The Effect of Aggregation on Egg and Larval Survival in Neodiprion swainei Midd. (Hymenoptera: Diprionidae)

1962 ◽  
Vol 94 (1) ◽  
pp. 49-58 ◽  
Author(s):  
L. A. Lyons
Keyword(s):  
Spatial Distribution ◽  
Larval Survival ◽  
Predatory Mite ◽  
Prey Population ◽  
Laboratory Studies ◽  
Encarsia Formosa ◽  
Natural Control ◽  
Greenhouse Whitefly ◽  
Rate Of Development ◽  
Recent Laboratory

Recent laboratory studies have shown that the type of spatial distribution of a host or prey population may affect the degree of natural control exerted by parasites and predators. For example, Burnett (1958) showed that the rate of paratisitism of the greenhouse whitefly, Trialeurodes vaporarium (Westw.), by Encarsia formosa Gahan, was considerably greater when the hosts were aggregated than when regularly distributed. In this case, searching parasites were better able to find groups of hosts than isolated ones. Similar results have been obtained by Huffaker (1958) in experiments with a predatory mite, Typhlodroms occidentalis Nesbitt, and a phytophagous mite, Eotetranychus sexmaculatus (Riley). Other important effects of aggregation are evident in the growing literature on this subject, as exemplified by the work of Long (1955), Mizuta (1960), and Morimoto (1960), who showed that the rate of development of some lepidopterous larvae in groups is greater than that of isolated larvae.

scholarly journals Predatory mite fauna associated with agri-horticultural crops and weeds from the Gangetic Plains ofWest Begal, India*

Zoosymposia ◽  
2011 ◽  
Vol 6 (1) ◽  
pp. 62-67 ◽  
Author(s):  
KRISHNA KARMAKAR ◽  
SALIL K. GUPTA
Keyword(s):  
Predatory Mite ◽  
Prey Population ◽  
Gangetic Plains ◽  
Neoseiulus Fallacis ◽  
Horticultural Crops ◽  
Neoseiulus Longispinosus ◽  
Amblyseius Largoensis ◽  
Period Of Occurrence ◽  
Cheletogenes Ornatus

Astudy was conducted in 2008–2009 to explore the predatory mite fauna from different agri-horticultural crops and weeds in the Gangetic plains ofWest Bengal. A total of 31 species belonging to nine genera, seven families and two orders were identified; they are listed along with their prey, period of occurrence and the plant habitats in which they were recorded. The most frequently collected specieswere the phytoseiids Amblyseius largoensis (Muma) and Neoseiulus longispinosus (Evans), the stigmaeids Agistemus spp. and the anystidWalzia indiana Smith-Meyer&Ueckermann.Given the frequencywithwhich these mites were found, they can be considered potentially useful in suppressing the associated prey mites. The phytoseiids Paraphytoseius multidentatus Swirski & Schechter, Euseius ovalis (Evans), Euseius coccineae (Gupta), Neoseiulus fallacis (Garman) and the cheyletid Cheletogenes ornatus (Canestrini&Fanzago) were less frequently found and less abundant, implying that their impact on prey population is less important. The remaining species were rare.

scholarly journals Recent Laboratory Photochemical Studies and Their Relationship to the Photochemical Formation of Cometary Radicals

1989 ◽  
Vol 116 (1) ◽  
pp. 313-332
Author(s):  
William M. Jackson
Keyword(s):  
Laboratory Studies ◽  
Laboratory Evidence ◽  
Photochemical Formation ◽  
Laboratory Techniques ◽  
Unstable Molecules ◽  
Experimental Laboratory ◽  
Recent Laboratory

AbstractExperimental laboratory techniques used in studying the photochemistry of stable and unstable molecules are discussed. The laboratory evidence for the photochemical formation of C2 from C2H, C3 from C3H2, and NH from NH2 is presented. Other recent results obtained in laboratory studies of H2O, H2S, NH3, and HCN are reported.

ASPECTS OF THE INTERACTION BETWEEN A CHALCID PARASITE AND ITS ALEURODID HOST

1967 ◽  
Vol 45 (4) ◽  
pp. 539-578 ◽  
Author(s):  
T. Burnett
Keyword(s):  
Larval Mortality ◽  
Trialeurodes Vaporariorum ◽  
Host Population ◽  
Population Variation ◽  
Encarsia Formosa ◽  
Greenhouse Whitefly ◽  
Parasite Abundance ◽  
Tomato Plants ◽  
Host Mortality ◽  
Dominant Process

Three populations of the greenhouse whitefly, Trialeurodes vaporariorum, and its chalcid parasite Encarsia formosa were propagated each year for three consecutive years on tomato plants in the greenhouse. The abundance of the host and parasite species fluctuated either with peaks of increasing amplitude, with peaks of decreasing amplitude, or with irregular peaks. The dominant process in the interaction was the occurrence of two qualitatively different types of host larval mortality: (a) parasitization, and (b) almost immediate killing after attack by adult parasites. Fluctuations in host and parasite abundance resulted from the almost immediate killing of small host larvae and the death of the short-lived adult parasites. The parasite population tended to destroy similar percentages of host populations of different densities but host mortality was also related to the age structure of the host population. Variation in host reproduction, caused by differences in rearing temperature and by seasonal variation in the physical environment, influenced host and parasite densities.

scholarly journals Convergent Evolution Driven by Rifampin Exacerbates the Global Burden of Drug-Resistant Staphylococcus aureus

mSphere ◽  
2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Romain Guérillot ◽  
Anders Gonçalves da Silva ◽  
Ian Monk ◽  
Stefano Giulieri ◽  
Takehiro Tomita ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Multidrug Resistant ◽  
Clinical Impact ◽  
Drug Resistant ◽  
Deleterious Mutations ◽  
Human Pathogen ◽  
Laboratory Studies ◽  
Increased Risk ◽  
Rifampin Resistance ◽  
Recent Laboratory

Increasing antibiotic resistance in the major human pathogen Staphylococcus aureus is threatening the ability to treat patients with these infections. Recent laboratory studies suggest that mutations in the gene commonly associated with rifampin resistance may also impact susceptibility to other last-line antibiotics in S. aureus; however, the overall frequency and clinical impact of these mutations are unknown. By mining a global collection of clinical S. aureus genomes and by mutagenesis experiments, this work reveals that common rifampin-induced rpoB mutations promote phenotypic plasticity that has led to the global emergence of stable, multidrug-resistant S. aureus lineages that are associated with increased risk of therapeutic failure through coresistance to other last-line antimicrobials. We recommend decreasing susceptibility breakpoints for rifampin to allow phenotypic detection of critical rpoB mutations conferring low resistance to rifampin and reconsidering the appropriate use of rifampin to reduce the fixation and spread of these deleterious mutations globally.

Influence of Light and Food on Larval American Lobsters, Homarus americanus

1986 ◽  
Vol 43 (11) ◽  
pp. 2303-2310 ◽  
Author(s):  
M. D. Eagles ◽  
D. E. Aiken ◽  
S. L. Waddy
Keyword(s):  
Light Intensity ◽  
Food Quality ◽  
Homarus Americanus ◽  
Larval Survival ◽  
Dark Phase ◽  
High Survival ◽  
Fourth Stage ◽  
Continuous Darkness ◽  
Low Light ◽  
Rate Of Development

Survival, size, and rate of development of larval American lobsters, Homarus americanus, to fourth stage are correlated postively with food quality. High survival requires that first-stage larvae encounter an abundance of food. Larval survival was higher in low light intensity than in a higher intensity that was well below that of full sunlight. Larvae reared on LD 12:12 photoperiods molted to the fourth stage predominantly during the dark phase, even when the timing of the light and dark phases was reversed. Larvae reared in continuous darkness developed faster and were almost twice the weight of larvae reared in a LD 12:12 photoperiod, but fewer survived to fourth stage.

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