The abundance and temporal distribution of caddisflies (Insecta: Trichoptera) caught by light traps on the Austrian Danube from 1986 to 1987

SUMMARY. 1. Adult Trichoptera were caught for 1 year (May 1986 to June 1987) on the banks of the Danube at Altenwörth, Lower Austria, using a set of three Jermy-type light traps. From a total of 62,693 specimens caught, the most abundant species were Brachycentrus subnubilus Curtis (Brachycentridae), the two hydropsychids Hydropsyche bulgaromanorum Mal. and Hydropsyche contubernalis McL., Tinodes waeneri L. (Psychomyidae) and the leptocerid Ceraclea dissimilis Steph.
2. The total catch included sixty-five of the 278 Austrian species from thirteen families. Hydroptila pulchricornis Pictet and Oecetis notata Ramb. were new to the Austrian fauna.
3.Of the meteorological parameters tested, only air temperature seemed to influence flight activity.
4. Twenty-four species were studied in detail; Halesus tesselatus Ramb. was the only autumn species, the remainder being summer species. In Tinodes waeneri , the flight period was divided into two well-defined peaks.
5. Of the total, 49.9% were caught during the first third of the night, 39.1% in the second and 11.0% in the last third.
6. In seventeen species the sex ratio was significantly different from 1:1, and it changed during the night.
7. The indication of water quality by light trap catches of caddisflies is discussed.     

The abundance and distribution of caddisflies (Insecta: Trichoptera) caught by emergence traps in the 'Ritrodat' research area of the Lunzer Seebach (Lower Austria) from 1980 to 1982

SUMMARY. 1. Adult Trichoptera were caught during 3 years (1980–82) in the ‘Ritrodat’ research area of the Upper Lunzer Seebach. a mountain brook near Lunz. Lower Austria, using a set of thirty pyramid type emergence traps. During the three collecting periods (112 collecting days) a total of 1810 specimens were caught. The most abundant species were Micrasema minimum McL. (Brachycentridae). Rhyacophila vulgaris Pictet (Rhyacophilidae), and the three Iimnephilid species Potamophylax cingulatus Steph., Allogamus auricollis Pictet and Ecclisopteryx guttulata Pictet. 2. In six species (Micrasema minimum, Rhyacophila vulgaris, Atlogamus auricollis, Ecclisopteryx guttulata, Drusus biguttatus Pictet, Chaetopteryx fusca Brauer) the sex ratio was significantly different from 1:1. In Micrasema minimum 422 females were caught but only three males. 3. In each year there were peaks in total emergence in early summer and early autumn. 4. The length of the emergence period of the most abundant species ranged from 38 days in Micrasema minimum to 210 days in Rhyacophila vulgaris (mean values 1980–82); there was also a difference in the intensity of emergence in these species: the percentage of time required for 50% of the animals to emerge (0%=onset of emergence, 100%= emergence completed) was 16% in Allogamus auricollis but 71% in Rhyacophila vulgaris (mean percentages 1980–82). 5. The distribution pattern of individuals per trap was tested against a Poisson distribution; in all three years the distribution was contagious. 6. The dry weight of specimens of Drusus biguttatus, Micrasema minimum. Ecclisopteryx guttulata and Wormaldia copiosa McL. was measured and. together with published dry weight values of other species (Malicky, 1976), these data were used to estimate the biomass emerging annually of twenty-three species of Trichoptera (99.2% of emergence, 1980–82). This was equivalent to 35.3 kJ m^?2 in 1981 and 32.5 kJ m^?2 in 1982.     

Light-Trapping of Caddisflies at the Thaya (Lower Austria), a River Influenced by Pulsating Hypolimnetic Water Release

Adult Trichoptera were caught from September 1999 to September 2000 at the Thaya River at Hardegg, Lower Austria, using a Jermy-type light trap. From a total of 11,711 specimens caught, the most abundant species were Psychomyia pusilla (Fabricius ), Lepidostoma hirtum (Fabricius ), Lasiocephala basalis (Kolenati ), Agapetus ochripes Curtis and Sericostoma flavicorne Schneider . In nine out of the eleven most abundant species the sex ratios significantly differed from 1:1, with an excess of females. Of the meteorological parameters tested, only the effect of air temperature was significant. An upstream shift of faunal zonation patterns from epipotamon to meta- and hyporhithron could be detected at the station which is influenced by hypolimnetic water release.     

Diel activity patterns of some field Carabidae

Abstract. 1. A 24 h time-sorting pitfall trap was used to collect Carabidae in a field in north-east England in 1974, 1976 and 1977.
2. Harpalus rufipes comprised 62% of the 5288 adult Carabidae caught. It was nocturnal, with an activity peak after midnight. The male activity pattern lagged behind that of females by about 1 h. The activity peak shifted to earlier in the night during September.
3. Activity curves are given for eighteen other common species. Large species were all nocturnal, but a third of the smaller species were active in the day. The numbers caught of twenty-eight less common species are tabulated and show the same trend. Overall, nearly 60% of all species caught were nocturnal and 20% diurnal; the remainder did not show a distinct pattern of day or night activity.
4. A total of eighty-two larvae of H.rufipes, Nebria brevicollis and Notiophilus biguttatus were caught, and showed similar activity patterns to those of the respective adult beetles.     

Weather-induced changes in moth activity bias measurement of long-term population dynamics from light trap samples

Interpretation of light trap catches of moths is complicated by daily variation in weather that alters flight activity and numbers caught. Light trap efficiency is also modified by wind and fog, and daily weather may effect absolute abundance (numbers actually present). However, actograph experiments and other sampling methods suggest that changes in daily activity are large by comparison to changes in absolute abundance. Daily variation in weather (other than wind and fog) is therefore a form of sampling error in absolute abundance estimates. We investigated the extent of this sampling bias in 26 years of population dynamics from 133 moth species. In a subset of 20 noctuid and geometrid species, daily numbers caught were positively correlated with temperature in 14 species, and negatively correlated with rainfall in 11 species. The strength of correlations varied between species, making it difficult to standardize catches to constant conditions. We overcame this by establishing how weather variation changed with time and duration of the flight period. Species flying later in the summer and for shorter periods experienced more variable temperatures, making sampling error greater for these species. Of the 133 moth species, those with shorter flight periods had greater population variability and more showed significant temporal density dependence. However, these effects were weak, which is encouraging because it suggests that population analyses of light trap data largely reflect factors other than sampling error.     

Flight activity of adult stoneflies in relation to weather

Abstract. 1. Dispersal of adult aquatic insects between streams may have important consequences for local and regional population dynamics, but little is known about how dispersal is affected by weather conditions.
2. The influence of meteorological variables on flight activity of adult stoneflies (Plecoptera: Leuctridae, Nemouridae, and Chloroperlidae) was investigated using Malaise traps adjacent to three upland streams in the Plynlimon area of mid Wales, U.K.
3. Numbers of adult stoneflies captured weekly in the traps were related positively to air temperature and related negatively to wind speed. Meteorological conditions during daylight showed stronger relationships with flight activity than did conditions at night.
4. There was inter-site variation in the strength of weather effects on stonefly flight. Wind speed was significant at only one site, which had higher average wind speed than the other sites.
5. Annual variation in weather conditions during adult flight periods may result in varying extent of dispersal between sites, influencing community dynamics over a wide area.     

Aerial distribution, flight behaviour and eggload: their inter-relationship during dispersal by the sweetpotato whitefly

1. The aerial distribution of Bemisia tabaci Gennadius (the sweetpotato whitefly) was studied during the early ascent phase of flight, to test the degree to which dispersal patterns reflect the flight behaviour of individuals.
2. Marked whiteflies were trapped at four heights between 0 and 7·2 m above fallow ground, and at six distances between 0 and 100 m from the insect source. Insects were trapped during a 2–3 h period after the initiation of flight activity during the summers of 1995 and 1996.
3. Analysis of trap catch data revealed a clear negative exponential relationship between height and aerial distribution, and a slightly weaker negative power relationship between distance and aerial distribution. Marked insects were caught in the uppermost traps adjacent to the source, indicating that a portion of the population had a strong capacity for ascent out of the flight boundary layer.
4. Eggload decreased with the height, but not the distance, at which whiteflies were trapped. Mean eggload close to the ground was significantly greater than that for those trapped at 4·8 and 7·2 m, supporting the hypothesis that there is a trade-off between flight and oogenesis in weak-flying insects.
5. Air temperatures during the trapping periods were positively correlated with the proportion of male and female B. tabaci caught in the highest traps, but not in the most distant traps.
6. The significance of these results for accurate prediction of whitefly dispersal is discussed, and the importance of individual's behaviour in determining dispersal patterns of small insects is emphasized.     

A new window trap used in the assessment of the flight periods of Chironomidae and Simuliidae (Diptera)

SUMMARY. 1. A window trap is described which has been found useful in the study of the fight periodicity of chironomids and simuliids. the trap is simple to construct and can be operated in high winds.
2. Window traps were operated in 1977 and 1478 at Lake Myvatn. Iceland, when thirty-nine chironomid species and two simuliid species were caught. Most of the chironomids had two peaks in flight activity per year. e.g. Eukiefferietla minor, Cricotftpus tibialis. Pogonocladius consohrinus, Tanytaraus gracilentus and Micropsectra airofasciata. Chironomus islandicus and Heterotrissocladius grimshawi had one peak in activity in all traps. The flight activity of Prodadius istandicus, Orthocladius oblidens and Micropsectra Undrothi varied greatly between traps and years. Simulium vittatum had two peaks in flight activity, corresponding to the two generations developing per year. Variation in trap catches of .S. vittatum reflected populalion changes measured independently in a study of larval population dynamic     

Evaluation of window flight traps for effectiveness at monitoring dead wood-associated beetles: the effect of ethanol lure under contrasting environmental conditions

1 Subsequent to the diversity of saproxylic beetles being proposed as a management tool in forestry, more explicit knowledge about the efficiency and selective properties of beetle sampling methods is needed.
2 We compared saproxylic beetle assemblages caught by alcohol-baited or unbaited window traps in different forest contexts. Considering that trap attractiveness depends on kairomone concentrations, we appraised whether the trap efficiency was influenced by trap environment (openness and local supply of fresh dead wood).
3 Saproxylic beetles were sampled using 48 cross-vane window flight traps, arranged in paired designs (alcohol-baited/unbaited), in eight ancient and eight recent gaps (open stands), and eight closed-canopy control stands in an upland beech forest in the French Pyrenees.
4 Baited traps were more efficient than unbaited traps in terms of abundance and richness in our deciduous forests. The ethanol lure did not have any repellent effect on the individual response of saproxylic taxa.
5 The influence of local environmental conditions on trap attractiveness was observed. Openness had a significant moderate effect on species richness. Trap attractiveness was slightly reduced in the alcohol-saturated environment of recent gaps probably due to a disruption by local fresh dead-wood concentrations of the kairomonal response of saproxylic beetles to baited traps ('alcohol disruption').
6 Because the ethanol lure enhanced the probability of species detection, it may be useful in early-warning surveillance, monitoring and control of wood borers, despite slight influences of local conditions on baited trap efficiency.     

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.     

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.     

Suitability of two carbon dioxide-baited traps for mosquito surveillance in the United Kingdom

Rapidly changing environments and an increase in human movement around the globe have contributed to a rise in new and emerging diseases, many of which are arthropod borne. The threat posed to the United Kingdom by such diseases is uncertain, and there is a real need to understand the distribution, seasonality and behaviour of potential vectors in the country. At present, there is no standard method for routine mosquito surveillance in the UK. Here we compared the catching efficiency of two carbon dioxide-baited traps, the CDC light trap and the MosquitoMagnet Pro trap, for collecting British mosquitoes. Two of each type of trap were operated at four sites in central and southern England from June to September, 2003. To determine whether trap height affected collections, three light traps were operated at 1, 2.5 and 5 m above the ground in one site in 2004. Both types of trap were efficient at catching mosquitoes, collecting 5414 mosquitoes of 16 species. MosquitoMagnet traps caught 2.7 times more mosquitoes than CDC light traps (P<0.001) and a wider range of species (16 species vs 11) than CDC light traps. Four to six times more female Culex pipiens s.l. were collected in light traps at 5 m (P<0.001) compared with traps at lower heights. MosquitoMagnet traps ran continuously for up to 8 weeks, whilst the battery of a CDC light trap had to be replaced every 24 hrs. Although MosquitoMagnets collected more specimens and a greater range of mosquito species, they were considerably more expensive, prone to breakdown and incurred higher running costs than the CDC light traps. MosquitoMagnets are useful tools for collecting mosquitoes during longitudinal surveys during the summer months, whilst CDC light traps are to be preferred for rapid assessments of the presence or absence of mosquitoes, particularly the important species Culex pipiens.     

The immigration of spiders (Araneida) into a new polder

Abstract. (1) The immigration of spiders into the Lauwerszeepolder (constructed in 1969) was studied during four years in four areas. The spider fauna was sampled weekly and 65 000 specimens of eighty-four species were caught using strip traps, window traps, simple pitfall traps and fences.
(2) About sixty species from all kinds of habitats were caught rarely; nineteen species were caught in numbers that suggest that they had established populations in the study areas.
(3) The four successful pioneer species, plus two marsh-dwelling species, were most abundant during 1969 and 1970. The 1971 catch was dominated by species from saline habitats; they became less abundant in 1972 when species from non-saline habitats increased. Only halotolerant species established populations.
(4) No evidence was found that dispersing spiders select certain areas. The differences between the spider fauna of the differennt study areas arise from degrees of success in colonization by immigrants. Pioneer species are least influenced by the abiotic environment.
(5) A greater aeronautic dispersal power is found in species inhabiting unstable habitats than in species from stable habitats.
(6) Aeronautic activity in adult linyphiids (s.l.) is not restricted to a special season, but is related to definite phases of the phenology.
(7) Male and female erigonids are equally active in aeronautic behaviour. In erigonids and linyphiids intense aeronautic activity coincides with great ground activity; on the ground males are more active than females.     

Comparative efficacy of three suction traps for collecting phlebotomine sand flies (Diptera: Psychodidae) in open habitats

The efficacy of three suction traps for trapping phlebotomine sand flies (Diptera: Psychodidae) was compared. Traps were baited with Co₂ and used without any light source. CO₂‐baited CDC traps were evaluated either in their standard downdraft orientation or inverted (iCDC traps). Mosquito Magnet‐X (MMX) counterflow geometry traps were tested in the updraft orientation only. Both updraft traps (iCDC and MMX) were deployed with their opening ～10 cm from the ground while the opening of the downdraft (CDC) trap was ～40 cm above ground. Comparisons were conducted in two arid locations where different sand fly species prevail. In the Jordan Valley, 3,367 sand flies were caught, 2,370 of which were females. The predominant species was Phlebotomus (Phlebotomus) papatasi, Scopoli 1786 (>99%). The updraft‐type traps iCDC and MMX caught an average of 118 and 67.1 sand flies per trap night, respectively. The CDC trap caught 32.9 sand flies on average per night, significantly less than the iCDC traps. In the Judean desert, traps were arranged in a 3×3 Latin square design. A total of 565 sand flies were caught, 345 of which were females. The predominant species was P. (Paraphlebotomus) sergenti Parrot 1917 (87%). The updraft traps iCDC and MMX caught an average of 25.6 and 17.9 sand flies per trap per night, respectively. The CDC trap caught 7.8 sand flies on average per night, significantly less than the iCDC traps. The female to male ratio was 1.7 on average for all trap types. In conclusion, updraft traps deployed with their opening close to the ground are clearly more effective for trapping sand flies than downdraft CDC traps in open habitats.     

Nocturnal migration of dragonflies over the Bohai Sea in northern China

Abstract.  1. A sudden increase and subsequent sharp decrease of catches of dragonflies in a searchlight trap, with Pantala flavescens Fabricius (Odonata: Libellulidae) predominating, observed at Beihuang Island in the centre of the Bohai Gulf, in 2003 and 2004, indicated a seasonal migration of these insects over the sea during the night in China. The movements were associated with the onset of fog.
2. Simultaneous radar observations indicated that the nocturnally migrating dragonflies generally flew at altitudes of up to 1000 m above sea level, with high density concentrations at about 200–300 or 500 m; these concentrations were coincident with the temperature inversion.
3. During early summer, the dragonflies oriented in a downwind direction, so that the displacement direction varied between different altitudes. In contrast, during late summer, the dragonflies were able to compensate for wind drift, even headwind drift, so as to orient south-westward no matter how the wind changed, and thus the displacement direction was towards the south-west.
4. The duration of flight, estimated from the variation of area density derived from radar data and hourly catches in the searchlight trap through the night, was about 9–10 h. The displacement speed detected using radar was ≈5–11 m s⁻¹. Therefore, the dragonflies might migrate 150–400 km in a single flight.
5. The dragonflies were thought to originate in Jiangsu province and they migrated into north-east China to exploit the temporary environment of paddy fields in early summer. Their offspring probably migrated back south during late summer and autumn.     

Inland dispersal of adult aquatic insects

1. Adult caddisflies (Trichoptera) and mayflies (Ephemeroptera) were light-trapped on summer evenings along the Detroit River and Lake St. Clair, near Windsor, Ontario, Canada. Light traps were located at the shore and at increasing distances inland up to 5 km, and were operated simultaneously for 2 h following sunset. Catches of five species of caddisflies of the family Hydropsychidae ( Cheumatopsyche campyla , Cheumatopsyche speciosa , Hydropsyche hageni , Hydropsyche phalerata , Macrostemum zebratum ) and the mayfly Hexagenia (Ephemeridae) were used to examine inland distribution.
2. Inland dispersal was limited: catches of caddisflies declined at a greater than exponential rate with increasing distance from shore. Mean dispersal distance from the shoreline ranged from 650 to 1845 m. Smaller caddisfly species dispersed shorter distances than larger caddisflies and Hexagenia .
3. Inland distribution of adult caddisflies exhibited considerable interspecific variation: distribution was inconsistent among trials for Hexagenia , possibly owing to timing of collections in relation to periods of peak emergence.
4. Sex ratios of caddisflies were female biased at most sites. No consistent bias was observed for Hexagenia . Different inland distribution patterns were observed for males and females. The differences appeared to reflect species-specific reproductive strategies.     

Relative performance of Lindgren multiple-funnel, Intercept panel, and Colossus pipe traps in catching Cerambycidae and associated species in the southeastern United States

In 2004, we evaluated the relative performance of 8-unit Lindgren multiple-funnel (funnel), Intercept panel (panel), and Colossus pipe (pipe) traps, baited with ethanol and ac-pinene lures, in catching saproxylic beetles (Coleoptera) in pine stands in northern Florida and western South Carolina. Panel traps were as good as, if not better than, funnel and pipe traps for catching Cerambycidae. In particular, more Monochamus titillator (F.) were captured in panel traps than in pipe and funnel traps. Of three species of Buprestidae captured in our study, most Buprestis lineata F. were caught in panel traps, whereas most Acmaeodera tubulus (F.) were caught in funnel traps. Catches of Chalcophora virginiensis Drury and the root-feeding weevils Hylobius pales Herbst an dPachylobius picivorus LeConte (Curculionidae) were unaffected by trap type. Among bark beetles (Curculionidae: Scolytinae), catches of Ips grandicollis (Eichhoff) were unaffected by trap type, whereas most Dendroctonus terebrans (Olivier) were caught in panel traps, most Hylastes salebrosus Eichhoff were caught in panel and pipe traps, and most Hylastes tenuis Eichhoff were caught in funnel traps. Among ambrosia beetles (Curculionidae: Scolytinae), panel traps caught the most Xyleborinus saxesenii (Ratzeburg), whereas pipe traps caught the most Xyleborus Eichhoff spp. More Xylosandrus crassiusculus (Motschulsky) and Dryoxylon onoharaensis (Murayama) were caught in panel and funnel traps than in pipe traps. Among bark beetle predators, more Platysoma Leach spp. (Histeridae) were caught in pipe and panel traps than in funnel traps, whereas most Lasconotus Erichson spp. (Zopheridae) were caught in funnel traps. Variation among trap performance for various species suggests that managers should consider more than one type of trap in their detection programs.     

Virginity in haplodiploid populations: a comparison of estimation methods

1. The presence of ovipositing virgin females, who are able to produce only male offspring, may have several important consequences for the evolution of reproductive strategies.
2. The prevalence of virginity for five fig wasp species was estimated using three different methods: (1) the proportion of females developing in fruit that contained no conspecific males; (2) dissection of females caught on sticky traps; and (3) dissection of females that had emerged from their galled flowers into the fruit cavity.
3. The estimates obtained by method 1 (females developing in single sex broods) were lower than those obtained by the other methods.
4. Across species, the estimates obtained by method 1 (females developing in single sex broods) were significantly correlated with those obtained by method 2 (sticky trap caught females).
5. Mating with sperm-depleted males is unlikely to occur in these species.     

Inland dispersal of adult aquatic insects

1. Adult caddisflies (Trichoptera) and mayflies (Ephemeroptera) were light-trapped on summer evenings along the Detroit River and Lake St. Clair, near Windsor, Ontario, Canada. Light traps were located at the shore and at increasing distances inland up to 5 km, and were operated simultaneously for 2 h following sunset. Catches of five species of caddisflies of the family Hydropsychidae ( Cheumatopsyche campyla , Cheumatopsyche speciosa , Hydropsyche hageni , Hydropsyche phalerata , Macrostemum zebratum ) and the mayfly Hexagenia (Ephemeridae) were used to examine inland distribution.
2. Inland dispersal was limited: catches of caddisflies declined at a greater than exponential rate with increasing distance from shore. Mean dispersal distance from the shoreline ranged from 650 to 1845 m. Smaller caddisfly species dispersed shorter distances than larger caddisflies and Hexagenia .
3. Inland distribution of adult caddisflies exhibited considerable interspecific variation: distribution was inconsistent among trials for Hexagenia , possibly owing to timing of collections in relation to periods of peak emergence.
4. Sex ratios of caddisflies were female biased at most sites. No consistent bias was observed for Hexagenia . Different inland distribution patterns were observed for males and females. The differences appeared to reflect species-specific reproductive strategies.     

Species diversity of Ichneurnonidae and Serphidae (Hymenoptera) in an English suburban garden

In the two-year period, 1972–73, 6445 Ichneumonidae of 455 species were caught in a Malaise trap operated in a suburban garden in Leicester, England. An additional 74 species were trapped in 1974. The collection includes a number of species new to the British list. The flight season of ichneumonids extended from March to November or December, with peak abundance and diversity in August. Size of trap samples fluctuated erratically, depending on air temperature. No species was particularly common and many were rare, 141 being taken once only in the two-year period. The commoner species were present throughout the season, supporting the suggestion that ichneumonids are niche-specific rather than host-specific. Parasites of aphidophagous Neuroptera and Syrphidae, of spiders, of micro-Lepidoptera, and of Diptera found in decaying plant material were especially abundant, as is characteristic of the British fauna as a whole. Adult ichneumonids are mobile, and it is assumed that the Malaise trap was sampling an area far larger than the garden in which it was sited, although suburban gardens are a particularly favourable habitat for ichneumonids. Twenty-two species of Serphidae were captured in the Malaise trap during 1972–74, five of them new to Britain.