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Significant Pest (significant + pest)
Selected AbstractsEfficacy of Beauveria bassiana (Bals.) Vuill. against the tarnished plant bug, Lygus lineolaris L., in strawberriesJOURNAL OF APPLIED ENTOMOLOGY, Issue 2 2008R. Sabbahi Abstract Beauveria bassiana has a high insecticidal potential to control the tarnished plant bug, Lygus lineolaris, a significant pest of strawberries. Screening experiments showed that L. lineolaris adults were susceptible to several B. bassiana isolates. Another screening test with Coleomegilla maculata, a natural enemy found in strawberries, was also performed in order to select the isolate having lower entomopathogenic impact on this insect. Based on data obtained from both insect species and on the ecozone origin of the B. bassiana isolates, INRS-IP and INRS-CFL isolates were selected for further experiments. The LC50 values of these two isolates against L. lineolaris adults were 7.8 × 105 and 5.3 × 105 conidia/ml, and average survival time (AST) values were 4.46 and 4.37 days at a concentration of 1 × 108 conidia/ml respectively. Results also indicated that L. lineolaris nymphs are susceptible to the selected isolates. During field experiments, using a randomized block design with four replicates, INRS-IP and INRS-CFL isolates were applied at two rates (1 × 1011 and 1 × 1013 conidia/ha) weekly during a period of 4 weeks. These multiple applications triggered a significant reduction of L. lineolaris nymphal populations in strawberries. Twenty-four days after the first application, a significant difference was observed between the mean population densities of surviving nymphs in all B. bassiana -treated plots (less than one insect per five plants) compared with those in control plots (four insects per five plants). During the field experiment, persistence of insecticidal activity and viability of B. bassiana conidia were also monitored. The results showed the presence of viable and infective conidia up to 6 days after each application on strawberry foliage. Moreover, the multiple applications of B. bassiana at the rate of 1 × 1013 conidia/ha triggered a significant reduction in strawberry fruit injuries induced by L. lineolaris feeding behaviour compared with the control plots. [source] The control of sirex wood wasp using biological control agents in Victoria, AustraliaAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2009N. G. Collett Abstract 1,The sirex woodwasp, Sirex noctilio has been a significant pest of radiata pine plantations in Victoria since 1961. Outbreaks are usually associated with susceptible trees being under some form of stress including the effects of drought and overcrowding. 2,This paper reviews the spread of sirex and the history and efficacy of biological control programmes implemented against sirex in Victoria from 1970 to 2006. 3,Of the numerous biological control agents released, the most effective in managing sirex have been the nematode Beddingia siricidicola and the parasitic wasp Ibalia leucospoides. Several other parasitic wasps such as Schlettererius cinctipes and Megarhyssa nortoni nortoni have also established but provide only minimal control. 4,While rates of I. leucospoides parasitism have improved over time, it is unlikely that this improvement will continue substantially past current levels. 5,In recent years, issues have arisen regarding a decline in the infectivity of B. siricidicola necessitating a re-evaluation of strategies and development of techniques to overcome this problem. 6,Ongoing research using Random Amplification of Polymorphic DNA (RAPD) testing is underway to accurately determine nematode strains and associated infectivity present in plantations in the field in order to develop management strategies to re-introduce more effective strains. [source] Systematics and biology of the Australian species of Balaustium von Heyden (Acari: Erythraeidae)AUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 4 2001RB Halliday Abstract The presence of Balaustium medicagoense Meyer and Ryke (Erythraeidae) in Australia is confirmed. Australian specimens previously identified as Balaustium murorum (Hermann) are shown to belong to B. medicagoense Balaustium medicagoense has been regarded as a beneficial predator in southern Australia, but it can also be a significant pest of cereal crops. It appears to have been introduced into Australia from South Africa. Some species previously described as Balaustium are transferred to Abrolophus, as Abrolophus newmani (Womersley) comb. n., Abrolophus glauerti (Womersley) comb. n., Abrolophus littorale (Womersley) comb. n., Abrolophus brevum (Womersley) comb. n., and Abrolophus ripicola (Womersley) comb. n. [source] Screening for resistance in the primary and secondary gene pool of barley against the root-lesion nematode Pratylenchus neglectusPLANT BREEDING, Issue 5 2009T. Keil Abstract Root-lesion nematodes of the genus Pratylenchus are significant pests in crop cultivation throughout many parts of the world. A study was initiated to determine the resistance of Hordeum vulgare and H. vulgare ssp. spontaneum (wild barley) against one major representative of the genus Pratylenchus, P. neglectus. A glasshouse test was first established. Barley seedlings were grown in 20 cm3 tubes filled with sand. Each plant was inoculated with 400 P. neglectus juveniles. After 12 weeks of cultivation nematodes were isolated from roots and sand using a misting chamber. The nematodes were counted under a microscope. A representative collection of 565 barley and wild barley accessions was tested in this way. The average number of nematodes per accession ranged from 350 to 12 000. In a verification experiment, 35 accessions with low and high infection rates were tested. This experiment identified a number of accessions with low infection rates. The perspectives for future breeding of barley cultivars resistant to root-lesion nematodes are discussed. [source] Analysis of expressed sequence tags from a significant livestock pest, the stable fly (Stomoxys calcitrans), identifies transcripts with a putative role in chemosensation and sex determination,ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 3 2010Pia Untalan Olafson Abstract The stable fly, Stomoxys calcitrans L. (Diptera: Muscidae), is one of the most significant pests of livestock in the United States. The identification of targets for the development of novel control for this pest species, focusing on those molecules that play a role in successful feeding and reproduction, is critical to mitigating its impact on confined and rangeland livestock. A database was developed representing genes expressed at the immature and adult life stages of the stable fly, comprising data obtained from pyrosequencing both immature and adult stages and from small-scale sequencing of an antennal/maxillary palp,expressed sequence tag library. The full-length sequence and expression of 21 transcripts that may have a role in chemosensation is presented, including 13 odorant-binding proteins, 6 chemosensory proteins, and 2 odorant receptors. Transcripts with potential roles in sex determination and reproductive behaviors are identified, including evidence for the sex-specific expression of stable fly doublesex - and transformer -like transcripts. The current database will be a valuable tool for target identification and for comparative studies with other Diptera. Published 2010 Wiley Periodicals, Inc., [source] Spider mites of sugarcane in Australia: a review of grass-feeding Oligonychus Berlese (Acari: Prostigmata: Tetranychidae)AUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 1 2003Jennifer J Beard Abstract In many areas of the world, spider mites are significant pests of sugarcane. Australia is currently fortunate in lacking the most destructive species, and usually suffers only sporadic damage. Herein, we provide a key to the genera of spider mites associated with sugarcane, review the most significant genus, Oligonychus Berlese, and provide a key to the species of grass-feeding Oligonychus in the Australasian region. The species O. araneum Davis, O. digitatus Davis, O. grypus Baker and Pritchard, O. orthius Rimando, and O. oryzae (Hirst) are redescribed, while the Australian O. zanclopes sp. n. Beard and Walter from sugarcane and rice, O. turbelli sp. n. Beard and Walter, O. ephamnus sp. n. Beard and Walter and O. festucolus sp. n. Beard and Walter from other grasses, are newly described. Previous records of O. grypus in Australia appear to be misidentifications of what is described here as the new species O. zanclopes. [source] | ||||||||||