bluuebunny/crossref_metadata_2025_split huggingface dataset:
The predatory mite Hypoaspis miles: biological and demographic characteristics on two prey species, the mushroom sciarid fly, Lycoriella solani, and the mould mite, Tyrophagus putrescentiae
Authors: Enkegaard A. , Sardar M. A. , Brødsgaard H. F. 
Published: October 2003

AbstractThe biology of Hypoaspis miles Berlese (Acarina: Hypoaspidae) fed on mushroom sciarid larvae (Lycoriella solani Winnertz) (Diptera: Lycoriidae) and mould mites (Tyrophagus putrescentiae Schrank) (Acari: Acaridae), was investigated by laboratory experiments at 20 °C, 75% r.h. and LD16:D8 hours. H. miles had a significantly shorter development time and a significantly lower juvenile mortality when fed on sciarid larvae than on mould mites, the development time being 14.5 days and the mortality 3.5% on the former prey. The preoviposition and postoviposition periods of H. miles were not uninfluenced by the prey species and were 5–9 and 32–37 days, respectively. Oviposition periods of 53.2 and 68.5 days and female longevities of 82 and 109.6 days were observed on diets of sciarid larvae and mould mites, respectively. Male longevity (168–219 days) was uninfluenced by the prey species. The egg production of H. miles on sciarid larvae was estimated to be 44.4 ± 4.33 eggs per female, as compared to 22.43 ± 1.79 eggs per female on mould mites. The sex‐ratio of the offspring was significantly influenced by the prey species, the ratios (♀/(♀+♂)) being 0.66 on sciarid larvae and 0.54 on mould mites. The net reproductive rate (R0) for H. miles fed on sciarid larvae was approximately 27 which was three times higher than for mites feeding on mould mites. The innate capacity of increase (rm) was highest (0.0747 day−1) when sciarid larvae served as food, giving a doubling time of 9.3 days as compared to 12.8 days on mould mites. The generation times were 44.28 on sciarid larvae and 40.67 days on mould mites. The daily food consumption rate of juvenile and adult H. miles was 0.24 and 0.86 sciarid larvae and 10.8 and 21.7 mould mites, respectively. In terms of weight consumed, however, the consumption of sciarid larvae was 2–3.5 times the weight of mould mites. The ratio of females to males influenced the oviposition period and egg production of H. miles, with virgin females laying fewer eggs over a longer period of time as compared with females with access to males. The egg production in relation to the sex‐ratio was described by models predicting a maximum number of eggs per female of 22.3 to be attained at a sex ratio of 0.69 (♀/(♀+♂)) and a maximum daily number of eggs per female of 0.33 to be attained at a sex ratio of 0.37 (♀/(♀+♂)).
Reproduction of Diaeretiella rapae on Russian wheat aphid hosts at different temperatures
Authors: Bernal Julio , González D. 
Published: October 2003

Abstract Diaeretiella rapae (M'Intosh), a polyphagous and cosmopolitan parasite of aphids, was imported from China to the USA for biological control of Diuraphis noxia (Mordwilko), a pest of small grains. We studied several aspects of its biology on D. noxia hosts in the laboratory at 3 constant temperatures, 10.0, 21.1, and 26.7 °C. Females lived significantly longer than males at all 3 temperatures, and longevity was greatest at 10 °C, followed by 21.1 and 26.7 °C. Fecundity (= number of mummies) did not differ significantly among the 3 temperatures studied. The ovarian egg‐load was 129.1 ± 9.3, and was significantly affected by the size of adult females. A pre‐oviposition period (0.95 ± 0.26 days) was detected at 10 °C, but not at the other temperatures. Pre‐imaginal survivorship was similar among temperatures, while Ro and Tc decreased with temperature, and rm increased with temperature. The offspring sex ratio (proportion females) was lowest at 26.7 °C, and similar between 10.0 and 21.1 °C. In addition, the offspring sex ratio significantly declined with the age of the female parent. The suitability of D. rapae for colonization against D. noxia in North America is discussed in relation to its responses to temperature and the climate of its home range.
Comparison of damage to Eucalyptus caused by Amorbus obscuricornis and Gelonus tasmanicus
Authors: Steinbauer M. J. , Taylor G. S. , Madden J. L. 
Published: October 2003

Abstract Amorbus obscuricornis (Westwood) and Gelonus tasmanicus (Le Guillou) (Heteroptera: Coreidae) are specific to Eucalyptus (Myrtaceae). A. obscuricornis feeds almost exclusively upon apical shoots and causes a characteristic wilting and necrosis. By comparison, the feeding activities of G. tasmanicus result in no obvious phytotoxicosis. Salivary gland extracts from both species exhibited sucrase activity but no pectinmethylesterase (PME) activity. Saliva from A. obscuricornis also exhibited considerable oxidase activity. Sucrase activity was significantly higher in extracts derived from G. tasmanicus than from A. obscuricornis, but this could not explain the observed differences in phytotoxic symptoms. It is suggested that differences in plant damage are attributable to the site of feeding activity (i.e. young versus mature tissue), which predetermines the reactivity of host tissues, and/or the quantity of salivary enzymes injected.
Response of Ceratitis capitata to citrus chemicals under semi‐natural conditions
Authors: Katsoyannos B. I. , Kouloussis N. A. , Papadopoulos N. T. 
Published: October 2003

AbstractResponses of Mediterranean fruit fly Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) adults to chemicals from citrus fruits were quantified in choice tests conducted in large field cages housing naturally planted orange trees, on the Greek island of Chios. Both sexes responded strongly to chemicals released from artificial cuts made in the pulp of peeled oranges and also to natural or commercial orange juice applied to the surface of yellow 7.0 cm diameter spheres. Males also responded strongly to chemicals released from cuts made in the oily region of the orange peel, or flavedo and less to sour orange and lemon. In contrast, females did not respond to flavedo chemicals. Male response to peel chemicals occurred throughout the day and increased as the number of cuts per fruit increased from 2 to 8. Contact of male mouthparts with sap from cuts, and mating attempts between males on or near the cuts were frequently observed. The males also responded to commercial essential orange oils applied to yellow spheres, but less to essential mandarin oils. The role of citrus chemicals in host finding behaviour of C. capitata and their potential use for the development of effective traps for monitoring and controlling the fly are discussed. The experimental method followed in this study can be used as a standard technique for evaluation of the quality of flies to be used in sterile insect technique programmes.
The response of German cockroaches to toxic baits:strain differences and the effects of selection pressure
Authors: Negus Tracy F. , Ross Mary H. 
Published: October 2003

AbstractStrain differences in the response of German cockroaches to toxic baits and their potential to evolve resistance to them was evaluated in choice tests. Percentage bait consumption (amount of bait consumed divided by total food consumed) was used to estimate relative attractancy/repellency of the baits. One strain apparently had low level resistance to abamectin, but no evidence of resistance was found in other strains tested with either Roach Ender or a gel bait (abamectin‐based baits). Incipient behavioral resistance occurred in two strains selected for three generations with Roach Ender; a stronger response in a strain selected with the gel bait is attributed to the development of behavioral resistance. Baygon bait was highly repellent. Low level resistance to propoxur caused a large decrease in mortality compared with susceptible strains. Strong behavioral resistance developed in strains selected with Stapleton's Magnetic Roach Food.
EAG measurement of pheromone distribution in apple orchards treated for mating disruption of Cydia pomonella
Authors: Milli Roland , Koch Uwe T. , de Kramer Jacobus J. 
Published: October 2003

AbstractPheromone concentrations were measured in an apple orchard using an advanced EAG device featuring short‐term recalibration of the antenna with two calibration standards, a lightweight remotely operated probe and automated measurement cycles. The effects of wind direction on pheromone density and distribution at the edge of the orchard were studied as well as the change of pheromone density with height from 1 to 6.5 m. Results show that pheromone can be found at heights of up to 6 m when moderate winds are present. Very low wind speeds tend to reduce the height of the pheromone cloud. Clean wind entering the orchard creates a transition zone up to 15 m wide where the pheromone is depleted. At the down‐wind edge of the orchard, pheromone signals were recorded at distances of up to 60 m downwind from the treated zone at concentrations in the same order of magnitude as within the treated orchards. The consequences of these results concerning the design and interpretation of mating disruption field tests are discussed.
Different sensitivities of the sugar receptor of the lateral styloconic sensillum in fourth‐ and sixth‐instar larvae of the spruce budworm Choristoneura fumiferana
Authors: Panzuto M. , Albert P. J. 
Published: October 2003

AbstractFemale fourth‐ and sixth‐instar larvae, Choristoneura fumiferana, were tested individually for the response of the sugar cell on the lateral styloconic sensillum to 25 mM/l concentrations of 12 carbohydrates. The spruce budworm showed an age‐related change in responsiveness of the sugar cell. The order of stimulating effectiveness for fourth‐instars was melibiose > sucrose > raffinose.These storage di‐ and trisaccharides are present in the host plant at the beginning of budbreak. Sixth‐instars responded to sucrose > fructose > m‐inositol. These findings are in accordance with those of a previous behavioural study on feeding preferences of sixth‐instars. The response for both melibiose and raffinose does not change from fourth‐ to sixth‐instars; however, it does for sucrose, fructose and m‐ inositol.
Effect of an entomopathogen on adaptation of Heliothis virescens populations to transgenic host plants
Authors: Johnson M. Tracy , Gould Fred , Kennedy George G. 
Published: October 2003

AbstractThe role of an entomopathogen in evolution of herbivore adaptation to partially resistant host plants was examined using a tritrophic system in the laboratory. We hypothesized that a pathogen should interact with herbivore behavior to accelerate herbivore adaptation to toxic plants: individuals not adapted to toxin tend to move more on toxic plants, and therefore are more likely to encounter a lethal dose of pathogen, further increasing the probability that they will be eliminated by selection. Heliothis virescens (F.) (Noctuidae) was selected for adaptation to transgenic tobacco containing a sublethal concentration of Bacillus thuringiensis Berliner toxin under two treatment regimes: larvae placed on plants treated with infective conidia of the entomopathogenic fungus, Nomuraea rileyi (Farlow) Samson, and larvae placed on plants without fungus.Selection was initiated with a genetically heterogeneous strain created by crossing two laboratory strains of H. virescens, one not adapted to B. thuringiensis toxin, and one highly adapted (>1000‐fold) to toxin. This cross was performed four times to create four independent populations. Selection was initiated with F2 offspring from each cross and continued for 8–10 consecutive generations. Adaptation to toxin within each treatment population was quantified every generation by measuring survival and growth of larvae on artificial diet containing a low concentration of B. thuringiensis toxin.In three of four replicates, H. virescens populations exposed to N. rileyi adapted to B. thuringiensis toxin more quickly than populations not exposed. These results supported our hypothesis that the pathogen should accelerate adaptation to toxic plants. However, this hypothesis was contradicted by the result in one replicate, in which the population not exposed to fungus adapted to toxic plants faster. This opposite result could not be explained, but it suggests that there may be substantial variation in herbivore evolution in tritrophic systems. H. virescens populations selected in the presence of fungus and in the absence of fungus did not differ in feeding or in mortality when placed on leaf disks treated with conidia. Thus, populations exposed to N. rileyi on plants for 7–8 generations displayed neither physiological nor behavioral adaptation to N. rileyi.
Control of codling moth in organically‐managed apple orchards by combining pheromone‐mediated mating disruption, post‐harvest fruit removal and tree banding
Authors: Judd G. J. R. , Gardiner M. G. T. , Thomson D. R. 
Published: October 2003

AbstractAn integrated programme of pheromone‐mediated mating disruption using Isomate‐C®, post‐harvest removal of fruit, and trapping overwintering larvae with cardboard tree bands, was used to control codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), in four commercial ‘organic’ apple orchards in Cawston, British Columbia during 1989–1992. One application of 1000 dispensers ha−1 on May 1 delivered estimated seasonal totals of 16.6, 16.5 and 19.9 g of E,E‐8,10‐dodecadien‐1‐ol [=codlemone] ha−1 in 1990, 1991 and 1992, respectively, at median rates of 8.4, 8.3, and 13.3 mg · ha−1· h−1 during dusk flight periods of first brood and 5.3, 4.7 and 4.6 mg · ha−1· h−1 in second brood, respectively. Over this 3‐year period damage from codling moth at harvest ranged from 0.08 to 2.4%, and averaged <0.7% in these four organic orchards, while damage in five conventional orchards receiving sprays of azinphosmethyl ranged from 0.02 to 1.85%, and averaged 0.5%. Damage in an experimental orchard that was banded only, ranged from 43.5 to 56.7%, and averaged 48.9%. Between 1990 and 1992 cumulative male catches in Pherocon 1‐CP wing traps baited with 10 mg of codlemone declined by 52% and densities of overwintering codling moth larvae declined an average of 49.5% in all organic orchards. Overwintering populations in the banded experimental orchard showed an increase of 57.7% during this study period. We conclude that an integrated programme of pheromone‐mediated mating disruption, post‐harvest fruit removal and tree banding, controls codling moth effectively enough to make organic apple production viable in British Columbia.
The influence of tactile and other non‐chemical factors on the ovipositional responses of the generalist herbivore Epiphyas postvittana
Authors: Foster S. P. , Howard A. J. , Harris M. O. 
Published: October 2003

AbstractA bioassay to test the ovipositional responses of the generalist herbivore, Epiphyas postvittana, was developed, and various non‐chemical factors that influenced the laying, and number of eggs laid, by females were tested. In choice experiments using various models, surface texture was found to be an important factor influencing ovipositional behaviour, with females preferring to lay on smoother rather than rougher surfaces. Another surface texture feature that influenced oviposition was a raised wax ridge on a smooth surface. The wax ridge stimulated more eggs to be laid within close proximity to the ridge. Observations of females showed that the increased numbers of eggs laid on models with a wax ridge resulted not from increased landing, time spent, or numbers of eggs laid per ovipositional bout, but rather through an increased probability of ovipositing after landing on models with a wax ridge compared to models without the ridge. Spatial features of the models were also found to influence egglaying by females. Females showed a tendency to lay on the upper rather than the lower surface of models, although this appeared to depend upon how stimulatory the upper surface of the model was. Females also laid more eggs on models with a dense array of leaves than on models with a more spread‐out array.
Provenance, experience and plant utilisation by the polyphagous aphid, Aphis fabae
Authors: Douglas A. E. 
Published: October 2003

AbstractTwenty‐nine clones of Aphis fabae Scopoli (Aphididae: Homoptera) were isolated into laboratory culture from the primary host plants Euonymus europaeus and Viburnum opulus and the secondary host plants Arctium lappus, Impatiens glandulifera, Tropaeolum majus and Vicia faba. All clones performed well on either T. majus or V. faba, with mean intrinsic rates of increase (rm) in the range 0.35–0.41 aphids aphid−1 day−1, but none performed well on both plant species. Each clone could, therefore, be described as affiliated to either V. faba or T. majus. All of the 13 T. majus‐affiliated clones and 15 of the 16 V. faba‐affiliated clones could not be maintained beyond two parthenogenetic generations on the contrary plant. These results confirm that the performance of A. fabae on T. majus and V. faba is negatively correlated. Exceptionally, one V. faba‐affiliated clone (clone AED95/119) persisted indefinitely on T. majus, exhibiting a progressive improvement in performance across four parthenogenetic generations: larval mortality dropped from 80% to <20%, mean adult weight almost doubled from 0.28 to 0.53 mg, and mean number of embryos per adult aphid increased threefold from 8.6 to 24.4 embryos. The mean rm of clone AED95/119 that had been reared on T. majus for more than 4 generations was 0.17 aphids aphid−1 day−1, significantly lower than the value of 0.34 aphids aphid−1 day−1 on V. faba. It was also shown that the rm on V. faba did not differ significantly between aphids of clone AED95/119 that had been derived from long‐term cultures on V. faba and T. majus. It is concluded that the negative correlation between performance on V. faba and T. majus is not genetically fixed, but may diminish with exposure to T. majus. The implication is that this clone may have a capacity to utilise T. majus that is independent of its capacity to utilise V. faba, and is expressed only on sustained exposure to T. majus. It is suggested that, although the ‘latent’ capacity to utilise T. majus is probably not exhibited widely under natural conditions, aphids possessing it may be at a selective advantage when more suitable host plants are temporarily unavailable.
Choosing a place to grow. Importance of within‐plant abiotic microenvironment for Yponomeuta mahalebella
Authors: Alonso Conchita 
Published: October 2003

AbstractThe caterpillars of Yponomeuta mahalebella Latr. (Lepidoptera: Yponomeutidae) are monophagous on Prunus mahaleb (Rosaceae) leaves. Adult females deposit eggs in batches, which determines larval gregarious behaviour. Coupled with gregarious behaviour, caterpillars spin silk tents within they will feed until pupation. Distribution of tents in the field, their effect in microenvironmental larval growth conditions and the consequences for adult body mass and survival of larvae were studied.There was a significant trend for tents to be placed with a southward orientation. Within‐plant tent orientation was related to the sun‐shade pattern experienced, which was the main effect determining thermal differences between the inside and the outside of the tent. These differences appeared to affect larval growth and survival, with higher survival of larvae and heavier adults emerging from tents oriented to the south‐east and east, respectively.
The impact of Meu1‐mediated resistance in tomato on longevity, fecundity and behavior of the potato aphid, Macrosiphum euphorbiae
Authors: Kaloshian I. , Kinsey M. G. , Ullman D. E. , Williamson V. M. 
Published: October 2003

AbstractThe effect of the tomato resistance gene, Meu1, on feeding, longevity, fecundity and developmental rate of the pink biotype of the potato aphid, Macrosiphum euphorbiae (Thomas) (Hemiptera, Aphididae), was determined using nearly isogenic tomato (Lycopersicon esculentum Mill, Solanaceae) lines. Aphid mortality was significantly higher on resistant plants, with 60% of the aphids dying by the 4th day of exposure. By the 10th day, all the aphids on the resistant plants were dead whereas 100% of the aphids on susceptible plants were alive. Meu1‐mediated resistance resulted in significantly decreased fecundity with a ten‐fold decrease in the net fertility rate (4.5 and 45.7 progeny per aphid on resistant and susceptible tomato, respectively). A qualitative analysis showed that honeydew was produced by aphids on resistant and susceptible plants, suggesting that aphids initiate feeding on both plant types. However, significantly lower quantities of honeydew were present when aphids were caged on resistant plants. There were also significant differences in aphid location on resistant and susceptible leaves. Experiments evaluating behavior in less than 24 h showed that aphids left resistant leaves after relatively short exposure (3–6 h). Aphids transferred from resistant to susceptible tomato at intervals between 3 h and 24 h resumed feeding as evidenced by presence of honeydew. Although the mechanism by which Meu1‐mediated resistance operates is not yet known, our data suggest that resistance factors act rapidly after initiation of feeding and that lower fecundity and longevity are related to reduction in aphid feeding.
Postharvest disinfestation of diapausing and non‐diapausing twospotted spider mite (Tetranychus urticae) on persimmons: hot water immersion and coolstorage
Authors: Lester Philip J. , Dentener Peter R. , Bennett Keren V. , Connolly Patrick G. 
Published: October 2003

AbstractThe mortality response of diapausing and non‐diapausing twospotted spider mite (Tetranychus urticae Koch) on persimmons to hot water immersion treatments between 44 and 54 °C was examined, for potential as a quarantine treatment. The mean immersion time for mean 99% mortality (LT99) of diapausing mites at 44 °C was 211 min, and this time decreased with increasing temperature to 3.6 min at 54 °C. Non‐diapausing mites were found to be less tolerant to temperatures below 48 °C, with an estimated LT99 of 102 min at 44 °C, but had similar thermotolerance above 48 °C. In 47 °C water the immersion time required to kill 99% of diapausing mites was estimated at 67 min. This time was not reduced by subsequent coolstorage at 0 °C for up to eight weeks. Rather, coolstorage had the effect of keeping mites alive, relative to LT99 estimates calculated for mites stored at 20 °C. Similarly the thermotolerance of mites did not change with increased time in diapause, even though mites in diapause for 12 weeks had high control mortality. Hot water immersion appears to be a potentially useful disinfestation method for persimmons.