A study of the olfactory responses of insect parasites to the food plant of their host

Parasitology ◽  
1938 ◽  
Vol 30 (4) ◽  
pp. 523-528 ◽  
Author(s):  
W. H. Thorpe ◽  
H. B. Caudle
Keyword(s):  
Pinus Sylvestris ◽  
Adult Life ◽  
Egg Laying ◽  
Food Plant ◽  
Next Generation ◽  
Considerable Time ◽  
Olfactory Responses ◽  
The Third ◽  
Pine Trees ◽  
Insect Parasites

1. Pimpla ruficollis is a parasite of the pine shoot moth Rhyacionia (Evetria) buoliana Schiff. (Eucosmidae) which emerges from its host a considerable time before the next generation of larvae are ready for oviposition. It seems that during this period the parasites leave the pine trees and feed on the flowers of certain Umbelliferae and probably other plants. Only after 3 or 4 weeks do they return to the pine trees where the shoots now contain larvae ready for egg laying.2. It has been shown by means of olfactometer experiments that during this first period of the adult life, the parasites are repelled by the odour of oil of Pinus sylvestris. At this time the ovaries are very small and are probably not ready for the production of eggs. After the third or fourth week of life the females become attracted by the oil of P. sylvestris and the ovaries are now relatively large.3. Since Geraniol is known to be a constituent of certain conifers, this substance was also tested. It was, however, found to be invariably repellent to the parasites.4. There is some evidence that conclusions reached as a result of experiments with P. ruficollis also apply to the ophionine ichneumonid Eulimneria rufifemur.

Investigations on the Cotton Bollworm, Heliothis armigera, Hübn

1940 ◽  
Vol 31 (2) ◽  
pp. 147-177 ◽  
Author(s):  
F. S. Parsons
Keyword(s):  
Heliothis Armigera ◽  
Egg Laying ◽  
Food Plant ◽  
Cotton Bollworm ◽  
Flowering Period ◽  
Flower Production ◽  
Plant Associations ◽  
The Given

Studies of the food-plant associations of Heliothis armigera have elicited the information that, for all practical purposes, egg-laying may be considered as confined to the period of florescence. Evidence of coincidence of the oviposition and flowering curves is submitted for 21 species of short-flowering crops and 8 species of long-flowering crops. All told, records taken in nearly 1,000 crops have been consulted for the conclusions drawn.As regards short-flowering species, the peaks, as well as the confines, of the oviposition and flowering curves are related closely. But oviposition on long-flowering species may decline while flowering is still in progress, or two or more waves of oviposition may be evident according to the number of moth flights spanned by the flowering period. The courses of oviposition on long-flowering species of crop in the given instances are interpreted through knowledge of the train of moth flights: although egg-laying in quantity occurs within the flowering period, peak layings frequently are not aligned with maximum flower production because the calendar times of moth flights are displaced in relation thereto.

scholarly journals Scots pine (Pinus sylvestris) dynamics in the Welsh Marches during the mid to late-Holocene

The Holocene ◽  
2021 ◽  
pp. 095968362199465
Author(s):  
Dael Sassoon ◽  
William J Fletcher ◽  
Alastair Hotchkiss ◽  
Fern Owen ◽  
Liting Feng
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Late Holocene ◽  
British Isles ◽  
Loss On Ignition ◽  
Peat Core ◽  
New Information ◽  
Pine Trees ◽  
Pollen Records

Around 4000 cal yr BP, Scots pine ( Pinus sylvestris) suffered a widespread demise across the British Isles. This paper presents new information about P. sylvestris populations found in the Welsh Marches (western central Britain), for which the long-term history and origins are poorly known. Two new pollen records were produced from the Lin Can Moss ombrotrophic bog (LM18) and the Breidden Hill pond (BH18). The LM18 peat core is supported by loss-on-ignition, humification analysis and radiocarbon dating. Lead concentrations were used to provide an estimated timeframe for the recent BH18 record. In contrast to many other Holocene pollen records from the British Isles, analysis of LM18 reveals that Scots pine grains were deposited continuously between c. 6900–300 cal yr BP, at frequencies of 0.3–5.4%. It is possible that individual Scots pine trees persisted through the wider demise on thin soils of steep drought-prone crags of hills or the fringes of lowland bogs in the Welsh Marches. At BH18, the record indicates a transition from broadleaved to mixed woodland, including conifer species introduced around AD 1850 including Picea and Pinus. The insights from BH18 suggest that the current populations may largely be the result of planting. Comparison of the LM18 findings with other regional pollen records highlights consistent patterns, including a Mid-Holocene maximum (ca. 7000 cal yr BP), long-term persistence at low pollen percentages and a Late-Holocene minimum (ca. 3000 cal yr BP). These distinctive trends encourage further studies on refugial areas for Scots pine in this region and elsewhere.

The influence of nutrition on egg-production and longevity in unmated female body-lice (Pediculus humanus corporis: Anoplura)

Parasitology ◽  
1941 ◽  
Vol 33 (1) ◽  
pp. 40-46 ◽  
Author(s):  
A. J. Haddow
Keyword(s):  
Female Body ◽  
Egg Production ◽  
Egg Laying ◽  
The Body ◽  
Unmated Female ◽  
Pediculus Humanus ◽  
The Third ◽  
Significant Difference ◽  
The Mean ◽  
Body Lice

1. Isolated unmated female body-lice were worn in pillboxes between the skin and the clothes. They were kept constantly on the body but, by a simple device, groups of ten were permitted feeding periods of different length. These groups were fed for 4, 8, 12, 16, 20 and 24 hr. per day respectively. Another group of ten were never allowed to feed after the last moult.2. Some of the figures for egg yield were high. Lice in the 24 hr. group were able to maintain a rate of ten eggs per day for 4−5 days at a time.3. No significant difference in longevity or rate of egg-laying was found to exist between the 12, 16, 20 and 24 hr. groups nor between the 4 and 8 hr. groups but a pronounced and significant difference exists between the 8 and 12 hr. groups. Below 12 hr. there is a sharp fall in longevity and rate of egg production. The unfed group all died, without laying, on the third day.4. The rate of laying as shown by the mode increases progressively with increase in time allowed daily for feeding.5. With regard to the mean eggs per louse the position is less clear. It is felt that the 24 hr. group may differ significantly from the 12, 16 and 20 hr. groups but this is uncertain.

scholarly journals Interpopulation genetic-ecological variation of Scots pine (Pinus sylvestris L.) in Serbia

Genetika ◽  
2011 ◽  
Vol 43 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Aleksandar Lucic ◽  
Vasilije Isajev ◽  
Rade Cvjeticanin ◽  
Ljubinko Rakonjac ◽  
Marijana Novakovic ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
Pinus Sylvestris ◽  
Plant Community ◽  
Plant Communities ◽  
Scots Pine ◽  
Seed Protein ◽  
Genetic Research ◽  
Community Research ◽  
Ecological Variation ◽  
The Third

The genetic-ecological variation of Scots pine (Pinus sylvestris L.) in Serbia was studied in the populations at five localities in western and south-western Serbia. Three groups of Scots pine (Pinus sylvestris L.) populations were differentiated based on genetic research (seed protein analysis) and plant community research. The first group consists of Scots pine populations on Sargan (FMU ?Sargan?) and on Tara (FMU ?Kaluderske Bare?), where the forests belong to the community of Scots pine and Austrian pine (Pinetum sylvestris-nigrae Pavlovic 1951). The second group covers the localities Stolovi (FMU ?Radocelo-Crepuljnik?) and Zlatar (FMU ?Zlatar I?), where the forests belong to the community of Scots pine and spruce (Piceo abietis-Pinetum sylvestris Stefanovic 1960). The third group comprises the Scots pine population on Pester (FMU ?Dubocica-Bare?) which belongs to the community of Scots pine with erica (Erico-Pinetum sylvestris Stefanovic 1963). Cluster analysis was performed on the basis of seed protein data and showed that there are three groups of Scots pine populations. The three populations coincide with plant communities. The community of Scots pine with erica (Erico-Pinetum sylvestris Stefanovic 1963) recorded on Pester at the locality ?Dubocica- Bare? in the area of FE ?Golija? Ivanjica, is a special Scots pine population displayed at the greatest distance from all other populations in the cluster analysis dendrogram.

scholarly journals CHRONIC IRRADIATION OF SCOTS PINE TREES (PINUS SYLVESTRIS) IN THE CHERNOBYL EXCLUSION ZONE: DOSIMETRY AND RADIOBIOLOGICAL EFFECTS

2011 ◽  
Vol 101 (4) ◽  
pp. 393-408 ◽  
Author(s):  
Vasyl I. Yoschenko ◽  
Valery A. Kashparov ◽  
Maxim D. Melnychuk ◽  
Svjatoslav E. Levchuk ◽  
Yulia O. Bondar ◽  
...  
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Chronic Irradiation ◽  
Exclusion Zone ◽  
Pine Trees ◽  
Radiobiological Effects

scholarly journals Experiments on the egg-laying instincts of the sawfly, Pontania salicis Christ., and their bearing on the inheritance of acquired characters; with some remarks on a new principle in evolution

1927 ◽  
Vol 101 (707) ◽  
pp. 115-126 ◽  
Keyword(s):  
Food Habits ◽  
Calluna Vulgaris ◽  
Egg Laying ◽  
Food Plant ◽  
Direct Result ◽  
Natural Manner ◽  
In Captivity ◽  
Inheritance Of Acquired Characters ◽  
Acquired Characters

In the course of genetical investigations (Harrison, 1920) in the lepidopterous genus Oporabia I conceived the idea that the inherited instinct of Oporabia filigrammaria HS. to deposit its eggs on heather ( Calluna vulgaris ) was the direct result of long-continued isolation on treeless heather-clad moorlands, involving a compulsory diet of that plant; in other words, I felt that the development of the instinct and its inheritance were Lamarckian effects. To test these views experimentally, by attempting a transference in the food habits of other insects, seemed far from difficult, and search was forthwith made for material easy to manipulate in captivity. No forms appeared more adapted for the purpose than the Geometrid moths Lycia hirtaria Cl. and Phigalia pedaria F., which I had employed in former experiments. However, the technique adopted, at any rate as applied to these insects, proved unsatisfactory and had therefore to be modified. Unexpected difficulties, riot in securing oviposition in a state of semicaptivity but in its taking place in a natural manner on the food plant, were immediately encountered.

scholarly journals Effects of pruning on heartwood formation in Scots pine trees

2012 ◽  
Vol 50 (No. 1) ◽  
pp. 11-16
Author(s):  
B. Bergström ◽  
R. Gref ◽  
A. Ericsson
Keyword(s):  
Growth Rate ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Heartwood Formation ◽  
Growth Rings ◽  
Significant Negative Effect ◽  
Growing Seasons ◽  
Pine Trees ◽  
Negative Effect ◽  
Proportional Increase

The object of this study was to investigate the effect of pruning on heartwood formation in mature Scots pine (Pinus sylvestris L.) trees. Fifty trees were treated by three different intensive pruning regimes: 42, 60 and 70 percentage of defoliation. After five growing seasons numbers of growth rings were counted and the width and the area of sapwood and heartwood were calculated. The results did not show any proportional increase or decrease in the heartwood area or in the number of growth rings in heartwood associated with the pruning. A statistically significant negative effect of pruning was found on the width of the five most recently formed sapwood growth rings. This decreased growth rate did not influence the ratio of sapwood and heartwood. However, it cannot be excluded that the proportion of heartwood may increase during a longer period. It is concluded that pruning is not a practicable silvicultural method for regulating heartwood formation in mature Scots pine trees.

scholarly journals Next-Generation Sequencing reveals relationship between the larval microbiome and food substrate in the polyphagous Queensland fruit fly

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rajib Majumder ◽  
Brodie Sutcliffe ◽  
Phillip W. Taylor ◽  
Toni A. Chapman
Keyword(s):  
Next Generation Sequencing ◽  
Illumina Miseq ◽  
Fruit Fly ◽  
Egg Laying ◽  
Food Sources ◽  
Natural Food ◽  
Next Generation ◽  
North East ◽  
Host Fruit ◽  
Generation Sequencing

Abstract Insects typically host substantial microbial communities (the ‘microbiome’) that can serve as a vital source of nutrients and also acts as a modulator of immune function. While recent studies have shown that diet is an important influence on the gut microbiome, very little is known about the dynamics underpinning microbial acquisition from natural food sources. Here, we addressed this gap by comparing the microbiome of larvae of the polyphagous fruit fly Bactrocera tryoni (‘Queensland fruit fly’) that were collected from five different fruit types (sapodilla [from two different localities], hog plum, pomegranate, green apple, and quince) from North-east to South-east Australia. Using Next-Generation Sequencing on the Illumina MiSeq platform, we addressed two questions: (1) what bacterial communities are available to B. tryoni larvae from different host fruit; and (2) how does the microbiome vary between B. tryoni larvae and its host fruit? The abundant bacterial taxa were similar for B. tryoni larvae from different fruit despite significant differences in the overall microbial community compositions. Our study suggests that the bacterial community structure of B. tryoni larvae is related less to the host fruit (diet) microbiome and more to vertical transfer of the microbiome during egg laying. Our findings also suggest that geographic location may play a quite limited role in structuring of larval microbiomes. This is the first study to use Next-Generation Sequencing to analyze the microbiome of B. tryoni larvae together with the host fruit, an approach that has enabled greatly increased resolution of relationships between the insect’s microbiome and that of the surrounding host tissues.

Variations in life history parameters and their influence on rate of population increase of different pathogenic isolates of the pine wood nematode, Bursaphelenchus xylophilus

Nematology ◽  
2005 ◽  
Vol 7 (3) ◽  
pp. 459-467 ◽  
Author(s):  
Yu Wang ◽  
Kazuo Suzuki ◽  
Daisuke Sakaue ◽  
Toshihiro Yamada
Keyword(s):  
Life History ◽  
Population Size ◽  
Botrytis Cinerea ◽  
Generation Time ◽  
Bursaphelenchus Xylophilus ◽  
Egg Laying ◽  
Population Increase ◽  
Pine Wood Nematode ◽  
Life History Parameters ◽  
Pine Trees

AbstractTwo virulent isolates and two avirulent isolates of Bursaphelenchus xylophilus and one isolate of B. mucronatus were used to investigate the relationships between life history parameters, rate of population increase and virulence. The results showed that on fungal cultures of Botrytis cinerea, virulent B. xylophilus completed one generation much faster than did avirulent B. xylophilus and B. mucronatus. There was a tendency that virulent B. xylophilus isolates laid more eggs during the egg laying period than did avirulent populations. Shorter generation time and higher fecundity resulted in a higher rate of population increase. Generation time and fecundity were primary factors determining rate of population increase. Difference in rate of population increase is closely related to variation of virulence: virulent B. xylophilus increased population size at the fastest rate, avirulent B. xylophilus was slower, and B. mucronatus was slowest. It is assumed that similar variations in life history parameters and rate of population increase are also expressed in pine trees and help to explain variation of virulence in the field.

Spawning Mode and Reproductive Output of the Tropical Cephalopod Idiosepius pygmaeus

1993 ◽  
Vol 50 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Andrew R. Lewis ◽  
J. Howard Choat
Keyword(s):  
Body Weight ◽  
Egg Size ◽  
Reproductive Output ◽  
Reproductive Potential ◽  
Adult Life ◽  
Somatic Growth ◽  
Egg Laying ◽  
Adult Life Span ◽  
Adult Weight ◽  
Food Stress

Reproductive biology of the tropical sepioid cephalopod Idiosepius pygmaeus was investigated in wild specimens and in individuals maintained in aquaria through the adult life span. This species produced multiple egg batches over 80% of the observable adult weight range, indicating a coordination of reproductive and somatic growth. Reproductive output was consistent within, but variable between, individuals. Oocyte synthesis and maturation occur continuously after sexual maturation has been reached. Senescence and death are not related to an exhaustion of reproductive potential. On average, captive female I. pygmaeus with access to unlimited food produced 640 eggs in 11 batches over 18 d. When reproductive output was expressed as a ratio of dry female body weight, on average, specimens had incorporated five times their body weight into eggs and egg coatings. Under food stress, captive specimens laid fewer eggs but maintained egg size and periodicity of egg laying. Food stress had no effect on either laying duration or weight at death. This study provides further evidence that terminal spawning modes are not ubiquitous amongst cephalopods.

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