bluuebunny/crossref_metadata_2025_split huggingface dataset:
All-female broods in field and laboratory populations of the Egyptian cotton leafworm,Spodoptera littoralis(Boisduval) (Lepidoptera: Noctuidae)
Authors: Brimacombe Linda C. 
Published: July 2009

AbstractEgg-batches ofSpodoptera littoralis(Boisd.) collected in Crete showed an abnormal sex ratio; 24% yielded predominantly female adults. The field data and data from nine generations of a laboratory strain, which also produced predominantly female offspring, showed that this abnormal condition was transmitted between generations by the females. The mean percentage hatch of egg-batches collected from the field which produced females only was 59·6, and the mean percentage hatch of the eggs of the laboratory strain was 58·8. These results suggest that the production of females only is a result of the mortality of the male embryos. Occasionally, abnormal females from the laboratory strain reverted to producing offspring of both sexes. This recovery from the abnormal condition became more common as successive generations were bred in the laboratory. One female of a normal strain produced all-female offspring and descendants of this female were similarly affected. The females of the unisexual laboratory strain were similar in appearance to normal females but laid significantly smaller egg-batches.
The phenology of Oscinella spp. (Diptera: Chloropidae)
Authors: Vickerman G. P. 
Published: July 2009

AbstractCounts were made of the numbers of Oscinella adults caught in water traps in plots of grass and oats and in a suction trap in north-eastern England in 1969 and 1970. The numbers of eggs laid by O. frit (L.), O. vastator (Curt.), O. nitidissima (Mg.), O. hortensis Collin and O. maura (Fall.) on their respective host-plants were also counted. In both years, there were two generations of O. nitidissima and O. nigerrima (Macq.) and one of O. maura. In 1969, there were two generations of O. frit and one of O. hortensis and O. vastator. In 1970, there were partial second generations of O. hortensis and O. vastator and a partial third generation of O. frit. O. nigerrima was the first species to appear in the spring, followed by O. frit and O. nitidissima. O. hortensis, O. vastator and O. maura emerged later, and these species dominated the trap catches in July. The proportions of O. frit and O. nitidissima increased in August, and by late September these species again dominated the catch. The proportions of O. vastator and O. hortensis in the suction-trap catches were much lower than in the water-trap catches. Adults of all species were always found in the grassland water traps before they were found in the suction trap. The migratory requirements of other species in the genus, in particular O. maura and O. vastator, may be less than those of O. frit. The oviposition period on particular grass species was relatively long, and thus control of Oscinella spp. on grassland would be difficult.
The influence of temperature and humidity on the life-cycle of Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae)
Authors: Cox P. D. , Crawford L. A. , Gjestrud G. , Bell C. H. , Bowley C. R. 
Published: July 2009

AbstractThe development of a stock of Corcyra cephalonica (Stnt.) from Burma was followed carefully on a diet of wheatfeed, glycerol and yeast at constant temperatures ranging from 15 to 37°C and humidities from 15 to 90% RH. Two other stocks, from Nigeria and Malawi, were also studied under a few conditions. Limits for complete development from egg hatch to adult emergence were about 17 and 35°C at 70% RH. At 15°C, all larvae died early in development, but at 37·5°C a few managed to pupate. Highest survival and most rapid development occurred at 30–32·5°C and 70% RH. Development was completed in the range 15–80% RH, but few adults emerged at 15% RH and none at 90% RH unless a mould-inhibitor was present in the food. No second-generation larvae were obtained from adults reared and kept at 20°C and 70% RH. Egg period was influenced by temperature but not by humidity in the range 20–80%, RH. Eggs hatched at temperatures from 17·5 to 32·5°C. Hatch was adversely affected by low humidity, and very few hatched at 20% RH. Considerable variation in the rate of egg hatch between the three stocks may have been due to differences in the length of time each stock had been reared in the laboratory. Cold tolerance of eggs of the Nigerian stock was low. All eggs died at 10°C after a seven-day exposure, and at 15°C, although a few 0–1-day-old eggs exposed for 14 days hatched, none completed development to the adult stage. Although older eggs were slightly more cold-tolerant than younger ones at 10°C, they were less so at 15°C. Adult males tended to emerge earlier and live longer than unmated females. Adults of the recently collected Malawi stock were heavier and lived longer than those of the Burma stock that had been reared in the laboratory for many generations.
Contribution to the distribution of Glossina (Diptera: Glossinidae) in Mali
Authors: Okiwelu S. N. , Van Wettere P. , Maiga S. , Bouare S. , Crans W. 
Published: July 2009

AbstractA ground survey to map the distribution of Glossina prior to the initiation of a control programme was undertaken in an area of more than 100 000 km2 in the Sudan and Guinea savanna zones of Mali. The area extends from 11°13′ to 14°15′N. and 5°53′ to 10°24′W. The Challier-Laveissière trap was the main survey tool, but other methods were used when the traps did not catch flies in areas suspected of being suitable for Glossina. The results are compared with existing distribution maps of the area, including one based solely on interpretations of earth satellite photography of the area. Infestation by G. morsitans submorsitans Newst. was continuous west of 8°20′W. and intermittent east of this. Apparent recent advances of G. m. submorsitans and G. palpalis gam-biensis Vanderplank were noted, but G. tachinoides Westw. seemed to have receded. Possible reasons for these differences between species are discussed.
The analysis and standardisation of light-trap catches of Heliothis armiger (Hübner) and H. punctiger Wallengren (Lepidoptera: Noctuidae)
Authors: Morton R. , Tuart L. D. , Wardhaugh K. G. 
Published: July 2009

AbstractHourly and nightly catches of Heliothis armiger (Hb.) and H. punctiger Wllgr. at a site adjacent to 2000 ha of commercial cotton in the Namoi Valley of New South Wales, were analysed in relation to various environmental factors and showed that wind speed, temperature, night-length and (H. armiger only) moonlight exerted a significant influence on trap-catch. For H. punctiger and H. armiger respectively, these factors accounted for 80 and 60% of the deviance in hourly catches but only 70 and 40% of the variation in nightly catches. Wind speeds of more than 1·7 m/s suppressed the catch of both species but had a greater effect on H. punctiger than H. armiger. Whereas with both species, the optimum temperature for trapping was about 27°C, temperature had a greater influence on the catch of H. punctiger than of H. armiger. Bright moonlight was estimated to reduce the catch of H. armiger by 49%, but no significant effect was detected for H. punctiger. The analysis revealed a number of occasions for both species in which the hourly distribution of catch and/or the change in catch between successive nights was aberrant. With H. armiger, these inconsistencies appeared to be associated with changes in population due to adult emergence, whereas for H. punctiger the most likely cause seemed to be changes due to movement. The combined effects of wind speed, temperature, night-length and moonlight were used to adjust the nightly catches of each species according to the environmental conditions prevailing on a ‘ standard’ night. This was defined as a typical summer's night with temperatures decreasing from 28·8°C at dusk to 20·6°C at dawn and ideal catching conditions, i.e. no moon and wind speed never exceeding 1·7 m/s. As such, the adjusted catches could be taken as indices of moth abundance. These showed that H. armiger had three discrete periods of abundance, characterised by the presence of large numbers of young moths and spaced at intervals suggesting successive generations. A similar pattern was lacking in H. punctiger, which was abundant only during the first half of the season. Except during periods of emergence (H.armiger), or once when spraying occured during daylight, the aerial application of insecticides to the cotton adjecent to the light-trap resulted in marked reductions in the populations of both species.
Some effects of three species of dung beetles (Coleoptera: Scarabaeidae) in south-western Australia on the survival of the bush fly, Musca vetustissima Walker (Diptera: Muscidae), in dung pads
Authors: Smith T. J. Ridsdill 
Published: July 2009

AbstractThe effectiveness of three species of scarabaeids in reducing the survival of Musca vetustissima Wlk. in cattle dung was compared in laboratory experiments in Australia at 27°C in which the arthropod fauna collected in dung-baited traps in different localities at different times of year was added to one-litre dung pads containing known numbers of M. vetustissima eggs. The dung was collected from each site at the time of the experiment. Onitis alexis Klug collected in October and December at Geraldton, and Onthophagus binodis (Thnb.) collected in January at Bunbury, shredded most of the dung, reducing fly survival to 4% of that in control pads. O. binodis collected in March and October at Bunbury, and O. ferox Har. collected in May and December at Busselton, mostly buried dung, reducing fly survival to 32% of that in controls. Factors other than the numbers of beetles were also important in determining the degree of suppression of the fly.
The role of blood intake in density regulation of populations of Triatoma infestans (Klug) (Hemiptera: Reduviidae)
Authors: Schofield C. J. 
Published: July 2009

AbstractThe growth of populations of Triatoma infestans (Klug) depends on temperature and blood-intake. Experiments are described which demonstrated the density-dependent relationship between population size, blood intake and population growth at different temperatures. The number of bugs feeding and their mean blood intake was lower at high bug densities than at low ones, both with restrained chickens and with unrestrained mice as hosts. When blood intake was restricted, the development times of all nymphal stages were increased, and female fecundity was decreased. Previous work showed also that reduced blood intake led to an increased tendency for adult flight. It is thought that at high bug density the three factors, increased development times, decreased fecundity and increased flight, operate to restore the population to a stable density without promoting an increase in mortality. The mechanism linking population density to nutritional status seemed to depend on host irritability, which interrupted the bugs' feeding. Bugs which passed a certain threshold meal size would not resume feeding if interrupted, even though their blood intake was well below normal. The difference between the minimal threshold meal and a normal meal is thought to provide the nutritional elasticity within which the development processes are regulated. It is suggested that this mechanism is characteristic of K-strategists, whereas r–strategists such as mosquitoes tend to continue attacking, even if interrupted, until they achieve a normal meal.
Control of pink boll worm, Pectinophora gossypiella (Saunders) (Lepidop-tera: Gelechiidae), in Egypt by mating disruption using an aerially applied microencapsulated pheromone formulation
Authors: Critchley B. R. , Campion D. G. , McVeigh L. J. , Hunter-Jones P. , Hall D. R. , Cork A. R. , Nesbitt B. F. , Marrs G. J. , Jutsum A. R. , Hosny M. M. , Nasr El-Sayed A. 
Published: July 2009

AbstractA large–scale mating disruption trial for the control of Pectinophora gossypiella (Saund.) was carried out in the Fayoum Province of Egypt during the 1981 cotton season. Two areas, each of 50 ha, were sprayed with a microencapsulated formulation of the sex pheromone (a 1:1 mixture of (Z, Z)- and (Z, E)-1, 11-hexadecadienyl acetate) as the sole means of controlling this pest. Five applications of 10 g a.i./ha were made during the season using fixed-wing aircraft. The pheromone treatments were compared with conventional insecticide spray treatments in two other 50-ha areas of cotton. From comparisons of treatments in terms of various plant damage criteria including the percentage of rosetted flowers, percentage boll infestation, gross yield of seed cotton and lint quality, it was concluded that the pheromone treatment was equal in effect to the insecticide sprays.
Light-trap catches of African armyworm moths, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae), in relation to rain and wind
Authors: Tucker M. R. 
Published: July 2009

AbstractThe association between weather and light-trap catches of Spodoptera exempta (Wlk.) was examined for four traps in East Africa, using whole–night catches and several years' data. Large increases in trap catch were found to be (1) significantly associated with rain at all four traps for the period December–March, but not for later in the season; (2) significantly associated with light wind periods at Muguga for December–May, but not later in the year, and not at Nakuru, due to the very high overall frequency of light winds there; and (3) not significantly associated with windshifts at either Muguga or Nakuru. These results suggest that high densities of flying moths, which may give rise to caterpillar outbreaks early in the year, often occur where the rather infrequent early–season rains fall.
Integration of insect sterility and insecticides for control of Glossina morsitans morsitans Westwood (Diptera: Glossinidae) in Tanzania. V. The impact of sequential releases of sterilised tsetse flies
Authors: Williamson D. L. , Dame D. A. , Gates D. B. , Cobb P. E. , Bakuli B. , Warner P. V. 
Published: July 2009

AbstractA field trial of the sterile insect technique was conducted in Tanzania using males of Glossina morsitans morsitans Westw. that were reared, irradiated and packaged at Tanga. The experimental site was a 195–km2 area 110 km to the south. Following two applications of endosulfan as an aerosol at an interval of 28 days, irradiated puparia of G. m. morsitans were released twice weekly at stations distributed throughout the experimental site. Each of the 120 release stations was serviced every 14 days with puparia which produced sterile adults synchronously within 30 min after placement. Over the 15–month experimental period, an average of 81% control of G. m. morsitans was obtained, whereas G. pallidipes Aust., against which no releases were carried out, recovered to prespray levels within five months. The released sterile insects were found to be highly competitive and to survive well in the field. Immigration of indigenous flies from outside the perimeter barrier surrounding the experimental plot provided a continuous influx of fertile flies that provided the nucleus of the 19% residual population. Under operational conditions, the prevention of migration should result in the elimination of an indigenous G. m. morsitans population subjected to the combined stress of population reduction by two applications of endosulfan aerosols and sequential releases of sterile males.
Environmental factors associated with fluctuations in the numbers of natural enemies of a population of citrus red scale, Aonidiella aurantü (Maskell) (Hemiptera: Diaspididae)
Authors: Atkinson P. R. 
Published: July 2009

AbstractNatural enemies of Aonidiella aurantü (Mask.) were counted in suction-machine samples taken fortnightly over 41 months from an orchard of orange trees in the Swaziland lowlands, a region where biological control of the scale is difficult. Changes in the log population intensity/‘twig’ (Δ log N) of four species were, in each case, calculated over four thermal constants of 5000, 10 000, 15 000 and 20 000 hour– degrees above 12°C (h°>12C). The middle two constants were assumed to approximate to the thermal constants of the generation times of the natural enemies. For each natural enemy, Δ log N measured over each thermal constant was related by regression analysis to climatic and biotic indices to see how the interval over which population change was measured affected the conclusions. The longer the interval, the greater was the percentage of the explained variation in Δ log N, and the greater the number of indices that became significant. However at 20 000 h°>12°C, population change was measured over rather long intervals for short–lived species like Aphytis. At both 10 000 and 15 000 h°>12°C, the number and the identity of the significant indices in the regression tended to be the same. Consequently, conclusions about the factors affecting the natural enemies were based on these regression results. A. africanus Qued–nau, Comperiella bifasciata How. and Rhyzobius lophanthae (Blaisd.) responded directly to changes in their host's numbers, but Habrolepis rouxi Comp. responded inversely and was unlikely to have been effective. Furthermore, it was sensitive to high summer temperatures, as was A. africanus and possibly R. lophanthae. C. bifasciata was not sensitive to high summer temperatures but was adversely affected by the hyperparasitoid Marietta javensis (How.). None of the natural enemies was affected by prevailing saturation deficits.
Electrophoretic study of enzymes from cereal aphid populations. II. Use of electrophoresis for identifying aphidiid parasitoids (Hymenoptera) of Sitobion avenae (F.) (Hemiptera: Aphididae)
Authors: Castañera P. , Loxdale H. D. , Nowak Kathy 
Published: July 2009

AbstractThe effect of parasitism by the aphidiid wasp Aphidius uzbekistanicus (Luzhetski) on the isoenzyme banding patterns of 14 soluble enzymes separated by one–dimensional slab polyacrylamide gel electrophoresis from crude homogenates of its main host, Sitobion avenae (F.), are described. Parasitism was found to be detectable using any 12 of these enzymes. The differences observed between the banding patterns for three enzymes (ester–ase, malate dehydrogenase and malic enzyme) separated from the adults of five primary parasitoid species attacking this aphid (A. picipes (Nees), A. uzbekistanicus, Ephedrus plagiator (Nees) Praon volucre (Hal.) and Toxares deltiger (Hal.)) are also described. Esterase was found to be the best enzyme for taxonomic differentiation of all aphidiid species examined. The use of electrophoresis for assessing percentage wasp parasitism in integrated management studies of cereal aphids is discussed.
Relative frequency of reproductive abnormalities in a natural population of Glossina morsitans morsitans Westwood (Diptera: Glossinidae) in Zambia
Authors: Madubunyi L. C. 
Published: July 2009

AbstractDissection of 2337 female Glossina morsitans morsitans Westw., collected over an 11-month period (118–420 per month) from a game reserve in Zambia, revealed that abortion is a regular feature of tsetse reproductive biology and apparently the most frequent reproductive abnormality in the tsetse population. It occurred among ifies in all ovarian cycles from 1 to 7+4n (minimum age 10–80 days) and apparently involved all pregnancy stages. Neither follicular degeneration nor egg retention was encountered, suggesting that these particular reproductive abnormalities are infrequent in nature.
The relative attractiveness of cattle, sheep and goats to Glossina morsitans morsitans Westwood and G. pallidipes Austen (Diptera: Glossinidae) in the Zambesi Valley of Rhodesia
Authors: Pilson R. D. , Boyt W. P. , MacKenzie P. K. I. 
Published: July 2009

AbstractA series of investigations was conducted to evaluate the comparative attractiveness of cattle, sheep and goats to Glossina morsitans morsitans Westw. and G. pallidipes Aust. in the Zambesi Valley, Rhodesia. It was shown that cattle are subjected to in excess of three times the challenge by male G. m. morsitans than either sheep or goats. Due to the repellent effect of man's presence on the attraction and feeding of female G. m. morsitansand both male and female G. pallidipes on the bait animals, no rational relationship could be postulated for them. Possible factors accounting for the difference of attractiveness between the three bait species are discussed.
The development rate of Metopolophium dirhodum (Walker) (Hemiptera: Aphididae) on winter wheat
Authors: Cannon R. J. C. 
Published: July 2009

AbstractIntensive monitoring of uncaged summer populations of Metopolophium dirhodum (Wlk.) (alienicolae) on winter wheat in southern England was carried out, mainly in 1979. Estimates for rates of development and reproduction are presented for both apterous and alate morphs. Relative nymphal instar lengths were calculated as percentages of the total juvenile period (instars I–IV inclusive), at a given mean temperature. The durations of the first three nymphal instars were uniform, but longer was spent in instars IV-apterous (21%) and IV-alatiform (45%) than in previous ones. Development rates are shown, firstly as cumulative summations of regression lines for individual instars, and secondly as a single regression for the whole period (I to IV inclusive), plotted separately against corresponding mean temperatures. A method of calculating the development threshold was devised that yielded an estimate of about 5°C for both morphs. Average and maximum daily rates of deposition (larviposition) are given for both morphs and, for apterae, results on the effects on this of leaf, date, temperature and aggregation are presented and discussed. Comparisons are made between this field study, and previous ones using M. dirhodum under constant temperature conditions in the laboratory. Development rates appeared to be similar under both constant and fluctuating temperatures, although slower in the field at low temperatures (10 or 11°C). Reproductive rates under the field conditions of this study appeared to be higher (on a daily rate basis) than those of previous studies, both in the laboratory (at constant temperature) and in the field. Reproduction in the field by apterae is considered to be concentrated over a shorter span of adult life than in the laboratory.
The distribution of five species of flies (Diptera: Muscidae) over the bodies of dairy heifers in England
Authors: Hillerton J. E. , Bramley A. J. , Broom D. M. 
Published: July 2009

AbstractFive species of Muscidae were found to be commonly associated with dairy heifers in three areas in southern England. The biting flies Haematobosca stimulans (Mg.) and Stomoxys calcitrans (L.) were relatively rare and fed from the back, flanks and legs. The horn fly, Haematobia irritans (L.), was present in highest numbers; it rested on the back and fed on the legs, belly and occasionally on the teats. Musca autumnalis Deg. was found mainly on the head and had a restricted season. Hydrotaea irritans (Fall.) had a marked diurnal variation in activity, being most abundant in the morning and evening. It was found on the head but predominantly on the belly and teats. When judged by its site preference on cattle, it is the fly most likely to be involved in the transmission of summer mastitis.