Tethered flight of the potato moth, Phthorimaea operculella

ABSTRACT. The effects of sex, age and mated state on average flight speed, duration and distance were determined for potato moths, Phthorimaea operculella (Zeller) (Lepidoptera, Gelechiidae), tethered to flight mills. Moths were classified as non-fliers (NFs), good-fliers (GFs) and remaining-fliers (RFs) on the basis of their performance over the first two flights. Some moths flew for over 5 h non-stop, while others tethered overnight flew between 20 and 30 km. Speed, duration and distance flown were greater during the first flight. First flight duration and distance flown by females decreased with age, whereas no trend was evident for males. Mated males and females flew slower first flights with increasing age, whereas virgin moths showed no marked trend. The analysis of fliers and NFs revealed that GFs were heavier than both RFs and NFs, GFs were faster than RFs, the percentage of NFs increased with age especially for mated females, and the percentage of GFs decreased with age. Age and mated state are important factors influencing flight performance especially for female moths. The relevance of these results to the field situation and the possible application of tethered flight to tests of potato moth quality are discussed.     

凹唇壁蜂成蜂体重与取食对其飞行能力的影响

凹唇壁蜂Osmia excavata Alfken被广泛应用于我国北方果树的传粉, 而其飞行能力是影响其传粉效率的重要因素。本研究通过飞行磨吊飞试验, 评估了凹唇壁蜂雌蜂和雄蜂飞行能力的差异以及取食对其飞行能力的影响。结果表明, 凹唇壁蜂雌蜂体重（116.30 mg）显著大于雄蜂（59.80 mg） (P<0.001), 雌蜂的最大飞行速度（3.44 km/h）显著大于雄蜂（2.36 km/h）, 雄蜂的飞行距离和最大飞行速度与其飞行前体重成显著的正相关性, 雌蜂的飞行时间与其飞行前体重成显著正相关性, 而雌蜂的平均飞行速度与其体重成显著负相关性; 雌蜂的日平均飞行距离为0.23 km, 根据雌蜂以巢为中心, 采集花粉繁殖后代的生物学习性, 蜂巢之间的放置距离应少于100 m。取食蜂蜜后, 雌雄壁蜂的飞行距离、 飞行时间、 最大飞行速度均有提高的趋势, 建议在田间应用时, 可在蜂巢附近放置蜂蜜或种植其他蜜源植物给初羽化的凹唇壁蜂提供食物补充能量。本研究明确了雌、 雄壁蜂的飞行能力和出茧后补充食物对于壁蜂飞行的促进作用, 为有效地利用凹唇壁蜂进行传粉提供了理论依据。     

美洲斑潜蝇在不同温度下的飞行能力

利用昆虫飞行磨测试了美洲斑潜蝇Liriomyza sativae在18℃到36℃条件下的飞行能力。结果表明：在33℃下美洲斑潜蝇的飞行能力最强,个体最大飞行距离、最高飞行速度和最长飞行时间分别为8.22 km、1.10 km/h和253.50 min,其平均飞行距离为0.95 km。其飞行的适温范围是21～36℃,18℃为其飞行的下限温度。从18～33℃,随着温度的升高平均飞行距离（0.08～0.95 km）和平均飞行时间(6.57～47.94 min)也在增加,但到36℃又开始下降;雌虫比雄虫飞行能力强。在理论上,美洲斑潜蝇能靠自身飞行扩散0.08～0.95 km。     

Laboratory evaluation of flight activity of the common cutworm, Spodoptera litura (Lepidoptera: Noctuidae)

Abstract  The flight activity of Spodoptera litura in tethered conditions is evaluated using a computer-mediated flight-mill in the laboratory. The 3–4-day-old moths fly longer and farther than those of other ages. Male and female moths exhibit similar flight activity. Mating status does not influence the flight duration and distance of 2-day-old females. However, these two flight parameters with a 6-day-old mated female is significantly lower than that of unmated ones. The optimum temperature for flight ranged from 16–24°C, whereas the optimum RH ranged from 60%–100%. During 72-h period, the total flight duration and distance of 1-day-old male and female moths were 19.6 h (± 5.8) and 83.3 km (± 28.4), and 24.0 h (± 7.0) and 105.4 km (± 37.4), respectively. These results indicate that S. litura has a great potential to undertake long-distance migratory flights.     

Simultaneous monitoring of flight and oviposition of individual velvetbean caterpillar moths

ABSTRACT. A 'pivot' flight actograph was combined with a rolling oviposition surface to characterize the flight and oviposition behaviour of velvetbean caterpillar moths, Anticarsia gemmatalis Hubner. Tethered, caged control females laid significantly more eggs that those flown on the actograph. Mated females laid more eggs than unmated ones. However, mating did not affect longevity nor fight frequency and duration. Laboratory-reared and wild-type females also did not differ signficantly in longevity and flight. Both laboratory and wild mated females laid most of their eggs during the first 7 days whereas unmated ones delayed their oviposition. None of the female types produced a definite hourly, daily or lifetime pattern in flight frequency or duration. Of the 7672 recorded flights, about 3% were greater than 0.5 h. 'Long' flights (>0.5h) were made by some females before oviposition, as in colonization migration, but most interspersed flight with oviposition, as in extended search migration.     

Visual ground pattern modulates flight speed of male Oriental fruit moth Grapholita molesta

Insects flying in a horizontal pheromone plume must attend to visual cues to ensure that they make upwind progress. Moreover, it is suggested that flying insects will also modulate their flight speed to maintain a constant retinal angular velocity of terrestrial contrast elements. Evidence from flies and honeybees supports such a hypothesis, although tests with male moths and beetles flying in pheromone plumes are not conclusive. These insects typically fly faster at higher elevations above a high‐contrast ground pattern, as predicted by the hypothesis, although the increase in speed is not sufficient to demonstrate quantitatively that they maintain constant visual angular velocity of the ground pattern. To test this hypothesis more rigorously, the flight speed of male oriental fruit moths (OFM) Grapholita molesta Busck (Lepidoptera: Tortricidae) flying in a sex pheromone plume in a laboratory wind tunnel is measured at various heights (5–40 cm) above patterns of different spatial wavelength (1.8–90°) in the direction of flight. The OFM modulate their flight speed three‐fold over different patterns. They fly fastest when there is no pattern in the tunnel or the contrast elements are too narrow to resolve. When the spatial wavelength of the pattern is sufficiently wide to resolve, moths fly at a speed that tends to maintain a visual contrast frequency of 3.5 ± 3.2 Hz rather than a constant angular velocity, which varies from 57 to 611° s^?1. In addition, for the first time, it is also demonstrated that the width of a contrast pattern perpendicular to the flight direction modulates flight speed.     

金纹细蛾飞行能力测定

【目的】明确金纹细蛾Lithocolletis ringoniella自身生理状态下的飞行能力,了解其飞行生物学的基础参数。【方法】利用昆虫飞行磨系统,室内测定了金纹细蛾雌雄成虫不同日龄和性别以及5日龄雌雄成虫补充营养(5%蜂蜜水)与交配状态下的飞行距离、飞行时间、飞行速度等参数。【结果】连续吊飞12 h的结果显示,金纹细蛾3-6日龄成虫飞行能力较强,5日龄成虫飞行能力最强; 5日龄雌成虫的平均 飞行距离、飞行时间和飞行速度分别为2.293±0.254 km, 5.341±0.617 h和0.711±0.126 km/h, 5日龄雄成虫的平均飞行距离、飞行时间和飞行速度分别为2.142±0.276 km, 5.132±0.628 h和0.620±0.132 km/h, 说明雌雄成虫间飞行能力差异不显著。金纹细蛾5日龄雌雄成虫取食5%蜂蜜水后其飞行能力较对照显著提高,取食5%蜂蜜水后5日龄雌成虫的飞行距离、飞行时间和飞行速度较对照(取食清水)的分别提高46.945%, 15.430%和15.978%;5日龄雄成虫的飞行距离、飞行时间和飞行速度较对照分别提高42.610%, 13.590%和6.529%。交配后5日龄雌成虫的飞行距离、飞行时间和飞行速度较未交配雌成虫的分别提高41.628%, 7.152%和39.925%,而5日龄雄成虫交配后飞行能力则较未交配雄成虫的分别降低35.823%, 17.888%和46.129%。【结论】金纹细蛾成虫具有一定的飞行能力,补充营养和雌雄交配状态对飞行能力有重要影响。     

Flying Beetles Respond as Moths Predict: Optomotor Anemotaxis to Pheromone Plumes at Different Heights

The current level of understanding of orientation mechanisms used by flying insects responding to pheromone sources, based almost entirely on studies of moths and flies, allows clear predictions to be made of how other, hitherto little-studied insect taxa, such as beetles (Coleoptera), should behave if the same mechanisms are used. Results are presented of the first test of such set of predictions, the effect of flight height on ground speed, on a beetle, Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae). The beetle P. truncatus flew upwind toward the source of horizontal pheromone plumes and responded to the movement of visible patterns on the floor of a sustained flight tunnel. Beetles flying at a greater height from the floor were less responsive to moving floor patterns. The flight speeds of P. truncatus increased with flight altitude, as found with moths, suggesting that they use orientation mechanism similar to those of moths.     

Flight behavior of methyl-parathion-resistant and -susceptible western corn rootworm (Coleoptera: Chrysomelidae) populations from Nebraska

Relative flight behavior of methyl-parathion-resistant and -susceptible western corn rootworm, Diabrotica virgifera virgifera LeConte populations, was studied as part of a larger effort to characterize the potential impact of insecticide resistance on adult life history traits and to understand the evolution and spread of resistance. A computer interfaced actograph was used to compare flight of resistant and susceptible individuals, and flight of resistant individuals with and without prior exposure to methyl-parathion. In each case, mean trivial and sustained flight durations were compared among treatments. In general, there were few differences in trivial or sustained flight characteristics as affected by beetle population, insecticide exposure, sex, or age and there were few significant interactions among variables. Tethered flight activity was highly variable and distributions of flight duration were skewed toward flights of short duration. Tethered flight activity was similar among resistant and susceptible beetles with the exception that susceptible beetles initiated more flights per beetle than resistant beetles. After sublethal exposure to methyl-parathion, total flight time, total trivial flight time, and mean number of flights per resistant beetle declined significantly. Because long-range flight was uncommon, short- to medium-duration flights may play an important role in determining gene flow and population spread of resistant D. v. virgifera. These results suggest that organophosphate-resistant beetles can readily move and colonize new areas, but localized selection pressure (e.g., management practices) and exposure to methyl-parathion may contribute to the small-scale differences in resistance intensity often seen in the field.     

Tracking butterfly flight paths across the landscape with harmonic radar

For the first time, the flight paths of five butterfly species were successfully tracked using harmonic radar within an agricultural landscape. Until now, butterfly mobility has been predominantly studied using visual observations and mark-recapture experiments. Attachment of a light-weight radar transponder to the butterfly's thorax did not significantly affect behaviour or mobility. Tracks were analysed for straightness, duration, displacement, ground speed, foraging and the influence of linear landscape features on flight direction. Two main styles of track were identified: (A) fast linear flight and (B) slower nonlinear flights involving a period of foraging and/or looped sections of flight. These loops potentially perform an orientation function, and were often associated with areas of forage. In the absence of forage, linear features did not provide a guiding effect on flight direction, and only dense treelines were perceived as barriers. The results provide tentative support for non-random dispersal and a perceptual range of 100-200 m for these species. This study has demonstrated a methodology of significant value for future investigation of butterfly mobility and dispersal.     

Reproductive status and flight activity of the overwintered Colorado potato beetle

Mating behavior of post-diapause Colorado potato beetles, Leptinotarsa decemlineata (Say), was observed within an overwintering site, a rotated potato field, newly colonized potato plants, and under laboratory conditions. The influence of spring mating on beetle flight in the presence and in the absence of host plants was investigated using a computer-linked flight mill system. Diapause was terminated simultaneously in male and female beetles, and the first matings were observed as early as within the first 24 h after the beetles emerged from the soil (60–90 DD accumulated). The beetles mated within the overwintering site, the potato field, and the fields rotated out of potatoes. Mating status did not affect flight behavior of overwintered beetles; however, unfed beetles displayed higher flight activity than fed beetles. Most flight activity took place soon after flight muscle regeneration, and then declined sharply by the 5th day after flight initiation. Mating in or near overwintering sites soon after diapause termination might be an important factor in providing gene flow between insecticide-resistant and insecticide-susceptible Colorado potato beetle populations, and should be considered in designing resistance management plans.     

Nocturnal windborne migration of ground beetles,particularly Pseudoophonus griseus (Coleoptera: Carabidae), in China

1 A network of light‐traps, an aerial net carried by kytoon (balloon) and two entomological radars were used to investigate whether ground beetles migrate nocturnally through China. The network‐wide, simultaneous sudden increase in light trap catches, and after subsequent decrease, indicated a seasonal long‐distance night migration of ground beetles, with Pseudoophonus griseus (Panzer) predominant, in August. 2 Aerial net trapping indicated that carabids were able to ascend to altitudes of at least 200 m and become windborne. Radar observations indicated that the migratory beetles formed high‐density layer concentrations at approximately 200–300 m. 3 These concentrations were coincident with the top of the temperature inversion and a wind speed maximum, which suggested that the carabids tended to select warm, fast moving air for their long‐distance migration. 4 The ground beetles orientated and displaced towards the downwind direction in southerly winds. Their air speed decreased as the tailwind increased and, thus, migrating beetles appeared to be conserving energy. 5 The mean ± SD displacement speed (ground speed) and air speed were 6.85 ± 1.73 m/s (n= 172) and 4.45 ± 1.54 m/s (n= 172), respectively. The duration of flight, estimated from the variation in area density derived from radar data, was approximately 9–10 h, indicating that the beetles might migrate hundreds of kilometres in a single flight.     

Cowpea weevil flights to a point source of female sex pheromone: analyses of flight tracks at three wind speeds

Abstract.  Two-day-old male cowpea weevils, Callosobruchus maculatus, fly upwind to a point source of female sex pheromone at three wind speeds. All beetles initiating flight along the pheromone plume make contact with the pheromone source. Analysis of digitized flight tracks indicates that C. maculatus males respond similarly to moths tested at several wind speeds. Beetles' mean net upwind speeds and speeds along their track are similar ( P  > 0.05) across wind speeds, whereas airspeeds increase ( P <  0.01) with increasing wind speed. Beetles adjust their course angles to fly more directly upwind in higher wind speeds, whereas track angles are almost identical at each wind speed. The zigzag flight paths are generally narrow compared with most moth flight tracks and interturn distances are similar ( P  > 0.05) at the wind speeds employed. The frequency of these counterturns across the wind line is almost constant regardless of wind speed, and there is little variation between individuals. The upwind flight tracks are more directly upwind than those typically seen for male moths flying upwind toward sex pheromone sources. Male moths typically produce a bimodal distribution of track angles to the left and right of the windline, whereas C. maculatus males' track angles are centred about 0°. Preliminary examination of two other beetle species indicates that they fly upwind in a similar fashion.     

取食和交配对苹小吉丁飞行能力的影响

【目的】苹小吉丁Agrilus mali是一种严重危害苹果树的钻蛀性害虫。本研究旨在明确苹小吉丁的飞行扩散能力及对其飞行能力产生影响的关键因子。【方法】以SUN-FL型智能飞行磨系统对苹小吉丁不同日龄雌雄成虫的飞行能力进行了测定,同时评价了取食和交配情况对其飞行能力的影响。【结果】苹小吉丁飞行能力均随日龄的增加先增强后逐渐降低,初羽化的成虫飞行能力最低,11日龄成虫的飞行能力最强。雌成虫飞行能力强于雄成虫。在24 h内雌雄成虫的最长飞行距离分别为0.4165和0.3559 km;最长飞行时间分别为0.4582和0.4873 h;最大飞行速度分别为2.4639和1.8561 km/h。取食的3日龄雌成虫的平均飞行距离和平均飞行时间分别为0.047 km和0.048 h,雄成虫的分别为0.044 km和0.042 h;而未取食的雌成虫平均飞行距离和平均飞行时间仅分别为0.016 km和0.013 h,雄成虫的仅分别为0.013 km和0.012 h。交配对飞行能力的影响存在性别差异,已交配雌成虫的飞行能力要强于未交配雌成虫的,而已交配雄成虫的飞行能力却低于未交配雄成虫的。【结论】日龄对苹小吉丁成虫的飞行能力影响作用显著。取食显著提高苹小吉丁雌雄成虫的飞行能力,交配显著提高雌成虫飞行能力。     

Electronic tags for the tracking of insects in flight: effect of weight on flight performance of adult Colorado potato beetles

The wing loading of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), was found to decrease slightly with increasing size over a wide range of individual sizes and independent of sex. This makes it possible to use tags of the same weight for beetles of all sizes and suggests that if the addition of light electronic tags has any effect on the beetle's flight it will be similar across beetle size. The wing loading of individual potato beetles ranged from an average minimum 10.9 N m^–2 to an average maximum of 15.6 N m^–2 as their weights fluctuated over time following water and food uptake or dispersal. However, tests carried out in flight chambers indicate that beetles become incapable of upward flight as they go beyond an average wing loading of 11.8 N m^–2, that is 101 N (10.3 mg) beyond their minimum weight. It is estimated from our results that electronic tags should weigh no more than 23–33% of the potato beetle's acceptable extra loading for the technique to have no or minimal impact on the number and quality of upward flights taken.     

Experimental analysis of the pattern of tethered flight in the Queensland fruit fly, Dacus tryoni

ABSTRACT. The tethered flight of the Queensland fruit fly, Dacus tryoni Frogg. (Diptera, Tephritidae), was investigated, and the duration of each flight during a 2-h experimental period was recorded. The pattern of flight was analysed, and related to the age, sex and origin of the specimens, and to the availability of host fruit during the rearing of the adults. The effect of adult crowding on the pattern of flight was also briefly examined. The results indicated that the origin of the flies had little effect on the pattern of flight; male and female flies showed different trends with respect to the proportion of short flights undertaken as the flies matured; and the availability of fruit had a marked effect on the pattern of flight in recently mature flies. These data are discussed with respect to the dispersive/non-dispersive movements of the flies postulated from previously documented field data. It is suggested that there is a characteristic pattern of tethered flight, which can be related to the absence of hosts in the immediate environment, and would be likely to lead to greater dispersal under natural conditions.     

Long flights in Cydia pomonella L. (Lepidoptera: Tortricidae) measured by a flight mill: influence of sex, mated status and age

Abstract. The flight capacity of Cydia pomonella L. (Lepidoptera: Tortricidae) was measured in the laboratory by using computer-linked flight mills. Codling moths showed a large variation in flight capacity between individuals. We defined arbitrarily a longest single flight (LSF) of more than 5 km as an index for long-flyers. About 16.7% of virgin and 10.0% of mated males and 20.0% of virgin and 7.4% of mated females undertook such flights. Based on the LSF and the total distance flown (TDF^we concluded that males and females have little or no difference in flight capacity and that both the within-and between-habitat flights are similar in number and magnitude for both sexes. In the field, females are therefore potentially able to undertake flights of up to 11 km, as reported for males by other authors. This ability was highest at ages of 2–7 days after emergence, i.e. the first third of their lifetime, for virgin and mated male moths and for virgin female moths. Mated females showed peak flight capacity between 1 and 3 days after eclosion, which corresponded with the major egg-laying period. Few long flights were undertaken before oviposition. These findings do not agree with the oogenesis flight syndrome described by other authors, and this theory is believed not to apply to C.pomonella. Our laboratory results are discussed in relation to field experiments in general and hypotheses are developed about the significance of long-flyers for this species.     

取食不同寄主植物的桃小食心虫飞行能力

【目的】评测取食不同寄主植物的桃小食心虫Carposina sasakii飞行能力,为该虫预测预报和防控提供参考。【方法】使用飞行磨装置测定了取食不同寄主植物(海棠、苹果和杏)的桃小食心虫雌雄成虫的飞行能力,比较了取食同一寄主植物的雌雄成虫间和取食不同寄主植物的同一性别个体间平均飞行距离、平均飞行时间、平均飞行速度和最大飞行速度4个飞行参数。【结果】在12 h的飞行测试中,桃食心虫成虫最长飞行距离为24.54 km,最长飞行时间接近12 h,最大飞行速度为5.88 km/h,飞行11~12h的个体占比最高(36.98%)。取食同一寄主的雌成虫各飞行参数值均大于雄成虫。取食苹果和海棠的成虫的平均飞行距离在雌雄间存在显著差异,取食苹果的雌成虫的平均飞行距离显著大于取食杏的个体,取食苹果的雌成虫平均飞行速度和最大飞行速度显著大于取食另外两种寄主的个体;但是取食不同寄主植物的雄成虫间各飞行参数值差异不显著。【结论】桃小食心虫成虫飞行能力较强,取食同一寄主植物的雌雄成虫间以及取食不同寄主植物的雌成虫间飞行能力存在差异。     

Metabolic costs of avian flight in relation to flight velocity: a study in Rose Coloured Starlings (Sturnus roseus, Linnaeus)

The metabolic costs of flight at a natural range of speeds were investigated in Rose Coloured Starlings (Sturnus roseus, Linnaeus) using doubly labelled water. Eight birds flew repeatedly and unrestrained for bouts of 6 h at speeds from 9 to 14 m s⁻¹ in a low-turbulence wind tunnel, corresponding to travel distances between 200 and 300 km, respectively. This represents the widest speed range where we could obtain voluntarily sustained flights. From a subset of these flights, data on the wing beat frequency (WBF) and intermittent flight behaviour were obtained. Over the range of speeds that were tested, flight costs did not change with velocity and were on an average 8.17±0.64 W or 114 W kg⁻¹. Body mass was the only parameter with a significant (positive) effect on flight costs, which can be described as EE_f=0.741 M ^0.554. WBF changed slightly with speed, but correlated better with body mass. Birds showed both types of intermittent flight, undulating and bounding, but their frequencies did not systematically change with flight speed.     

Modulation of whitefly take-off and flight orientation by wind speed and visual cues

The effect of different wind speeds on take-off and flight orientation of the sweetpotato whitefly, Bemisia tabaci Gennadius (Homoptera: Aleyrodidae), was studied in the presence of a green visual stimulus which reflected 550 ± 10 nm light, or a white stimulus of the same intensity. When the white light was present, take-off was negatively correlated with wind speed. Analysis of the flight tracks of whiteflies in 0, 15 and 30 cm/s wind with the white light present showed that flight was not directed toward the stimulus in zero wind, and that insects were carried downwind as the wind increased. Net displacement downwind was significantly slower than the wind speed, indicating that B. tabaci can control its rate of displacement relative to its surroundings, and is not always passively transported by the wind. In the presence of the green visual stimulus, take-off and flight behaviour of B. tabaci was markedly different to that observed in the presence of the white light. Taking off was more likely and whiteflies made upwind orientated flights, landing on the illuminated section of the screen when it reflected green light. At all wind speeds tested, the mean ground speeds of B. tabaci were approximately 20 cm/s whether the insects were flying upwind or downwind. This uniformity of ground speed regardless of the changing effects of wind-induced drift in different directions strongly suggests that whiteflies actively control their ground speed using visual flow fields in a manner similar to all other flying insects examined thus far.