Studies of hypodermataceous needle diseases. I. Isthmiella quadrispora sp. nov., causing needle blight of alpine fir

1968 ◽  
Vol 46 (11) ◽  
pp. 1377-1381 ◽  
Author(s):  
Wolf G. Ziller
Keyword(s):  
Life Cycle ◽  
Host Range ◽  
Western Canada ◽  
Abies Lasiocarpa ◽  
Field Observations ◽  
Apparent Lack ◽  
Host Trees ◽  
Individual Host ◽  
Biologic Control ◽  
Needle Blight

A new parasite causing needle disease of alpine fir (Abies lasiocarpa (Hook.) Nutt.) in western Canada and named Isthmiella quadrispora sp. nov. is illustrated and described. It resembles I. faullii (Darker) Darker in morphology, pathogenicity, life cycle, host range, and associated fungi; but differs from I. faullii in its apparent lack of an imperfect state, the subcuticular position of its ascomata, its stipitate, narrow, four-spored asci, and the germination of its spores. Field observations indicate a 2-year life cycle and great differences in susceptibility of individual host trees. Several secondary associated fungi prevent spore formation of I. quadrispora, thus acting as biologic control agents.

Gene deletion suggests a role for Trypanosoma cruzi surface glycoprotein GP72 in the insect and mammalian stages of the life cycle

1993 ◽  
Vol 106 (4) ◽  
pp. 1023-1033 ◽  
Author(s):  
A.R. de Jesus ◽  
R. Cooper ◽  
M. Espinosa ◽  
J.E. Gomes ◽  
E.S. Garcia ◽  
...  
Keyword(s):  
Life Cycle ◽  
Trypanosoma Cruzi ◽  
Gene Deletion ◽  
Surface Glycoprotein ◽  
Triatoma Infestans ◽  
Insect Vector ◽  
Null Mutant ◽  
Apparent Lack ◽  
Targeted Gene Deletion ◽  
Mouse Macrophages

We have explored the biological function of a surface glycoprotein (GP72) of Trypanosoma cruzi by studying a null mutant parasite, generated by targeted gene deletion. GP72 deletion affected parasite morphology in several stages of the life cycle. Insect midgut (epimastigote) forms had a detached flagellum (apomastigote) in the null mutant. The abnormal flagellar phenotype persisted during development of the infective (metacyclic) forms but there was no impairment in the acquisition of complement resistance, sialidase expression or cell infectivity. The GP72 null mutant could efficiently infect and proliferate in mouse macrophages and non-phagocytic L6E9 cells. The mammalian stages of the life cycle also showed major morphological abnormalities. During early subcultures in L6E9 cells, few extracellular fully flagellated forms, expressing markers characteristic of trypomastigotes, were seen. The extracellular population consisted almost exclusively of rounded forms with short flagella (micromastigote), which expressed an amastigote-specific surface marker and no sialidase. The propagation of the parasite was not affected, despite the apparent lack of the trypomastigote forms, which are thought to be primarily responsible for cell invasion. After some subcultures, the extracellular population changed to about equal numbers of micromastigotes and a range of flagellated forms that still did not include true trypomastigotes. Instead, the kinetoplast remained close to the nucleus and the flagellum emerged from the middle of the cell (mesomastigote). Half of the flagellum adhered to the cell body and the remainder was free at the anterior end. In Triatoma infestans, the survival of the mutant was dramatically reduced, suggesting that either GP72 itself, or the altered properties of the flagellum, were critical for establishment in the insect vector.

Pratylenchus in sugarcane: a diminishing problem?

2021 ◽  
pp. 66-72
Author(s):  
Prabashnie Ramouthar
Keyword(s):  
South Africa ◽  
Life Cycle ◽  
Host Range ◽  
Geographical Distribution ◽  
Economic Importance ◽  
Nematode Management ◽  
Pratylenchus Brachyurus ◽  
Damage Symptoms

Abstract This chapter focuses on the economic importance, host range, geographical distribution, damage symptoms and biology and life cycle of Pratylenchus brachyurus, P. neglectus, P. scribneri and P. zeae infesting sugarcane in South Africa. Information on their interactions with other nematodes and pathogens, the efficacy and optimization of some recommended integrated nematode management programmes and future nematode research requirements are also presented.

Root-knot and reniform nematodes: double trouble for soybeans in the southern United States.

2021 ◽  
pp. 125-131
Author(s):  
Edward J. Sikora
Keyword(s):  
United States ◽  
Life Cycle ◽  
Host Range ◽  
Geographical Distribution ◽  
Management Practices ◽  
Economic Importance ◽  
Southern United States ◽  
Rotylenchulus Reniformis ◽  
Future Outlook ◽  
Reniform Nematodes

Abstract This chapter focuses on the economic importance, host range, geographical distribution, symptoms of damage and biology and life cycle of root-knot and reniform nematodes (Meloidogyne spp. and Rotylenchulus reniformis) infesting soyabeans in southern USA. Some information on the efficacy and optimization of some recommended integrated nematode management practices and future outlook and research requirements are also presented.

Mitigating a galling problem in California's carrot production.

2021 ◽  
pp. 284-289
Author(s):  
J. Ole Becker
Keyword(s):  
Life Cycle ◽  
Host Range ◽  
Geographical Distribution ◽  
Meloidogyne Incognita ◽  
Integrated Management ◽  
Economic Importance ◽  
Future Research ◽  
Future Developments ◽  
Management Optimization ◽  
Damage Symptoms

Abstract This chapter discusses the economic importance, geographical distribution, host range, damage symptoms, biology and life cycle, interactions with other nematodes and pathogens, recommended integrated management, and management optimization of Meloidogyne incognita infesting carrots in California, USA. Future research requirements and future developments are also mentioned.

scholarly journals Bud blight (Gemmamyces piceae) in the eastern part of the Krušné hory Mountains

2020 ◽  
Vol 66 (No. 8) ◽  
pp. 309-317
Author(s):  
Jiri Sefl ◽  
Veronika Mottlová ◽  
Iva Schořálková
Keyword(s):  
Life Cycle ◽  
Blue Spruce ◽  
Picea Pungens ◽  
Host Trees ◽  
Sprouting Ability ◽  
Trend Assessment ◽  
Krušné Hory Mountains

A survey was carried out in 2013–2019 on the life cycle of the bud blight Gemmamyces piceae (Borthw.) Casagrande and the trend assessment in the infestation of the Colorado blue spruce Picea pungens Engelm. stands. Four ecologically different plots were chosen in the Fláje region in the Eastern part of the Krušné hory Mountains. The pycnidia were formed at the beginning of June on buds infested the previous year. Later, in the second half of June, they formed on the spring attack buds. Conidia occurred in the first week of July on the buds of the old infestation, or later in the case of the spring attack buds, in the middle of July. The production of conidia lasted till the end of September. Ascospores occurred in the middle of July and were produced until the end of September. The ability of host trees to sprout became continually weaker, along with the defoliation progress. A distinct decline in the sprouting ability was noticed on stands with a dense crown canopy and on stands with competition of broad-leaved trees – with an admixture of birch.

scholarly journals Natural history of Ctenus medius Keyserling, 1891 (Araneae, Ctenidae) I: observations on habitats and the development of chromatic patterns

2000 ◽  
Vol 60 (3) ◽  
pp. 503-509 ◽  
Author(s):  
C. E. ALMEIDA ◽  
E. F. RAMOS ◽  
E. GOUVÊA ◽  
M. do CARMO-SILVA ◽  
J. COSTA
Keyword(s):  
Life Cycle ◽  
Natural History ◽  
National Park ◽  
Common Species ◽  
Field Observations ◽  
Mata Atlântica ◽  
Adult Females ◽  
History Of ◽  
Males And Females ◽  
Phoneutria Nigriventer

Ctenus medius Keyserling, 1891 is a common species in several spots of Mata Atlântica, however there is a great lack of studies in all aspects of its natural history. This work aims to elucidate aspects of ecotope preference compared to large spiders, and to provide data on the development of chromatic patterns during its life cycle. The observations on the behavior of C. medius were done in the campus of Centro Universitário de Barra Mansa (UBM) by means of observations and nocturnal collections using cap lamps. For observations on the development of chromatic patterns, spiderlings raised in laboratory, hatched from an oviposition of a female from campus of UBM, and others spiderlings collected in field were used. The field observations indicate that: C. medius seems to prefer ecotopes characterized by dense shrub vegetation or herbal undergrowth; Lycosa erythrognatha and L. nordeskioldii seems to prefer open sites; Phoneutria nigriventer seems to prefer shrub vegetation and anthropogenic ecotopes as rubbish hills; Ancylometes sp. seems to prefer ecotopes near streams. Concerning chromatic patterns, it was observed that males and females show well distinct patterns during the last two instars, allowing distinction by sex without the use of a microscope. Through chromatic patterns it was also possible to draw a distinction between C. medius and C. ornatus longer that 3 mm cephalothorax width. 69 specimens of C. medius (males and females) collected in the campus of UBM did not show a striking polymorphism in chromatic pattern, but one among 7 adult females collected in National Park of Itatiaia, showed a distinct chromatic pattern.

Multi-instar descriptions of cave dwelling Erythraeidae (Trombidiformes: Parasitengona) employing an integrative approach

Zootaxa ◽  
2019 ◽  
Vol 4717 (1) ◽  
pp. 137-184 ◽  
Author(s):  
SAMUEL GEREMIAS DOS SANTOS COSTA ◽  
HANS KLOMPEN ◽  
LEOPOLDO FERREIRA DE OLIVEIRA BERNARDI ◽  
LUCIANA CARDOSO GONÇALVES ◽  
DANTE BATISTA RIBEIRO ◽  
...  
Keyword(s):  
Life Cycle ◽  
Cytochrome Oxidase ◽  
Molecular Analysis ◽  
Species Delimitation ◽  
Morphological Changes ◽  
Molecular Data ◽  
Coi Gene ◽  
Integrative Approach ◽  
Larval Instars ◽  
Individual Host

The life cycle of Parasitengona includes major morphological changes precluding an instar association based only on the morphology. This makes rearing and/or molecular data necessary to associate the heteromorphic instars. Most of the described species are known from either post larval instars or larva. Following a previous study on Palearctic Erythraeidae, in the present study the instar association was made through an integrative approach including rearing trials and molecular analysis of the cytochrome oxidase I (COI) gene with the Bayesian Generalized Mixed Yule Coalescent (bGMYC) algorithm for species delimitation. Two new cave dwelling Erythraeidae (Trombidiformes: Parasitengona) species are described Lasioerythraeus jessicae sp. nov. and Leptus sidorchukae sp. nov. including all active instars. Additionally, a complete description of the previously unknown adults of Charletonia rocciai Treat & Flechtmann, 1979 is provided with notes on the larva and deutonymph. We also demonstrate experimentally that Ch. rocciai larvae are not attached to the same individual host during the entire feeding stage. We discuss the presence of troglomorphisms in Le. sidorchukae sp. nov.; and the distribution of the species. 

STUDIES OF WESTERN TREE RUSTS: VI. THE AECIAL HOST RANGES OF MELAMPSORA ALBERTENSIS, M. MEDUSAE, AND M. OCCIDENTALIS

1965 ◽  
Vol 43 (2) ◽  
pp. 217-230 ◽  
Author(s):  
Wolf G. Ziller
Keyword(s):  
Life History ◽  
Host Range ◽  
Western Canada ◽  
Host Reaction ◽  
New Host ◽  
New Host Records

Results from controlled inoculation experiments show that conifers of six genera (Abies, Larix, Picea, Pinus, Psendotsuga, and Tsuga) are susceptible to the poplar (Populus) rusts of western Canada. Twenty-one new host records are established. It is suggested that Melampsora albertensis Arth. be reduced to synonymy with M. medusae Thüm., because they appear to be indistinguishable from each other in morphology, life history, host range, and host reaction.

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