Some Larvae of the Genus Itame Hübner (Lepidoptera: Geometridae)

1956 ◽  
Vol 88 (1) ◽  
pp. 6-16 ◽  
Author(s):  
W. C. McGuffin
Keyword(s):  
Life History ◽  
Forest Floor ◽  
The Other ◽  
External Morphology ◽  
Boreal Zone ◽  
Forest Insect ◽  
Forest Insects ◽  
Insect Survey ◽  
Reservoir Hosts

Although many forest insects feed in or on trees, a larger number live on the shrubs and herbs of the forest floor. The shrub and herb feeders should not be overlooked since they comprise an important part of the fauna and may serve as reservoir hosts of parasites of the more destructive forest insects. Some larvae of the genus Itame are tree feeders but many of them feed on shrubs. These larvae are frequently collected within the Boreal Zone of Canada. As no means for the identification of the larvae could be found in the literature this paper was written. It consists of an account of the life history and external morphology of the larvae of the genus, a key to separate the mature larvae and descriptions of ten species. These species are: I. ribearia (Fitch), I. evagaria (Hlst.), I. brunneata (Thunb.), I. andersoni Swett, I. occiduaria (Pack.), I. anataria (Swett), I. exauspicata (Wlk.), I. bitactata (Wlk.), I. denticulodes (Hlst.), and I. decorata (Hlst.). Studies of the first four species are based on material obtained on loans and studies of the other species were made on material reared by the Forest Insect Survey of the Forest Zoology Laboratory, Calgary, Alberta.

The Life History and Dispersal of the Bruce Spanworm, Operophtera bruceata (Hulst), (Lepidoptera: Geometridae)

1962 ◽  
Vol 94 (10) ◽  
pp. 1103-1107 ◽  
Author(s):  
C. E. Brown
Keyword(s):  
United States ◽  
Life History ◽  
The United States ◽  
American Continent ◽  
Forest Insect ◽  
North American Continent ◽  
The Third ◽  
The North ◽  
Insect Survey ◽  
Bruce Spanworm

The Bruce spanworrn, Operophtera bruceata (Hulst), is most common in the mid latitudes of the North American Continent; in Canada it occurs from Newfoundland to the interior of British Columbia (Prentice, In Press) and has been reported from Vermont and Wisconsin in the United States (Craighead, 1950.) Three outbreaks of this insect have been recorded in Alberta. The first occurred in 1903 (de Gryse, 1925) and was apparently of short duration. The second reported by Wolley Dod (1913) occurred in 1913 and denuded hundreds of acres of aspen poplar. Heavy defoliation in the third outbreak became evident in 1957 (Brown, 1957) but an examination of Forest Insect Survey records revealed that population buildup began about 1951. The outbreak continued to expand until 1958 and began to decline in 1959; by 1961 populations were again low except for one or two isolated areas where moderate to low populations persisted. At the peak of the outbreak in 1958 approximately 50,000 square miies were moderately or heavily infested and many more lightly infested.

A New Species ofNepticulav. Heyd. on Birch (Lepidoptera: Nepticulidae)

1962 ◽  
Vol 94 (5) ◽  
pp. 522-523 ◽  
Author(s):  
T. N. Freeman
Keyword(s):  
Life History ◽  
New Species ◽  
Companion Paper ◽  
Betula Papyrifera ◽  
White Birch ◽  
Yellow Birch ◽  
Forest Insect ◽  
Insect Survey ◽  
A New Species

In 1957, some officers of the Forest Insect Survey of Canada discovered a species ofNepticulamining the leaves of white birch (Betula papyriferaMarsh.) and yellow birch (Betula luteaMichx. f.) in Ontario. At that time the species was considered to be undescribed, but to confirm this it was necessary to study the life-history. This has been done by Mr. O. H. Lindquist, Forest Insect Laboratory, Sault Ste. Marie, Ontario, and the results of his studies are being presented in a companion paper. His investigations confirmed that the species had not been named and the following description is presented.

Observations on the Life History, Distribution, and Abundance of Two Species of Cecidomyia (Diptera, Cecidomyiidae) on Jack Pine in Manitoba and Saskatchewan

1960 ◽  
Vol 92 (2) ◽  
pp. 154-160 ◽  
Author(s):  
W. A. Reeks
Keyword(s):  
Life History ◽  
Pinus Banksiana ◽  
Jack Pine ◽  
Forest Insect ◽  
Insect Survey

The occurrence of midges on jack pine, Pinus banksiana Lamb., in Manitoba has been reported by Lejeune (4), Barker and Wong (1), and Prentice and Hildahl (5, 6). The Forest Insect Survey also reported a species of Retinodiplosis on jack pine in Ontario, and Barnes (2) suggested that this may have been R. resinicola (Osten Sacken). This name was also provisionally assigned to a species found near Stead, Manitoba, in 1956 (7). Vockeroth (8) now shows that Retinodiplosis Kieffer is a synonym of Cecidomyia Meigen, which is represented by at least two species on jack pine in Manitoba and Saskatchewan. These are C. reeksi and C. banksianae. The former is the more common and undoubtedly was the species most frequently represented in the early reports of pine midges in Manitoba.

NEW DESCRIPTIONS OF LARVAE OF FOREST INSECTS: LARVAE OF THE GENUS EUPITHECIA (LEPIDOPTERA, GEOMETRIDAE)

1945 ◽  
Vol 77 (3) ◽  
pp. 53-55 ◽  
Author(s):  
W. C. McGuffin
Keyword(s):  
Forest Insect ◽  
Forest Insects ◽  
Insect Survey

During the last seven years, larvae representing more than a dozen species of the genus Eupithecia have been received by the Forest Insect Survey of Canada. With the hope that some of these larvae may be recognized more readily, two species are described herewith; additional notes are given on three species already described, and a key for the separation of mature larvae of these five species is presented at the end of this article.

NEW DESCRIPTIONS OF LARVAE OF FOREST INSECTS. INTRODUCTION; I. PANTHEA (LEPIDOPTERA, PHALAENIDAE)

1942 ◽  
Vol 74 (1) ◽  
pp. 8-12 ◽  
Author(s):  
A. W. A. Brown ◽  
W. C. McGuffin
Keyword(s):  
Larval Stage ◽  
Considerable Proportion ◽  
Forest Insect ◽  
The Past ◽  
Forest Insects ◽  
Insect Survey

During the past five years several thousand samples of lepidopterous larvae have been collected from spruce in the course of the Canadian Forest Insect Survey (1). It was found that a considerable proportion of the species had been hitherto unknown in the larval stage, and that many others had been only briefly or superficially described. In this paper, and in subsequent instalments, descriptions will be presented for those species whose larvae, to the author's knowledge, have never been described before.

NEW DESCRIPTIONS OF LARVAE OF FOREST INSECTS, V, EUPITHECIA, HYDRIOMENA (LEPIDOPTERA, GEOMETRIDAE)

1942 ◽  
Vol 74 (8) ◽  
pp. 150-153 ◽  
Author(s):  
W. C. McGuffin
Keyword(s):  
Forest Insect ◽  
Forest Insects ◽  
Insect Survey

The geometrid larvae feeding on spruce form a large and varied group. In collections taken from all parts of Canada where spruce is found, the Forest Insect Survey has identified 31 species (Brown, 1). To the best of the author's knowledge, there are descriptions for only 16 of these species. In this and the two following papers, seven more are described and two are redescribed.

A field study of competition and interaction between Lemna minor and Lemna trisulca

1989 ◽  
Vol 67 (10) ◽  
pp. 2904-2911 ◽  
Author(s):  
Alexander L. McIlraith ◽  
Gordon G. C. Robinson ◽  
Jennifer M. Shay
Keyword(s):  
Life History ◽  
Field Study ◽  
Key Words ◽  
Field Experiments ◽  
Lemna Minor ◽  
Survey Methods ◽  
The Other ◽  
Transplant Experiment ◽  
Replacement Series ◽  
Vegetative Biomass

Field experiments and survey methods were used to assess competition and interaction between Lemna minor L. and Lemna trisulca L. at Delta Marsh, Manitoba. Sites were dominated by one or the other species or codominated by both. Replacement series experiments predicted codominance of L. minor and L. trisulca in an unshaded eutrophic site but predicted L. minor dominance when run for a longer time. Similar experiments conducted in a shaded eutrophic site predicted L. minor dominance. Addition series experiments showed that intraspecific and interspecific competition occurred in the unshaded site. In a eutrophic unshaded ditch, high densities of L. minor suppressed L. trisulca. In a eutrophic shaded site, high densities of L. minor and green algae inhibited L. trisulca, and in a sunny, less eutrophic site high density of each species inhibited the other. In a transplant experiment, L. minor biomass in shaded enclosures approached that found naturally in two shaded sites. Lemna trisulca persisted when shaded. Vegetative biomass trends in an unshaded eutrophic marsh ditch indicated spring and fall L. trisulca dominance and summer L. minor dominance. Shaded eutrophic sites were dominated by L. minor, whereas a less eutrophic site was dominated by L. trisulca. A model is developed to explain dominance patterns, and seasonal life-history responses are considered. Key words: Lemna, duckweed, competition, interaction, resources, light, nutrients.

scholarly journals On Apogamy and the development of Sporangia upon fern prothalli

1898 ◽  
Vol 63 (389-400) ◽  
pp. 56-61
Keyword(s):  
Life History ◽  
Point Of View ◽  
The Other ◽  
Normal Life ◽  
Other Hand ◽  
General Importance ◽  
Two Generations ◽  
History Of ◽  
Alternation Of Generations

The two most important deviations from the normal life-history of ferns, apogamy and apospory, are of interest in themselves, but acquire a more general importance from the possibility that their study may throw light on the nature of alternation of generations in archegoniate plants. They have been considered from this point of view Pringsheim, and by those who, following him, regard the two generations as homologous with one another in the sense that the sporophyte arose by the gradual modification of individuals originally resemblin the sexual plant. Celakovsky and Bower, on the other hand, maintaint the view tha t the sporophyte, as an interpolated stage in the life-history arising by elaboration of the zygote, a few thallophytes.

NEW DESCRIPTIONS OF LARVAE OF FOREST INSECTS: SEMIOTHISA, DYSMIGIA (LEPIDOPTERA, GEOMETRIDAE)

1947 ◽  
Vol 79 (6) ◽  
pp. 113-116 ◽  
Author(s):  
W. C. McGuffin
Keyword(s):  
Transition Period ◽  
Larval Instar ◽  
Larval Period ◽  
The Other ◽  
Forest Insects ◽  
Other Hand ◽  
Larval Moult

Some geometrid larvae exhibit dimorphism in colour. Several interesting observations of this phenomenon were made during the study of larvae of the species, Semiothisa sexmaculata Pack., Dysmigia loricaria Evers., and Nepytia canosaria Wlk.In these observations, certain points stand out. Although larvae of S. sexmaculata are always green until they reach the last instar, both brown and green phases occur in that stage. After the last larval moult, a transition period of approximately two days is required for larvae to acquire the colouring of the brown phase. On the other hand, specimens of D. loricaria may pass their entire larval period in either a brown or a green phase (as do the larvae of N. canosaria, descriptions of which may be found in Can. Ent. 75: 186-189) or they may change (as do some larvae of S. sexmaculata) from the green phase to the brown phase in the last larval instar. For Dysmigia larvae to undergo this transformation, approximately three days are required.

scholarly journals Effect of NaCl on seed germination in some Centaurium Hill. Species (Gentianaceae)

2007 ◽  
Vol 59 (3) ◽  
pp. 227-231 ◽  
Author(s):  
S. Zivkovic ◽  
M. Devic ◽  
B. Filipovic ◽  
Z. Giba ◽  
D. Grubisic
Keyword(s):  
Life History ◽  
Salt Tolerance ◽  
Seed Germination ◽  
Gibberellic Acid ◽  
White Light ◽  
The Other ◽  
Distilled Water ◽  
Nacl Concentration ◽  
History Of ◽  
Species Specific

The influence of high NaCl concentrations on seed germination in both light and darkness was examined in the species Centaurium pulchellum, C. erythraea, C. littorale, C. spicatum, and C. tenuiflorum. Salt tolerance was found to depend on the life history of the seeds. To be specific, seeds of all five species failed to complete germination when exposed to continuous white light if kept all the time in the presence of 100-200 mM and greater NaCl concentrations. However, when after two weeks NaCl was rinsed from the seeds and the seeds were left in distilled water under white light for an additional two weeks, all species completed germination to a certain extent. The percent of germination not only depended on NaCl concentration in the prior medium, but was also species specific. Thus, seeds of C. pulchellum, C. erythraea, and C. littorale completed germination well almost irrespective of the salt concentration previously experienced. On the other hand, seeds of C. tenuiflorum completed germination poorly if NaCl concentrations in the prior media were greater than 200 mM. When seeds after washing were transferred to darkness for an additional 14 days, they failed to complete germination if previously imbibed on media containing NaCl concentrations greater than 400 mM. However, the seeds of all species, even if previously imbibed at 800 mM NaCl, could be induced to complete germination in darkness by 1 mM gibberellic acid. .

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