Diurnal flight pattern of Platypus koryoensis (Coleoptera: Platypodinae) in relation to abiotic factors in Korea

The diurnal flight pattern of Platypus koryoensis (Murayama) was examined using sticky traps attached to the trunks of oak trees in central Korea in 2010 and 2011. The flight activities of the beetle were estimated on the basis of 3-h intervals for trap catches from 11:00 to 14:00 on the next day, on June 25–26 and July 1–2, 2010, and on the basis of 2-h intervals for trap catches from 5:00 to 17:00, between June 9 and July 21, 2011 (the peak flight period of the beetle). Over 77% of the beetles were caught from 9:00 to 13:00, with the daily variations in the facing slope. The beetles began to be caught when the air temperature reached around 16 °C, and were the most active when the temperature ranged from 20 to 27 °C. No beetles were caught during rainfall, suggesting that rainfall is one of the factors that hinder beetle flight. The beetles were caught by traps in the east-facing plot earlier than those in the south- and west-facing plots suggesting that the flight behavior of the beetle can be affected by the light. Direction of the beetle flight during the peak of daily flight (from 09:00 to 13:00) was downward along the slope.     

Abundance and species diversity of tabanids (Diptera) in the biosphere reserve Ipassa-Makokou (Gabon) during the rainy season

The abundance and species diversity of tabanids were evaluated by trapping of insects using Vavoua traps, during the rainy season, from October 4 to November 30, 2009, in three different habitats: primary forest, secondary forest and village, in the biosphere reserve Ipassa-IRET Makokou in Gabon. Eight species belonging to three genera of tabanids have been identified for a total of 402 specimens caught. The tabanid species numerically the most abundant were: Tabanus secedens Walker, 1854 (55.2%), Tabanus obscurehirtus Ricardo, 1908 (13.9%), Chrysops dimidiatus Wulp, 1885 (11.2%) and Chrysops silaceus Austen, 1907 (10.7%). The less abundant species were Tabanus par Walker, 1854 (3.2%), Tabanus besti arbucklei Austen, 1912 (3%), Tabanus marmorosus congoicola Bequaert, 1930 (1%) and Ancala fasciata fasciata (Fabricius, 1775) (0.5%). Specimens of the genera Tabanus and Chrysops could not be identified, these insects represented respectively 0.7% and 0.5% of the insects trapped. The highest proportion of tabanids was trapped in secondary forest (75.1%) and the lower in primary forest (4.5%).     

弄岗熊猴的活动节律和活动时间分配

2005年9月至2006年9月,采用瞬时扫描取样法,在弄岗国家级自然保护区对野生熊猴(Macaca assamensis)进行了连续跟踪观察,收集相关的活动节律和活动时间分配的数据,通过分析其与气候及食物组成的关系,从中探讨影响熊猴活动节律及活动时间分配的因素。研究结果发现:在熊猴的日活动节律中,觅食活动表现为逐渐增强的趋势,最高峰值出现在下午15:00,休息活动在中午出现一个小的高峰;其日活动节律表现出明显的季节性差异,主要表现为旱季大部分时间段的觅食强度均高于雨季,且早上7:00-10:00出现一段长时间的休息,而雨季里长时间的休息则发生在中午12:00-14:00;在活动时间分配上,熊猴平均花费39.6%时间用于休息,33.2%用于移动,18.3%用于摄食,5.1%用于理毛,2.4%用于玩耍,1.4%用于其他行为,其活动时间分配也表现出明显的季节性差异;与雨季相比,在旱季熊猴明显增加用于觅食的时间,而相应地减少用于休息的时间,活动时间分配的季节性变化明显与食物组成的变化有关;在不同年龄组个体间,青少年猴花费更多的时间用于玩耍,而用于休息和理毛的时间明显少于成年猴。     

A comparison of trapping methods for Tabanidae (Diptera) in North Queensland, Australia

The ability to monitor the abundance and diversity of tabanid flies over wide areas requires effective and low-cost surveillance methods. Such monitoring activities help to quantify the risk of transmission of pathogens by tabanids. Here we examine the effectiveness and practicality of two types of trap (canopy traps and Nzi traps) and two types of attractant (octenol and carbon dioxide) for monitoring tabanid flies in tropical Australia. The Nzi trap consistently caught more tabanids and more species of tabanids than the canopy trap. It was also more robust and therefore required less maintenance in remote locations. The use of attractants substantially increased capture rates, both of individuals and species, and traps using both attractants were consistently the most effective. However, in remote locations, where it is not possible to check traps frequently, the use of attractants may not be feasible. When attractants were not used, the canopy trap caught very few tabanids, but the Nzi trap remained effective enough to be useful as a monitoring device. In addition, the number of tabanid species caught by the Nzi traps remained high, and included those that were most abundant. We therefore conclude that, in this region, Nzi traps are preferable for tabanid monitoring and that attractants greatly improve their effectiveness. However, for longterm monitoring, especially in remote locations, Nzi traps without attractants are a satisfactory option.     

The diurnal flight activity and influential factors of Frankliniella occidentalis in the greenhouse

Abstract The daily flight activity of western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) was examined using color, yellow-light and chemical attractant traps in a cucumber greenhouse and under controlled laboratory conditions. In the greenhouse, flying thrips were most abundant between hours 08:00–10:00, declined at mid-day, and then slightly increased during hours 14:00–16:00; however they decreased to a very low level at 18:00. The use of light traps showed no thrip flight activity during the night. The total number of thrips that flew onto cards on rainy or cloudy days was higher than that on sunny days. We reconfirmed that traps treated with attractant attracted 4.0–9.4 times more thrip than the untreated traps. Under laboratory controlled conditions, thrip flight activity was highest under light intensity between 4 000 and 6 000 lux, air temperature of 28°C, and RH of 70%. In addition, starved thrips flew more readily than non-starved thrips.     

Comparison of sticky wing and cone pheromone traps for monitoring seasonal abundance of black cutworm adults and larvae on golf courses

Black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), flight activity was monitored on three golf courses in Wisconsin by using two types of pheromone traps: the Texas cone trap and sticky wing trap. The Texas cone trap caught significantly more black cutworm males compared with the sticky wing trap, capturing almost 12-fold more males. Black cutworm males were most abundant during mid-July in 2001 and 2002, between 700 and 800 cumulative degree-days. Flight activity also was detected in early May and mid-August, but these peaks were not as pronounced as in mid-July. No definitive relationship between black cutworm flight activity and subsequent larval infestations on golf course putting greens occurred.     

Seasonality and relative abundance of Tabanidae (Diptera) captured on horses in the Pantanal, Brazil.

Once a month, from June 1992 to May 1993, collections of tabanids on horse were conducted in the Nhecolandia, Pantanal State of Mato Grosso do Sul, Brazil. Tabanid catches using hand nets were conducted from sunrise to sunset at grassland and cerrad?o (dense savanna) habitats. A total of 3,442 tabanids from 21 species,12 genera, and 3 subfamilies were collected. Although species abundance varied seasonally depending on habitat, no habitat specificity was observed for the most abundant species. In the grassland, 1,625 (47.2%) tabanids belonging to 19 species were collected, while 1,817 (52.8%) tabanids from 17 species were caught in the cerrad?o. The number of tabanid species varied from 7 during winter (July/August) to 15 in the spring (October). Tabanus importunus (56%) was the most abundant species, followed by T. occidentalis (8.2%), and T. claripennis (8.1%). The tabanid peak, in October, coincided with the beginning of the rainy season. The population peak of most species, including those with higher vector potential, suggests that the rainy season can be considered as the period of potentially higher risk of mechanical transmission of pathogens by tabanids to horses in the region.     

斜纹夜蛾性诱剂的诱蛾效果

对斜纹夜蛾Spodoptern litura(Fabricius)性引诱剂诱芯的型状、盛虫器的颜色以及夜间不同时间段的诱蛾效果进行试验。结果表明,线状诱芯比杯状诱芯有效期长;不同颜色的盛虫器对诱虫效果没有影响;上半夜诱蛾百分率显著比午夜和下半夜的少,午夜与下半夜的之间没有显著性差异。筒型性诱捕器比水盆(用杯状诱芯)诱集斜纹夜蛾成虫效果好。     

First survey of seasonal abundance and daily activity of Stomoxys spp. (Diptera: Muscidae) in Kamphaengsaen Campus, Nakornpathom province, Thailand

The seasonal changes and the daily activity of Stomoxyine species (Diptera: Muscidae) were examined, using Vavoua traps, in a dairy and a beef cattle farm in Nakhonpathom province, Thailand during July 2004 to June 2005. Over this period, Stomoxys calcitrans was the most commonly trapped species, followed by S. sitiens and S. indica. For the later species, this is the first report of its presence in Thailand. A total of 80 % of flies were captured during the rainy season from May to October and 20 % during the dry season from November to April. No major difference of fly density was observed between the dairy and the beef cattle farm. The activity pattern of S. calcitrans was diurnal with a peak between 08:00 am to 10:00 am and another less marked one in the afternoon. The activity pattern of S. sitiens and S. indica was mainly crepuscular with 2 peaks, early in the morning (06:00 a.m.) and late in the afternoon (6:00 p.m.). Those species are important pests of livestock in Thailand, where they are known as a mechanical vector of trypanosomes. A better knowledge of their ecology is a prerequisite for more efficient control measures.     

Pheromone‐trapping the nun moth,Lymantria monacha (Lepidoptera: Lymantriidae) in Inner Mongolia,China

The nun moth, Lymantria monacha L., is one of the most important defoliators of Eurasian coniferous forests. Outbreaks during 2011–2015 in the natural/planted larch, and larch‐birch mixed forests of the Greater Khingan Range in Inner Mongolia, China, caused tremendous timber losses from severe defoliation and tree mortality. A series of trapping experiments were conducted in these outbreak areas to evaluate the efficacy of a synthetic species‐specific pheromone lure based on the female pheromone blend of European nun moth populations. Our results clearly show that the nun moth in Inner Mongolia is highly and specifically attracted to this synthetic pheromone, with few gypsy moths (Lymantria dispar) captured. Flight activity monitoring of L. monacha male moths using pheromone‐baited Unitraps at 2 locations during the summer of 2015 indicated that the flight period started in mid‐July, peaking in early August at both locations. Based on male moth captures, there was a strong diurnal rhythm of flight activity throughout the entire scotophase, peaking between 22:00 and 24:00. Unitraps and wing traps had significantly and surprisingly higher catches than the gypsy moth traps. Unitraps fastened to tree trunks 2 m above ground caught significantly more male moths than those at the ground level or at 5 m height. Male L. monacha moths can be attracted to pheromone‐baited traps in open areas 150–200 m distant from the infested forest edge. Our data should allow improvement on the performance of pheromone‐baited traps for monitoring or mass‐trapping to combat outbreaks of this pest in northeastern China.     

山西平陆越冬大天鹅日间行为模式

2011年12月至2012年2月和2012年11月至2013年1月,采用瞬时扫描法,对山西平陆黄河湿地越冬的大天鹅进行了日间行为时间分配和活动节律的研究。结果表明,大天鹅在越冬期的主要行为是静息、运动和取食,分别占全部行为比例的(40.5±1.4)%、(22.8±0.9)%和(18.2±0.8)%。在日间节律方面,大天鹅的取食行为呈现早晚双高峰,静息行为的高峰则出现在早上和中午。对不同地点的大天鹅的行为时间分配研究表明,大天鹅在两地的行为时间分配存在明显差异。其中,在干扰强度较大的三湾村,运动和争斗行为更多;在干扰较小的关家窝村,静息和警戒行为更多。在行为时间分配与温度变化关系的研究中,通过Pearson相关性分析发现,大天鹅的取食、运动和理羽行为与温度成显著正相关,静息和警戒行为与温度呈现显著负相关。     

Distribution and adult activity of Popillia quadriguttata (Coleoptera: Scarabaeidae) on golf courses in Korea

Japanese beetle traps baited with the Popillia japonica Newman (Coleoptera: Scarabaeidae) pheromone lure and a eugenol feeding attractant were placed at five golf courses in Korea to determine how well they work for detecting activity of a closely related species, Popillia quadriguttata (F.) (Coleoptera: Scarabaeidae), a turf pest in Korea. The traps also were used to determine the time of day and time of year that P. quadriguttata is most active. Nineteen scarab species of 13 genera were attracted to the Japanese beetle traps with P. quadriguttata clearly being the most abundant (383 beetles per trap), followed by Adoretus tenuimaculatus Waterhouse (10 per trap), Popilliaflavosellata Fairmaire (seven per trap), Exomala orientalis Waterhouse (four per trap), and Maladera japonica (two per trap). Other scarab species were trapped at a rate of <1.0 per trap. Popillia quadriguttata adults were active over a 5-wk period in late June and early July. At Yongwon Golf Club in 2002, peak adult activity was during the last week of June in visual counts and approximately 1 wk later in the Japanese beetle traps. In Korea, P. quadriguttata adults are most active between 12:00 p.m. and 4:00 p.m. This information should be helpful to golf course superintendents in Korea and to entomologists interested in finding natural enemies of P. quadriguttata to evaluate as potential biocontrol organisms for the very closely related species, the Japanese beetle.     

Diurnal Variation of Plasmatic Melatonin,Corticosterone and Variation of General Activity in Pigeons under Light-Dark Cycle and Constant Light

This work analyzed the diurnal variation of general activity and plasmatic levels of melatonin and corticosterone in pigeons submitted to a 12:00:12:00 h light-dark cycle (lights on at 6:00 a.m.) or to constant light. In both conditions pigeons were observed in 5-min sessions at times 03:00, 06:00, 09:00, 12:00, 15:00, 18:00, 21:00 and 24:00 h during two successive days. Behavior was video taped in the home cages for posterior categorization and quantification. Radioimmunoassays were used to evaluate plasmatic levels of melatonin and corticosterone. Blood samples were obtained at the times of behavioral observation. In the light-dark condition the results showed day-night variation of general activity (p &lt; 0.001) and a robust diurnal rhythm of plasmatic melatonin (p &lt; 0.001). Both of these variations as well as the oscillatory secretion of corticosterone disappeared under constant light condition. The parallel changes in general activity and blunting of melatonin rhythm secretion in constant light condition agree with previous evidences that melatonin may regulate behavioral oscillations in the pigeon. The present data are related to the proposition that the timing system in pigeons may involve neuroendocrine relations characterized by interactions between blood born signalization by melatonin and corticosterone.     

Diversity of Stomoxys spp. (Diptera: Muscidae) and diurnal variations of activity of Stomoxys indicus and S. calcitrans in a farm, in Wang Nam Khiao District, Nakhon Ratchasima Province, Thailand

A study of species diversity of Stomoxys spp. and diurnal variations of activity of the most abundant was performed during a one year period at a local dairy cattle farm in Wang Nam Khiao District, Nakhon Ratchasima Province, Thailand. Four species of stomoxyine flies were morphologically identified, including Stomoxys indicus Picard 1908, S. calcitrans (Linnaeus 1758), S. sitiens Rondani 1873 and S. uruma Shinonaga and Kanao 1966. The most common species were S. indicus (50.2%) and S. calcitrans (49.5%). S. sitiens and S. uruma were found in small proportions (< 1%). The number of flies captured was significantly different among the three seasons with the greatest number in the rainy season (mean = 66%; df = 2, P < 0.05). The variations of diurnal activity were observed during different period of times (06:00 to 18:00) during three seasons. Both sexes of S. indicus and males of S. calcitrans showed unimodal activity pattern in cool and summer seasons. But a bimodal activity pattern was recorded in rainy season. For females S. calcitrans, a unimodal peak of activity was observed in cool season and a constant variation of activity all along the day in summer and rainy seasons, with an increase from the morning to the evening. A better understanding of stomoxyine fly behavior, especially the daily flight activity, can assist in prioritization and design of appropriate vector prevention and control strategies.     

Circadian organization in a diurnal rodent, Arvicanthis ansorgei Thomas 1910: chronotypes, responses to constant lighting conditions, and photoperiodic changes

Little information is available on circadian organization in diurnal mammals. In the present study, the daily patterns of wheel-running activity were described in a diurnal rodent, Arvicanthis ansorgei Thomas 1910, as assessed by karyological analysis. Among 108 animals born in the colony and studied under a 12:12 light-dark cycle (lights on at 7:00 a.m.), the authors determined the timing of daily activity (i.e., mean onsets and offsets of pattern of locomotor activity) and the level of wheel-running activity performed during daytime versus nighttime. The activity pattern was essentially diurnal in 84% of individuals, 46% being active only during the light period +/- 1 h (activity onsets and offsets at 6:20 a.m. and 7:40 p.m., respectively) and 38% being diurnal with a period of nocturnal activity longer than 1 h (activity onsets and offsets at 5:40 a.m. and 9:30 p.m., respectively). Of the 108 animals, 16% expressed a nocturnal activity with diurnal overlaps no longer than 1 h. In 6 diurnal individuals first exposed to constant light and then to constant dim red light, the endogenous period was shortened from 24.6 +/- 0.1 to 24.0 +/- 0.1 h, respectively. The numbers of wheel revolutions per day and during the active period remained unchanged between the two lighting conditions. In response to different photoperiodic changes from 16:08 to 08:16 light-dark cycles, the phase angle of photic synchronization, estimated by the daily onset of wheel-running activity in 6 diurnal animals, showed marked changes, its timing occurring 2 h before and 0.5 h after the onset of light under short and long photoperiods, respectively. The numbers of wheel revolutions per 24 h and during the active period were modified similarly according to photoperiodic changes. Finally, in 5 diurnal animals exposed to a 12:12 light-dark cycle, the daily pattern of general locomotor activity, determined by telemetry, was not modified by wheel availability. The data indicate that A. ansorgei is an interesting experimental model to understand the regulation of the circadian timing system in day-active species.     

The relative performance of pheromone and light traps in monitoring the seasonal activity of both sexes of the eastern hemlock looper, Lambdina fiscellaria fiscellaria

The seasonal flight activity of both sexes of the eastern hemlock looper, Lambdina fiscellaria fiscellaria Guenée (Lepidoptera: Geometridae) was studied during two consecutive years in Quebec and Newfoundland, using light (L), pheromone (P) and combined light and pheromone (LP) traps. Moth density significantly affected the performance of the different traps, with P traps being more effective at low than high density. However, P trap catches decreased just prior to the onset of female captures, probably as a result of competition between traps and virgin calling females. Nearly all females caught in L and LP traps were already mated and even the first females caught had laid at least half of their egg complement. In Quebec under warm nights, the pattern of male activity occurred at different times, with peak P catches being later in the scotophase than those of L traps, but overall similar numbers of males were caught in both traps. In contrast, under cool nights, males were caught early in the night in both P and L traps, suggesting a strong competition effect between traps, although more males were caught in P than L traps overall. In Newfoundland, the pattern of male captures in L and P traps was similar at both high and low temperatures, so competition between trap types would always be high. Under these conditions P traps were more effective than L traps. Irrespective of the region, year or temperature, significantly more males were captured in LP, with the effect of L and P being additive. In both regions, females responded similarly to L and LP traps with peak activity occurring early in the night. Captures of females were lower than those of males under cool temperatures, suggesting that the temperature threshold for flight is higher for females. The use of L and P traps simultaneously and/or in combination is discussed in relation to integrated pest management programs and ecological considerations.     

Trap type, chirality of alpha-pinene, and geographic region affect sampling efficiency of root and lower stem insects in pine.

Root and lower stem insects cause significant damage to conifers, vector phytopathogenic fungi, and can predispose trees to bark beetle attacks. The development of effective sampling techniques is an important component in managing these cryptic insects. We tested the effects of trap type and stereochemistry of alpha-pinene, in combination with ethanol, on catches of the root colonizing weevils (Coleoptera: Curculionidae) Hylobius spp. [mostly Hylobius pales (Herbst)], and Pachylobius picivorus (Germar), the root colonizing bark beetle (Coleoptera: Scolytidae) Hylastes porculus Erickson, and the lower stem colonizing bark beetle Dendroctonus valens (LeConte). We tested for inter-regional differences by conducting similar field assays in the northern (Wisconsin) and southern (Louisiana) United States. The more effective trap type varied with region. Root weevils were caught primarily in pitfall traps in Wisconsin, whereas they were caught mostly in lower stem flight traps in Louisiana. In Wisconsin, root colonizing bark beetles were also caught primarily in pitfall traps, but lower stem colonizing bark beetles were caught primarily in lower stem flight traps. The root feeding weevils preferred (-) over (+)-alpha-pinene in both regions. Some exceptions relating to trap type or gender occurred in southern populations. The two root and lower stem colonizing bark beetles in Wisconsin showed no preference between (+) and (-)-alpha-pinene in combination with ethanol. No bark beetles were caught in the south. Our results suggest that modifying trap type and enantiomeric ratios of monoterpenes for different insect groups and in different regions can improve sampling efficiency for these important pests.     

广东横石水河流域溪流大型底栖动物漂流的昼夜节律

比较了广东横石水河流域二条相邻的3级溪流大型底栖动物的漂流种类组成及昼夜节律,其中一条溪流受广东大宝山矿外排的酸性矿山废水严重污染,水体pH值仅为3.45且重金属严重超标,而另一条为相邻的清洁溪流.结果表明：清洁溪流中大型底栖动物的数量和种类远比受酸性矿山废水污染的溪流丰富.在清洁溪流中共采获漂流底栖动物6 871头,隶属10目52类群,其中水生昆虫的数量和种类占绝对优势 (99.5%).但总漂流密度占优势的类群（相对多度超过5%）不多,主要集中在以下几种水生昆虫：七鳃假二翅蜉 (28.5%)、宜兴似动蜉 (13.8%)、短脉纹石蛾(13.2%)、白背锯形蜉（7.5%)、摇蚊科(6.5%) 和肖扁泥甲(5.0%).蜉蝣目种类和数量最多,占全部漂流底栖动物总个体数的65%,其中又以四节蜉科居多,占蜉蝣目总个体数的63%.毛翅目昆虫的数量（18%）仅次于蜉蝣目.大型底栖动物的漂流表现出明显的昼夜节律,漂流主要在夜间进行,未发现有日漂者.漂流密度高峰出现在21:00和2:00,漂流密度分别为（70.3±10.8）和（289.0±124.6） 头·100 m^-3.大多数优势种类漂流高峰出现的时段略有不同,但有些优势种类（如摇蚊科和肖扁泥甲）并未表现出明显的漂流昼夜差异.在受酸性矿山废水污染的溪流中,漂流动物只有1种嗜酸性的多足摇蚊,其漂流活动也在夜间进行,并有3个明显的漂流高峰,分别出现在19:00、0:00和4:00,最高漂流密度仅为（6.7±5.2)头·100m^-3.说明酸性矿山废水不仅降低了溪流中漂流底栖动物的物种多样性和数量,也改变了其漂流模式.     

The effects of pitfall trap diameter on ant species richness (Hymenoptera: Formicidae) and species composition of the catch in a semi-arid eucalypt woodland

Abstract Ants play an important role in Australian biodiversity and environmental impact assessments, with pitfall-trapping being the principal sampling method. However, the relationship between trap diameter and ant species catch has not been investigated in the context of survey design. Using four different trap diameters, each at a density of one trap per 100 m2, the present study asks three questions: (i) given an equal number of traps, do traps with larger diameters catch more species than smaller-diameter traps?; (ii) do traps with small diameters bias against large or rare species?; (iii) for equal area of the trap mouth, do small but more numerous traps catch more species than fewer but large traps? A total of 84 species were sampled within the 1600 m2 study site, with numbers of species for trap diameters of: 18mm (46 species), 42mm (56 species), 86mm (62 species) and 135mm (64 species). At equal trap density, 18 mm traps caught significantly fewer species than larger traps. Traps of 86 mm and 135mm were no more efficient than 42mm traps. Only 86mm and 135mm traps caught all species > 10mm in length (6 species). For equal area of the trap mouth, small traps were more efficient than large traps. Differences in the catch of the different-sized traps were due primarily to different capture rates of the rare species (40 species): 18mm traps caught 25% of rare species, 42 mm caught 41%, 86 mm caught 44% and 135 mm caught 52%. The role of rare ant species in environmental impact studies is discussed.     

光照、温度和湿度对桔小实蝇飞翔活动的影响

于2004年6月在云南元江芒果园内通过性诱剂诱捕,对桔小实蝇Bactrocera dorsalis(Hendel)的飞翔活动日节律进行了全天24h的监测,并就光照、温度和相对湿度3个环境因子的影响进行了测试和综合分析。研究表明,桔小实蝇雄成虫仅在白天有光照的情况下进行飞翔活动,夜晚停止飞翔。在1d内有2个飞翔活动高峰期,分别发生在上午8∶00~9∶00和下午18∶00~20∶00,且前者进行飞翔活动的虫量相对后者要大。在下午2∶00左右进入白天飞翔活动的低谷。光刺激是桔小实蝇飞翔活动的基本条件,其趋光性因芒果园内树荫下的光照强度变化而异,在100~200lux之间对桔小实蝇飞翔活动明显有利,而当光照强度低于100lux或高于200lux,飞翔活动也相应减小。气温总体上位于桔小实蝇飞翔活动的适宜范围,而下午低于60%的相对湿度对其飞翔活动有一定的抑制作用。气温、湿度和光照对桔小实蝇飞翔活动的作用机理各不相同并且各因子之间也相互作用,最终对桔小实蝇的飞翔活动产生综合效应。