bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of fruit fly host, fruit species, and host egg to female parasitoid ratio on the laboratory rearing of Biosteres arisanus
Authors: Harris Ernest J. , Bautista Renato C.
Published: March 2011

The host suitability of the oriental fruit fly, Bactrocera dorsalis (Hendel), for development of Biosteres arisanus (Sonan), a braconid parasitoid, was compared with three other fruit fly species, namely, Mediterranean fruit fly, Ceratitis capitata Weidemann, melon fly, Bactrocera cucurbitae Coquilett, and Malaysian fruit fly, Bactrocera latifrons (Hendel). In addition, effects of five different fruit species, namely, Carica papaya L. (solo papaya), Musa sapientum (L.) O. Ktze. (apple banana), Mangifera indica (L.) (Haden mango), Terminalia catappa (L.) (false kamani), and Citrus aurantiifolia (Christman) Swingle (common lime), on the parasitization rate of B. dorsalis and sex ratio of parasitoid progenies were evaluated. Effects of host egg to female B. arisanus ratios on parasitoid progeny yields were likewise determined. The host suitability of fruit flies for development of B. arisanus was ranked as: B. dorsalis>C. capitata = B. latifrons = B. cucurbitae. Based on percent parasitization of B. dorsalis, preference of B. arisanus females for host eggs varied with fruit species, however, preferential oviposition displayed by female parasitoids did not influence sex ratios of subsequent parasitoid progenies. Increases in host egg to female parasitoid ratios of 5:1, 10:1, 20:1, 25:1, and 30:1 corresponded with increases in parasitoid progeny yield reaching a plateau at 20:1.
Dimethyl trisulphide is a strong attractant for some calliphorids and a muscid but not for the reindeer oestrids Hypoderma tarandi and Cephenemyia trompe
Authors: Nilssen Arne C. , Tømmerås Bjørn Åge , Schmid Rudolf , Evensen Sissel Barli
Published: March 2011

A field test with synthetic dimethyl trisulphide as attractant in flight traps was carried out in Finnmark, northern Norway, in July 1992 and 1994. The reindeer oestrids Hypoderma (= Oedemagena) tarandi (L.) and Cephenemyia trompe (Modeer) (Diptera: Oestridae), previously shown to react positively to dimethyl trisulphide on the olfactory receptor level, were only caught in small numbers, with no significant differences between baited and unbaited traps. In both years, however, the baited traps caught significantly more individuals of Calliphoridae and Hydrotaea anxia (Zetterstedt) (Diptera: Muscidae) than unbaited control traps. In 1992, Protophormia terraenovae (Robineau‐Desvoidy) (Diptera: Calliphoridae) and H. anxia were the predominant species (78.5% and 20.5%, respectively). In 1994, H. anxia was the most prevalent species (73.6%). Seven species of Calliphoridae were caught, with P. terraenovae, Calliphora vomitoria (L.), C. uralensis (Villeneuve) and C. loewi (Enderlain) as the most numerous ones. Dimethyl trisulphide is probably a decomposition product from bacterial activity and may be one of the major cues for calliphorid host finding. The significance of the reaction for oestrids on the receptor level, but evidently not on a behavioural level, remains unclear.
Identity and bioactivity of oviposition deterrents in pine oil for the onion maggot, Delia antiqua
Authors: Ntiamoah Y. A. , Borden J. H. , Pierce H. D.
Published: March 2011

The oviposition deterrent properties of pine oil (Norpine 65, Northwest Petrochemicals, Anacortes, Washington) for the onion maggot, Delia antiqua (Meigen), were verified using a two‐choice bioassay with onion oil as an attractive control. The principal deterrent property of this pine oil was found to reside in three monoterpenes, 3‐carene, limonene, and p‐cymene, which were the primary constituents identified in the most deterrent of two fractions made by preparative gas chromatography of steam‐distilled pine oil. At release rates of 220, 320 and 320 μg per 24 h in two‐choice bioassays these monoterpenes respectively caused 73.2, 65.4 and 56.3% deterrency of oviposition, while the ternary mixture released at 320 μg per 24 h caused 88.6% deterrency. The ternary mixture also caused 62.5% deterrency in a no‐choice bioassay. Of eight other monoterpenes tested, myrcene, α‐phellandrene, α‐terpinene, β‐phellandrene, γ‐terpinene, terpinolene, and β‐pinene were significantly deterrent in declining order, while α‐pinene was inactive. The ternary mixture was released from glass capillary tubes or flexible plastic cylinders in further bioassays that challenged caged females to oviposit around the base of 35 potted onion seedlings with release devices placed on the soil surface. The most effective deterrency (85.3%) was achieved at a release rate of 280 μg per 24 h per pot if plastic cylinder devices were deployed 24 h before the treated pot was exposed to D. antiqua females. If female D. antiqua were given only a treated pot, deterrency of oviposition on potted onion seedlings was significant, but low (11.7–63.2%). Because of incomplete efficacy, a monoterpene‐based deterrent formulation would be best used operationally if combined with other deterrents, or if it were integrated with some other tactic.
Interspecific competition between two parasitoids of Helicoverpa zea: Eucelatoria bryani and E. rubentis
Authors: Reitz Stuart R.
Published: March 2011

Multiple parasitism of Helicoverpa zea (Lepidoptera: Noctuidae) had differential effects on the gregarious endoparasitoids Eucelatoria bryani and E. rubentis (Diptera: Tachinidae). Both species were able to survive in multiparasitized hosts. However while the survival of E. bryani was not affected by the presence of E. rubentis, E. rubentis survival was reduced when competing with 24‐h older E. bryani. The presence of E. rubentis did not result in a decrease in the size of E. bryani except when E. rubentis was 24‐h older than E. bryani. The presence of E. bryani tended to result in smaller E. rubentis. The presence of similarly aged heterospecific competitors often resulted in prolonged development time for both species. Naïve females did not alter oviposition between unparasitized and heterospecifically parasitized fifth‐instar larvae of H. zea, either by ovipositing less frequently in parasitized hosts than unparasitized ones, or by reducing clutch size in parasitized hosts. These results indicate that in H. zea, E. bryani is a superior competitor compared with E. rubentis. These factors should be considered in evaluating the potential of E. bryani and E. rubentis as biological control agents of H. zea.
Identity, spatial distribution, and variability of induced chemical responses in tomato plants
Authors: Stout Michael J. , Workman Kathi V. , Duffey Sean S.
Published: March 2011

Using four‐leaf tomato plants (Lycopersicon esculentum Mill) as a model system, we examined the spatial distribution of damage‐induced changes in foliar protein activities. Terminal leaflets of third leaves of tomato plants were subjected to one of four types of damage, and the activities of four putative defenses – polyphenol oxidase, peroxidase, lipoxygenase, and proteinase inhibitors – were determined at four leaflet positions relative to the damaged leaflet. Multiple proteins were differentially induced by the different damage types. For a given damage type, the spatial pattern of induction was different for different proteins. More exhaustive spatial mapping of the polyphenol oxidase response to feeding by Helicoverpa zea Boddie revealed that damaged plants were more variable, both within and between plants, in the activity of this enzyme than undamaged plants. The spatial patterns of induction of these four putative defenses throughout the plant suggest that the induced plant is chemically heterogeneous and that different mechanisms of defense operate in different regions of the plant. These data are critical to an elucidation of cause‐effect relationships between induced chemicals and induced resistance in tomato foliage. In addition, these data suggest that induction functions, in part, to increase chemical variation in tomato plants; the potential role of phytochemical variation in plant defense is discussed.
Characterization of induced resistance in tomato plants
Authors: Stout Michael J. , Duffey Sean S.
Published: March 2011

We have characterized, using several types of bioassays, the resistance induced in young tomato plants by feeding of the corn earworm, Helicoverpa zea. Beet armyworm larvae, Spodoptera exigua, and leafminers, Liriomyza trifolii, were used to assay the induced resistance. In whole‐plant experiments, damage localized to a single leaflet of four‐leaf tomato plants induced a systemic increase in resistance such that beet armyworm larvae confined to previously damaged (induced) plants grew at a rate about half that of larvae raised on control plants and consumed less leaf tissue from induced plants than from control plants. In experiments using excised leaves, beet armyworm larvae suffered increased mortality when reared on leaves from induced plants. The strength of this induced resistance varied spatially relative to the damaged position; moreover, the spatial distribution of induced resistance changed over a three‐week period following damage. Other experiments demonstrated that the mechanism of induced resistance in tomato foliage involves both a decrease in larval preference for and a decrease in the nutritional value of induced foliage. Induction also retarded the oviposition and/or early development of leafminers. Thus, induced resistance has relatively severe effects on the biology of subsequent herbivores. These data should allow us to begin to elucidate cause‐effect relationships between induced resistance and induced chemistry in tomato plants.
Effects of temperature, multiple allelochemicals and larval age on the performance of a specialist caterpillar
Authors: Yang Yuelong , Stamp Nancy E. , Osier Tod L.
Published: March 2011

To understand the mechanisms underlying plant‐insect herbivore interactions, it is necessary to examine the simultaneous effects of temperature, food quality and larval age. We examined the simultaneous effects of three allelochemicals (tomatine, rutin and chlorogenic acid) on the performance of first and second instar Manduca sexta larvae under two representative thermal regimes 21: 10°C and 26: 15°C for spring and summer, respectively. Thermal regime and allelochemicals interacted to influence the time from egg hatch to ecdysis to the third instar. On average, it took about half as much time to reach the third instar at 26: 15°C as it did at 21: 10°C. Separately, tomatine and rutin had a negative effect on developmental time from egg hatch to the third instar, but their simultaneous effects were not additive. Chlorogenic acid significantly reduced the negative effect of tomatine. The magnitude of the allelochemical effect was larger at the cooler thermal regime compared to the warmer regime. For instance, chlorogenic acid by itself had no effect at the 26: 15°C regime, but at the 21: 10°C regime it significantly shortened total developmental time. The effect of chlorogenic acid on stadium duration was distinctly different for the two instars. Chlorogenic acid shortened stadium duration of first instar larvae. However, depending on thermal regime and the presence of tomatine, chlorogenic acid had a negative, positive or neutral effect on stadium duration of second instar larvae. Molting duration of second instar larvae was shortened by a half day at the warmer thermal regime but was not affected by the allelochemicals. Final larval weight was influenced by rutin and chlorogenic acid. Caterpillars fed diets containing 20 μmoles of rutin were on average 10% lighter than those fed plain diet, whereas those fed diets containing 20 μmoles of chlorogenic adic were on average 7% heavier. However, the effect of chlorogenic acid depended on thermal regime. Overall, our results indicated that: 1) temperature and food quality can interact to influence insect performance and 2) these effects are influenced by larval age.
Chemosensory basis of feeding and oviposition behaviour in herbivorous insects: a glance at the periphery
Authors: VAN Loon Joop J. A.
Published: March 2011

Recent advances in our understanding of the relationship between chemosensory and behavioural responses to phytochemicals come from a number of studies on ovipositional and food selection behaviour of flies, butterflies, moths and beetles. Establishing input‐output relationships has provided insight into the way in which the activity of chemoreceptors is translated into host‐plant selection behaviour. This was achieved for both the qualitative contrast acceptance/rejection and for quantifiable preference hierarchies. By now it is clear that the subtlety of coding the complex phytochemical profiles offered by potential host plants relies on across‐fibre patterns or ensemble‐firing of taste neurons. Progress along these lines depends on unravelling processing pathways in the central nervous system, still a largely unexplored area in herbivorous insects. Increased interest can be noted for the mechanisms operating during the most peripheral events of chemoreception: the interaction of phytochemical and chemoreceptor, determining the specificity of recognition. Evidence for ‘peripheral integration’ has accumulated. Deterrent receptors have an especially puzzling nature. Although such cells respond to a wide array of structurally diverse secondary plant metabolites, their sensitivity profile differs between closely related species. To what extent membrane‐bound receptor molecules are involved and what degree of specificity is conferred by these, is largely unknown. Sensitivity to a certain group or class of compounds is determined by single genes in several cases. This allows for a scenario in which single gene mutations affect stimulus‐receptor interactions, which might concurrently affect host‐plant selection behaviour.
Trade‐offs in larval performance on normal and novel hosts
Authors: Thompson John N.
Published: March 2011

The evolution of host specialization in phytophagous insects is generally thought to involve genetic trade‐offs that prevent individuals from maximizing fitness simultaneously on two or more hosts. Several hypotheses, however, have suggested that trade‐offs may not be evident in experiments comparing larval performance on normal and novel hosts. Tests on survivorship, growth rate, and pupal mass among families of the swallowtail butterfly Papilio oregonius on its normal host and on a novel host provide support for these hypotheses, although they do not discriminate among them. Families differed in their relative performance on the hosts, but there was no evidence of a negative genetic correlation between hosts for any of the measures of performance. In addition, there were no correlations among the different measures, corroborating an earlier result suggesting that these different components of performance in the P. machaon species group are under at least partially separate genetic control. These results and similar results published for other insects have now produced a body of studies indicating that genetic trade‐offs in individual components of larval performance may not be a major factor preventing shifts onto novel host plants. Trade‐offs leading to the evolution of host specialization are more likely to involve coordination among the various components of performance together with ecological factors that allow higher fitness on one host than on others.
Diversity and variability of plant secondary metabolism: a mechanistic view
Authors: Hartmann Thomas
Published: March 2011

Based upon a brief historical view, the typical features of plant secondary metabolism and its role in chemical interactions between plants and their environment are discussed. Facts and arguments are presented favouring the hypothesis that secondary metabolism evolved under the selection pressure of a competitive environment. The high ‘degree of chemical freedom’ of secondary metabolism which, in contrast to primary metabolism, allows structural modifications with almost no restrictions, is stressed as mechanistic basis for the generation of chemical diversity. Biochemical and physiological properties of secondary metabolism are in accordance with such a view. It is suggested that the great chemical diversity and intraspecific variability of secondary metabolism is the result of processes of natural selection which act upon highly variable chemical structures. This view is exemplified by the pyrrolizidine alkaloids, a typical class of secondary compounds.
Physiology and costs of resistance to herbivory and disease in Brassica
Authors: Mitchell‐Olds T. , Siemens D. , Pedersen D.
Published: March 2011

We used artificial selection experiments to study genetic allocation costs and physiological mechanisms of resistance to herbivory and fungal disease. Genetic costs to resistance were present in some instances and absent in others. Genetic resistance to the fungal pathogen, Leptosphaeria maculans was cost‐free, while resistance to Peronospora parasitica showed a negative genetic correlation between disease resistance and growth rate. Leptosphaeria resistant genotypes had 13% higher chitinase activity. Genetic increases in myrosinase activity were correlated with increased resistance to flea beetles (Phyllotreta cruciferae), but resulted in lower plant fecundity, presumably due to production costs of myrosinase. Genetic costs of resistance may maintain genetic variation in natural plant populations. These studies demonstrate the predictive and explanatory power of a functional approach to plant‐herbivore and plantpathogen interactions.
Electrical penetration graphs of the damson‐hop aphid, Phorodon humuli on resistant and susceptible hops (Humulus lupulus)
Authors: Paul Therasa A. , Darby Peter , Green Colin P. , Hodgson Chris J. , Rossiter John T.
Published: March 2011

Electrical penetration graphs (EPG's) were used to locate resistance to Phorodon humuli (Schrank) (Homoptera, Aphididae) in hops (Humulus lupulus, Cannabinaceae). Aphids on those hops showing resistance had a much reduced E2 pattern (uptake of phloem). In addition, many aphids on the resistant plants spent time non‐probing within two minutes of withdrawing from the phloem. This was not observed with aphids on susceptible hops. The results suggest that resistance is located in the phloem. The involvement of a mechanical factor such as the blocking of aphid stylets, the presence of antinutritional factors, or simply an inadequate supply of nutrients, are discussed as possible resistance mechanisms.
Binomial sampling plans for estimating and classifying population density of adult Bemisia tabaci in cotton
Authors: Naranjo Steve E. , Flint Hollis M. , Henneberry Thomas J.
Published: March 2011

We used an empirical relationship to develop models for estimating and for classifying the population density of adult Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) in cotton based on the proportion of infested leaves. We examined models based on tally thresholds (the minimum number of insects present before a leaf is considered infested) of 1, 2, 3, 4, 5, and 6 adults per fifth mainstem node leaf from the terminal. For the estimation of density, sampling precision (SE/mean) increased with higher tally thresholds (T); however, there was negligible improvement in precision with T ≥ 3 adults per leaf. Using T = 3 as few as 30 samples were necessary to achieve a precision of 0.25 over a wide range of population densities. To evaluate these binomial models for the classification of population density for pest management application, we used simulation analyses to determine operating characteristic curves (error probabilities), and to estimate average sample size and cost functions. Error probabilities and average sample sizes declined with higher values of T, but there was negligible decline in error probabilities using T ≥ 3 adults per leaf, and the overall cost of sampling was lowest for T = 3. Wald's sequential probability ratio test was used to formulate sequential sampling stop lines for classifying population density relative to two nominal action thresholds, 5 or 10 adults per leaf. Simulation analysis indicated that by using T = 3, fewer than 30 samples, on average, were needed to classify populations relative to either action threshold. However, simulated error probabilities consistently exceeded the nominal error probabilities used to initially formulate sequential sampling stop lines regardless of the tally threshold. Comparing binomial models using T = 1 or T = 3 to independent data from four field sites, the model for T = 1 was generally biased towards overprediction of mean density, but the T = 3 model was a robust and relatively unbiased predictor of mean density. The binomial sampling plans presented here should permit the rapid estimation of population density and enhance the efficiency of pest management programs based on the prescriptive suppression of B. tabaci in cotton.
Insect‐crop interactions in a diversified cropping system: parasitism by Aleochara bilineata and Trybliographa rapae of the cabbage root fly, Delia radicum, on cabbage in the presence of white clover
Authors: Langer Vibeke
Published: March 2011

Parasitism of the cabbage root fly, Delia radicum (L.) by the staphylinid Aleochara bilineata Gyllenhal and the cynipid Trybliographa rapae Westwood was examined in a cabbage monoculture and a mixed stand of cabbage undersown with white clover. Number of overwintering cabbage root fly pupae per plant was consistently reduced in the mixed stand, and the incidence of plants attacked by cabbage root fly was either reduced or not different in the mixed stand compared to cabbage monoculture. For both parasitoids, the probability of D. radicum attacked plants having at least one parasitized pupa increased with density of cabbage root fly pupae around the plant. For A. bilineata, this positive relation between presence of parasitism and host density was consistently stronger in cabbage monoculture than in cabbage undersown with clover. Location of a host plant by T. rapae was not consistently affected by the presence of clover. D. radicum attacked plants situated in the cabbage and clover mixture were found by T. rapae as easily as in cabbage monoculture. Overall, the ‘total risk of parasitism’ for a cabbage root fly pupa by A. bilineata was reduced in the mixed stand compared to the cabbage monoculture, whereas the risk of parasitism by T. rapae was not consistently affected by clover. For both parasitoids, intensity of parasitism showed a variable relationship with host density on individual plants attacked by the cabbage root fly. Overall, in spite of consistently lower total density of pupae in the mixed cabbage – clover than in cabbage monoculture, the density of unparasitized pupae was reduced by the presence of non‐host plants only in two of the four experiments. The results emphasize the need to include not only herbivore and crop, but also other plant species as well as natural enemies when evaluating management methods.
Snowdrop and wheatgerm lectins and avidin as antimetabolites for the control of sugarcane whitegrubs
Authors: Allsopp P. G. , McGhie T. K.
Published: March 2011

Snowdrop and wheatgerm lectins were found to be insecticidal and growth inhibiting dietary proteins for larvae of the sugarcane whitegrub Antitrogus parvulus. At concentrations as low as 0.5 mg of snowdrop lectin per gram of semi‐artificial diet, growth was inhibited by 21 days of feeding and significant mortality was apparent by 28 days. Wheatgerm lectin was active at similar concentrations, although expression of the effects was slower. Avidin was found to be a growth inhibiting dietary protein for larvae of Antitrogus consanguineus. At levels as low as 0.01 mg g–1 of diet, growth was inhibited by 28 days of feeding. Avidin caused no significant mortality after 35 days of feeding. Snowdrop and wheatgerm lectins and avidin are insect growth‐inhibiting proteins whose genes potentially could be manipulated into sugarcane and improve host‐plant resistance to whitegrubs.
Effects of diet on longevity and fecundity of the spined stilt bug, Jalysus wickhami
Authors: Jackson D. Michael , Kester Karen M.
Published: March 2011

We evaluated the suitability of selected food items for the adult spined stilt bug, Jalysus wickhami Van Duzee (Hemiptera: Berytidae), by providing one of seven diet treatments: (1) prepupae of the parasitoid, Cotesia congregata (Say) (Hymenoptera: Braconidae), on a leaf of tobacco (Nicotiana tabacum L., ‘NC 2326’) (Solanaceae); (2) C. congregata prepupae alone (i.e., no tobacco leaf); (3) eggs of the parasitoid's host, Manduca sexta (L.) (Lepidoptera: Sphingidae), on a tobacco leaf; (4) M. sexta eggs alone; (5) tobacco aphids, Myzus nicotianae Blackman (Homoptera: Aphididae), on a tobacco leaf; (6) a tobacco leaf alone; and (7) no prey and no tobacco. A tobacco leaf was necessary for the long‐term survival of stilt bugs, but prey source did not affect longevity. Regardless of the prey type, stilt bugs with access to a tobacco leaf lived 21–23 days, while stilt bugs without access to tobacco lived less than 12 days. Animal prey provided a protein source required for egg deposition in J. wickhami, and prey species differed in their relative nutritive values. Female stilt bugs that fed on M. sexta eggs or on C. congregata prepupae were significantly more fecund (102 and 106 nymphs per female, respectively) than females that fed on tobacco aphids (24 nymphs per female). Results suggest that stilt bugs may feed on tobacco aphids and C. congregata prepupae when other prey are unavailable.
Variation between laboratory populations of Encarsia formosa in their parasitization behavior on the host Bemisia tabaci
Authors: Henter Heather J. , Brasch Klara , VAN Lenteren Joop C.
Published: March 2011

We tested the hypothesis that two populations of the parasitoid Encarsia formosa Gahan (Hymenoptera: Aphelinidae) differed in their behavioral interactions with the whitefly host Bemisia tabaci Gennadius (Homoptera: Aleyrodidae). The two wasp populations were studied because previous work suggested large differences between the populations in performance on this host. In this study the populations differed behaviorally in both the number of hosts encountered and their reactions to hosts once encountered. The population reared for many years on Trialeurodes vaporariorum Westwood (Homoptera: Aleyrodidae) that previously performed more poorly on B. tabaci had a higher host encounter rate but rejected hosts more frequently. The population reared for a number of years on B. tabaci encountered fewer hosts but accepted a higher percentage of hosts for oviposition. The number of parasitized hosts did not differ between the two populations, however. These data demonstrate that there are heritable differences between these two populations of asexual wasps in host‐associated behavioral traits. These behavioral differences in host acceptance do not explain performance differences seen in the earlier study, however, possibly due to different conditions between the two experiments.
Field trapping of Metamasius hemipterus with synthetic aggregation pheromone
Authors: Ramirez‐Lucas Pamela , Rochat Didier , Zagatti Pierre
Published: March 2011

The five synthetic pheromone components of the West Indian sugarcane borer (WISB), Metamasius hemipterus (L.) (Coleoptera, Curculionidae) were tested in the field. The combination of sugarcane (SC) and the major pheromone compound, 4‐methyl‐5‐nonanol (1) was attractive. However, the addition of 2‐methyl‐4‐heptanol (2) or 2‐methyl‐4‐octanol (3) was required to reach high catch levels while 5‐nonanol (4) or 3‐hydroxy‐4‐methyl‐5‐nonanone (5) did not enhance WISB attraction. The redundancy phenomenon, here reported for the first time in rhynchophorinous species, was observed between compounds 2 and 3. SC + 1 + 3 was more attractive than living male baits, however, the sex‐ratio of the catches was equivalent between both treatments. The sex‐ratio of catches was affected by the qualitative composition of the pheromone formulation. Compound 3 had a sexual role, attracting more females while 5 seemed to play an aggregation role, luring both sexes in the same proportion.
Host finding and recognition by Altica carduorum, a defoliator of Cirsium arvense
Authors: Wan F.‐H. , Harris P.
Published: March 2011

Altica carduorum Guer. (Coleoptera: Chrysomelidae) populations aggregate on vigorously growing stands of its host, the thistle Cirsium arvense (L.) Scop. (Asteraceae). The beetle needs contact to recognize a Cirsium species and biting to distinguish its host C. arvense. Feeding or mechanical damage on C. arvense, but not other Cirsium species, aggregates the beetles. Also feces from feeding on C. arvense, but not other Cirsium species, aggregates the opposite sex. Adults also aggregate on larval feces. We suggest that initial host location in the spring depends on random encounter by beetles overwintering in a stand of C. arvense. The beetles commonly make short flights after feeding and either land on another C. arvense plant, which establishes a secondary aggregation centre, or return to the original one. In this manner beetles released on a stand of C. arvense in China spread a radius of 600 m in a year, but those released 35 m away from their host failed to find it. Altica carduorum will develop on any Cirsium species to which it is confined, but is monophagous in the field because host finding is dependent on aggregation to wound and feces substances that are specific to C. arvense.
The fate of immunoglobulin G fed to larvae of Ostrinia nubilalis
Authors: Ben‐Yakir David , Shochat Chen
Published: March 2011

Since plants can be transformed genetically to produce functional antibodies, an immunological approach may be developed for controlling their arthropod pests. Specific antibodies would protect plants from arthropods if they could gain access to the pest antigen in sufficient amounts such that the normal function of the antigen is disrupted. In order to study the fate of ingested antibodies in the body of the European corn borer (ECB), Ostrinia nubilalis (Hübner), (Lepidoptera: Pyralidae), we fed the larvae on serum‐containing diet. When larvae were fed on the serum‐containing diet for various lengths of time between 12 and 96 h, no significant differences were noted in the immunoglobulin G (IgG) concentration in their body. Immediately after the larvae stopped feeding, the concentrations of the IgG in their midgut was about one half that of the diet itself, but it decreased significantly after 6 h and again after 18 h (about 3 and 10 fold, respectively). Immediately after the larvae stopped feeding, the concentration of the IgG in their hemolymph was about 1/500 that in the diet. The concentration of IgG in the hemolymph of ECB larvae was influenced directly by the titer of antibodies in their diet. During the first 6 h after the larvae stop feeding the concentration of IgG in their hemolymph did not decrease significantly; however, it did so after 18 h (about 6 fold). The possibility that specific antibodies will gain access to antigens in the ECB body is discussed.
Alteration of developmental rate and growth of Choristoneura fumiferana parasitized by Tranosema rostrale: role of the calyx fluid
Authors: Doucet Daniel , Cusson Michel
Published: March 2011

We studied the effect of parasitism by Tranosema rostrale (Brischke)* (Hymenoptera: Ichneumonidae) on the developmental rate and growth of its host, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae). In the laboratory, T. rostrale completed its larval development in 13–14 days and its prepupae always emerged from 6th instar hosts, irrespective of host age (day 2 of the 4th, 5th or 6th instar) at the time of parasitization. Parasitism by T. rostrale did not affect the developmental rate of C. fumiferana parasitized as 4th instar larvae, but significantly lengthened the developmental period of hosts parasitized as 5th or 6th instars, with a doubling of duration in the latter case. In addition, T. rostrale significantly reduced the growth of its host: the maximum fresh mass reached by larvae parasitized as 4th, 5th or 6th instars was about half that of unparasitized larvae and their dry mass gain varied between 7 and 20% of that measured for their unparasitized counterparts. Parasitism also significantly lowered the production of faeces by host larvae. We examined the possibility that accessory fluids from the female wasp were responsible for the observed parasitism‐induced alterations. Calyx fluid (CxF) injected into 6th instar larvae lengthened the time to pupation whereas venom had no effect on development. Although total faeces production was not affected by injection of either fluid, the rate of faeces production was significantly reduced in larvae injected with CxF at 0.5 female‐equivalent. Injection of CxF treated with psoralen and UV did not delay pupation of C. fumiferana. These results indirectly suggest that polydnavirus transcription is required for this developmental alteration to be effected.
Effects of host plant and cucurbitacin on growth of larval Diabrotica undecimpunctata howardi
Authors: Hirsh I. S. , Barbercheck M. E.
Published: March 2011

The effects of host plant and dietary cucurbitacin on the growth of larval southern corn rootworm (SCR), Diabrotica undecimpunctata howardi Barber (Chrysomelidae: Luperini), were investigated. SCR were reared on four hosts: corn, Zea mays; peanuts, Arachis hypogaea; and two squash varieties, Cucurbita pepo cv. Ambassador (containing cucurbitacin D (0.08 mg g−1 fr.wt.) = bitter), and C. pepo cv. Early Yellow Crookneck (lacking cucurbitacin = non‐bitter). Larval growth was significantly greater on corn and peanuts than on either squash variety. After four weeks, adults had emerged from corn and peanut plants, while squash‐reared larvae had not yet entered the pupal stage. There was no difference in larval growth on the two varieties of squash. Primary metabolite measurements showed no nutritional differences between the two squash varieties. Artificial diet experiments were used to test the effect of three concentrations of cucurbitacin D (0.0, 0.1, and 0.6 mg g−1 diet) on growth of larval SCR. Larvae reared on diet containing 0.6 mg g−1 cucurbitacin weighed significantly less than larvae reared on diet containing 0.1 mg g−1 or no cucurbitacin after 10 d. No significant difference in growth was measured between the 0.1 mg g−1 diet and the 0.0 mg g−1 diet. Results are discussed relative to theories about the relationship between diabroticites and cucurbitacins.
Host location and discrimination mediated through olfactory stimuli in two species of Encyrtidae
Authors: van Baaren Joan , Nénon Jean‐Pierre
Published: March 2011

The role of olfactory stimuli in host detection and evaluation was studied in two encyrtid Hymenoptera. The first, Epidinocarsis lopezi De Santis, is a monophagous parasitoid of the cassava mealybug Phenacoccus manihoti Matile‐Ferrero, itself feeding exclusively on cassava, Manihot esculenta Crantz. The second, Leptomastix dactylopii Howard, is a monophagous parasitoid of the Citrus mealybug, Planococcus citri Risso, but this latter is highly polyphagous. The behaviour of females of both parasitoids (attraction and locomotion) was compared in a tubular olfactometer for the odours of their respective hosts on cassava and poinsettia. Tests were made using: 1) healthy host‐plant alone; 2) host‐plant infested with unparasitized mealybugs; 3) unparasitized mealybugs only; 4) host‐plant infested with parasitized mealybugs and 5) parasitized mealybugs only. Only E. lopezi was attracted by the odour of the host‐plant alone, but both species were attracted by the odour of an infested host‐plant and that of unparasitized mealybugs. The odour of parasitized mealybugs, alone or on host‐plant, induced an undirected activity. The attraction of E. lopezi to the odour of the host‐plant alone could be linked to the monophagous diet of its host, whereas the attraction of the two species of parasitoids to the odours of infested host‐plants and unparasitized mealybugs could be due to the fact that both parasitoids are specialists. The behavioural response of both species to the odour of parasitized mealybugs revealed a new aspect in host discrimination: the identification of parasitized hosts could be partly mediated through olfactory stimuli, and not only through gustatory stimuli.
Quality and environmental factors affecting Trichogramma brassicae efficiency under field conditions
Authors: Dutton Ana , Cerutti Fabio , Bigler Franz
Published: March 2011

Field parasitism of the egg parasitoid Trichogramma brassicae Bezdenko (Hymenoptera, Trichogrammatidae) (synonymous to T. maidis Pint. et Voegele) on Ostrinia nubilalis Hübner was compared to four single quality parameters (walking speed, fecundity on the factitious host Ephestia keuhniella Zeller, fecundity on the natural host O. nubilalis, and life span) previously measured in the laboratory and, a quality index calculated from three of the measured parameters. A single quality parameter (fecundity on E. keuhniella) and the calculated quality index showed a correlation to T. brassicae field parasitism, for different T. brassicae populations. The number of female Trichogramma released clearly influenced parasitism but not in the same proportion for all populations tested, reflecting that numbers released can only to some extent compensate for low quality in Trichogramma. Variation indegree hours above 18 °C also influenced field parasitism. When incorporating degree hours to the quality index a significant correlation R2 = 0.56 (P = 0.01) is obtained. In this work fecundity of T. brassicae on E. keuhniella can be as good an indicator for the potential field performance of T. brassicae, as the quality index which takes into account three quality parameters. Since environmental factors can obscure the potential performance of a population, i.e., one which under optimal laboratory conditions performs well, the quality index gives only a partial indication of how the released strains will perform in the field.
Behavioral responses of leafroller larvae to apple leaves and fruit
Authors: Suckling D. M. , Ioriatti C.
Published: March 2011

Larvae of Epiphyas postvittana and Planotortrix octo were released onto branches cut from apple trees, and allowed to colonize a range of types of artificial nests. Both species exhibited similar strong preferences for nests comprising leaf‐leaf or leaf‐fruitlet combinations, followed by nests comprising leaf‐plastic leaf, leaf‐plastic fruitlet or plastic leaf‐fruitlet combinations. Nests involving fresh plant material alone (shoot, fruitlet or leaf alone) were also colonized to a lesser extent, but no larvae were found on nests consisting of plastic leaves or fruitlets alone or in combinations of the two. In another experiment, more E. postvittana larvae colonized nests with leaf and fruitlet combinations, compared to leaf and glass ball, or leaf and treated wax ball combinations, where the wax had been in contact with fresh apples or fruitlets. Choice tests, conducted using larval traps, showed that larvae were caught in traps baited with odors collected and released by wax which had been in contact with mature apples and leaves. Chloroform extracts from apple skin also caught larvae in choice tests. These results suggest that both physical and chemical cues are important to leafroller larval establishment.
Molecular markers locate genes for resistance to the Colorado potato beetle, Leptinotarsa decemlineata, in hybrid Solanum tuberosum x S. berthaultii potato progenies
Authors: Yencho G. Craig , Bonierbale Meredith W. , Tingey Ward M. , Plaisted Robert L. , Tanksley Steven D.
Published: March 2011

The wild Bolivian potato, Solanum berthaultii Hawkes, has been used as a source of resistance to the Colorado potato beetle (CPB), Leptinotarsa decemlineata Say, one of the most significant pests of potato. In this study, two reciprocal backcross S. tuberosum x S. berthaultii potato progenies, BCB and BCT, were mapped with RFLP markers and screened for resistance to CPB consumption, oviposition and defoliation. The genotypic and phenotypic data were combined and analysed to locate quantitative trait loci (QTLs) for resistance to CPB. Three QTLs on three chromosomes in BCB, and two QTLs on two chromosomes in BCT influenced resistance. The QTLs were generally additive but one instance of epistasis was noted. Each QTL accounted for 4–12% of the phenotypic variation observed in resistance. In the more resistant BCB population, a three QTL model explained ca. 20% of the variation in CPB oviposition. When alleles at the three QTLs were homozygous S. berthaultii, oviposition was reduced ca. 60% compared to the heterozygotes. The QTLs for resistance to CPB were compared to those previously identified for the type A and B glandular trichomes, which have been implicated in resistance in the same progenies. Generally, the QTLs for resistance to CPB coincided with loci associated with the glandular trichomes confirming the importance of the glandular trichomes in mediating resistance. However, a relatively strong and consistent QTL for insect resistance in both BCB and BCT on chromosome 1 was observed that was not associated with any trichome traits, suggesting the trichomes may not account for all of the resistance observed in these progenies.
Waxes enhance Plutella xylostella oviposition in response to sinigrin and cabbage homogenates
Authors: Spencer Joseph L.
Published: March 2011

Oviposition by the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae), on substrates treated with host stimuli (cabbage homogenate or sinigrin) and/or waxes (paraffin or a mixture of 10 single chain n‐alkanes) was quantified using continuous observations and endpoint bioassays. Paraffin or an n‐alkane mixture applied over cabbage homogenate or sinigrin caused an increase in oviposition compared to that on any single stimulus in choice tests. Sinigrin alone at 10−5 M to 10−2 M is an ovipositional stimulant; addition of alkane over sinigrin made all sinigrin concentrations (10−6 M to 10−2 M) significantly more stimulatory than controls. Waxes alone do not stimulate oviposition. In choice tests, insect movement between sinigrin/alkane treatment combinations was random, however, once encountered, visit duration was significantly longer on sinigrin with alkane than on sites treated with either stimulus alone. Given the ubiquity of waxes on plant surfaces and the interaction between waxes and host‐specific chemical stimuli, waxes should be included when considering factors that significantly influence herbivore host acceptance.
Sodium polyacrylamide polyacrylate, a gelling agent in diets for cabbage looper, omnivorous looper and western avocado leafroller
Authors: Honda Jeffrey , Han Man‐Wi , Leppla Norman C.
Published: March 2011

Ingredient substitutions for agar or carrageenan in artificial diets for lepidopterous larvae were evaluated. A sodium polyacrylamide polyacrylate gelling agent, Water‐Lock G‐400, was compared with agar for solidifying diets of the cabbage looper, Trichoplusia ni (Hübner), omnivorous looper, Sabulodes aegrotata (Gueneé), and the western avocado leafroller, Amorbia cuneana Walsingham. Water‐Lock G‐400 is considerably less expensive than agar or carrageenan, it does not require heating to gel, and it is made from a dependable supply of agricultural starch.

Sabulodes aegrotata pupae from larvae reared on agar were significantly heavier than those reared on Water‐Lock G‐400. However, the remainder of the variables observed (larval survival, developmental times, fecundity, sex ratio and pupal weights for A. cuneana and T. ni) were all independent of diet. Decreasing the total amount of ingredients in a Water‐Lock‐G‐400 diet produced fewer and smaller T. ni pupae than did an agar diet when the larvae were reared using a mass production protocol. However, these lower values were still above acceptable levels for mass production and reduced the cost of diet production by 65%.

Further ingredient substitutions impaired larval development (i.e., replacing pinto beans with soy protein or combinations of soy protein and α‐cellulose), while others did not (i.e., excluding pinto beans and reducing water content and replacing pinto beans with α‐ cellulose or corn cob grits). Moisture control by adding corn cob grits to diets increased the yield of pupae, while removing water from diets increased survivorship and the yield of pupae.
Effect of beetle size on predation of cabbage root fly eggs by ground beetles
Authors: Finch S.
Published: March 2011

Laboratory studies were done to determine the numbers of cabbage root fly (Delia radicum L.) (Diptera: Anthomyiidae) eggs eaten by sixty species of ground beetles (Coleoptera: Carabidae) collected from a range of habitats. For 35 species that were between 2.7 mm and 10 mm long, there was a linear relationship between the numbers of eggs eaten and beetle length. For each 1 mm increase in length above 2.7 mm, an additional 18 eggs were eaten/beetle/day. Eight further species within the above size range did not eat any fly eggs, as these species are known to be either phytophagous or to feed on moving prey. Large numbers of eggs were eaten by beetles in 13 of the 25 genera tested. Based on size, maximum numbers of eggs were eaten by 7 species of Agonum Bonelli, 5 species of Amara Bonelli and seven species of Bembidion Latreille. Only one of the 6 species of Pterostichus Bonelli tested, P. strenuus (Panz.), ate the expected numbers of eggs, the other species being too large to feed from such small prey items as cabbage root fly eggs. The numbers of beetles larger than 10 mm that ate eggs was highly variable and so 10 mm was considered the upper size limit of carabid predators of cabbage root fly eggs.
A prospective clinical trial of single Astra Tech 4.0 or 5.0 diameter implants used to support two‐unit cantilever bridges: results after 3 years
Authors: Palmer Richard M. , Howe Leslie C. , Palmer Paul J. , Wilson Ron
Published: March 2011

Objective: To evaluate the use of a single Astra Tech implant to support a two‐unit cantilever fixed dental prosthesis.

Materials and method: Twenty‐nine subjects with an edentulous space (at least equivalent to two bicuspid units) in the premolar/molar segments of the maxilla or mandible with opposing natural teeth or a fixed/removable prosthesis were treated. They were provided with either a 4 or 5.0 mm diameter fixture MT OsseoSpeed. Prostheses were constructed using a cast‐to abutment as a one‐piece unit with porcelain fused to precious metal to allow direct screw retention.

Results: Subjects expressed a high satisfaction with treatment, including appearance and function. The most important complication was abutment screw loosening. It occurred as a single episode in four subjects and in another six subjects the loosening was recurrent. Bone levels were stable and there were no significant differences in radiographic bone height between cantilever and non‐cantilever sides of the implant at any time point.

Conclusion: Single implants can be successfully used to support two‐unit cantilever FDPs in the premolar region. A common factor could not be identified in relation to abutment screw loosening.

To cite this article: Palmer RM, Howe LC, Palmer PJ, Wilson R. A prospective clinical trial of single Astra Tech 4.0 or 5.0 diameter implants used to support two‐unit cantilever bridges: results after 3 years. Clin. Oral Impl. Res. 23, 2012; 35–40. doi: 10.1111/j.1600‐0501.2011.02160.x