Interpreting ultraviolet-light and fermentation trap catches of Mythimna convecta (walker) (Lepidoptera: Noctuidae) using phenological simulation

1986 ◽  
Vol 76 (3) ◽  
pp. 419-431 ◽  
Author(s):  
A. M. Smith ◽  
G. McDonald
Keyword(s):  
Ultraviolet Light ◽  
Larval Instar ◽  
Light Traps ◽  
Trap Site ◽  
Phenological Model ◽  
Peak Period ◽  
Field Peak ◽  
The Times ◽  
Trap Catches ◽  
Lepidoptera Noctuidae

AbstractUltraviolet-light and fermentation trap catches of adults of Mythimna convecta (Walker) in Victoria, Australia, could be related to the times of various stages of larval development in oat crops by means of a day-degree accumulation model. Mated females were more attracted to fermentation than ultraviolet-light traps, and predicted oviposition times closely coincided with fermentation trap catches. The phenological model successfully mimicked the observed larval instar development in the field. Peak moth flights occurred within three periods. The first peak period (October to mid-November) usually contained mated moths which generated larval populations in maturing oat crops; in 1983, these moths probably occurred in late August. The second (mid-November to December) contained unmated females; in 1983–84, moth flights during this period could be related to the emergence of moths from crops 70–130 km north of the trap site. The third peak period (January to February) also comprised unmated moths which had usually emerged locally and were probably emigrating.

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.

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.

The influence of behaviour modifying chemicals on mating success of the red bollworm Diparopsis castanea Hmps. (Lepidoptera, Noctuidae) in Malawi

1976 ◽  
Vol 66 (2) ◽  
pp. 279-300 ◽  
Author(s):  
R. J. Marks
Keyword(s):  
Sex Pheromone ◽  
Sexual Attraction ◽  
Practical Method ◽  
Pheromone Trap ◽  
Cotton Field ◽  
Field Cage ◽  
Synthetic Sex Pheromone ◽  
Trap Catches ◽  
First Time ◽  
Lepidoptera Noctuidae

AbstractThe synthetic sex pheromone (dicastalure) of the red bollworm of cotton, Diparopsis castanea Hmps., in Central and Southern Africa, and an inhibitor of male sexual attraction (trans-9-dodecenyl acetate,=IIA), were used in an enclosed 0·2 ha cotton field-cage to reduce successful female matings. Over one month dicastalure at 21·0 and 42·3 g/ha produced average reductions in mating of 47·9% and 72·5% respectively and 37·9 g IIA/ha produced an overall reduction in mating of 71·5%, or 79·5% in released moth populations, over the same period. The proportion of virgin females present in disruption situations was significantly greater than in untreated populations and was density-independent for moth populations of up to 2 200/ha. The proportion of fertile eggs in disruption situations was correspondingly reduced to 30·2% from an average of 67·9% in control cycles. Reduction in sex pheromone trap catches is an unsatisfactory indicator of the extent to which males are prevented from inseminating females and considerably over-estimates the true degree of disruption. This is the first time that a naturally occurring inhibitor has been used successfully to disrupt mating in a field population of insects and it indicates the potential of the method for the control of high density pest populations in cotton. However, use of polyethylene dispensing mechanisms similar to those used in the field-cage disruption experiments would be unsuitable as a practical method of dispensing behaviour modifying chemicals and it is suggested that, for suitably controlled release of such chemicals, currently available microencapsulation technology offers the best prospects.

Sex Attractant System in Polia pisi L. (Lepidoptera: Noctuidae)

1980 ◽  
Vol 35 (11-12) ◽  
pp. 990-994 ◽  
Author(s):  
Ernst Priesner
Keyword(s):  
Sex Attractant ◽  
Pheromone Receptor ◽  
Receptor Cells ◽  
Electrophysiological Analysis ◽  
Hair Sensilla ◽  
Tetradecenyl Acetate ◽  
Different Types ◽  
Trap Catches ◽  
Lepidoptera Noctuidae

Electrophysiological analysis of olfactory hair sensilla in male P. pisi has revealed four different types of presumed pheromone receptor cells, maximally responsive to (Z)-11-tetradecenyl acetate (Z11-14:Ac), (Z)-9-tetradecenyl acetate (Z9-14:Ac), (Z)-11-hexadecenyl acetate (Z11-14:Ac) and (Z)-7-dodecenyl acetate (Z7-12: Ac), respectively. These four compounds were tested, singly and in various combinations, for efficacy in attracting P. pisi males in the field. High trap catches were obtained with mixtures of Z11-14: Ac/Z9-14: Ac in the ratio 100/100, whereas the 100/30 and 30/100 mixtures of the two compounds were only slightly attractive. No male P. pisi were captured by single chemicals or binary combinations of Z11-14: Ac/Z11-16: Ac, Z11-14:Ac/Z7-12:Ac, Z9-14:Ac/Z11-16:Ac, Z9-14:Ac/Z7-12:Ac, or Z11-16:Ac/Z7-12:Ac. Various compounds, including Z11-16: Ac and Z7-12:Ac, were tried as third chemicals in addi­tion to 100 μg Z11-14: Ac + 100 μg Z9-14: Ac but none increased trap catches over the basic lure.

Sex-Specific Attraction of Moth Species to Ultraviolet Light Traps

2010 ◽  
Vol 9 (3) ◽  
pp. 427-434 ◽  
Author(s):  
Heath W. Garris ◽  
John A. Snyder
Keyword(s):  
Ultraviolet Light ◽  
Light Traps ◽  
Moth Species

Light-trap catches of African armyworm moths, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae), in relation to rain and wind

1983 ◽  
Vol 73 (2) ◽  
pp. 315-319 ◽  
Author(s):  
M. R. Tucker
Keyword(s):  
East Africa ◽  
Light Trap ◽  
Spodoptera Exempta ◽  
Trap Catch ◽  
Early Season ◽  
African Armyworm ◽  
Light Wind ◽  
Trap Catches ◽  
Lepidoptera Noctuidae ◽  
Very High

AbstractThe association between weather and light-trap catches of Spodoptera exempta (Wlk.) was examined for four traps in East Africa, using whole–night catches and several years' data. Large increases in trap catch were found to be (1) significantly associated with rain at all four traps for the period December–March, but not for later in the season; (2) significantly associated with light wind periods at Muguga for December–May, but not later in the year, and not at Nakuru, due to the very high overall frequency of light winds there; and (3) not significantly associated with windshifts at either Muguga or Nakuru. These results suggest that high densities of flying moths, which may give rise to caterpillar outbreaks early in the year, often occur where the rather infrequent early–season rains fall.

Predicting the severity of Spodoptera exempta (Lepidoptera: Noctuidae) outbreak seasons in Tanzania

1995 ◽  
Vol 85 (4) ◽  
pp. 479-487 ◽  
Author(s):  
A.W. Harvey ◽  
G.A. Mallya
Keyword(s):  
East Africa ◽  
Negative Correlation ◽  
Seasonal Pattern ◽  
Light Trap ◽  
Spodoptera Exempta ◽  
Convergence Zone ◽  
Light Traps ◽  
Inter Tropical Convergence Zone ◽  
African Armyworm ◽  
Lepidoptera Noctuidae

AbstractOutbreaks of the African armyworm, Spodoptera exempta (Walker), in East Africa follow a seasonal pattern related to the movement of the inter-tropical convergence zone. The season typically begins in central Tanzania with primary outbreaks that coincide with the arrival of the rains. An analysis of 27 years' light trap records shows a high negative correlation between the total number of moths caught by light traps during the season over the whole country and the number of rain days during November in central Tanzania. Out of the 27 seasons, 22 could have been correctly predicted as ‘light’ or ‘severe’, using the November rainfall at one station, Dodoma, in time to give two months' warning before the peak of the season.

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