bluuebunny/crossref_metadata_2025 huggingface dataset:
Biology and population structure of Osmia tricornis Latreille (Hym., Megachilidae)
Authors: Vicens N. , Bosch J. , Blas M.
Published: August 2009

Osmia 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.

Biologie 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

Cold 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.

Zur Kälteresistenz des Ulmensplintkäfers, Scolytus laevis Chapuis 1873 (Col., Scolytidae) und dessen Bedeutung für die Ausbreitung des Ulmensterbens in den nördlichsten Ulmenwäldern Europas

Es 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

The 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.

Chirale 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

The 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.

Geruchsorientierte 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

In 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.

Effekt 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

Field 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

While 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

A 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

A 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

Fundamental 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.
Eggsac parasitism of money spiders (Araneae, Linyphiidae) in cereals, with a simple method for estimating percentage parasitism ofErigonespp. eggsacs by Hymenoptera
Authors: Van Baarlen P. , Sunderland K. D. , Topping C. J.
Published: August 2009

Observations on parasitism of eggsacs of the linyphiid spidersErigonespp.,Oedothoraxspp.,Bathy‐phantes gracilisandLepthyphantes tenuisby four species of hymenopterous parasitoids in a field of winter wheat are described. The dominant parasitoids emerging from eggsacs wereGelis festinans(Ichneumonidae) andBaeussp. (Scelionidae). Percentage parasitism of introduced and naturally occurring eggsacs was compared for the months of May, June and July. No eggsacs ofOedothoraxspp. andB. graciliswere parasitized.Oedothoraxspp. females were observed, in both laboratory and field, to guard their eggsacs efficiently against attack by parasitoids. The percentage of naturally occurring eggsacs ofErigonespp. parasitized byG. festinanswas not significantly different from the percentage parasitism of eggsacs introduced into the field in modified Petri dishes; the Petri dish introduction method therefore provides a simple and efficient means of assessing parasitism in the field.
Functional response of Diaeretiella rapae (McIntosh) (Hym., Aphidiidae) to Diuraphis noxia (Mordwilko) (Hom., Aphididae) hosts
Authors: Bernal J. S. , Bellows T. S. , González D.
Published: August 2009

Functional‐response experiments involving the parasitoid Diaeretiella rapae (McIntosh) (Hym., Aphidiidae) and Diuraphis noxia (Mordwilko) (Homo., Aphididae) hosts were conducted. The host densities used were 10, 20, 40, 80, and 160 hosts per arena per day. Searching bouts lasted 24 h, and female parasitoids were allowed to search over two consecutive days. New hosts were offered to parasitoids after the first 24 h. Temperature was maintained at ca. 21°C, photoperiod was set at 14L:10D, and humidity ranged from 50 to 70 % RH. In general, the offspring sex ratio did not appear to vary significantly with a host density of up to 80 hosts per female per day. However, the proportion of female offspring increased when female parasites were offered 160 hosts per day. In addition, the overall proportion of female offspring produced across all host densities offered decreased on day 2 (0.582 ± 0.037) relative to day 1 (0.661 ± 0.023). Diaeretiella rapae displayed a Type 2 functional response to D. noxia hosts during the first 24 h. The functional response displayed during the second 24 h was unlike any response commonly reported in the literature, with an initial rise followed by a sharp decline in numbers of mummies produced when more than 40 hosts were offered. This was presumably due to the greater depletion of the female parasitoid's egg complement after 24‐h exposures to high host densities (80 and 160 hosts), rather than to lower host densities (10, 20 and 40 hosts). The functional response parameters for day 1 were à =1.341 arenas per day and Th = 0.017 days per mummy. The maximum attack rate per 24‐h period (i.e. 1/Th) was 59.5 mummies.
Studies on the population dynamics of the potato tuber moth (Phthorimaea operculella Zell. (Lep., Gelechiidae) in the Republic of Yemen
Authors: Kroschel J. , Koch W.
Published: August 2009

The development of the potato tuber moth is strongly determined by climatic factors. In Yemen, mass propagation takes place in summer between June and August. Within 1 year, the potato tuber moth develops eight generations. The period of development from the egg to the adult stage takes less than 30 days in summer and at least 70 days in winter. After the crop‐free winter season (November‐February), the population has to build up again in the field. To some extent, non‐harvested tubers serve as places for hibernation. Secondary host plants as Datura stramonium L. are destroyed by frost and do not contribute to hibernation, The build‐up of the potato tuber moth population results predominantly from the farmers' practice of using infestea seed potatoes. The parasitoids Diadegma molliplum Holm. (Hym., Ichneumonidae) and Chelonus phthorimaeae Gah. (Hym., Braconidae) reach parasitization rates of 30–40% at the beginning of the vegetation period, from March to April, and 60–80% in the second potato‐cultivation period from August to September. Along with numerous entomophages of Carabidae, Coccinellidae, Staphylinidae, Syrphidae and Chrysopidae, a specific granulosis virus occurs endemically in the production system. These factors are discussed as part of an integrated pest‐management programme for the potato tuber moth.
Choice of pupal habitats by a moth, Zeiraphera diniana Gn. (Lep., Tortricidae), defoliating lodgepole pine, Pinus contorta (Douglas), in northerly, non‐alpine zones
Authors: Day K. R.
Published: August 2009

Higher rates of pupation within the larval feeding habitat (foliage) are reported from a non‐alpine plantation forest of lodgepole pine than are normal in alpine larch forests where pupation occurs in the soil. Experimental evidence suggests that neither host plant species nor temperature conditions are responsible for the difference. High rates of pupal mortality in the soil of wetter non‐alpine forests may have resulted in selection of an alternative pupal habitat.
Influence of rainfall on feeding behavior, growth, and mortality of larvae of the beech caterpillar, Quadricalcarifera punctatella (Motschulsky) (Lep., Notodontidae)
Authors: Kamata N. , Igarashi Y.
Published: August 2009

A series of observations and experiments were conducted to examine the direct influence of rainfall on feeding behavior, growth, and mortality of larvae of the beech caterpillar, Quadricalcarifera punctatella. Rainfall restricted feeding, especially of the young larvae; first and second instars stopped feeding and moved to the backside of a leaf and/or to another leaf when rain began. More than 90 % of hatched larvae died of starvation under a condition of experimentally man‐made continuous rain. Last instar larvae stopped feeding in a heavy rain but more than half of them continued to feed when rain was light. Larvae reared under the man‐made continuous rain during their last instar stage weighed 14.722.0 % less than control when they matured and pupated, and those reared under the rain during the 1st instar stage were also small when they molted to the 2nd instar, undergoing one extra instar stage before the last instar. This extra stage lengthened the overall larval duration but body size regained when subsequent conditions were more favorable. Thus, rainfall in young larval stages resulted in high mortality and a prolongation of the larval period, and rainfall in late larval period curtailed body growth.
Discovery of the larger grain borer in a tropical deciduous forest in Mexico
Authors: Ramírez‐Martínez M. , de Alba‐Avila A. , Ramírez‐Zurbía R.
Published: August 2009

We report on the first records of natural host plant utilization by Prostephanus truncatus. Spondias purpurea (‘ciruelo’) and Bursera fagaroides (‘cuajiote amarillo’) branches cut down by Oncideres albomarginata chamela were colonized by P. truncatus in the tropical deciduous forest of the Pacific Coast of México. An average of 328 P. truncatus individuals were captured in pheromone traps and 48 adults in direct samplings of S. purpurea twigs. Five host tree records collected previously are mentioned, all were recorded in the dry season. Strong preferences for cacahuazintle maize were detected by P. truncatus from S. purpurea twigs under laboratory conditions. All beetles had moved to the grain in 19 days. No P. truncatus were observed in either maize fields or rural storage houses of the region, only Sitophilus zeamais was detected, while the pheromone traps in the forest were capturing P. truncatus. Populations of P. truncatus are considered to be utilizing the natural vegetation as possible dissemination points for colonizing neighboring agricultural fields as food sources to which they were suited by chance.
Demographical parameters of Frankliniella occidentalis (Pergande) (Thysanoptera, Thripidae)
Authors: Gerin C. , Hance Th. , Impe G. Van
Published: August 2009

In less than 3 years (1986–1988) Frankliniella occidentalis, imported from USA, had spread throughout Europe. It is a polyphagous Thysanoptera which causes important yield loss in greenhouses, in both vegetable and ornamental crops. However, insufficient data are available on its basic biology. The purpose of this work was thus to establish its life table. A cohort of 95 individuals were observed daily during their whole lifetime. The development time is short, 14.2 days, and no significant difference has been observed between males and females. The mean fecundity is high, as 43.17 larvae were produced by a single female. The intrinsic rate of natural increase is 0.140, meaning that the theoretical population may double in 4.94 days.
The introduction and establishment of Aphidius colemani Viereck (Hym., Aphidiinae) in Tonga
Authors: Wellings P. W. , Hart P. J. , Kami V. , Morneau D. C.
Published: August 2009

In this paper we describe the introduction and establishment of the polyphagous parasitoid Aphidius colemani into Tonga in an attempt to control the banana aphid, Pentalonia nigronervosa. P. nigronervosa is a serious pest of Musa spp. because of direct feeding damage and, more importantly, as a vector for banana bunchy top virus disease. A. colemani was introduced to Tonga from Australia, cleared through post‐entry quarantine and mass reared for field release. More than 32000 parasitoids were released on Tongatapu Island, Tonga, between April 1990 and November 1991. Results of surveys conducted during the project have not provided evidence for the parasitoid attacking P. nigronervosa in the field. However, A. colemani was recovered from Aphis gossypii on taro, Colocasia esculenta about 9 months after the cessation of releases confirming its establishment. A. gossypii is one of a number of other species present in the Tongan aphid fauna that are suitable hosts for Aphidius colemani. Experimental studies on the acceptance of alternate aphid hosts by A. colemani are presented; along with information on host suitability. These data show that P. nigronervosa is readily parasitized in the absence of ants.
Pheidoleants as potential biological control agents of the boll weevil,Anthonomus grandis(Col., Curculionidae), in Southeast Brazil
Authors: Fernandes W. D. , Oliveira P. S. , Carvalho S. L. , Habib M. E. M.
Published: August 2009

This study evaluates the potential of ants as natural biological control agents of the boll weevil (Anthonomus grandis), during the between‐season period, in South‐east Brazil. Active adults ofAnthonomuswere experimentally distributed on the ground of the cotton field. Results show that 20% of the adultAnthonomusare attacked and removed by foraging ants. The native antPheidole oliveiraiwas by far the most efficient predator, accounting for 94 % of the predation onAnthonomus.Recruited workers ofP. oliveiraiwere usually very fast at transporting the weevils to their nests. The potential benefit of suppressing overwintering adultAnthonomusduring the between‐season period is mainly that of reducing the risk of high level infestations during the next cropping cycle.
Evaluation of Mediterranean fruit‐fly traps for use in sterile‐insect‐technique programmes
Authors: Katsoyannos B. I.
Published: August 2009

This paper contains information on a 5‐year experimental programme, coordinated by the International Atomic Energy Agency (I.A.E.A.), on Mediterranean fruit‐fly (medfly); Ceratitis capitata (Diptera, Tephritidae) trapping. The aim of the experiments was to standardize trapping methods for use in sterile‐insect‐technique programmes under various climatic and ecological conditions. The experiments were conducted in Greece during the months July‐September, 1987–1991, in a citrus orchard on the island of Chios. Seven different trap types and several trap treatments consisting of combinations of visual and olfactory (food, sexual) attractants were tested according to the coordinated protocol. Additional trap types and treatments were also assessed in additional experiments. Among the treatments tested, the most effective in terms of total captures was the International Pheromones' Plastic McPhail Trap (IPMT), baited with a water solution containing the protein Nulure 9%, borax 3 % and having a Trimedlure (TML) plug in a basket hung from the trap ceiling. This treatment captured predominantly males and was relatively selective for medflies since, apparently, TML has repellent effects on non‐target insects and in part, on medfly females. The same treatment without TML was almost as effective as the above treatment, capturing predominantly females but also a large number of non‐target insects which renders it problematic. The IPMT was as effective as the other McPhail Trap version tested, including the classical glass trap. The internationally used Jackson Trap baited with a TML plug was the most convenient in terms of handling and performed well under low to medium population densities. However, with high populations, its sticky surface was too small to capture the corresponding proportions of males. Under high population densities, larger sticky traps or dry traps with a much bigger carrying capacity are more suitable. Some of the Nadel‐type traps such as a Hawaiian and a Moroccan version (the Maghrebmed trap), or even a dry IPMT baited with TML and DDVP, were very effective and are probably suitable for dry and dusty areas. However, with some of the traps, such as the Hawaiian type, most of the captured flies were frequently removed by yellowjacket wasps (Vespula germanica L.) entering into the trap.
Abundance and emergence of spruce cone insects in different parts of Switzerland
Authors: Wermelinger B. , Hirschheydt J. v. , Fecker B.
Published: August 2009

In 1989 a total of 4471 spruce cones was harvested at 29 locations distributed over the five main geographic regions of Switzerland, i.e. Jura, Central Plateau, North, Central and South Alps. The cones were incubated in a controlled environment chamber and the emerging insects were collected and identified. This analysis excludes parasitoids except for the most abundant Torymus spp. Twelve insect species and some 14000 individuals in total were identified. On the average, every cone was inhabited by three insects. The most numerous species were Kaltenbachiola strobi (Winn.), Cydia strobilella (L.), and Torymus spp., amounting together to 95% of the total insect number. Though the abundance peaks varied for different species, most insects were reared from cones from the alpine area. Vegetation type (alliance) was related to the abundance of several species but did not correlate with total infestation rate. For two species their number was related to sampling site altitude. Likewise, a positive, linear correlation was found between the frequencies of the parasitoid Torymus spp. and its host K. strobi, the ratio between the two species averaging 0.7. Cone setting did not correlate with infestation level, but tree age was positively related to total insect number per cone.

In the laboratory C. strobilella and K. strobi were the earliest species to emerge; they had the shortest emergence period as well. The percentage of K. strobi with prolonged diapause (emergence in second year after cone sampling) was 51%, while the corresponding values for all other species were lower than 20%. Neither sampling site elevation nor cone setting affected diapause length.
Factors affecting choice of buds by larvae of the ash bud moth Prays fraxinella Bjerk. (Lep., Yponomeutidae), and the implications for ash dieback
Authors: Foggo A. , Speight M. R.
Published: August 2009

Ash dieback is a chronic condition affecting a high percentage of mature pre‐senescent individuals of Fraxinus excelsior L. growing in hedgerows in mainland Britain. The ash bud moth has been mooted as a possible causal agent of dieback through attacking terminal buds of twigs and curbing tree growth: dieback is characterised by failure of terminal buds to flush. Patterns of winter bud utilisation by larvae of the ash bud moth Prays fraxinella were determined by examination of samples gathered during a field survey in 1989. Further twigs gathered in 1993 were used to determine mean values for various characteristics of buds which might influence bud choice by larvae. These bud characteristics were used to generate expected patterns of larval utilisation of buds at different positions on the twig; observed and expected distributions were compared by G‐tests. P. fraxinella larvae display a complex preference for buds situated at different points on the twigs, with preference for buds being strongly affected by bud size, and with preference for buds in the middle of the twigs being higher than that for either apical or basal buds possibly due to interactions between bud size, scales thicknesses, and availability of food within the buds. These findings suggest that failure of terminal buds to flush in instances of ash dieback are not likely to be due to bud moth attack. Size based preference for buds may have deleterious consequences for young trees, however, in which lateral buds are often too small to provide adequate resources for P. fraxinella larvae.
On‐farm analysis of attacks by the pea weevil (Sitona lineatus L.; Col., Curculionidae) and the resulting damage to pea (Pisum sativum L.) crops
Authors: Doré T. , Meynard J. M.
Published: August 2009

The study measures intensity of attacks by Sitona lineatus L. on pea crops in farmers' fields and the resulting damage. Insect attacks were measured on the aerial parts of the plant at the vegetative stages and on roots at the start of flowering of the crop. Attack intensity varied between and within plots. Early sown crops were at greater risk of severe damage. There was a good correlation between leaf damage at the beginning of the crop cycle and damage to nodules at the start of flowering in unsprayed crops. Aerial spraying did not completely prevent nodule damage in crops severely injured by insects at the early vegetative stage. The effects of the attacks on nitrogen nutrition of the pea crop were also assessed; these results are discussed with regard to the consequences for crop management.
Studies on the strains of Trichogramma evanescens Westwood (Hym., Trichogrammatidae) collected from different hosts in Northern Maldova
Authors: Ram Pala , Tshernyshev W. B. , Afonina V. M. , Greenberg Sh. M.
Published: August 2009

Biological and morphological characteristics together with electrophoretic patterns were compared for five strains of Trichogramma evanescens W., collected from the eggs of Mamestra brassicae L., Ostrinia nubilalis Hb. and Agrotis segetum Schiff. in northern Maldova. Significant differences were observed in the biological characteristics including the proportion of female progeny, developmental period, longevity and fecundity. The strains also differed in the ratio of antennal hair length to the maximum width of flagellum in males. Patterns of esterase systems indicated that the strains differed in the mobility and intensity of esterase bands. All the strains had a strong preference for the host from which they were collected in the field. Crossing of the strains indicated that one strain was reproductively isolated. The results have application in selecting the strategy for establishing initial colony in mass rearing of parasitoids and for research on Trichogramma ecology and evolution.
Eggs of the stick insect Graeffea crouanii Le Guillou (Orthoptera, Phasmidae). Mortality after exposure to natural enemies and high temperature
Authors: Rapp G.
Published: August 2009

The eggs of the coconut stick insect Graeffea crouanii develop on the ground beneath the palms where they are subject to desiccation and attacks by parasitoids or predators. Eggs were exposed in petri dishes to assess the significance of natural enemies in the field. After 1 year the parasitoids Paranastatus verticalis and P. nigriscutellatus had emerged from only 1% of a total of 240 eggs, predators had attacked 70%. Eggs were offered to potential predators. The ants Pheidole megacephala and Tapinoma melanocephalum and the rodents Rattus exulans and R. rattus accepted them. Egg mortality after exposure to different temperatures was observed in climatic chambers. Nymphs emerged from 62% of a total of 120 eggs kept at 20°C. All eggs exposed to 30°C and 40°C became desiccated.
Cereal aphids, their parasitoids and coccinellids on oats in central Poland
Authors: Pankanin‐Francz M. , Ceryngier P.
Published: August 2009

The aim of this work was to study the complex role of coccinellids and parasitic Hymenoptera in reducing the populations of cereal aphids on oat crops. The studies were conducted in 1988–1991 in Dziekanów Polski near Warsaw. The dynamics of number of aphids and coccinellids and degree of parasitization of aphids by parasitoids were examined. Moreover, the species composition of the studied groups of insects was also determined.

The studies allowed to determine the occurrence of three species of cereal aphids: Rhopalosiphum padi L., Sitobion avenae F. and Metopolophium dirhodum Walk. The first two were the most numerous. The dynamics of the individual species was different in the separate years of the study. The first to appear was usually R. padi. On the studied fields eight species of predatory Coccinellidae and seven species of parasitic Hymenoptera belonging to the family Aphidiidae were found.

The studies revealed considerable differences in the abundance of the species of cereal aphids in the individual years, course of its dynamics and also synchronization between the development of aphids and their natural enemies. The role of aphidophages should be separately considered for the individual aphid species. R. padi is usually attacked by coccinellids after the peak of numbers, whereas S. avenae during the increase of population.S. avenae is also reduced to a considerable extent by parasitoids.
Sublethal effects of acephate and biphenate on fecundity, longevity, and egg viability in greenhouse whitefly (Hom., Aleyrodidae)
Authors: Omer A. D. , Leigh T. F.
Published: August 2009

Sublethal effects of acephate (an organophosphate) and biphenate (a pyrethroid) on greenhouse whitefly (Trialeurodes vaporariorum Westw.) were investigated by measuring male and female longevity, daily rate and lifetime fecundity per female, and egg viability for cohorts exposed to LC50s when Acala SJ‐2 cotton was a host. Males T. vaporariorum were more sensitive to sublethal concentrations than females. Significant reductions in male longevity were caused by exposure to acephate and biphenate, whereas female longevity was not significantly affected by exposure. Exposure to biphenate and acephate treatments reduced lifetime fecundity by 29% and 37%, respectively. Viability of eggs laid by treated females was not affected. Analysis of patterns and heterogeneity of reproduction suggests that timing and magnitude of oviposition, average level of daily oviposition and reproductive decline were influenced by sublethal concentrations of insecticides. Results of repeated‐measures analysis of variance confirmed reductions in fecundity of females T. vaporariorum exposed to sublethal concentrations.
Etude du mécanisme de la confusion sexuelle pour l'Eudémis de la vigne Lobesia botrana Den. et Schiff. (Lep., Tortricidae). I. Rôles respectifs de la compétition, du camouflage de la piste odorante et de la modification du signal phéromonal
Authors: Schmitz V. , Roehrich R. , Stockel J.
Published: August 2009

Disruption mechanisms of pheromone communication in the European grape moth Lobesia botrana Den, et Schiff. — I Respective roles of competition, camouflage of female signals and modification of pheromonal signal

The mechanisms implied in confusion were studied by experiments in vineyard using the technique of males released and captured, completed in laboratory by tests in the olfactometer. The following results were found: (1) The sex behaviour of males was not inhibited by the presence of a source of synthetic pheromone up to the dose of 500 mg. (2) The main mechanism was the competition between females and source of synthetic pheromone. This competition was more and more favourable to the dispenser when the dose of pheromone increased. (3) It was also a camouflage of the smelling trail of the females. That caused a decrease of active space in which the males were able to locate the females. This effect was got for high doses only. (4) Addition of minor compounds of natural pheromone to synthetic products had no influence on competition and camouflage.

Les mécanismes impliqués dans la confusion ont été étudiés par des expérimentations en vignoble basées sur la technique des lâchers et captures, et complétées au laboratoire par des essais en olfactomètre. Les résultats suivants ont été dégagés: (1) Le comportement sexuel des mâles n'est pas inhibé par la présence d'une source de phéromone synthétique jusqu'à la dose de 500 mg. (2) Le mécanisme principal est la compétition entre les femelles et les sources de phéromone synthétique. Cette compétition est de plus en plus favorable au diffuseur lorsque la dose de phéromone augmente. (3) II existe aussi un camouflage de la piste odorante des femelles amenant une diminution de l'espace actif dans lequel les mâles peuvent les repérer. Cet effet apparait pour les doses élevées de phéromone. (4) L'adjonction des composants minoritaires de la phéromone naturelle aux produits de synthèse n'a aucune influence sur la compétition et le camouflage.
Effect of temperature and plant size on the infestation dynamics of oilseed rape plants by Baris coerulescens Scop. (Col., Curculionidae) in field conditions
Authors: Lerin J. , Koubaiti K.
Published: August 2009

The plant infestation dynamics of winter oilseed rape, Brassica napus L. var. oleifera Metzger, by Boris coerulescens was investigated during a 3 years study in field conditions. Each year, plant infestation started at the end of March and reached a maximum ca. 23 June, then dropped drastically. Mortality was very low up to the maximum of population then increased abruptly. The main cause for mortality was plant desiccation caused by fungal diseases, harvest or degeneration of the cortex of the root. Mortality was higher in big plants than in small ones. Plant infestation can be described as a function of time by a logistic curve from the beginning to the end of the increase in population. Egg accumulation in plants is linearly linked to degree days during most of the ascending phase of plant infestation. The number of immature individuals per plant (from egg to nymph) is linearly linked to plant size, as measured from the root crown diameter. The relationship is density dependent. The infestation level at harvest is a very poor indicator of the overall level reached during the whole plant cycle because of higher mortality in big, heavily infested plants than in less infested small ones.