The influence of moonlight on catches of insects in light-traps in Africa. III. The effective radius of a mercury-vapour light-trap and the analysis of catches using effective radius

1975 ◽  
Vol 65 (2) ◽  
pp. 303-348 ◽  
Author(s):  
John Bowden ◽  
Marjory G. Morris
Keyword(s):  
Full Moon ◽  
Light Trap ◽  
Effective Radius ◽  
Mercury Vapour ◽  
Light Traps ◽  
Primary Determinant ◽  
New Moon ◽  
Insect Activity ◽  
The Times ◽  
Trap Catches

AbstractUsing the inverse square law, estimates can be made of the distances at which illumination from a light-trap is equal to that from background sources. From these distances an index of trap radius can be constructed which can be considered as a measure of trap potential. Between new moon and full moon trap radii vary, depending upon the times of the night at which the trap may be operating, in ratios from about 10:1 to 15:1. A comparable index of light-trap catches can be calculated which allows catches to be examined in relation to changing radius of the trap. Analysis of a series of catches in Uganda and Ghana shows that many species are more abundant than expected in periods of moonlight, particularly at and near full moon, the biggest difference between new moon and full moon being about 10:1 for Marasmia trapezalis (Gn.), whereas the Isoptera, Bostrychidae and Spodoptera triturata (Wlk.) are 3–4 times more frequent at full moon. The ratios between catch at new moon and catch at full moon suggest that the primary determinant of catch is the frequency with which insects cross the boundary of a region of influence whose size is determined by a radius of equal energy. Deductions about the pattern of insect activity through a lunation, and nightly, and the general agreement between curves describing the change in radius of the trap and those of trap catches suggest that changes in catch over a lunation can be explained by changes in the effectiveness of the trap. When corrections are made to allow for such changes, all taxa show some increase in numbers in moonlit periods and in many taxa this increase is substantial. Correction of catches should take account of flight periodicity and this periodicity should, if possible, be confirmed by methods independent of light-traps.

Effects of lunar phase on light trap catches of the Malayan black rice bug, Scotinophara coarctata (Heteroptera: Pentatomidae)

1993 ◽  
Vol 83 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Kiyomitsu Ito ◽  
Hachiro Sugiyama ◽  
Nik Mohd. Noor b. Nik Salleh ◽  
Chang Poon Min
Keyword(s):  
Full Moon ◽  
Light Trap ◽  
Physiological Status ◽  
Growth Stages ◽  
Lunar Phase ◽  
Starvation Period ◽  
Rice Bug ◽  
New Moon ◽  
Fat Bodies ◽  
Trap Catches

AbstractDaily light trap catches of Scotinophara coarctata (Thunberg) were analysed from mid-September 1986 to December 1990 and the physiological status of the trapped adults was examined. The catch size fluctuated synchronously with the lunar phase; large catches occurred around the full moon period and very few adults were trapped around the new moon period. Seasonally, the catches were large from January to March and from July to September, while they were small from May to June and October to November. The seasonal fluctuations of the catches seemed to be related to the growth stages of the rice plants on which the adults multiplied. The sex ratio of trapped adults was biased toward males, unlike that of the cage-reared insects which was 1:1. Most of the trapped females showed undeveloped ovaries and some of these females appeared to have oviposited previously. Light-attracted adults showed a considerable tolerance to starvation and survived for 20–30 days when they were given water, but for only two days in the absence of water. When the light-attracted females were supplied with food, their ovaries developed rapidly and females with mature eggs were produced after nine days. When the starvation period was prolonged, the ovaries remained immature and the fat bodies reduced in size. The nocturnal take-off of the adults was not triggered simply by the full moon illumination. Adult eclosion did not synchronize with the moon cycle.

Moonlight and the biting activity of Culex (Melanoconion) portesi Senevet & Abonnenc and C. (M.) taeniopus D. & K. (Diptera, Culicidae) in Trinidad forests

1975 ◽  
Vol 65 (1) ◽  
pp. 81-96 ◽  
Author(s):  
John B. Davies
Keyword(s):  
Full Moon ◽  
Light Trap ◽  
Ground Level ◽  
The Moon ◽  
Light Traps ◽  
Baited Traps ◽  
Suction Traps ◽  
New Moon ◽  
Phases Of The Moon ◽  
Increased Activity

AbstractThe biting activity of Culex (Melanoconion) portesi Senevet & Abonnenc and C. (M.) taeniopus D. & K. in a secondary seasonal marsh forest in Trinidad was studied by means of catches by six mouse-baited suction traps, and a single light-trap. The traps were cleared at hourly intervals between 17.00 h and 07.00 h on nights which approximated to the new, first quarter, full and last quarter phases of the moon. The catches were compared with illumination at canopy and ground level which was estimated by selenium photocells whose output was recorded on the continuous chart of a servo-potentiometer. Humidity, rainfall, temperature and cloud cover were also recorded. In the suction traps both species showed peaks of activity at evening and dawn twilight at new moon, although the dawn peak was not very pronounced with C. taeniopus, but this pattern was modified on other nights in a manner which was consistent with moon age. At full moon the evening and dawn peaks were replaced by increased activity during moonrise and the middle of the night. The light-traps failed to show the evening and dawn activity and did not always duplicate the baited traps during darkness. Two hypotheses based on either a permissive range of illumination or an underlying circadian rhythm are discussed; neither fully explains the observed biting activity. Although an association between moonlight and biting activity does exist, an understanding of its nature will require more experimental data.

The influence of moonlight on catches of insects in light-traps in Africa. Part II. The effect of moon phase on light-trap catches

1973 ◽  
Vol 63 (1) ◽  
pp. 129-142 ◽  
Author(s):  
J. Bowden ◽  
B. M. Church
Keyword(s):  
Light Trap ◽  
Lunar Cycle ◽  
Early Morning ◽  
Insect Behaviour ◽  
Moon Phases ◽  
Insect Activity ◽  
The Times ◽  
Phases Of The Moon ◽  
Night Illumination ◽  
Trap Catches

AbstractNightly light-trap catches of insects, covering periods of 2–5 years, from two sites in Africa within 10° of the equator are examined in relation to the regular changes in night illumination of the lunar cycle. For several species average log catches at different phases of the moon are almost linearly related to (log) night illumination, catches of some species, such as Isoptera and Bostrychidae, increasing and of others, such as Marasmia trapezalis(Gn.) (Pyralidae), Lampyridae and Dorylus spp. (Formicidae), decreasing with moonlight. Relative catches of M. trapezalis and Bostrychidae varied by a factor of 30:1 between no moon and full moon. Analysis of whole-night catches gives some evidence on the pattern of insect activity through the night, identifying Syntomis monothyris (Hmps.) (Ctenuchidae) and Stemorrhages sericea (Dru.) (Pyralidae) in particular as early morning fliers. Evidence on how night illumination affects catch, and on the times of night when illumination has most effect, is consistent for the two sites and for different years. However, any adjustment of nightly catches to those expected under standard conditions of illumination can only be approximate. Although most of the differences between catches at different moon phases are accounted for by night illumination, many factors influence catch on an individual night, and moonlight is a major factor only for certain species. A hypothesis about how a light-trap may affect insect behaviour allows changes in catch of some species over the lunar cycle to be explained by the influence of background illumination on trap effectiveness.

Light-trap and suction-trap catches of insects in the northern Gezira, Sudan, in the season of southward movement of the Inter-Tropical Front

1973 ◽  
Vol 62 (4) ◽  
pp. 571-596 ◽  
Author(s):  
John Bowden ◽  
David G. Gibbs
Keyword(s):  
Full Moon ◽  
Light Trap ◽  
Lunar Cycle ◽  
Light Traps ◽  
Trap Site ◽  
Long Distance ◽  
Suction Trap ◽  
Displacement System ◽  
Source Populations ◽  
Trap Catches

Catches in light-traps adjoining cotton were obtained at the time of seasonal southward movement of the Inter-Tropical Front (ITF) in October, and during most of the following two months. Taxa studied were mostly Orthoptera and moths, many associated with sorghum, others long-distance migrants. Suction-trap catches at three heights up to 50 ft were obtained for short periods in October and November, and aircraft catches at 250 ft were also available on two days. Suction-trap catches of grass-feeding Homoptera suggest that displacement of these insects was associated with changes in wind direction marking movement of the ITF in October. The exact form of the displacement system in relation to the front cannot be reconstructed from catches at a single place, but it seems likely that proximity of the front at or soon after the time of a brief period of crepuscular activity stimulates insects to take flight and rise to 50 ft or more so that they are displaced. In many taxa, light-trap catches showed a regular pattern of increase, with only slight nightly fluctuations from a logarithmic trend, following full moon. Other increases were superimposed on this pattern at times when the ITF passed north of the trap site, and in some taxa particularly when it was far north. The pattern of change after full moon, shown most clearly in taxa with source populations close to the trap, was related to the moon's influence on the range of trap effectiveness. But various qualitative variations suggest that, in addition, aspects of behaviour or development may have adaptive relationships to the lunar cycle; variations include differences between taxa, particularly in timing of catch changes, and increasing proportion and decreasing maturity of females of certain taxa at the time of the regular increases in catch.

Distribution of fish larvae within a weakly tidal mangrove lagoon

2017 ◽  
Vol 68 (2) ◽  
pp. 396
Author(s):  
J. Jaxion-Harm ◽  
M. R. Speight
Keyword(s):  
Dna Analysis ◽  
Full Moon ◽  
Hydrodynamic Force ◽  
Fish Larvae ◽  
Early Stage ◽  
Shallow Waters ◽  
Light Traps ◽  
Larval Distribution ◽  
New Moon ◽  
Distribution Of Fish

Mangroves have been shown to provide valuable nursery grounds to juvenile fishes, yet little is known regarding larval distribution and settlement processes in this habitat. To investigate fish larvae in mangrove habitat in a semi-isolated lagoon (surface area 750m2), we employed multiple catch methods: plankton tows, minnow traps, and light traps during June–August 2008 and 2009. Overall, nine families of fish larvae were caught in the light traps. Light traps caught significantly more fish larvae during the new moon compared with the full moon. Plankton tow nets caught early-stage, unidentifiable (without DNA analysis) larvae. Minnow traps only caught a total of three fish larvae. Overall, scarids (parrotfish) and lutjanids (snappers) were the most common larvae from coral-reef fish families and were found at sites over 1km upstream of the mouth of the mangrove lagoon. Without the aid of tidal influence (and nets requiring hydrodynamic force), sampling is difficult in these turbid, shallow waters.

Relationship to human biting collections and influence of light and bednet in CDC light-trap catches of West African malaria vectors

1998 ◽  
Vol 88 (5) ◽  
pp. 503-511 ◽  
Author(s):  
C. Costantini ◽  
N.F. Sagnon ◽  
E. Sanogo ◽  
L. Merzagora ◽  
M. Coluzzi
Keyword(s):  
Light Trap ◽  
West African ◽  
Malaria Vectors ◽  
Prototype Model ◽  
Light Traps ◽  
Mosquito Net ◽  
Cdc Light Trap ◽  
Incandescent Bulb ◽  
Human Landing ◽  
Trap Catches

AbstractThe efficiency of miniature CDC light-traps in catching West African malaria vectors was evaluated during two rainy seasons in a village near Ouagadougou, Burkina Faso. Traps were employed both indoors and outdoors using human baits protected by an insecticide-free mosquito-net and different sources of light. Indoors, light from incandescent bulbs increased the catch of Anopheles gambiae s.l. (mainly A. arabiensis Patton and the Mopti chromosomal form of A. gambiae s.s. Giles) and A. funestus Giles c. 2.5 times as compared to traps whose light bulb was removed. Conversely, the difference was not significant when a UV ‘Blacklight-blue’ fluorescent tube was compared to the incandescent bulb. Protecting the bait with a mosquito-net increased the catch c. 3 times for A. gambiae s.l. and c. 3.5 times for A. funestus. A prototype model of double bednet gave intermediate yields. Outdoors, the addition of incandescent bulbs to unlighted traps did not significantly increase the number of vectors caught, but the addition of the mosquito-net to the unprotected human bait did so by c. 1.5–4 times. Thus, the CDC light-trap hung close to a human sleeping under a bednet and fitted with an incandescent bulb, was considered the most practical and efficient in terms of numbers of vectors caught, consequently its indoor efficiency was compared to human landing catches on single collectors and estimated to be 1.08 times and density-independent. Outdoor light-trap catches were either not significantly correlated to biting collections (as for A. gambiae s.l.), or density-dependent in their efficiency (as for A. funestus); thus, they were not considered a reliable means for estimating malaria vector outdoor biting densities in this area. No difference was found in the parous rate of A. gambiae s.l. samples obtained with CDC light-traps and human landing collections.

scholarly journals Abundance of early life stages of the surf silverside Notocheirus hubbsi (Teleostei, Atheriniformes) in the coastal nearshore of central Chile

2021 ◽  
Vol 56 (1) ◽  
pp. 74
Author(s):  
Francisca Zavala-Muñoz ◽  
Mauricio F. Landaeta ◽  
Valentina Bernal-Durán ◽  
Claudia A. Bustos ◽  
Bryan S. Dyer
Keyword(s):  
Full Moon ◽  
Light Trap ◽  
Lunar Cycle ◽  
Early Life Stages ◽  
Entire Study Period ◽  
Austral Spring ◽  
Entire Study ◽  
Central Chile ◽  
New Moon ◽  
Set Up

The abundance of early stages of the surf silverside Notocheirus hubbsi in nearshore waters of central Chile, collected in samplings set up to assess the lunar cycle during austral spring and summer is reported. A total of 19 specimens were collected with light traps, 16 larvae (7.89-16.20 mm SL) in austral spring and 3 juveniles (30.70-34.60 mm SL) in summer. Capture per unit effort (CPUE) varied from 0.33 to 2.00 ind. light trap-1 night-1 during the entire study period (September 2015-February 2016, and September 2016-February 2017). N. hubbsi catches recorded maximum abundance during the new moon and no catches during full moon.

Monitoring wheat bulb fly, Delia coarctata (Fallén) (Diptera: Anthomyiidae), with light-traps

1979 ◽  
Vol 69 (1) ◽  
pp. 129-139 ◽  
Author(s):  
John Bowden ◽  
Margaret G. Jones
Keyword(s):  
Winter Wheat ◽  
Seed Treatment ◽  
Full Moon ◽  
Flight Activity ◽  
Light Traps ◽  
New Moon

AbstractThe flight activity of adult Delia coarctata (Fall). was studied on Rothamsted Farm from 1969 to 1977 using light-traps. These catch, almost exclusively, dispersing mature females, more being caught at full moon than at new moon. Dispersal begins in response to an acceleration in the rate of decrease of daylength, and at Rothamsted begins on 10 July, soon after the rate of decrease accelerates. Maturation of eggs is controlled by temperature; at Rothamsted, the first mature females appear when temperature accumulation above 5° C has reached 314·5±10·5° after 12 June. Maturation usually coincides with dispersal, but females that have matured before 10 July do not disperse until after that date. Catches of females in light-traps are correlated with the numbers of emerging females per hectare and the numbers of eggs per hectare. Light-traps could be used as a simple way of forecasting numbers of eggs early enough to give advice on seed treatment for winter wheat on land subject to attack by D. coarctata.

scholarly journals Light-Trap Catch of the Harmful Moths Depending of Moonlight in North Carolina and Nebraska States of USA

ISRN Zoology ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
László Nowinszky ◽  
János Puskás
Keyword(s):  
North Carolina ◽  
Light Trapping ◽  
Light Trap ◽  
The Moon ◽  
Light Traps ◽  
Trap Catch ◽  
Moon Phases ◽  
Number Of Species ◽  
Individual Number ◽  
New Moon

The present study discusses the light trapping of harmful insects depending on the moonlight, its polarized percentage, and the moon phases. The trapping data were taken from light traps of North Carolina and Nebraska States of USA. We examined five species. The maximum individual number of species was collected at new moon or near the first quarter and last quarter. The farmers can use our results to forecast their plant protecting works.

Latitudinal and seasonal changes of nocturnal illumination with a hypothesis about their effect on catches of insects in light-traps

1984 ◽  
Vol 74 (2) ◽  
pp. 279-298 ◽  
Author(s):  
John Bowden
Keyword(s):  
Seasonal Changes ◽  
Light Trap ◽  
Light Sources ◽  
Summer Solstice ◽  
Light Traps ◽  
Time And Space ◽  
Trap Catches ◽  
Trap Sample ◽  
Over Time

AbstractAn account is given of changes in nocturnal illumination at the spring and autumn equinoxes and summer and winter solstices at latitudes between 50 and 60°N. A Relative Trap Index (RTI) was devised to describe changes in light-trap effectiveness and used to adjust catches of Noctuidae and Geometridae for change in trap effectiveness caused by seasonal and latitudinal change in nocturnal illumination at latitudes between 50 and 58°N. When so adjusted, catches were frequently larger in northern than in southern latitudes, not smaller as unadjusted catches show. It is clear that unless light-trap catches are adjusted to allow for changes of illumination, comparisons over time and space, particularly those which involve assumptions about sample constancy, are suspect. Because of the large differences in RTI that may exist between northern and southern traps, particularly in summer and between the summer solstice and other times, it may be necessary to use different light sources at different times of year to maintain a consistent trap sample.

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