bluuebunny/crossref_metadata_2025_split huggingface dataset:
Location of immature stages of the mushroom insect pest Megaselia halterata in mushroom‐growing medium
Authors: Scheepmaker J. W. A. , Geels F. P. , Smits P. H. , Van Griensven L. J. L. D. 
Published: October 2003

AbstractExperiments were conducted to examine the location of oviposition by the phorid fly Megaselia halterata (Wood) (Diptera: Phoridae) in uncased and cased compost. Clearly, a majority of the gravid females choose oviposition sites directly after entering the top layer of the compost. In uncased compost, 60% of all adults emerged from the top of four compost layers of equal thickness. When the compost was covered by a casing layer which was still uncolonized by Agaricus bisporus, oviposition was further concentrated in the top compost layer. In this situation, 91% of all adults emerged from the top compost layer whereas only 1.5% emerged from the casing. When the casing layer was colonized by mushroom mycelium, 45% of all adults emerged from the casing layer and 53% emerged from the top compost layer. Further concentration in the top compost layer and the casing layer occurred as a result of upward migration of larvae. When compost was cased after oviposition, up to 43% of all adults emerged from the casing layer. We concluded that in the control of phorid infestations with insect pathogenic nematodes, applications in uncased compost can be restricted to the upper compost layer. When compost and casing are filled simultaneously, nematode applications in the casing layer only could be considered.
Weather‐induced changes in moth activity bias measurement of long‐term population dynamics from light trap samples
Authors: Holyoak M. , Jarosik V. , Novák I. 
Published: October 2003

AbstractInterpretation of light trap catches of moths is complicated by daily variation in weather that alters flight activity and numbers caught. Light trap efficiency is also modified by wind and fog, and daily weather may effect absolute abundance (numbers actually present). However, actograph experiments and other sampling methods suggest that changes in daily activity are large by comparison to changes in absolute abundance. Daily variation in weather (other than wind and fog) is therefore a form of sampling error in absolute abundance estimates. We investigated the extent of this sampling bias in 26 years of population dynamics from 133 moth species. In a subset of 20 noctuid and geometrid species, daily numbers caught were positively correlated with temperature in 14 species, and negatively correlated with rainfall in 11 species. The strength of correlations varied between species, making it difficult to standardize catches to constant conditions. We overcame this by establishing how weather variation changed with time and duration of the flight period. Species flying later in the summer and for shorter periods experienced more variable temperatures, making sampling error greater for these species. Of the 133 moth species, those with shorter flight periods had greater population variability and more showed significant temporal density dependence. However, these effects were weak, which is encouraging because it suggests that population analyses of light trap data largely reflect factors other than sampling error.
Importance of plant size, distribution of egg masses, and weather conditions on egg parasitism of the European corn borer, Ostrinia nubilalis by Trichogramma ostriniae in sweet corn
Authors: Wang Baode , Ferro David N. , Hosmer David W. 
Published: October 2003

Abstract Trichogramma ostriniae (Hym: Trichogrammatidae), an egg parasitoid of the European corn borer, Ostrinia nubilalis (Lep: Pyralidae), were released into sweet corn (Zea mays L.) fields to study the effects of weather, plant size and distribution of egg masses on egg parasitism by the wasp. Sentinel European corn borer eggs were stapled onto leaves located in the upper, middle and lower third of sweet corn plants 5 to 35 meters away from the wasp release point in either a radial or grid manner. Weather conditions and plant architecture were monitored during the experiments. Logistic regression was used to analyze the data. The results indicated that percentage of eggs parasitized was negatively related to an increase in leaf area as well as an increase in distance eggs were located from the point of release of wasps. Eggs distributed on plants at different directions from the release point received different levels of parasitism. Eggs that were stapled onto leaves in the upper third of a corn plant received much less parasitism than those on the middle and lower third of the plant. Higher mean temperature adversely affected the level of parasitism during hotter times of the season and conversely, lower temperatures (<17 °C ) reduced the egg parasitism during cooler times of the season. The longer the exposure of eggs to wasps, the higher the level of egg parasitism. However, the levels of egg parasitism for 2 day's exposure were almost the same as that for 3 day's exposure due to the limited longevity and egg‐laying behavior of the wasp. These results suggest that inundative releases of T. ostriniae should be made every two to three days, with multiple release points per hectare. In addition, weather conditions and plant architecture, especially temperature, plant height and leaf area must be taken into consideration to optimize levels of parasitism.
Mortality of eggs, larvae and pupae and larval dispersal of the cabbage moth, Mamestra brassicae, in white cabbage in south‐eastern Norway
Authors: Johansen Nina Svae 
Published: October 2003

AbstractThe mortality of eggs, larvae and pupae and larval dispersal of the cabbage moth, Mamestra brassicae (L.) (Lepidoptera: Noctuidae) was investigated in a series of small‐scale field experiments in white cabbage, Brassicae oleracea var. capitata (L.), and in the laboratory during 1990–1992 in south–eastern Norway. The highest mortality was found in young larvae and in hibernating pupae. In 1990, larval mortality in the first instar was 80% (range 9–97% for the individual cohorts). Most larvae died within the first 1–3 days after hatching. The dispersal activity during these days was high, and failure to establish feeding sites and predation were probably the main mortality causes. Pupal mortality during winter was 90% on average for 1990–1993 (range 81–100%). The main mortality factor was probably unfavourable weather conditions, and indications of cold stress were found. The impact from parasitoids and diseases was generally low. Trichogramma semblidis (Aurivillius) (Trichogrammatidae) was reared from M. brassicae eggs in very low numbers in 1991. Larval parasitism increased from < 1% in 1990 to almost 24% in 1992, and was almost totally caused by the braconids Microplitis mediator (Haliday) and Aleiodes (Aleiodes) sp. Predation of frozen larvae on the soil surface was 75% on average (range 63–96%) during 1990–1992 in first instar larvae and decreased gradually with larval age. The consumption rates of Philonthus atratus (Gravenhorst) (Staphylinidae) and the carabids Bembidion tetracolum (Say), Pterostichus melanarius (Illiger) and Harpalus rufipes (Degeer) on M. brassicae eggs and larvae were investigated in non‐choice experiments in the laboratory. A preliminary survival model based on estimates of the mortality factors identified in this study is presented.
Peripheral‐zone treatments for plum curculio management: validation in commercial apple orchards
Authors: Vincent C. , Chouinard G. , Bostanian N. J. , Morin Y. 
Published: October 2003

AbstractPeripheral applications of organophosphate insecticides were evaluated as an alternative strategy for controlling adult plum curculio, Conotrachelus nenuphar Herbst (Coleoptera: Curculionidae) in four commercial orchards in Quebec, Canada. Each orchard was partitioned into a reference and an experimental plot to compare the classical full plot treatment with a peripheral treatment alternative. The experimental plots were divided into five zones, i.e. central, North, South, West and East. Peripheral zones were defined as the first five rows of apple trees (or 20 m wide). Plum curculio adults were monitored weekly by limb tapping. Fresh oviposition scars were evaluated by examining 20 fruitlets per tree on each outermost tree in the peripheral zone and 20 fruit on 25 trees in the central zone. Azinphosmethyl treatments were carried out in the zones where more than 1% fruitlets bore fresh ovipositional scars. Fruit damage was mostly (92%) found in the peripheral zones. Plum curculio damage at harvest varied from 0.0 to 0.7% and from 0.0 to 0.8% in the experimental and reference plots respectively. Total insect damage on fruit at harvest varied from 1.3 to 3.8% in the experimental plots, and from 0.4 to 5.0% in the reference plots. In 1991, there were no significant differences between population indices of the spotted tentiform leafminer, the apple aphid, leafroller species and cicadellids in the peripheral versus central zones. In the experimental plots, populations of woolly apple aphid, two‐spotted spider mite and apple rust mite were significantly higher in peripheral zones than in the central zones. In 1992, there were no significant differences between population indices of peripheral versus central zones for both experimental and reference plots. All localities and years pooled, peripheral zones of experimental plots received 1.22 insecticide treatments, against 1.29 for reference plots. However, central zones of experimental plots received 0.38 insecticide treatments, against 1.13 for reference plots. Assuming a 20 m peripheral zone and a 10 ha square orchard, the percent reduction in insecticides would be ca. 75%.
Effects of linear furanocoumarins on the herbivore Spodoptera exigua and the parasitoid Archytas marmoratus: host quality and parasitoid success
Authors: Reitz Stuart R. , Trumble John T. 
Published: October 2003

AbstractWe assessed the effects of three photoactivated linear furanocoumarins, secondary plant metabolites present in Apium spp. (Apiaceae) and other taxa, on the larval‐pupal parasitoid, Archytas marmoratus (Townsend) (Diptera: Tachinidae) and the host Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), in the presence and absence of ultraviolet radiation. These results then were compared with previously described responses of Archytas marmoratus and other hosts to different plant allelochemicals. Ultraviolet radiation had no consistent detrimental effects. Increasing concentrations of linear furanocoumarins (from 0 to 0.029% of fresh weight) increased mortality of both the host and parasitoid. Increasing linear furanocoumarin levels also prolonged larval development of surviving S. exigua, but had no effect on pupal developmental time or pupal mass. Consequently, there was no effect of increasing linear furanocoumarin levels on surviving parasitoid development time (from the time of host pupation) or size. These results indicate the effects of linear furanocoumarins are mediated through effects on the host. Because reported responses of Ar. marmoratus to other allelochemicals (e.g., flavones, methyl ketones) are mediated through host effects, these results support the hypothesis that Ar. marmoratus displays a generalized response to plant allelochemicals that are predictable based on host mediated effects.
Spatial distribution of bibionid larvae in agricultural grassland
Authors: Blackshaw R.P. , D'Arcy‐Burt S. 
Published: October 2003

AbstractThe distribution of bibionid larvae in agricultural grassland was investigated. They tend to occur sporadically and at low population density. More detailed sampling within a field showed that numbers were highest adjacent to a hedgerow with most being found 6–11 m from the hedge. Log variance/log mean relationships were established for counts of Bibio johannis and Dilophus febrilis larvae collected from soil cores in grassland. Both species were highly aggregated. An area of grassland (160 cm × 80 cm) was divided into 128 soil blocks and B. johannis larvae extracted. Almost all larvae were associated with aggregations. The two‐phase mozaic method of Pielou (1974) was applied to larval counts from different sized concentrically collected soil cores. Larval patches were not randomly distributed. Time‐lapse video studies of bibionid larvae were made and showed both aggregation and processional behaviour. This was associated with chemical stimulation which is probably used to maintain larval groupings in the field. There was evidence for two levels of aggregation. The first is due to groups of larvae arising from eggs laid by a single female and the second, larger scale, aggregation is due to factors that influence the distribution of adult flies.
Effect of entomopoxvirus infection of the smaller tea tortrix, Adoxophyes sp. on the development of the endoparasitoid, Ascogaster reticulatus
Authors: Nakai Madoka , Sakai Takuro , Kunimi Yasuhisa 
Published: October 2003

AbstractInfection of Adoxophyes sp. (Lepidoptera: Tortricidae) larvae by an entomopoxvirus (AsEPV) adversely affected the development of the endoparasitoid, Ascogaster reticulatus Watanabe (Hymenoptera: Braconidae). Parasitoid larvae developing in AsEPV‐infected hosts grew more slowly and spent more time in their hosts than did parasitoid larvae developing in noninfected hosts. Percentages of emergence of larval parasitoids that developed in AsEPV‐infected hosts were significantly lower than those of parasitoids that developed in noninfected hosts. Parasitoid larvae in AsEPV‐infected host perished when their hosts died of AsEPV infection. Significant numbers of parasitized and infected larvae exhibited apolysis to the final instar, whereas noninfected‐parasitized larvae died in the penultimate instars due to emergence of parasitoids.
Density‐related sterility in Eretmocerus mundus
Authors: Gerling Dan , Fried Rivka 
Published: October 2003

AbstractWhile studying the reproductive capacity of Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) we found that varying numbers of females were sterile. Investigations showed that sterility occurred also in field populations, but at a very low rate. Laboratory sterility was significantly correlated with crowding of the parental females during oviposition. Whitefly hosts from which fertile of sterile females emerged did not differ in size, neither did the hind tibiae of fertile females differ in dimensions from those of sterile ones. Behavior of sterile females differed from that of the fertile ones in several parameters. They exhibited less leg drumming, used the ovipositor more frequently and for shorter durations, and changed more readily from probing to host stinging, and from a number of activities to walking. Altogether, their behavior appeared more restless and caused them to contact more hosts than fertile females. The possibility that the sterility is caused by crowding alone, or by the activity of microorganisms acting under crowded conditions, and the merits of the phenomenon for biological pest control are discussed.
Effect of host diet on acceptance of eastern spruce budworm eggs by Trichogramma minutum
Authors: Song S. J. , Bourchier R. S. , Smith S. M. 
Published: October 2003

AbstractThe acceptance behaviour of the parasitic wasp, Trichogramma minutum Riley (Hymenoptera: Trichogrammatidae), was studied on two types of egg masses of eastern spruce budworm (SBW), Choristoneura fumiferana Clemens. Host eggs were obtained from moths that had been fed balsam fir or artificial diet during their larval stages. Parasitoids were reared from both types of hosts. Host acceptance assays were conducted where females were provided with a single egg mass and with a choice between egg masses. Regardless of the parasitoid's rearing host, females parasitised hosts reared from artificial diet more often than those from balsam fir. Response was consistent in both no‐choice and choice assays. Rejection of hosts tended to occur during the examining stage of behaviour, suggesting that acceptability is judged externally. If a host was accepted, the same number of eggs were laid per egg mass regardless of treatment.
Allozyme variation among Brazilian and U.S. populations of Rhyzopertha dominica resistant to insecticides
Authors: Guedes Raul Narciso C. , Kambhampati Srinivas , Dover Barry A. 
Published: October 2003

AbstractThe lesser grain borer (Rhyzopertha dominica (F.)) is an important pest of stored grain in many parts of the world (Paleartic, Ethiopian, Oriental, Australian, Neotropical, and Neartic regions) with the ability to fly long distances. These insects have been shown to be resistant to organophosphorus insecticides in several studies. Polyacrylamide gel electrophoresis was used to assess the genetic variability within and among eight Brazilian and seven United States populations of R. dominica and to determine how insecticide resistance may be spreading within both countries. Significant variation in allele frequency among populations was observed at all six polymorphic enzyme loci that were examined. The Brazilian and U.S. populations were genetically differentiated from one another; populations within the U.S. and those within Brazil were also differentiated from one another. The mean genetic similarity among the seven U.S. populations collected in a small region in northeast Kansas was smaller than that among eight Brazilian populations collected in a relatively large geographical area. These results are consistent with the resistance ratios to chlorpyriphos‐methyl in R. dominica populations from Brazil and the U.S. and the information available concerning patterns of flight activity in this insect.
Field‐scale effects of farming practices on linyphiid spider populations in grass and cereals
Authors: Thomas C.F.G. , Jepson P.C. 
Published: October 2003

AbstractLinyphiid spiders were sampled in three grass and four cereal fields, between October 1989–October 1990, and from one grass and one cereal field, from June–August 1991. Population growth and decline were characteristic of field type and pattern of management. Agricultural operations caused large population depletions: insecticide applications, cutting grass for silage and autumn cultivations reduced spider populations by 56% to 96%; heavy grazing caused virtual extinction. Aerial dispersal activity, monitored by water traps, showed high dispersal frequency with highest intensity in June, July and August. The results are discussed with reference to the large‐scale spatial structure of linyphiid spider populations and the use of spatially dynamic models to predict metapopulation size as a function of patterns of crop management, land‐use and landscape structure.
Prediction of flight of apple sawfly, Hoplocampa testudinea, using temperature sums
Authors: Zijp J. P. , Blommers L. H. M. 
Published: October 2003

AbstractA method to predict the beginning of the flight of apple sawfly, Hoplocampa testudinea (Klug) (Hymenoptera, Tenthredinidae) is presented. Adults were monitored during 8 years at the experimental orchard ‘De Schuilenburg’, Kesteren, The Netherlands, with visual sticky traps. Temperature sums, accumulated until the day of the first capture of sawfly, were calculated for different starting dates of the summations. Beginning on 1 January, variation of the temperature sums, calculated in each of 8 years, decreased when later starting dates for temperature summation were chosen, reaching a minimum on 1 April for soil temperatures (−5 cm). The soil temperature sum, accumulated from 1 April until the first capture, was on average 134 day‐degrees above a threshold of 4 °C. So this was the most suitable starting date to predict the beginning of sawfly flight activity. As use of the summation method based on air temperatures is in practice more appropriate for timing of trap installation by extension services and apple growers, trap deployment is recommended at an adapted value of 157 day‐degrees from 15 March.
The effects of parasitism by an encyrtid parasitoid, Anagyrus pseudococci on the survival, reproduction and physiological changes of the mealybug, Planococcus citri
Authors: Islam K. S. , Perera H. A. S. , Copland M. J. W. 
Published: October 2003

AbstractSurvival, reproduction and some biochemical changes in the citrus mealybug, Planococcus citri (Risso) parasitized by the endoparasitoid, Anagyrus pseudococci (Girault) are reported. The parasitized younger mealybugs were more likely to die than be successfully parasitized. The mean duration (±SE) required for mortality other than mummification were 1.85 ± 0.06, 2.48 ± 0.14 and 2.89 ± 0.17 days for first, second and third instar P. citri respectively. Hosts parasitized in the first instar did not produce any mummies while the second and third instar nymphs and adult stages of the mealybugs were mummified on average 8 to 11 days after attack. Parasitization caused cessation of normal fecundity as well as induction of early egg maturation of the mealybugs. The mealybugs parasitized in the adult stage produced a few eggs but the fecundity of unparasitized mealybugs was about 40 fold higher than that of parasitized mature adults. Parasitized pre‐ovipositing and mature adults laid eggs within 24 h of attack. SDS‐PAGE analysis of the body content of the parasitized mealybugs after 24 h and 48 h of parasitization and before egg hatch revealed an increase in the concentration of some proteins. Response to wound reactions was not visible either as formation of extra protein bands or increased density of the existing bands. The possible effect of parasitism on the changes of the reproductive physiology of the host is discussed.
The influence of temperature on the life table of Hyperaspis notata
Authors: Dreyer B. Stäubli , Neuenschwander P. , Bouyjou B. , Baumgärtner J. , Dorn S. 
Published: October 2003

AbstractThe coccinellid Hyperaspis notata Mulsant was introduced into Africa for the biological control of the cassava mealybug, Phenacoccus manihoti Matile‐Ferrero. Two cohorts of strains, one originating from Southern Brazil and Paraguay feeding on P. manihoti, and one from Colombia feeding on Phenacoccus herreni Cox & Williams were studied at different temperatures between 15 and 34 °C and age‐specific life tables were constructed. Although in the areas of origin the climatical conditions and the food sources are different, the survivorship and developmental times at the same temperature differed little among the two strains, the Colombian strain being slightly more tolerant to high temperatures. Jacknife estimates of the intrinsic rates of increase (rm) peaked very close to 30 °C for the two strains.