous, laying only male eggs; eggs laid by mated females produced males and females in the ratio of 1:3 in favour of females.
The location of floral nectar sources by mosquitoes: an advanced bioassay for volatile plant odours and initial studies withAedes aegypti(L.) (Diptera: Culicidae)
Authors: Jepson P. C. , Healy T. P. 
Published: July 2009

AbstractThe development and testing of a bioassay system to evaluate the potency of floral odours as mediators of long-range floral nectar source location by mosquitoes are described. The bioassay is quantitative and behaviourally discriminating, upwind flying and landing acting as indices of behavioural activity over the 24-h light:dark cycle. In initial tests, the responses ofAedes aegypti(L.) to the flowers and floral odours of ox-eye daisy (Leucanthemum vulgare) were investigated.A. aegyptiexhibited a biphasic diel cycle of nectar-feeding behaviour and landed on modified flowers that retained either their disc or ray florets. Most significantly, the mosquitoes responded in a similar way to the odour ofL. vulgarein the absence of visual stimuli or nutritional cues. They did not respond to solvent extracts of ox-eye daisy flowers.
Differential survival of British and Mediterranean strains of Pieris rapae (L.) (Lepidoptera: Pieridae) on different brassica cultivars
Authors: Gilbert N. , Coaker T. H. 
Published: July 2009

AbstractIn laboratory and field trials in the UK, larvae of Pieris rapae (L.) from the UK survived better than larvae from the Mediterranean region on Brussels sprouts, broccoli and field kale. A similar difference, associated with latitude, was found in Australia. The implications of these results are discussed.
The abilities of the aphid parasitoids Aphidius ervi Haliday and A. rhopalosiphi De Stefani Perez (Hymenoptera: Braconidae) to transfer between different known host species and the implications for the use of alternative hosts in pest control strategies
Authors: Powell W. , Wright A. F. 
Published: July 2009

AbstractA series of host-transfer trials using both laboratory-cultured and field-collected individuals of the aphid parasitoids Aphidius ervi Haliday and A. rhopalosiphi De Stefani Perez were done in order to clarify inconsistent results from several previous studies. A. ervi cultured on Acyrthosiphon pisum (Harris) produced very few mummies when confined with Microlophium carnosum (Buckton), whereas those cultured on M. carnosum produced as many mummies on A. pisum as they did on their original host. Mummy production was correlated with the attack rate of adult parasitoids on potential hosts. The production of mummies on M. carnosum by parasitoids reared on A. pisum was often greatly improved if their male parent had been reared on M. carnosum, suggesting that genotype strongly influences host preference. Aphidius rhopalosiphi from laboratory cultures produced significantly more mummies on Metopolophium dirhodum (Walker) than on Sitobion avenae (F.) regardless of their original host, but this preference was not shown by parasitoids from field populations. It is concluded that inadvertent selection occurs in laboratory cultures of aphid parasitoids as a result of low founder numbers, genetic drift and genetic bottlenecks and that this can strongly influence experimental results in biology and behaviour studies, which has important implications for biological control workers.
Rastrococcus spp. (Hemiptera: Pseudococcidae) and their natural enemies in India as potential biocontrol agents for R. invadens Williams
Authors: Narasimham A. U. , Chacko M. J. 
Published: July 2009

AbstractRastrococcus invadens Williams, a pest of fruit and ornamental trees in West Africa, was introduced from the Oriental Region. In 1986, a search was initiated in India for natural enemies of Rastrococcus spp. with a view to selecting potential biocontrol agents for introduction into West Africa. The results of the survey, laboratory breeding of the hosts and their natural enemies and host-specificity of the natural enemies are reported. Based on host-acceptance tests, two encyrtids, Gyranusoidea tebygi Noyes and Anagyrus sp., have been sent to UK for further screening.
Rubidium marking of the rice pests Nilaparvata lugens (Stål) and Sogatella furcifera (Horváth) (Hemiptera: Delphacidae) for field dispersal studies
Authors: Padgham D. E. , Cook A. G. , Hutchison D. 
Published: July 2009

AbstractThe method and evaluation of a field application of rubidium chloride for the purpose of a mark-and-recapture experiment are described. In the Philippines, populations of the rice pests Nilaparvata lugens (Stål) and Sogatella furcifera (Horv.) were successfully marked by a foliar spray of rubidium chloride plus surfactant applied to a rice field at 1·03 g/hill. Individual insects marked with rubidium, which were easily distinguishable from unmarked individuals for at least seven weeks, were generated at this dose level, and even after one year elevated rubidium levels could be detected in pooled samples. Other phytophagous and entomophagous insects also became marked.
Decision trees to assess the risk of cereal aphid (Hemiptera: Aphididae) outbreaks in summer in England
Authors: Dewar Alan M. , Carter Nick 
Published: July 2009

AbstractRecent studies on the ecology of two cereal aphid species, Sitobion avenae (F.) and Metopolophium dirhodum (Wlk.), are reviewed. The most important factors affecting their abundance were used to construct decision trees to assess the risk of outbreaks of these species in the summer in England. These factors for S. avenae were crop sowing date, the size of the autumn migration, the severity of the winter, the size of the spring migration and the incidence of natural enemies in spring and early summer. For M. dirhodum, only the last two factors were considered as it does not occur on cereals until the spring in England. These decision trees were successfully tested using field data from 1983, when no outbreaks of either species occurred due to the effects of natural enemies.
Local variation in the population dynamics of Glossina palpalis palpalis (Robineau-Desvoidy) (Diptera: Glossinidae). II. The effect of insecticidal spray programmes
Authors: Randolph Sarah E. , Rogers David J. , Kuzoe Felix A. S. 
Published: July 2009

AbstractAn analysis of the population changes of Glossina palpalis palpalis (R.-D.) during and after two insecticide trials in Ivory Coast revealed that the effects of insecticide application depend very strongly on the characteristics of the population ecology of the fly, which showed considerable local variation. At sites with high fly populations and low natural mortality rates, the populations declined rapidly during the spray period as the insecticide killed a large proportion of the local, mainly resident, population. The high resilience of the populations, however, permitted rapid recovery, largely through reinvasion from neighbouring areas, so the reduction in fly numbers lasted for only 3–4 months at a time of year when, in the absence of insecticide, the population showed a significant seasonal decline lasting for up to three months. At other sites, with low populations and high natural mortality rates, the local populations were supported chiefly by immigrants and therefore insecticides only affected a very small proportion of the total population and thus did not cause an immediate decline in fly numbers. The low resilience of these populations, however, means that any repeated low additional mortality (such as that caused by removal trapping or deterioration of environmental conditions) would cause the populations to decline. Thus at both types of site, but for rather different reasons, single or short-term insecticide applications had a limited effect on the populations, and longterm, repeated control procedures are considered to be the only ones likely to reduce the populations significantly; through economic necessity these must rely on low-technology devices such as insecticide-impregnated screens or traps.
A population study of the coconut pest Segestidea uniformis (Willemse) (Orthoptera: Tettigoniidae) on an equatorial island
Authors: Room P. M. , Perry C. H. , Bailey P. T. 
Published: July 2009

AbstractA population of the coconut pest Segestidea uniformis (Willemse) was monitored on a small island 2° from the equator in Papua New Guinea between 1973 and 1978. Totals of 54 000 first-instar nymphs were caught on sticky traps on palm trunks and 8750 other nymphs and adults were recovered from the crowns of palms. Generations were completely overlapping, and there was no evidence of seasonality in population fluctuations. The sex ratio was 50:50 in the first six instars, but 90% of seventh instars and 30% of adults were female. Explanations for these variations are given. The population declined from an annual mean of 24 individuals of all ages per palm crown in 1973 to 9 in 1976 and increased again to 29 in 1978. Most post-hatching mortality occurred as first instars climbed from the ground to the crown of palms, probably due to the lizard Gehyra oceanica and rainfall. The number of adults was more sensitive to mortality occurring after the first instars had arrived in the crowns. This mortality appeared to be related to the duration of periods without rainfall, supporting earlier observations that damaging outbreaks of S. uniformis populations do not occur in places which experience a regular dry season. Production of coconuts appeared to be inversely related to the population density of S. uniformis, which did not rise above a level estimated to cause 20% defoliation of the palms during the study. Nut production also seemed to be related to the number of hours of sunshine received in the preceding 12 months. Biological control aimed at nymphs and adults in palm crowns is suggested as an option for controlling S. uniformis which deserves investigation.
An assessment of some methods for the bioassay of changes in cattle dung as insect food, using the bush fly, Musca vetustissima Walker (Diptera: Muscidae)
Authors: Matthiessen J. N. , Haylesa L. , Palmer M. J. 
Published: July 2009

AbstractSeveral methods for the bioassay of changes in cattle dung as insect food were defined and simultaneously assessed using Musca vetustissima Wlk. Size of emerging adults, in particular head width, was a reliable estimator of changes in the dung, but survival was not. Freezing of dung for 24 h had no effect. Flies of similar size emerged from dung placed on moist sand (field capacity moisture) and on an impermeable membrane; on dry sand, size was greatly reduced when the dung was coarse and less nutritious. The optimal method was deemed to be use of fresh dung on sand at field capacity moisture, leaving flies to emerge and die before measuring the head widths in a sample.
Numicia gauhati sp.n. (Homoptera: Fulgoroidea: Tropiduchidae) from rice in India, with taxonomic notes on other Indian Numicia species
Authors: Wilson M. R. 
Published: July 2009

AbstractNumicia gauhati sp.n., collected from rice in Assam, India, is described and illustrated. It is compared with other known species of Numicia from the Oriental Region. N. maculosa pusana Ghauri is raised to specific status.
Pentatomid bugs (Hemiptera) that transmit a flagellate disease of cultivated palms in South America
Authors: Dolling W. R. 
Published: July 2009

AbstractDescriptions are given of two new species of pentatomid bug, one known to transmit the disease ‘marchitez’ (caused by Phytomonas staheli) of oil palm in Ecuador and the other associated with hartrot (caused by the same flagellate) in coconut palm in French Guiana. Notes are included on a third species also associated with hartrot in French Guiana. The species are Lincus lethifer sp.n., L. apollo sp.n. and L. croupius Rolston.
Implications for comparability of laboratory experiments revealed in studies on the effects of population density on vigour in Coptotermes lacteus (Froggatt) and Nasutitermes exitiosus (Hill) (Isoptera: Rhinotermitidae & Termitidae)
Authors: Lenz M. , Barrett R. A. , Williams E. R. 
Published: July 2009

AbstractThe vigour, i.e. survival and wood consumption, of groups of Coptotermes lacteus (Frogg.) and Nasutitermes exitiosus (Hill) was measured when termites were kept at different population densities by changing group size and/or volume of the holding container. A characteristic pattern emerged for subterranean termite species. At low population densities (<0·01 g termites/ml), performance improved with an increase in group size; at higher densities, it tended to decline. The impact of altering group size and container volume on termite vigour was most pronounced at low population densities; at higher population densities, performance tended to be more stable but declined markedly when termites became overcrowded. In most jar-type experiments on termites, especially those conducted in Europe and the USA, small groups of termites are housed in disproportionately large jars, resulting in very low, sub-optimal population densities. Suggestions are made for improvement in experimental design that would lead to an enhancement of the comparability of results from different laboratories.
The relationship between pre-flight reproduction and migratory urge in alatae ofAphis fabaeScopoli (Hemiptera: Aphididae)
Authors: Kidd N. A. C. , Cleaver A. M. 
Published: July 2009

AbstractAlatae ofAphis fabaeScop. which reproduced before their first flight (flyers) were compared in the laboratory with those which did not (migrants) in order to test whether this difference in behaviour could be taken as an expression of migratory urge. No difference in live weight or dry weight could be found between the two groups. Flyers, however had a higher wingloading than migrants after the final moult but not after pre-flight reproduction. Flyers also had a lower fat/dry weight ratio than migrants and appeared to have more embryos, including a greater number in an advanced state of development. The significance of these observations is discussed in relation to two hypotheses which could account for the different behaviour of migrants and flyers. The results support the hypothesis that migrants have an innately greater urge to take off than flyers, mediated by their crowding experience during development, and that this is likely to result in migratory as opposed to trivial flight.
A new genus and species of encyrtid (Hymenoptera: Chalcidoidea) parasitic on the cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae)
Authors: Noyes J. S. 
Published: July 2009

AbstractParapyrus manihoti gen. et sp. n., an encyrtid parasite of Phenacoccus manihoti Matile-Ferrero in South America, is described from the adults of both sexes. The parasite is of potential use as a controlling agent of this mealybug in West and Central Africa where it is established as a pest of cassava.
The effect of attack by Amblypelta cocophaga China (Hemiptera:Coreidae) on growth of Eucalyptus deglupta in the Solomon Islands
Authors: Bigger M. 
Published: July 2009

AbstractReduction in growth of saplings of Eucalyptus deglupta resulting from die-back caused by Amblypelta cocophaga China was studied in forestry plantations in the Solomon Islands. At a standard spacing of 10 × 3 m, a comparison was made of tree growth and incidence of A. cocophaga attack on saplings planted in strips 2 m wide cut through secondary forest, with those from which all inter-row vegetation was cut back prior to planting. Initially, a greater proportion of trees was infested on the cleared than the uncleared plots, but at the end of the first year, at which time the attack was at its peak, no differences could be detected. From the fifth to the thirteenth month after planting out, uninfested trees on the cleared plots increased in height at an average rate of 60 cm per month. For every week that at least one A. cocophaga was recorded on a tree, this rate was depressed by 1·3 cm. On the uncleared plots, the average rate of increase of uninfested trees was only 42 cm per month and this was reduced by 1·0 cm for every week that an insect was recorded. By the end of the first year, an estimated 37% (in cleared plots) and 41% (in uncleared plots) of the potential stand was rendered useless for future timber production due to A. cocophaga damage. In terms of total stem volume (not log production), about 1 m3/h out of a potential 3 m3/h was lost in the uncleared plots and 0·2 m3/h out of a potential 0·6 m3/h in the uncleared ones. Whilst clearing did not reduce the incidence of A. cocophaga attack, the advantage of clearing in terms of increased tree growth was considerable.
Age grades and infection rates of Rhipicephalus appendiculatus Neumann (Acari: Ixodidae) to assess theileriosis challenge in the field
Authors: Walker Alan R. , Fletcher June D. 
Published: July 2009

AbstractData are presented from five series of 240 adults of Rhipicephalus appendiculatus Neumann kept in the laboratory, in which a steady decline in the numbers of granules in e cells of type 3 acini of the salivary glands occurred. This was readily detected in whole gland preparations of the salivary glands stained with methyl green and pyronin, and the same specimens could be used for detecting Theileria parasites in the salivary glands. Characteristics for grading these ticks into three physiological age grades are given, and a formula is provided for incorporating the age grade with infection rate. This gives a value for comparative estimates of the challenge posed by field populations of ticks for the transmission of Theileria to cattle.