bluuebunny/crossref_metadata_2025_split huggingface dataset:
Olfactory preferences of Cotesia glomerata (L.) (Hym., Braconidae) to volatiles from the plant‐host complex in a flight tunnel
Authors: Vernède R. , Pak G. A. 
Published: August 2009

AbstractOlfactory preferences in the host location process of the braconid wasp Cotesia glomerata (L.) (Hym., Braconidae) were investigated by observing the orientation behavior of individual females to various host‐habitat related odor cues in a flight tunnel. Responsive wasps showed positive anemotaxis after release into the odor plume. Dual odor‐choice tests revealed that wasps can discriminate between cabbage leaves infested by larval Pieris brassicae (L.) (Lep., Pieridae) and uninfested leaves. Infested plants were a preferred source of volatiles attracting the wasps. Feces and host larvae, two major components of a plant‐host complex, were less attractive. Wasps probably respond to host‐induced synomones, because host‐infested leaves were more attractive than mechanically damaged cabbage leaves. Furthermore, the odor from the latter was preferred over that from damaged nonhost plants (tomato), indicating a response the host‐plant specific synomones. The flight behavior and responsiveness of the wasps are discussed in relation to the different odor stimuli.ZusammenfassungWindtunnel‐Untersuchungen zur olfaktorischen Präferenz bei Cotesia glomerata (L.) (Hym., Braconidae) gegenüber Duftstoffen des WirtspflanzenkomplexesIn einem Windtunnel wurden die Geruchspräferenzen bei der Wirtsfindung der Schlupfwespe Cotesia glomerata (L.) (Hym., Braconidae) untersucht. Hierbei wurde das Orientierungsverhalten einzelner Weibchen an verschiedenen Wirtsstandorten mit verwandten Düften beobachtet. Empfängliche Wespen zeigten nach der Freigabe in dem Duftstrom eine positive Anemotaxis. Tests mit zweifacher Wahlmöglichkeit ergaben, daß Wespen unbefallene Kohlblätter von solchen mit Raupen des Weißlings Pieris brassicae (L.) (Lep., Pieridae) befallenen unterscheiden können. Befallene Blätter bildeten eine anziehende und bevorzugte Duftquelle der Wespen. Kot und Raupen, zwei Hauptbestandsteile des Wirtskomplexes waren weniger anziehend. Die Wespen reagieren vermutlich auf die von den Wirten induzierten Synomone, weil mit Raupen befallene Blätter eine größere Anziehungskraft hatten als mechanisch beschädigte Kohlblätter. Jedoch wurde der Duft der letzteren bevorzugt gegenüber beschädigten Nichtwirtspflanzen (Tomate). Dies deutet auf eine Reaktion auf wirtspflanzen‐spezifische Synomone hin. Das Flugverhalten und die Empfänglichkeit der Wespe werden in bezug auf die verschiedenen Düfte besprochen.
Biology and population structure of Osmia tricornis Latreille (Hym., Megachilidae)
Authors: Vicens N. , Bosch J. , Blas M. 
Published: August 2009

AbstractOsmia tricornis Latreille is a univoltine species that in NE Spain flies from April to June. In 1990 and 1991 two populations were reared in the laboratory. Bees were incubated at 25–30 °C during the summer and overwintered in refrigerators at 3–7 °C for 112 and 167 days respectively. In spring bees were released in the field and provided with nesting materials with holes of different diameters. Bees that had been exposed to longer over‐wintering periods emerged sooner and expressed lower overwintering mortality than bees exposed to shorter over‐wintering periods. Females preferred to nest in holes of 7 mm i.d. The nesting season lasted from 2 to 2,5 months. O. tricornis is a highly polylectic species and collected pollen mainly from flowers producing little or no nectar (Quercus, Cistus, Papaver, Ranunculus, etc.). Several parasites and predators were found in the nests: Chaetodactylus osmiae (Dujardin), Monodontomerus obsoletus Fabricius, Anthrax anthrax Schrank, Trichodes alvearius Fabricius, Melittobia sp. Westwood, Cacoxenus sp. Loew, Sapyga quinquepunctata (Fabricius), Stelis phaeoptera (Kirby) and Ptinus sexpunctatus Panzer. In both years, populations obtained at the end of the flying season were larger than populations initially released. O. tricornis showed very similar biological features to those of other Osmia (s. str.) Panzer species currently being used as crop pollinators.ZusammenfassungBiologie und Populationsstruktur von Osmia tricornis Latr. (Hym., Megachilidae)Osmia tricornis ist eine univoltine Art, deren Flugzeit im Nordosten Spaniens in die Monate April bis Juni fällt. 1990 und 1991 wurden zwei Populationen im Labor gezüchtet. Die Bienen wurden im Sommer bei 25–30 °C gehalten und während der Wintermonate für 112 bzw. 167 Tage im Kühlschrank bei 3–7 °C. Im Frühjahr wurden diese Bienen ins Freiland gebracht, wo ihnen Nestmaterial mit Löchern verschiedener Durchmesser angeboten wurde. Bienen, die einer längeren Überwinterungsphase ausgesetzt waren, schlüpften früher und wiesen eine geringere Überwinterungs‐Sterblichkeit auf als Bienen mit der kürzeren Überwinterungszeit. Die Weibchen bevorzugten Nester mit Löchern von 7 mm Durchmesser. Die Brutsaison dauerte zwei bis zweieinhalb Monate. O. tricornis gehört zu den polylektischen Arten und sammelt überwiegend den Pollen von Blüten mit geringem oder keinem Nektargehalt (Quercus, Cistus, Papaver, Ranunculus etc.). In den Nestern konnten folgende Parasiten und Räuber festgestellt werden: Chaetodactylus osmiae (Dujardin), Monodontomerus obsoletus Fab., Anthrax anthrax Schrank, Trichodes alvearius Fab., Melittobia sp. Westwood, Cacoxenus ssp. Loew, Sapyga quinquepunctata (Fab.), Stelis phaeoptera (Kirby) und Ptinus sexpunctatus Panzer. In beiden Versuchsjahren waren die Völker am Ende der Flugsaison größer als die ursprünglich freigesetzten. O. tricornis zeigte sehr ähnliche biologische Merkmale wie andere Osmia‐Arten, die bereits zur Bestäubung im Getreide eingesetzt werden.
Cold hardiness of the elm bark beetle Scolytus laevis Chapuis, 1873 (Col., Scolytidae) and its potential as dutch elm disease vector in the northernmost elmforests of Europe
Authors: Hansen L. O. , Sømme L. 
Published: August 2009

AbstractCold hardiness was studied in overwintering larvae of the elm bark beetle (Scolytus laevis) which is an important vector of the dutch elm disease in northern Europe. Mean SCPs were as low as −29°C in mid‐winter and increased to −21°C in May. Corresponding melting points varied from −6.5 to −0.7 °C with thermal hysteresis freezing points 0.2–0.3°C lower during the winter. Glycerol was the main low molecular weight cryoprotectant substance. Frozen larvae became active shortly after thawing, but subsequently died or were unable to pupate at 21°C. In the early part of the winter supercooled larvae survived extended periods at −19°C but were killed at this temperature in the spring. It is concluded that cold hardiness will not be the limiting factor for the distribution of the elm bark beetle within the limits of the elm in Norway.ZusammenfassungZur Kälteresistenz des Ulmensplintkäfers, Scolytus laevis Chapuis 1873 (Col., Scolytidae) und dessen Bedeutung für die Ausbreitung des Ulmensterbens in den nördlichsten Ulmenwäldern EuropasEs wurde die Kälteresistenz der überwinternden Larven des Ulmensplintkäfers, Scolytus laevis, der ein wichtiger Vektor des Ulmensterbens ist, untersucht. Im Winter lag die durchschnittliche untere Temperaturgrenze bei −29°C und stieg im Mai auf −21°C an. Die entsprechenden Auftautemperaturen lagen zwischen −6,5 und −0,7°C, wobei im Winter der Gefrierpunkt 0,2‐0,3°C niedriger lag. Glycerol war das wichtigste niedermolekulare Gefrierschutzmittel. Die gefrorenen Larven wurden kurz nach dem Auftauen aktiv, waren aber bei 21°C entweder nicht verpuppungsfähig oder sie starben. Im frühen Winter überlebten herabgekühlte Larven eine längere Zeit bei −19°C, aber im Frühjahr wurden sie bei dieser Temperatur abgetötet. Aus den Ergebnissen wird ersichtlich, daß die Kälteresistenz kein limitierender Faktor für die Verbreitung des Ulmensplintkäfers innerhalb des Verbreitungsgebiets der Ulmen in Norwegen darstellt.
Response of four American engraver bark beetles, Ips spp. (Col., Scolytidae), to synthetic racemates of chiral pheromones
Authors: Kohnle U. , Vité J. P. , Meyer H. , Francke W. 
Published: August 2009

AbstractThe enantiomer composition of terpene alcohol pheromones produced by host selecting males of 4 American Ips spp. was determined as (S)‐(‐)‐ipsenol (> 99% [S]‐[‐]) in I. grandicollis, as (S)‐(+)‐ipsdienol (90% [S]‐[+]) in I. avulsus, as an enantiomer mixture of 77% (R)‐(‐)‐ and 23% (S)‐(+)‐ipsdienol in I. calligraphus calligraphus and as (S)‐(+)‐ipsdienol (> 99% [S]‐[+]) and (S)‐(‐)‐ipsenol (99% [S]‐[‐]) in I. paraconfusus. Field experiments were carried out to investigate the beetles' response to baits containing different concentrations of commercial (±)‐ipsdienol and (±)‐ipsenol, respectively. The tests revealed the following response pattern: a) I. c. calligraphus catch numbers increased with (±)‐ipsdienol concentrations but were reduced by (±)‐ipsenol; b) in contrast, I. grandicollis response was reduced by (±)‐ipsdienol but enhanced by (±)‐ipsenol; c) I. avulsus catch numbers increased with concentrations of racemates of both terpene alcohols; d) I. paraconfusus barely responded to traps baited with the synthetic racemates. The later phenomenon obviously was based on the inhibitory effect of non‐natural (R)‐(‐)‐ipsdienol which rendered the racemic test material an inhibitor for I. paraconfusus.ZusammenfassungChirale Borkenkäferpheromone: Einfluß synthetischer Racemate auf die Aggregation von amerikanischen Borkenkäferarten der Gattung Ips (Col., Scolytidae)Bei pheromonproduzierenden Männchen verschiedener Borkenkäferarten der Gattung Ips wurde für die Pheromone Ipsdienol und Ipsenol folgende Zusammensetzungen bestimmt: 99,5% (S)‐(‐)‐Ipsenol bei Ips grandicollis, 90,0 % (S)‐(+)‐Ipsdienol bei I. avulsus, ein Enantiomerengemisch von 77 % (R)‐(‐)‐ und 23% (S)‐(+)‐Ipsdienol bei I. calligmphus calligrapbus sowie 99,5% (S)‐(+)‐Ipsdienol und 99,0% (S)‐(‐)‐Ipsenol bei I. paraconfusus. Verschiedene Freilandversuche sollten klären, wie synthetische Racemate (±) dieser chiralen Pheromonkomponenten die Aggregation beeinflussen. Dabei zeigte sich folgendes: a) die Fangzahlen von I. c. calligraphus nahmen mit steigenden (±)‐Ipsdienol‐Konzentrationen zu und wurden durch (±)‐Ipsenol reduziert; b) umgekehrt nahmen die Fangzahlen von I. grandicollis mit steigenden (±)‐Ipsenol‐Konzentrationen zu, jedoch mit steigenden (±)‐Ipsdienol‐Konzentrationen ab; c) bei I. avulsus erhöhten sowohl steigende (±)‐Ipsdienol‐ als auch steigenden (±)‐Ipsenol‐Konzentrationen die Fangzahlen; d) im Gegensatz zu diesen Arten wurden nahezu keine I. paraconfusus mit Ködergemischen gefangen, die nur (±)‐Ipsdienol, (±)‐Ipsenol und cis‐Verbenol enthielten. Offenbar verursachte das im (±)‐Ipsdienol enthaltene nicht‐natürliche (R)‐(‐)‐Enantiomer eine Hemmwirkung des Racemats und verringerte auch bei Zugabe von (±)‐Ipsdienol die Lockwirkung pheromonproduzierender I. paraconfusus Männchen.
Olfactory oriented migration through soil by root‐living Hylobius abietis (L.) larvae (Col., Curculionidae)
Authors: Nordenhem H. , Nordlander G. 
Published: August 2009

AbstractThe pine weevil Hylobius abietis (L.) is known to oviposit in the inner bark of roots of recently killed coniferous trees, where larvae develop as subcortical feeders. In laboratory experiments we demonstrated that many H. abietis larvae abandoned a crowded host substrate and migrated through sand to a previously unoccupied substrate 100 mm away, where they established themselves. Ethanol and the host monoterpene α‐pinene were shown to act synergisticafly in attracting the larvae. Larval migration towards fresh host material was demonstrated also in first instar larvae hatching from eggs laid in sand more than 50 mm away from the host substrate. Oviposition in the sand was induced by denying the ovipositing females access to the host material by covering it with nylon mesh. We suggest that the facultative migratory behaviour shown by H. abietis larvae in the two situations reported here can play an important role in increasing their survival as well as their ability to utilize available host material in the field.ZusammenfassungGeruchsorientierte Wanderung durch den Boden von in Wurzelstöcken lebenden Hylobius abietis (L.)‐Larven (Col., Curculionidae)Vom Großen Braunen Rüsselkäfer, Hylobius abietis ist es bekannt, daß er seine Eier unter die Rinde von Wurzelstöcken frisch gefällter Kiefern ablegt, wo die Larven sich im Bast entwickeln. In Labor‐experimenten konnten wir nachweisen, daß viele H. abietis‐Larven ein dicht besiedeltes Wirtssubstrat aufgeben und durch den Sandboden zu einem noch freien Substrat in etwa 10 cm Entfernung wandern und sich dort einbohren. Äthanol und das im Wirtsholz vorhandene Monoterpen α‐Pinen wurden als Substanzen nachgewiesen, die synergistisch anziehend auf die Larven wirken. Die Larvenwanderung zu frischem Wirtssubstrat wurde auch bei frisch geschlüpften Larven beobachtet, die 5 cm vom Wirtsholz entfernt im Sandboden aus dort abgelegten Eiern schlüpften. Die Eiablage in den Sandboden wurde dadurch induziert, daß ablegebereite Weibchen nicht am natürlichen Brutmaterial ablegen konnten, weil dieses mit Nylonnetzen abgedeckt war. Aus den Ergebnissen wird gefolgert, daß die fakultative Wanderung von H. abietis‐Larven in den zwei gegebenen Situationen zur Verbesserung der Überlebenschancen und zur Verbesserung der Ausnutzung des verfügbaren Wirtssubstrats eine wichtige Rolle spielen können.
Effect of photoperiod on the bionomics of Frankliniella occidentalis (Pergande) (Thysanoptera, Thripidae)
Authors: Brødsgaard H. F. 
Published: August 2009

AbstractIn many glasshouse ornamental crops, daylength is controlled in order to regulate plant growth. To investigate whether short daylength influences the bionomics of Frankliniella occidentalis (Pergande), life table parameters of F. occidentalis reared on bean leaves at 25°C and photoperiods of 4:20, 8:16 or 16:8 (L:D) h were calculated. The immature developmental time significantly increased with decreasing daylength from 13.15 to 14.75 days at 16:8 and 4:20 (L:D) h photoperiod, respectively. The effect was expressed primarily in second larval instars. The immature mortality increased with decreasing daylength from 67.3% to 87.5% at photoperiods of 16:8 and 4:20 (L:D) h, respectively. Female adult longevity was significantly longest with 13.3 days at 4:20 (L:D) photoperiod. However, mean preoviposition period and fertility did not differ among different daylengths. Life table parameters differed between photoperiods of 16:8; 8:16 and 4:20 (L:D) as follows: Net reproductive rate (Ro) = 12.2; 7.6 and 3.7 (generation 1); intrinsic rate of increase (rm) = 0.14; 0.11 and 0.06 (day−1); mean generation time (T) = 17.9; 18.3 and 21.1 (days), and doubling time (DT) = 5.0; 6.3 and 11.2 (days), respectively. This study shows that short daylength at 25 °C reduces reproductive fitness of F. occidentalis but does not induce reproductive diapause in this species.ZusammenfassungEffekt der Photoperiode auf die Bionomie von Frankliniella occidentalis (Pergande) (Thysanoptera, Thripidae)In vielen Treibhäusern wird die Tageslänge geregelt, um das Pflanzenwachstum zu regulieren. Zwecks der Untersuchung des Einfluβes der kurzen Tageslänge auf die Bionomie von Frankliniella occidentalis (Pergande) wurden die Lebensparameter von F. occidentalis, die auf Bohnenblättern bei 25 °C und Photoperioden von 4:20, 8:16 oder 16:8 (L:D) Stunden gezücht wurden, berechnet. Bei abnehmender Tageslänge (16:8 bzw. 4:20 (L:D)) stieg die Entwicklungszeit der Larven signifikant an (13,5 bzw. 14,75 Tage). Dieser Effekt war im zweiten Larvenstadium besonders deutlich. Die Mortalitätsrate der Larven stieg mit abnehmender Tageslänge von 67,3% bei 16:8 L:D auf 87,5% bei 4:20 (L:D) Stunden Photoperiode. Die durchschnittliche Prä‐Eiablageperiode und die Fertilität unterschieden sich nicht in Abhängigkeit von der Tageslänge. Die Parameter der Lebenstabelle variierten in Abhängigkeit von der Tageslänge (16:8, 8:16 bzw. 4:20 (L:D)) wie folgt: Die Nettoreproduktionsrate (Ro) = 12,2; 7,6 bzw. 3,7 (Generation−1); innere Zuwachsrate (rm) = 0,14; 0,11 bzw. 0.06 (Tag−1); durchschnittliche Generationszeit (T) = 17,9; 18,3 bzw. 21,1 (Tage), und Verdoppelungszeit (DT) = 5,0; 6,3 bzw. 11,2 (Tage). Diese Untersuchung zeigt, daβ eine kurze Tageslänge bei 25°C die Reproduktion von F. occidentalis reduziert, aber daβ sie keine reproduktive Diapause in dieser Art induziert.
Habitat manipulations increasing spider densities in agroecosystems: possibilities for biological control?
Authors: Alderweireldt M. 
Published: August 2009

AbstractField experiments with habitat manipulations were conducted in Belgian crop fields in order to follow changes in abundances and species composition of the spider taxocoenosis. Spider densities increased spectacularly in plots with holes (up to 13 times) in the soil. Moreover, this density increase depends on the diameter of the holes, with diameter 9.5 and 5 cm being the most effective. Species composition in the plots with holes also changed considerably compared to control plots. Exclusively web building Linyphiidae (Bathyphantes gracilis and Lepthyphantes tenuis) took far more advantage of the new possibilities offered by the habitat for web construction than non web‐building spiders. B. gracilis preferred holes with a diameter of 5 cm whereas L. tenuis was more abundant in the D9.5 cm plots. It is concluded that this kind of relatively simple habitat manipulations are advantageous for population levels of certain beneficial polyphagous predators, such as spiders. This might offer possibilities for biological control of pest populations.
Effects of some new proinsecticide type fenoxycarb derivatives and related compounds on some scale insects and their hymenopterous parasitoids
Authors: Darvas B. , El‐Kareim A. I. Abd , Camporese P. , Farag A. I. , Matolcsy Gy. , Ujváry I. 
Published: August 2009

AbstractWhile Insegar and the sulfenylated carbamate juvenoid NKI‐43049 totally inhibited the egg production of Carulaspis juniperi (Hom., Diaspididae), only approximately 1% of the Applaud or NKI‐35120 treated females laid eggs. Applaud and the sulfinylated carbamate derivative NKI‐35120 resulted a very low egg‐production (16% and 4% of the untreated control, respectively). Importantly, the tested fenoxycarb‐related compounds did not reduce the rate of parasitization caused by Aphytis mytilaspidis (Hym., Aphelinidae), Applaud, however, had a moderately adverse effect on it.NKI‐35120 gave an excellent result at a concentration of 0.1 a.i.% on Lepidosaphes beckii (Hom., Diaspididae). Insegar (0.1 a.i. %) and Applaud (0.05 a.i%) had good activity as well. Males were more sensitive than females for the treatments. NKI‐35120 and Insegar strongly reduced the egg production of the females. The treatments did not reduce significantly the rate of parasitization caused by Aphytis lepidosaphes (Hym., Aphelinidae).NKI‐35120 and Insegar at a concentration of 0.025 a.i. % strongly affected Ceroplastes japonicus (Hom., Coccidae) development since none of the treated larvae could develop to female. Surprisingly, Applaud had only moderate affectivity on C. japonicus.
Insectivorous activities of spiders in United States field crops
Authors: Nyffeler M. , Sterling W. L. , Dean D. A. 
Published: August 2009

AbstractA survey of average spider numbers in U.S. field crops (considering a geographic range from the east to the west coast) gave an overall mean density of ≅ 1 plant‐dwelling spider/m2(± 0.18 SEM). This value is more than 100 times lower than Turnbull's famous ‘overall mean value’ (= 130.8/m2) computed from 37 published censuses of spider numbers in a wide variety of environments from all over the world. Crop fields are disturbed systems whose spider numbers are drastically reduced by agricultural practices such as pesticide use, cultivation, harvest, etc. Small sized spider individuals (including large percentages of immatures) numerically dominate the faunas of U.S. field crops, and these feed primarily on tiny prey organisms (< 4 mm in length). Small web‐building spiders are almost strictly insectivore (insects constituting > 99% of total prey). In contrast, the ‘hunters’ (nonweb‐building spiders) that actively search the plant surface for prey, exhibit a mixed strategy of araneophagic and insectivorous foraging patterns (insects constituting ≅ 90% of total prey). The aggressive ‘active searchers’ are highly polyphagous (compared to the small web‐weavers), but can narrow their feeding niche significantly when a suitable prey species reaches high numbers relative to other prey groups. The numerically dominant spider predators in U.S. field crops feed heavily on small plant‐sucking insects such as plant bugs (Miridae), fleahoppers (Miridae), leafhoppers (Cicadellidae), treehoppers (Membracidae), planthoppers (Delphacidae), and aphids (Aphididae), which is of interest from a biocontrol point of view. A typical agroecosystem spider (i.e., striped lynx spider) may capture an average of ≅ 1 prey per rainfree day in the field (by multiplying this value with the overall mean spider density of 1/m2, it follows that the average prey kill may be in the order of magnitude of ≅ 1 prey/m2/day). At prey densities of 100–300/m2 (as recorded in literature), spiders kill perhaps ≅ 0.3‐1 % of the potential prey per day. Extensive field and laboratory observations, experiments, and computer models conducted by research groups in different parts of the U.S. indicate that the collective predation impact of spiders may contribute significantly to lower pest levels in some crop fields.
Cone entomofauna of fir Abies alba Mill. in the St. Cross Mts. National Park in Poland during 1987–19921
Authors: Bak J. 
Published: August 2009

AbstractA total of 14,537 individuals representing 22 insect species were obtained from 2204 cones of Abies alba Mill. The coenotic groups of insects have been given and the indexes of domination (D), stability of incidences (C), species diversity (d) and Agrell's index of species co‐existence (Ag) have been calculated. Investigations were conducted during 1987–1992 in 14 compartments of the St. Cross Mts. National Park in central Poland.
Seasonal dynamics of rodent fleas and its implication on control strategies in Lushoto district, north‐eastern Tanzania
Authors: Makundi R. H. , Kilonzo B. S. 
Published: August 2009

AbstractFundamental to the development of a comprehensive pest management system for rodent fleas in the western Usambara Mountains, is an understanding of their seasonal dynamics. In this study data collected in Lushoto district in the Usambara mountains, north‐east Tanzania, from July 1989 to May 1991 have been used to elucidate the seasonal dynamics of corporeal fleas of Mastomys natalensis and other rodent species. Prevalence (proportion of hosts infested by fleas) reached peak levels in December and January, for M. natalensis and the other species of rodents. Generally prevalence was high in the period October to March. The intensity of fleas (flea indices) was highest in December/January and declined rapidly in April/May at the peak of the rainy season. It was further observed that fleas were most abundant on rodent hosts when ambient temperatures were 22–26°C during November to April. This is probably due to increased progeny production in rodent nests as a result of favourable conditions of temperature and humidity. It is concluded that if a programme of flea control on field rodents is to be implemented, it has to be carried out from November to May when flea abundance and intensity are high. In view of the problems of controlling rodent fleas using conventional methods over a large geographical area, it is proposed that the most appropriate method for adoption in the Lushoto plague focus is to use bait stations and bait boxes treated with an effective insecticide against fleas.