Flight Activity and Displacement in the Rutherglen Bug Nysius Vinitor (Hemiptera: Lygaeidae).

1973 ◽  
Vol 21 (3) ◽  
pp. 413 ◽  
Author(s):  
M Kehat ◽  
M Wyndham
Keyword(s):  
Host Plants ◽  
Population Studies ◽  
Weather Conditions ◽  
Flight Activity ◽  
Migratory Behavior ◽  
Seasonal Fluctuations ◽  
Large Numbers ◽  
Seasonal Migrations ◽  
Population Source ◽  
Short Time

Population studies for determining seasonal fluctuations of N. vinitor indicated that the appearance or disappearance of populations within a short time can be attributed mainly to its highly migratory behavior. N. vinitor always migrated when host plants dried up, and sometimes also when they were still green. Continuous quantitative records of flight activity, made near the population source, showed that the seasonal migrations of N. vintor closely reflected its population curve. As populations increased and declined throughout the season, migrants were produced continuously, resulting in a fairly smooth succession of departing individuals which became particularly obvious when large numbers suddenly discharged which occurred when special weather conditions caused sudden excessive flights.

scholarly journals Controlling Shipping Along the North European Trade Axis

1971 ◽  
Vol 24 (4) ◽  
pp. 553-556
Author(s):  
D. J. Lindsay
Keyword(s):  
Weather Conditions ◽  
North Coast ◽  
Baltic Basin ◽  
Long Distance ◽  
The North ◽  
Large Numbers ◽  
Straight Line ◽  
European Trade ◽  
Trade Route ◽  
The Baltic

By the North European Trade Axis is meant the trade route from Ushant and Land's End, up the English Channel, through the Dover Strait fanning out to serve eastern England, the north coast of continental Europe and leading to the Baltic Basin. Recent events in this area have left a feeling that some form of tightening of control is not only desirable, but is rapidly becoming imperative. There is a basic conflict between the two forms of shipping using the area: the local users who use the area more or less constantly, and the long-distance traders, usually much larger, which arrive in the area for a brief stay after a prolonged period at sea, which has usually been in good weather conditions. Frequently these latter ships have a very poor notion of the hornet's nest into which they are steaming when they arrive. The net result is all too often the same: the local users, with familiarity breeding contempt, wander about as they see fit, with scant regard for routing or the regulations; all too often the big ships arrive from sea with navigating staffs who are too confused, sometimes too ignorant—and sometimes too terrified—to do much more than blunder forward in a straight line hoping for the best. Quite obviously this is not a total picture, and there are large numbers of ships which navigate perfectly competently, but the minority of those which do not seem to be rising rapidly, and show every sign of continuing to increase.

Spodoptera frugiperda (fall armyworm).

2021 ◽  
Author(s):  
Ivan Rwomushana
Keyword(s):  
Spodoptera Frugiperda ◽  
Host Plants ◽  
Indian Subcontinent ◽  
Fall Armyworm ◽  
Climatic Conditions ◽  
Vegetable Crops ◽  
Large Numbers ◽  
Significant Damage ◽  
Lepidopteran Pest ◽  
The Ideal

Abstract The fall armyworm, Spodoptera frugiperda, is a lepidopteran pest that feeds in large numbers on the leaves, stems and reproductive parts of more than 350 plant species, causing major damage to economically important cultivated grasses such as maize, rice, sorghum, sugarcane and wheat but also other vegetable crops and cotton. Native to the Americas, it has been repeatedly intercepted at quarantine in Europe and was first reported from Africa in 2016 where it caused significant damage to maize crops. In 2018, S. frugiperda was first reported from the Indian subcontinent (Ganiger et al., 2018; Sharanabasappa Kalleshwaraswamy et al., 2018). It has since invaded Bangladesh, Thailand, Myanmar, China and Sri Lanka (IPPC, 2018b, 2019; FAO, 2019c). The ideal climatic conditions for fall armyworm present in many parts of Africa and Asia, and the abundance of suitable host plants suggests the pest can produce several generations in a single season, and is likely to lead to the pest becoming endemic.

scholarly journals Evaluation of Different Methods for Estimating the Fraction of Sunlit Leaves and Its Contribution for Photochemical Reflectance Index Utilization in a Coniferous Forest

2019 ◽  
Vol 11 (14) ◽  
pp. 1643 ◽  
Author(s):  
Huang ◽  
Qiu ◽  
Fan ◽  
Liu ◽  
Zhang
Keyword(s):  
Coniferous Forest ◽  
Weather Conditions ◽  
Short Time Scale ◽  
Canopy Reflectance ◽  
Climate Conditions ◽  
Photochemical Reflectance Index ◽  
Use Efficiency ◽  
Direct Outcome ◽  
Short Time ◽  
Penumbra Region

Proper determinations of light use efficiency (LUE) and absorbed photosynthetically active radiation (APAR) are essential for LUE models to simulate gross primary productivity (GPP). This study intended to apply the photochemical reflectance index (PRI) to track LUE or APAR variations in a subtropical coniferous forest using tower-based PRI and GPP measurements. To improve the ability of using PRI to track LUE or APAR, a two-leaf approach differentiating sunlit and shaded leaves was used to process the remote sensing and flux data. However, penumbra region, the ‘grey region’ between sunlit and shaded leaves, increases the difficulty for quantifying the fractions of sunlit and shaded leaves. Firstly, three methods with different ways on treating the penumbra region were investigated for estimating the fraction of sunlit leaves (PT). After evaluating the correlations between observed PRI (PRIobs) and inversely retrieved PRI (PRIinv) from estimated PT using the three methods, we found that treating a substantial portion of penumbra region as sunlit leaves was reasonable and using the ratio of canopy reflectance to leaf reflectance as PT was accurate and efficient. Based on this, we used the two-leaf approach to estimate the canopy-level PRI, aiming to evaluate the ability of using PRI as a proxy for LUE or APAR. Results showed that PRI was able to capture half-hourly and daily changes in LUE and APAR, and the two-leaf approach could enhance the correlations between PRI and both LUE and APAR at both half-hourly and daily time steps. Strong diurnal correlations (averaged R = 0.82 from 173 days) between two-leaf PRI and APAR were found on more than 80% days and the relationship between them over the whole study period was also very significant (R2>0.5, p<0.0001) regardless of different climate conditions, suggesting that the two-leaf PRI was probably a better proxy for APAR than for LUE at short-term scale as PRI mainly represented the absorbed energy allocated to photoprotection at short time scale and was a direct outcome driven by APAR. However, the scattered relationships of PRI with LUE and APAR indicated there were still many limitations in usage of PRI to accurately estimate physiological parameters affected by changing weather conditions, pigment pool size, etc., which needed further exploration.

A Method of Marking Isolated Adult Locusts in Large Numbers as an Aid to the Study of their Seasonal Migrations

1956 ◽  
Vol 46 (4) ◽  
pp. 797-802 ◽  
Author(s):  
J. T. Davey
Keyword(s):  
Locusta Migratoria ◽  
Locusta Migratoria Migratorioides ◽  
Dense Vegetation ◽  
Large Numbers ◽  
Seasonal Migrations ◽  
Small Hand ◽  
Light Oil ◽  
Low Toxicity ◽  
High Winds ◽  
Spray Gun

A method of marking adult locusts, particularly useful when numbers are low and hand marking would be difficult, is described. It involves the use of a small hand spray gun from which a jet of paint can be directed at the locusts in spurts at ranges up to about 15 ft. The paints tested consisted of suspensions of pigments in light oil.The paints are of low toxicity and the marks remain visible for many weeks. By the use of this method far more locusts can be marked in a given time than could be marked by hand. The efficiency of the method is reduced by high winds and dense vegetation, and it is more costly than hand marking. Most of the marked locusts cannot be recognised as such without being captured.Some results obtained with this method in the French Sudan are given. In two months more than 50,000 locusts, Locusta migratoria migratorioides (R. & F.), were marked with a red paint; four were recovered 60 kilometres or more from the area in which they were marked, and the paint was clearly visible after five weeks.Ways of improving the technique, and other possible methods of marking, are discussed.

Euphilomedes chupacabra (Ostracoda: Myodocopida: Philomedidae), a new demersal marine species from coastal Puerto Rico with male-biased vespertine swimming activity

Zootaxa ◽  
2008 ◽  
Vol 1684 (1) ◽  
pp. 35 ◽  
Author(s):  
KIMBERLY E. LUM ◽  
ANNA E. SYME ◽  
ANASTASIA K. SCHWAB ◽  
TODD H. OAKLEY
Keyword(s):  
Puerto Rico ◽  
Marine Species ◽  
Peak Time ◽  
Sexually Dimorphic ◽  
Ancestral State ◽  
Western Atlantic ◽  
Large Numbers ◽  
Multiple Species ◽  
Short Time ◽  
A New Species

A new species of Philomedidae is described: Euphilomedes chupacabra from coastal Puerto Rico. This is the first described species of Euphilomedes from the Western Atlantic, a genus of particular interest for its sexually dimorphic lateral eyes. As E. chupacabra can be easily caught in large numbers and may have a short generation time, it has potential to be used as a laboratory animal to study questions of dimorphic eye development. Males of E. chupacabra are abundant in plankton for a short time; the average time of peak activity was 103.6 minutes after sunset, and the density range at the peak time on different nights was 24 to 862 males/m 3 . Males were preferentially attracted to pier lights. There is evidence that species from all myodocopid families display vespertine (post-sunset) migratory behavior, probably associated with mating. We hypothesize that vespertine planktonic mating is an adaptive behavior that exists in many myodocopids and is either the ancestral state for the group or partially or fully convergent in multiple species.

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