bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dispersal in the aphid parasitoid, Lysiphlebus cardui (Marshall) (Hym., Aphidiidae)
Authors: Weisser W. W. , Völkl W. 
Published: August 2009

AbstractDispersal 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

AbstractThe 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

AbstractA 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

AbstractExposing 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

AbstractThe 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

AbstractEgg 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

AbstractThe 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

AbstractTannins 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

AbstractAdults 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

AbstractThe 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

AbstractFive 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

AbstractSince 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

AbstractThe 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

AbstractVolatile 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

AbstractSpider 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

AbstractInformation 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%.