bluuebunny/crossref_metadata_2025 huggingface dataset:
Deterrent effect of the chinaberry extract on oviposition of the diamondback moth, Plutella xylostella (L.) (Lep., Yponomeutidae)
Authors: Chen Chien‐chung , Chang Shu‐jen , Hou R. F. , Cheng Ling‐lan
Published: August 2009

Abstract: Oviposition of the diamondback moth, Plutella xylostella (L.), was deterred by extracts from fruits of the chinaberry, Melia azedarach L., grown in Taiwan. The oviposition was significantly reduced by 49.6, 86.6 and 93.5% in choice tests and 46.2, 72.1 and 80.2% in no‐choice tests at concentrations of 0.5, 2.0 and 4.0%, respectively. In addition to ovipositional deterrence, chinaberry fruit extract showed repellency to the moth when applied to rape seedlings.
Viability of green lacewing Chrysoperla carnea Steph. (Neuropt., Chrysopidae) eggs stored in potential spray media, and subsequent effects on survival of first instar larvae
Authors: McEwen P. K.
Published: August 2009

Abstract: At 4°C, green lacewing, Chrysoperla carnea eggs can be stored for one day in 0.125%; agar solution or in water without any reduction in hatch rate or larval survival compared with eggs kept in air. For eggs kept in solution for two or more days, hatch rate was clearly reduced, but those larvae that emerged survived as long as those emerging from eggs stored in air. No larvae emerged from eggs stored in solution for 8 days.
Seasonal and annual change of a folivorous insect guild in the Siebold's beech forests associated with outbreaks of the beech caterpillar,Quadricalcarifera punctatella(Motschulsky) (Lep., Notodontidae)
Authors: Kamata N. , Igarashi Y.
Published: August 2009

Abstract:Seasonal and annual change of folivorous insects of beech associated with outbreaks of the beech caterpillar,Quadricalcarifera punctatella, were investigated in northern Japan from 1988 through 1992. Lepidopteran larvae sampled from branches and fallen frass were used for the analysis. Sixty‐nine species were found over a 5 year period. Most species in the families Tortricidae, Geometridae, and Noctuidae infested in early seasons in the year, while Notodontidae fed in late seasons. Although the number of species decreased, the size of those infesting became larger in later seasons. There were three peaks in seasonal changes of falling frass: the first was in June and was constant over the years and locations; the second, caused mainly byQ. punctatellain August, varied greatly among years; and the third peak was sometimes ambiguous. Total frass was strongly influenced byQ. punctatelladensity. The density of this species changed with a magnitude of 10000, but the weight of frass produced by the other folivorous insects was estimated to fluctuate 10 times at most. The frass of other insects decreased the year following conspicuous defoliation byQ. punctatella. The results indicate that delayed induced response of the Siebold beech caused byQ. punctatellainfluenced not only the species itself but also other folivorous insects.Q. punctatellawas the main factor determining the biomass of folivorous insects in the beech forests in northern Japan during the period studied.
The effect of Liriomyza trifolii (Burgess) (Dipt., Agromyzidae) on fruit production and growth of tomatoes, Lycopersicon esculentum (Mill) (Solanaceae)
Authors: Kotze D. J. , Dennill G. B.
Published: August 2009

Abstract: The serpentine leafminer, Liriomyza trifolii (Burgess) (Agromyzidae) has, during the past 8 years, become an increasingly important pest on tomatoes, the second most important vegetable crop in South Africa. In some areas where weekly chemical applications are made on the basis of a threshold level of 0.25 mines per plant, it is feared that this pest has become resistant. In the present study, examination of the effect of various levels of infestation on growth and yield of tomatoes showed that neither growth nor yield were negatively affected by infestation levels of up to 1092 and 468 mines per plant in a glasshouse and field trial, respectively. A comparison of yield on control plants with 1–50, 51–100 and > 100 mines per plant (field trial) indicated that low L. trifolii infestations of 1–50 mines/plant in fact increased the yield by c. 60%. The phenology of L. trifolii feeding (before or during and after flowering) had no effect on yield and the effect of herbivory by L. trifolii was not obscured by any relationship between fruit production and growth of the tomato plants. These results were confirmed by a field trial and it is thus clear that even the threshold level being applied in the USA (four mines per three terminal leaflets per plant) is unrealistically low. Low correlations between number of mines per plant and percentage of pinnae or leaves infected indicated that assessing levels of infection by counting mines could not be replaced by the easier counting of pinnae or leaves infected.
Persistence of Bacillus thuringiensisδ‐endotoxin and β‐exotoxin on stored grains and their potency against Plodia interpunctella and Sitotroga cerealella
Authors: Salama H. S. , Aboul‐Ela R. , Abdel‐Razek A.
Published: August 2009

Abstract: The persistence of B. thuringiensis, δ‐endotoxin and β‐exotoxin was determined. The decrease in activity was slow over a period of 150 days. The reduction in larval mortality of Indian meal moth, Plodia interpunctella was more obvious with the increase of storage period and also with the decrease of the concentration of δ‐endotoxin. The decay in activity, in the case of β‐exotoxin, was more obvious at lower concentrations than at higher concentrations as the time of storage increased. Data showed that the potency of the δ‐endotoxin decreased 15 days after application at 27 and 35°C against both tested species, but with a lower degree in the case of Indian meal moth. On the other hand, the β‐exotoxin showed a rapid decay 15 days after application on both stored wheat and crushed corn against both tested insect species.
The biology of Agriotes ustulatus Schäller (Col., Elateridae). I. Adults and oviposition
Authors: Furlan L.
Published: August 2009

Abstract: Adult behaviour and egg development of Agriotes ustulatus Schäller were studied under field as well as laboratory conditions in north‐eastern Italy over a 5‐year period. Adults proved to be active in daylight only, particularly in the morning. The flight of A. ustulatus could be well monitored both by sticky traps and sweep net used on Umbelliferae flowers. Light yellow and white sticky traps proved to be significantly more attractive than red and green ones, while black ones showed no effectiveness at all. Sticky trap efficiency was highest when the trap level was lowest and it was not affected by orientation. Adult swarming occurred during a period from late June to early September; most of the specimens (from 68 to 98% of the total amount) were captured in July when the capture peaks were recorded (more frequently in the second half of the month, just after mid‐month). The capture level was high only when last instar larvae populations were over 10 larvae/m2. Sex ratio was about 1:1. Oviposition started 5–7 days after adults had darkened and was completed within 2–4 days. Eggs (0.61 × 0.46 mm) were laid in clusters in the upper layers of the soil. The average number of eggs laid by single females was 78 (SD = 27.9). Embryonic development took 45 days at 15°C, 14.1 at 25°C and 12.6 at 29°C. The hatching percentage ranged between 95 and 100% of the oviposited eggs.
A survey of the spruce web‐spinning sawflies of the genus Cephalcia Panzer in north‐eastern China, with a guide to the identification of prepupae (Hym., Pamphiliidae)
Authors: Battisti A. , Sun Jiang‐hua
Published: August 2009

Abstract: The spruce web‐spinning sawflies of the genus Cephalcia have been surveyed on two host plants (Picea koraiensis and P. jezoensis) in both natural and artificial stands of north‐eastern China. Ornamental trees were also included in the study. Five sites situated in the Provinces of Heilongjiang and Jilin and characterized by various elevations were considered in 1992–93. A total of nine species have been found, in the following decreasing order of abundance: C. abietis, C. arvensis (with two forms), C. fallenii, C. pallidula (new to China), C. alashanica, C. erythrogaster, C. fulva, C. klugii, and an unknown species. In most cases the adult specimens from China show a darker and more extended pigmentation with respect to the European ones. Some biological attributes (emergence period of adults, oviposition features, larval instars and feeding habits) are given for each species and compared with those known from European populations. A key for the practical identification of prepupae is presented. All information could be useful in monitoring, since these sawflies are considered among the main pests of various spruce species in this region.
Abundance and age structure of the predatory mosquito larva, Toxorhynchites towadensis (Dipt., Culicidae) in relation to prey community structure
Authors: Yasuda H.
Published: August 2009

Abstract: The larval ecology including the abundance and age structure of the predatory mosquito larva, Toxorhynchites towadensis, was studied in relation to prey community structure. The number of larvae observed per pool was small. The larvae living in each pool were of same instars and 86% were fourth instars. Females of T. towadensis laid a number of eggs into one oviposition cup irrespective of the existence of conspecific larvae in the laboratory. These results suggest that intense cannibalism by fourth instars to younger larvae occurred in the field. Seven species of mosquitoes including two predatory species, T. towadensis and Culex halifaxii, were observed. The number of prey larvae in pools decreased with an increase of the number of larvae of T. towadensis and the development of the predator. Aedes albopictus was the dominant species in the pools without T. towadensis. However, in the pools with T. towadensis larvae, the dominant species was Orthopodomyia anopheloides. Therefore, the prey community structure seems to be shifted by the predatory larvae.
Protein and isozyme patterns among isolates of Beauveria brongniartii with different virulence to European cockchafer larvae (Melolontha melolontha L.)
Authors: Reineke A. , Zebitz C. P. W.
Published: August 2009

Abstract: It was the purpose of this study to elucidate whether sodium dodecyl sulfate‐polyactylamide gel electrophoresis (SDS‐PAGE) of soluble proteins and isozyme analysis of intracellular enzymes are useful methods to distinguish between 31 Beauveria brongniartii isolates of different virulence to Melolontha melolontha larvae. Cluster and principle coordinate analysis of data from soluble proteins demonstrated a high level of intraspecific variation and little correlation with virulence to M. melolontha larvae. The isozymes of the esterase, acid phosphatase and malate dehydrogenase showed high activity and gave consistent band resolution, resulting in 18 different enzyme types, whereas the enzyme systems of the alkaline phosphatase, catalase, glutamate oxalacetate transaminase, peroxidase and superoxide dismutase were not suitable for further evaluation. Levels of intraspecific variation after isozyme analysis were lower than in total protein analysis. Although two of the four B. brongniartii isolates with the lowest virulence against M. melolontha larvae differed in their enzyme patterns from the other isolates, a clear distinction between groups of different virulent isolates was not possible. Thus, analysis of the isozyme patterns of intracellular enzymes could only be a first step in selecting more promising B. brongniartii pathotypes for development as biocontrol agents.
Microbiological changes in the nests of leaf‐cutting ants fed on sesame leaves
Authors: Pagnocca F. C. , Carreiro S. C. , Bueno O. C. , Hebling M. J. , Da Silva O. A.
Published: August 2009

Abstract: The number of bacteria and yeasts occurring in the organic matter inside the nests were determined both in colonies of leaf‐cutting ants reared on Eucaliptus alba (control) or Sesamum indicum (experimental). Sesame leaves induce imbalance and nests usually die. In control nests the number of bacteria in newer sponge and in older sponge were similar (3.6 × 105 and 1.4 × 105 CFU/g, respectively) whereas in waste deposit the mean reached 7.3 × 107 CFU/g. The Most Probable Number (MPN/g) of yeasts were 2.7 × 104, 1.3 × 105/g and 2.2 × 104 for newer sponge, older sponge and waste deposit, respectively. Using material from older sponge for comparison, the number of bacteria and yeasts reared on sesame leaves showed significant differences. The number of bacteria was 3.3 × 107 CFU/g, a value close to that found in waste deposit of normal (control) nests, whereas the number of yeasts was 6.7 × 105/g. These changes in microbial populations due to the effect of sesame leaf uptake could be a significant factor in nest imbalance and mortality when leaf‐cutting ants are consuming toxic plants.
Toxicological effects of selected insecticides on Nephaspis oculatus (Col., Coccinellidae), a predator of Bemisia argentifolii (Hom., Aleyrodidae)
Authors: Liu T.‐X. , Stansly P. A.
Published: August 2009

Abstract: Toxicological effects of selected biorational insecticides were tested in the laboratory against all developmental stages of Nephaspis oculatus (Blatchley), a predator of whiteflies including silverleaf whitefly, Bemisia argentifolii Bellows & Perring. Biorational insecticides included a mineral oil (Sunspray Ultra‐Fine Oil), an insecticidal soap (M‐Pede), and a mixture of sucrose and glucose esters (a detergent‐like extract of Nicotiana gossei Domin). A pyrethroid (Capture 2EC) was used for comparison and water as control. N. oculatus has four distinct instars but the larvae were divided into two size categories (small and large) for bioassays. Pyrethroid was toxic to all developmental stages of N. oculatus and insecticide soap was toxic to larvae, but not to adults, eggs or pupae. Mineral oil was moderately toxic to eggs, but had no significant effect on other stages. Mixture of sucrose and glucose esters was innocuous to all life stages of the beetle. These results indicated that the use of pyrethroid would be incompatible with biological control of whitefly by N. oculatus and that considerable interference with predator activity could be expected from insecticidal soap, depending on the timing of application. On the other hand, mineral oil and especially N. gossei extract could be used against the whitefly with relative impunity to the coccinellids.
Comparative suitability of soybean and cowpea as host plants for the brown cowpea coreid bug, Clavigralla tomentosicollis Stal. (Hem., Coreidae)
Authors: Ntonifor N. N. , Jackai L. E. N.
Published: August 2009

Abstract: Suitability of the pods of cowpea (Vigna unguiculata (L.) Walp) and soybean (Glycine max (L.) Merrill) as food for Clavigralla tomentosicollis was determined in the laboratory using development, food substitution and host switch experiments. On soybean pods, nymphs survived for 8 days and adults for 12 days; on cowpea, all nymphal instars developed into adults and lived for 80–100 days. Teneral adults that were switched from cowpea to soybean lost weight, while adults that were moved from soybean to cowpea gained weight with slight differences between the sexes. The shortest critical survival threshold (duration with at least 50% survival) of adults on cowpea was greater than the longest on soybean. The likelihood of C. tomentosicollis exploiting soybean as a trophic niche in areas of tropical Africa where production of this crop is on the increase and usually contiguous with cowpea production, is discussed.
Influence of temperature and age of Nezara viridula L. eggs on the scelionid egg parasitoid, Trissolcus megallocephalus (Ashm.) (Hym., Scelionidae)
Authors: Awadalla S. S.
Published: August 2009

Abstract: Laboratory experiments were carried out to study the influence of temperature and age of Nezara viridula eggs on the rate of parasitism by Trissolcus megallocephalus, the rate of emerged parasitoids, the duration of developmental stages, the adult longevity and the daily rate of oviposition.

The results indicated that the highest rate of parasitism 55.4 ± 2.37/female (92.33%) and the highest number of emerged parasitoids 55.10 ± 2.60 individuals/female (91.83%) were obtained when the females were reared at a constant temperature of 25°C. At 30°C, egg‐larval stage, pupal stage and total developmental stages showed the shortest developmental time. Results showed also a negative response between adult parasitoids longevity and temperature. Females deposited the highest number of eggs during the first day at the highest temperature of 30°C, while the females which were reared at 25°C, 20°C and 21–36°C fluctuating temperature deposited the highest number of eggs during the second day.

The results also indicated that the parasitoid females attacked host eggs at all developmental stages before hatching. The rate of parasitism and the number of emerged parasitoids were relatively high except for host eggs more than 3 days old. The shortest duration of developmental stages (14.2 ± 2.86 days) were obtained at host eggs of two days old, and increased to (17.8 ± 2.39 days) at 5 days old with a significant difference (P < 0.05). No significant differences were obtained between the adult longevity and the different ages of host eggs.
Crude aqueous‐extract (kairomone) from Aphis fabae Scop. (Hom., Aphidae) and its effect on the behaviour of the predator Metasyrphus corollae Fabr. (Dipt., Syrphidae) female
Authors: Shonouda M. L.
Published: August 2009

Abstract: Female Metasyrphus corollae Fabr., a syrphid predator on the bean aphid Aphis fabae Scop., responded to aqueous extract containing kairomones of the prey. The crude aphid‐extract was topically dropped onto clean leaves of Vicia faba. After application of aqueous‐extract at different aphid densities on the clean leaves, the predator showed variations in oviposition and searching behaviours in comparison with untreated leaves (control). The variations are summarized as follows: (1) the aqueous‐extract of aphids stimulate M. corollae females to lay eggs at all aphid densities. The number of eggs were directly proportional with aphid concentrations; (2) the predator M. corrolae female intensified its searching behaviour by increasing the total path length walked; (3) the number of turns exhibited is significantly higher as compared with those of control; and (4) the retention time spent by M. corollae females with treated plant is much more than that with clean plant at all aphid densities. The present results showed that the aphid aqueous‐extract contains the active ingredients (kairomones) which induce a considerable change in the searching pattern and increase the oviposition rate of the predator syrphid females.
Life history traits of castor whitefly, Trialeurodes ricini Misra (Hom., Aleyrodidae), on eight host plant species
Authors: Shishehbor P. , Brennan P. A.
Published: August 2009

Abstract: The life history traits of the castor whitefly, Trialeurodes ricini, on eight host plant species were evaluated. Number of eggs during a 48 h period, immature survival, development time, adult size and sex ratio were examined to determine host plant suitability. Significant differences were found in oviposition rate among host plant species. Number of eggs was highest on aubergine, intermediate on potato, cotton and French bean, and lowest on melon, cucumber and tomato. Survival on hosts ranked as follows: aubergine > cotton > pumpkin > French bean > potato. No individual survived to adult eclosion on melon, cucumber or tomato. For four of the eight plant species tested, there was an association between ovipositional and survival rates. Host plant species had a significant effect on development time, adult size and sex ratio of T. ricini.
Rearing of Triatoma infestans Klug (Het., Reduviidae) in the absence of a live host. II. Egg yolk as a diet supplement
Authors: Núñez J. A. , Insausti T. C. , Lazzari C. R.
Published: August 2009

Abstract: The effect of the addition of egg yolk to a blood meal on the development of Triatoma infestans (Klug) was analysed. Egg yolk was added in different quantities to heparinized, citrated or defibrinated bovine blood, which was offered in an artificial feeder. Control groups were fed on either non‐supplemented blood or hen in vivo. Results indicated that the addition of egg yolk to a blood meal reduced the intermoult interval and the moult success increased when egg yolk was added to the diet. The effect was more dramatic for the less suitable diets, as follows: citrated blood > defibrinated blood > heparinized blood. The minimal and most effective concentration of egg yolk in the diet was 10% v/v. When the egg yolk was centrifuged in a density‐gradient, fractions with different performance could be obtained; middleweight fractions, but not the heaviest or lightest ones reproduced the observed effects of the whole yolk at the corresponding concentration. Growth rate and moulting success showed to be differentially affected by the diets and the growth performance of in vivo‐fed experimental groups could be completely reproduced by adding yolk to the blood diets offered in artificial feeders.
Effect of some kairomones and pheromones on two hymenopterous parasitoids Apanteles ruficrus and Microplitis demolitor (Hym., Braconidae)
Authors: Zaki F. N.
Published: August 2009

Abstract: Kairomones and two sex pheromones were tested on two larval parasitoids, Apanteles ruficrus and Microplitis demolitor. Adult females of A. ruficrus were attracted to the kairomone extracted from the host larvae, Agrotis ipsilon. At the same time, the synthetic sex pheromone of A. ipsilon revealed a strong kairomonal effect on the adult females of the parasitoid. Similar effects were obtained with M. demolitor when the kairomone extracted from Spodoptera littoralis was used. In field experiments, A. ipsilon and S. littoralis kairomones significantly raised the rate of parasitism from 5.6 and 11.8% in control plots to 19.5 and 26% in treated plots by A. ruficrus and M. demolitor, respectively. Meanwhile, kairomones extracted from larvae of Autographa ni and S. exigua showed less effect on the two tested parasitoids.
Effects of some insect pathogens on the Africanized honey bee, Apis mellifera L. (Hym., Apidae)
Authors: Alves S. B. , Marchini L. C. , Pereira R. M. , Baumgratz L. L.
Published: August 2009

Abstract: Young bees were treated either per os or topically with an iridovirus, a granulosis virus, a nuclear polyhedrosis virus, and the fungi Nomuraea rileyi, Beauveria bassiana and Metarhizium anisopliae, and maintained in cages mounted into a brood frame of Langstroth hives. Infection was only confirmed in bees treated with B. bassiana or with M. anisopliae and no effect of other pathogens was observed. Beauveria bassiana and M. anisopliae conidia (l g) were also applied to field hives containing 20 000–25 000 bees. These fungi caused low mortality and infection of bees in treated hives but no noticeable effect on bee behaviour, larval development or colony characteristics. In the laboratory, bees fed a diet containing B. bassiana conidia had significantly higher mortality than control bees maintained at 35°C. Bees maintained at 26°C had high mortality independent of the treatment received. The results suggest that B. bassiana and M. anisopliae may be incapable of causing epizootic in field hives and most likely will not cause bee mortality following field applications for pest control.
Untersuchungen zur Bionomie und zur biologischen Bekämpfung des Kartoffelkäfers (Leptinotarsa decemlineata Say, Col., Chrysomelidae) an zwei Standorten in Südhessen (BRD)
Authors: Schrod J. , Basedow Th. , Langenbruch G. A.
Published: August 2009

Abstract: Studies on bionomy and biological control of the Colorado Potato Beetle (Leptinotarsa decemlineata Say, Col., Chrysomelidae) in Hesse (FRG). Studies were conducted on the bionomy of the Colorado Potato Beetle at one site in Hesse (FRG), 1994. Furthermore, at another site, a field trial with natural insecticides gave answers on the efficiency of the preparations, and on the evaluation‐methods. A hatching‐rate of 79.5% from laid eggs to L1‐larvae was determined. Tests on the cannibalism of eggs showed that adults destroyed up to 31% (x̄ = 19%) of the eggmasses. A clear relation between beetle density and rate of cannibalism could not be found, however. A field‐trial with a preparation of Bacillus thuringiensis var. tenebrionis (B.t.t.; ‘Novodor’) and a Azadirachtin‐preparation (‘NeemAzal‐T’) took place. Two different concentrations per preparation and one combination showed, that an effective pest‐management with biological insecticides is possible. Due to the evaluation method, efficiency rates higher than 90% (Novodor 41/ha) and 88% (NeemAzal‐T 1.21/ha) were measured. However, the analysis of plant‐damages caused by the feeding of the beetles and larvae was also important to evaluate the efficiency of the preparations tested. A reduction to only 25% plant‐defoliation at mid‐July proved to be possible by NeemAzal (1.2 1/ha), as well as by Novodor (41/ha). The untreated plots showed 80% plant‐damage at that time. Defoliation rates at 21. July reached 93% in untreated plots, 32% with neem and 64% with B.t.t. To recognize possible long‐term effects, surviving L4‐larvae were collected and observed in the greenhouse concerning their ability to pupate. While all larvae treated with B.t.t. grew up to adults like untreated larvae, neem‐treated larvae died in the prepupal stage.
Dispersal in the aphid parasitoid, Lysiphlebus cardui (Marshall) (Hym., Aphidiidae)
Authors: Weisser W. W. , Völkl W.
Published: August 2009

Dispersal of the aphid parasitoid Lysiphlebus cardui (Hym., Aphidiidae) between patches of its host. Aphis fabae cirsiiac anthoidis (Hom., Aphididae), was investigated in a field study and in laboratory and field experiments. Colonization patterns of thistle (Cirsium arvense L.) patches in the field suggested that most females of L. cardui parasitized A.f. cirsiiacanthoidis‐colonies on ramets within an encountered plant stand of C. arvense while few females left to colonize new plant stands. In a release experiment L. cardui‐females successfully travelled only up to 20 m to a new host patch. Observations and mummy counts suggest that a high proportion of the females released died without having laid any of their eggs. The behaviour of newly emerged parasitoid adults was observed in the laboratory and showed that, in contrast to two other aphid parasitoid species, L. cardui tended to stay and oviposit in the aphid colony in which it had developed. The dispersal patterns of L. cardui described in this study are discussed with respect to predictions of foraging models analysing the influence of mortality risks on parasitoid foraging behaviour.
Effect of natural enemy exclusion on mortality of Ips typographus japonicus Niijima (Col., Scolytidae) in Hokkaido, Japan
Authors: Lawson S. A. , Furuta K. , Katagiri K.
Published: August 2009

The impact of natural enemies on the reproduction and survival of Ips typographus japonicus Niijima in Hokkaido was tested by sequentially caging off cohorts of a single beetle generation so as to investigate the effects of natural enemies at different developmental stages. A consistent increase in mortality of between 17–18% in the first 2–3 weeks of exposure to natural enemies was observed, after which mortality remained relatively constant. Natural enemies which were found to occur in logs exposed during this time were the predators Medetera sp., Thanasimus substriatus, and the adult parasitoid Tomicobia watanabei. Of these, only the first two were found to be significantly associated with beetle brood mortality.

However, a confounding factor was the fact that beetle density also significantly increased in logs during the period when mortality was increasing. It was found that larval mine density, and hence intraspecific mortality, was the single most important factor correlated with beetle mortality during this period. It was thus concluded that increased intraspecific competition was responsible for most of the increase in mortality during the first 2–3 weeks exposure, with predators playing a more minor role. Parasitoids were observed to occur in logs late in the exposure period when mortality was relatively constant and so appeared to have little effect on beetle reproduction and survival.

The results of this study were compared to results from similar previous exclusion experiments with bark beetles and the fact that beetle density‐dependent effects as a mortality factor was not considered in many of these studies noted. It is therefore suggested that some of these previous studies may have overestimated the importance of natural enemies and associates as mortality factors and subsequently underestimated the importance of intraspecific competition. Suggestions are made to improve bark beetle exclusion methodology so as to remove the confounding factor of beetle density from the analysis.
Insect induced resistance in Lodgepole pine: effects on two pine feeding insects
Authors: Trewhella K. E. , Leather S. R. , Day K. R.
Published: August 2009

A series of experiments was performed in order to establish if the insect defoliators Panolis flammea (D&S) (Lept., Noctuidae) and Neodiprion sertifer (Geoff.) (Hym., Dripionidae) cause an induced response in lodgepole pine, Pinus contorta, and if so, what affect this response is likely to have on the two insects. Survival and growth of P. flammea was significantly affected by defoliation of seedling Skeena River lodgepole pine (KLP). On mature foliage from one forest site P. flammea larvae showed no significant difference in feeding preference between heavily defoliated trees and trees with less than 10% defoliation. On foliage from another forest site P. flammea larvae preferred trees with no previous defoliation. N. sertifer larvae significantly preferred foliage from previously defoliated trees. Insect defoliation of mature trees resulted in significant changes in the terpenoid compounds in leaf and stem resins. It is possible that both P. flammea and N. sertifer are affected by the carbon‐nutrient balance of their host. It seems that P. flammea however, unlike N. sertifer, is also affected by induced defences in lodgepole pine, particularly in younger trees. These differences are probably related to the feeding strategies of the two insects: P. flammea feeds on both current and previous year foliage, while N. sertifer feeds only on previous year foliage. The outbreak dynamics of P. flammea and N. sertifer in commercial lodgepole pine plantations are discussed in light of the results obtained.
Competitive interaction between the braconid parasitoid, Meteorus rubens Nees and the entomogenous nematode, Steinernema carpocapsae (Weiser) on larvae of Agrotis ipsilon Hufn. (Lep., Noctuidae)
Authors: Zaki F. N. , Awadallah K. T. , Gesraha M. A.
Published: August 2009

Exposing A. ipsilon larvae to S. carpocapsae nematode after 24 h of parasitism by M. rubens resulted in preventing the emergence of M. rubens from host larvae, especially at concentrations of 15 Infective Juvenile Stage (IJS) and more. The effect of S. carpocapsae decreased when exposure was delayed to 7 and 12 days after parasitism by M. rubens. The survival of A. ipsilon larvae was shorter when exposure to IJS was delayed from 24 h to 7 and 12 days.
Artificial selection in pheromone permeated air increases mating ability of the European grape vine moth Lobesia botrana (Lep., Tortricidae)
Authors: Torres‐Vila L. M. , Stockel J. , Lecharpentier P. , Rodríguez‐Molina M. C.
Published: August 2009

The existence of L. botrana genotypes more suitable to mating in synthetic pheromone permeated air in olfactometer was investigated by artificial selection through two consecutive generations. The major compound of the female pheromone blend (7E, 9Z)‐7, 9‐dodecadienyl acetate 7E, 9Z DDA was used, the only one commercialized at present both for monitoring and for mating disruption. The adults mated in a mating disruption atmosphere in the parental generation (G1) were reared separately to make up the selected filial generation (G2). Trial was carried out at the doses of 0 (control), 0.5 and 1 μg of 7E, 9Z DDA. In G1 83.33% (50/60 pairs), 18.87% (50/265) and 8.62% (31/360) mated respectively. In the selected generation (G2) 76.67% (46/60), 20.91% (69/330) and 14.38% (64/445) mated respectively. Thus, control mating percentages in both generations were similar. Nevertheless, after selection the increase in mating was significant at 1 μg dose (G = 6.53; d.f. = 1; P < 0.05) but not at 0.5 μg (G = 0.38; d.f. = 1; P > 0.05). On the other hand, selection for increasing mating ability in sex pheromone permeated air at the doses tested, was not linked with a decrease in the dusk time elapsed before mating (mean: 24–30 min). With regard to the controls without pheromone (mean: 10–12 min), matings were significantly delayed (F(5,04) = 18.52; P < 0.01). The differences in response to selection between pheromone doses show the possible effect of the genetic homeostasis. These preliminary results suggest a genetic basis for mating ability and are a complementary hypothesis to explain the lack of an absolute efficiency in control by mating disruption. Finally, the possible factors that could interact and counteract the studied selection pressure are discussed, since resistance to the mating disruption method has not been observed at this time in field conditions.
Dispersal of Trichogramma platneri Nagarkatti (Hym., Trichogrammatidae) from point‐source releases in an apple orchard in California
Authors: McDougall S. J. , Mills N. J.
Published: August 2009

Egg parasitoids of the genus Trichogramma are commonly released in inundative biological control programmes for lepidopteran pests in a range of cropping systems. In this study we evaluated the dispersal of Trichogramma platneri from a central release point in an apple orchard in relation to time and the number of parasitoids released. Dispersal was monitored by parasitism of codling moth eggs from an insectary culture—used as sentinel eggs. Higher release rates of T. platneri resulted in greater parasitism of sentinel eggs during the first 3 days, increasing from about 18% for a release rate of 5 400 to about 36% for a release rate of 32 400. T. platneri parasitized a greater percentage of sentinel eggs on the north side of the tree. Parasitism of sentinel eggs declined by 50% during the second 3 day period following release from a point source release in comparison to the first 3 day period. Parasitism of sentinel eggs declined from a mean of 62% at the point–source to less than 10% 14 m away during the first 3 days after release.
The impact of foraging ants on populations of Coccus hesperidum L. (Hem., Coccidae) and Aonidiella aurantii (Maskell) (Hem., Diaspididae) in an Australian citrus grove
Authors: James D. G. , Stevens M. M. , O'Malley K. J.
Published: August 2009

The impact of honeydew‐seeking ants (Iridomyrmex rufoniger gp. spp.) on citrus canopy populations of the honeydew‐producing soft scale insect, Coccus hesperidum, and the non‐honeydew‐producing armoured scale, Aonidiella aurantii, was evaluated during two seasons in southern New South Wales. Numbers of C. hesperidum and A. aurantii were substantially greater (3–12 times) in trees containing foraging ants than in trees from which ants were excluded. It is likely that I. rufoniger gp. spp. protects both scale species by disrupting the activity of natural enemies. Effective control of honeydew‐seeking ants appears to be a prerequisite for biological control‐based management of honeydew‐producers in Australian citrus groves.
The relationship between tannins concentration in some cotton varieties and susceptibility to piercing sucking insects
Authors: Mansour M. H. , Zohdy N. M. , El‐Gengaihi S. E. , Amr A. E.
Published: August 2009

Tannins have been implicated in the resistance of some cotton varieties to insect attack. The relationship between tannin concentration and susceptibility of some Egyptian cotton varieties to piercing sucking insects has been undertaken in the present work. Eight Egyptian cotton derived from Gossypium barbadense and one variety from G. hirsutum were evaluated. There is a significant negative linear relationship between the concentration of tannins in two Egyptian varieties, Giza 70 and Giza 76, and the population density of piercing sucking insects. On the contrary, a positive correlation existed between piercing sucking insect infestation and tannin concentrations in the two cotton varieties, Giza 80 and Giza 81. This may be attributed to the low level of tannins in these two varieties.
Prey capture ability of Podisus nigrispinus (Dallas) (Het., Pentatomidae) reared for successive generations on a meridic diet
Authors: Saavedra J. L. D. , Zanuncio J. C. , Zanuncio T. V. , Guedes R. N. C.
Published: August 2009

Adults and nymphs of Podisus nigrispinus reared for three and four generations, respectively, on a meat‐based artificial diet were able to find, capture and feed on velvetbean caterpillar (Anticarsia gemmatalis Hüb. (Lep., Noctuidae)) in laboratory and in greenhouse. In laboratory, nymphs reared on artificial diet were more aggressive to their prey than those reared on house fly larvae (Musca domestica L. (Dipt., Muscidae)), an alternative prey currently used for rearing this predatory species. Adults reared on the artificial diet behaved similarly to those reared on house fly larvae. In greenhouse, adults and nymphs of P. nigrispinus previously reared on artificial diet and released on soybean plants (Glycine max (L.) Merr.) exhibited prey capture ability comparable to those reared on house fly larvae. Therefore, predators reared on this meat‐based artificial diet seem to be as suitable for biological control programmes as those reared on house fly larvae.
Distribution and excretion of juvenoid in the locust Locusta migratoria migratorioides (R. et L.) (Orth., Oedipodinae)
Authors: Němec V. , Bennettová B. , Tykva R. , Wimmer Z. , Rejzek M.
Published: August 2009

The distribution and the excretion rate of topically administered 3H and 14C‐labelled juvenoids, derivatives of 2‐(4‐hydroxybenzyl)‐1‐cycloalkanone were analyzed in the last instar nymphs and imagoes of the African migratory locust, Locusta migratoria migratorioides. It was found that the main process of elimination of juvenoid is the excretion. About 80% of the total applied label was excreted within the first 2 days after topical application. The maximum quantity of the topically applied juvenoid penetrated in the locust body within the first 2 days after application. However, the administered juvenoid was deposited in cuticle for a long time. It was found that 7–8% of the total applied label was deposited in cuticle (exuvies) that have been casted off after 12 days from application. In the other analysed organs (brain, fat body, thoracic muscles, intestine, gonads, haemolymph) only a small part of the administered radioactivity was found.
Anti‐herbivore mechanisms of economically important Proteaceae species in the African Cape Fynbos
Authors: Coetzee J. H. , Wright M. G. , Giliomee J. H.
Published: August 2009

Five economically important species of the family Proteaceae were investigated to determine which leaf characteristics possibly contributed to deterring insect herbivory. The presence of phenolic compounds such as tannins in the leaves of all five plant species and the ability of these to precipitate proteins varied between the plant species. The young leaves of Leucadendron laureolum exhibited a pronounced cyanogenic capacity, while those of Leucospermum cordifolium and Protect neriifolia were covered by a thick layer of trichomes. The glabrous young leaves of P. repens and P. cynaroides were apparently protected by phenolic compounds. The increasingly sclerophyllous character of ageing proteaceous leaves may afford these leaves some protection against certain insects. The importance of these findings is discussed in terms of the development of insect resistant Proteaceae cultivars.
Quality control of the parasitoid Aphidius colemani (Hym., Aphidiidae) used for biological control in greenhouses
Authors: Fernández C. , Nentwig W.
Published: August 2009

Since several years the aphid parasitoid Aphidius colemani is used in greenhouses to control Myzus persicae and Aphis gossypii. Aphidius is reared by different commercial producers under artificial conditions and due to inbreeding runs the risk of losing some of its quality. The IOBC (International Organisation for Biological Control) designed quality control tests and guidelines to maintain products of high quality and to avoid negative advertisement against biological control. This study was set out to determine the quality of A. colemani from four commercial producers using tests proposed by the IOBC in conjunction with additional parameters. Quality control was performed after all packaging procedures and transport. Quality of the following parameters was assessed under laboratory conditions: parasitoid species, quantity, adult mortality, sex ratio, longevity, flight capacity, parasitation rate and number of hyperparasitoids. Eleven shipments of 1000 parasitoids each were used for the tests. The results showed that the quality of A. colemani was frequently unsatisfactory. Quality of products from the same producer often differed as much as products between producers. Conditions during transport had a great influence on the quality of the parasitoids. Different parameters to improve the present lack of quality are discussed.
Host specificity ofLongitarsus quadriguttatus(Pont., 1765) (Col., Chrysomelidae), an agent for the biological control of hound's tongue (Cynoglossum officinaleL., Boraginaceae) in North America
Authors: Jordan T.
Published: August 2009

The host specificity of the European flea‐beetleLongitarsus quadriguttatuswas investigated between 1991 and 1993 as a potential agent for the biological control of hound's‐tongue(Cynoglossum officinale), a weed of European origin that has become naturalized in North America. Life‐history studies showed a good synchronization of the univoltine flea‐beetle with its host plant. Adults feed on leaves and deposit eggs on host plant rosettes. The larvae develop inside the roots. Host specificity screening tests comprising adult feeding‐, oviposition‐ and larval development tests were carried out with 49 European plant species. Adults or larvae exclusively attacked plants in the family Boraginaceae. The 18 test plant species in nine other families remained free from feeding and oviposition and supported no larval development. Adults nibbled on most of the 31 Boraginaceae species tested. Normal adult feeding was mainly found on plants in the tribe Cynoglosseae, which were preferrably attacked in oviposition tests. Larvae developed mainly in roots of Cynoglosseae species. Occasional attack of other Boraginoideae species in laboratory tests could not be verified under field conditions. Host acceptance tests showed normal feeding, oviposition and development on the North American biotype of hound's‐tongue.L. quadriguttatushas a narrow host range and a good potential for controlling the target plant in North America.
EAG and orientation tests on the parasitoid Lysiphlebia japonica (Hym., Aphidiidae) to volatile chemicals extracted from host plants of cotton aphid Aphis gossypii (Hom., Aphidae)
Authors: Hou Z. Y. , Chen X. , Zhang Y. , Guo B. Q. , Yan F. S.
Published: August 2009

Volatile chemicals from the four summer host plants of cotton aphid Aphis gossypii were extracted and identified, and the behavioural and EAG responses of the parasitoid Lysiphlebia japonica to these volatile chemicals were also studied. According to GC‐MS data analysis and authentic samples, 21 volatile compounds were finally confirmed from cotton extract, and 17, 23 and 24 compounds from cucumber, pumpkin and towel gourd extracts, respectively. There are significant differences in components among the four plants. Cotton volatiles contain quantities of terpenes, most of which are monoterpenes and sequiterpenes such as myrcene, β‐caryophellene and α‐humulene, while the other three melon plants contain more short chain aldehydes, alcohols, acids, acetates and their derivatives. Benzaldehyde was not found in cotton leaf extracts, however, it was found in all the three melon plant leaves. Among the four host plants of cotton aphid, only cotton leaves (intact) attracted to the parasitoids, and the parasitoids did not express any more interest to the three melon plants. The two‐odour‐choice tests demonstrated that the mechanical damaged cotton leaves and the aphid‐honeydew‐plant leaf complex were more attractive to the parasitoids than the intact ones. These phenomena agree well with the EAG results and the field observation, i.e. female L. japonica showed stronger EAG and behavioural responses to cotton leaf extract than to the other three plant extracts.
'Thompson Seedless' grapevine vigour and abundance of Pacific spider mite (Tetranychus pacificusMcGregor) (Acari, Tetranychidae)
Authors: Hanna R. , Zalom F. G. , Wilson L. T.
Published: August 2009

Spider mite outbreaks have been frequently related to factors that reduce plant vigour. We conducted a field study to determine the relationship between the abundance of Pacific spider mite,Tetranychus pacificusMcGregor, and abiotic factors related to the vigour of ‘Thompson Seedless’ grapevines,Vitis viniferaL. Our study supports previous observations on the relationship between Pacific mite abundance and vine vigour, and partially explains these differences in terms of the previously proposed hypotheses of differences in leaf N and leaf temperature on vines of different vigour. Pacific mite densities were 5.5‐fold higher on low‐vigour compared with high‐vigour vines. Total leaf N was weakly correlated with vine vigour and Pacific mite abundance. Average daily and afternoon leaf temperatures were higher on low‐vigour vines resulting in 45.3°D greater accumulation on low‐vigour vines compared with high‐vigour vines during the increasing phase of Pacific mite population growth. This difference represented 37.4% of the °D requirements for the development of 1 Pacific mite generation and could be partially responsible for the observed difference in Pacific mite abundance in relation to vine vigour. Other confounding factors are discussed and an additional hypothesis is proposed to further explain the relationship between vine vigour and Pacific mite abundance.
Effects of parasitoid spatial heterogeneity, sex ratio and mutual interference on the interaction between the olive bark beetle Phloeotribus scarahaeoides (Col., Scolytidae) and the pteromalid parasitoid Cheiropachus quadrum (Hym., Pteromalidae)
Authors: Lozano C. , Kidd N.A.C. , Jervis M.A. , Campos M.
Published: August 2009

Information on parasitoid sex ratio, mutual interference and spatial heterogeneity, obtained from both field and laboratory experiments, was integrated into a model of the interaction between the solitary pteromalid, Cheiropachus quadrum, and the olive bark beetle pest, Phloeotribus scarahaeoides. Parasitism was predominately aggregated in its distribution within the beetle breeding logs, while percentage parasitism ranged from spatially random to spatially density dependent between logs. The effects of spatial density dependence in the model was, however, overshadowed by the effects of both parasitoid mutual interference and competition between female beetles for oviposition ‘space’. Searching efficiency (area of discovery) declined with increasing adult parasitoid density as a result of mutual interference. This density dependent change in searching efficiency had a strong stabilizing influence on the parasitoid‐host interaction. Crowding of adult parasitoids also led to a decline in the proportion of female progeny emerging. Such density‐dependent changes in the secondary sex ratio had very little effect on either stability or equilibrium levels. The model predicts that whilst C. quadrum has the potential to strongly regulate beetle populations, its contribution in practice is only to suppress P. scarahaeoides populations by a mere 20%, which is insufficient to reduce the beetle numbers to non‐damaging levels. A major constraint on the effectiveness of the parasitoid appears to be mutual interference, without which the emerging beetle population could be reduced by about 70%.