The present work aimed to study the effects of high constant and alternating temperatures on the development and prey consumption by Dicyphus tamaninii Wagner (Het., Miridae) with Aphis gossypii Glover (Hom., Aphididae) as prey.Results showed that the predator was able to successfully develop and reach the adult stage, on average, after 20.1 (♀♀) and 20.6 (♂♂) days at a temperature of 30 ± 1 °C with A. gossypii as prey. On the other hand, it was not able to develop at 35 ± 1 °C, here all N1 instars used at the beginning of the experiments had died even before moulting to N2 instar. At alternating temperatures of 25/15 ± 1 °C, the predator reached the adult stage 23.7 (♀♀) and 23.5 (♂♂) days after egg hatching, whereas when the temperatures were increased to 35/22 ± 1 °C, it took a significantly shorter period: 20.6 (♀♀) and 20.9 (♂♂) days. In general, the highest mortality occurred during the first two nymphal instars. The total percentage mortality during development from N1 to adult stage was 30 % and 100 % at the constant temperatures 30 ± 1 °C and 35 ± 1 °C, respectively. At the alternating temperatures of 25/15 ± 1 °C, it was lowest with 16.5 %, while at 35/22 ± 1 °C, it was 20 %.The results of the experiments on prey consumption showed that an individual D. tamaninii consumed during its development to adult stage at 30 ± 1 °C an average of 442.2 (♀♀), 433.6 (♂♂) aphids. At the constant temperature of 35 ± 1 °C, the average daily prey consumption started with 4 aphids and decreased continuously till it approached nil on the 9th day, where all predatory nymphs died. At the alternating temperatures of 25/15 ± 1 °C, the total prey consumption during development was, on average, 359.3 (♀♀) and 297.0 (♂♂) aphids, while at 35/22 ± 1 °C it was 348.5 (♀♀) and 334.0 (♂♂) aphids. The effect of the four temperatures on the prey consumption by D. tamaninii during the first 10 days after emergence was also studied. At a constant temperature of 30 ± 1 °C, a total of 446.4 (♀♀) and 372.0 (♂♂) aphids were consumed, compared to 40.6 (♀♀) and 39.0 (♂♂) at 35 ± 1 °C. At alternating temperatures of 25/15 ± 1 °C, the predatory adult consumed, on average, a total of 267.0 (♀♀) and 207.0 (♂♂) aphids. Increasing the temperature to 35/22 ± 1 °C resulted in a higher prey consumption by the adult predator, reaching 351.5 (♀♀) and 267.7 (♂♂) aphids over the same period.In conclusion, results indicated that D. tamaninii is a promising predator of the melon aphid at a temperature spectrum ranging from 15 ± 1 °C up to 35 ± 1 °C.

The predatory mite Typhlodromus pyri Scheuten (Acari, Phytoseiidae) has been reported as an important predator of the European red mite, Panonychus ulmi (Koch) (Acari, Tetranychidae) in apple culture and vineyards at below 25 °C. However, sufficient biological data was lacking on its efficiency at temperatures above 25 °C. Therefore, the purpose of the present laboratory work was to obtain experimental data on prey consumption during development as well as longevity and reproduction of T. pyri on apple leaf discs and in Plexiglas cells at constant temperatures of 25 ± 2 °C and 30 ± 2 °C with P. ulmi as prey. The results showed that mean daily and total prey consumption by both the nymphs and adults of T. pyri decreased significantly on both the arenas as the temperature was increased from 25 °C to 30 °C, whereby adult prey consumption, both mean daily and total, was higher than that of nymphs. Prey consumption by both the nymphs and adults was significantly higher in the Plexiglas cells than on the leaf discs at both temperatures. Mean total prey consumption during nymphal development was 16.1 (♀♀) and 12.8 (♂♂) at 25 °C compared to 7.0 (♀♀) and 5.8 (♂♂) preys at 30 °C on the apple leaf discs and 46.0 (♀♀) and 38.5 (♂♂) at 25 °C compared to 25.2 (♀♀) and 20.3 (♂♂) preys at 30 °C in the Plexiglas cells. Mean duration of nymphal development was similar for the two sexes at the same temperature, but it was longer at 25 °C than at 30 °C. It was 6.0 and 4.0 days on the apple leaf discs while 7.0 and 6.0 days in the Plexiglas cells at 25 °C and 30 °C, respectively. Mean daily and total prey consumption by both male and female adults also decreased with the increasing temperature, whereby the females consumed more than double the mean total number of prey than the males on both the arenas of observation and at both temperatures: 355.4 versus 149.7 preys at 25 °C and 192.2 versus 85.6 preys at 30 °C on the leaf discs and 826.8 versus 374.5 preys at 25 °C and 488.9 versus 187.9 preys at 30 °C in the Plexiglas cells. Longevity of the females was longer than males on both arenas and at both temperatures and it was longer at 25 °C than at 30 °C. Mean total longevity on the apple leaf discs was 68.3 (♀♀) and 50.8 (♂♂) days at 25 °C compared to 52.5 (♀♀) and 36.8 (♂♂) days at 30 °C, while in the Plexiglas cells it was 91.0 (♀♀) and 65.8 (♂♂) days at 25 °C compared to 75.3 (♀♀) and 48.5 (♂♂) days at 30 °C. Reproduction in females also decreased significantly with increasing temperature. It decreased from 62.0 to 39.0 eggs/female on the leaf discs and 75.0 to 47.1 eggs/female in the Plexiglas cells. The females laid significantly higher numbers of eggs at both temperatures in the Plexiglas cells than on the leaf discs. Oviposition period in females was 30 days at 25 °C on both the arenas, while at 30 °C it was 26 days on the apple leaf discs and 27 days in the Plexiglas cells.

A study concerning the parasitism of Cameraria ohridella, a pest of Aesculus hippocastanum invading Europe, has been carried out in Serbia and Macedonia in 1998 and 1999. From C. ohridella 14 species of parasitoids were reared, which are polyphagous and occur in the whole of Europe. Twelve of the species found belong to the Chalcidoidean family Eulophidae. The rates of parasitism at different sampling dates did not exceed 25 %. The results, when compared with data from central Europe, showed that C. ohridella most certainly does not originate from Serbia or Macedonia – the regions in which C. ohridella was observed for the first time – as an indigenous leaf miner on A. hippocastanum.

The present paper deals with laboratory studies on side-effects of the mixed biocide GCSC-BtA on Plutella xylostella (L.) (Lep., Plutellidae) and its predators, e. g. Amblyseius longispinosus (Evans) (Acari, Phytoseiidae), Erigonidium graminicola (Sundvall) (Araneae, Linyphiidae), Orius similis Zheng (Het., Anthocoridae) and Coccinella septempunctata L.(Col., Coccinellidae), in comparison to the commercial insecticides, e. g. Abamectin, Tebufenozide, Dichlorvos, Cartap and Lambda-cyhalothrin.

The present paper deals with the effect of the biocide GCSC-BtA on population dynamics of cabbage pests, i. e., Plutella xylostella (L.) (Lep., Plutellidae), Brevicoryne brassicae (L.) (Hom., Aphididae), Liriomyza sativae Blanch. (Dip., Agromyzidae), Phyllotreta vittata Fabric. (Col., Chrysomelidae) and their natural enemies, i. e., Apanteles plutellae Kurdj. (Hym., Braconidae), Erigonidium graminicola (Sundv.) (Araneida, Linyphiidae), Coccinella septempunctata L. (Col., Coccinellidae), in common head cabbage (Brassica oleracea var. capitata) fields in the southeastern China. The experiments were conducted at the experimental farm of Fujian Academy of Agricultural Sciences, Fuzhou, PR China in April – June, 2001. The results showed that, at the end of sampling, the pest populations of P. xylostella, B. brassicae and P. vittata reached averages of 39.7, 68.3 and 6.2 ind. / 30 plants in the plot treated with GCSC-BtA, which were about 1.5, 11 and 0.7 times lower than those treated with methomyl, respectively. In contrast, the natural enemy populations were, on average, 23.5 ind./30 plants for A. plutellae, 24.6 ind./30 plants for E. graminicol and 12.2 ind./30 plants for C. septempunctata in the plot treated with GCSC-BtA, about 6, 5 and 3 times higher than for those treated with methomyl, respectively. The GCSC-BtA biocide demonstrated greater effectiveness in controlling the cabbage pests, e. g., P. xylostella, B. brassicae and P. vittata, having final decreasing ratios of 83.60, 97.05 and 53.67 % compared to 57.63, 64.89 and 30.88 % with the methomyl insecticide. However, it was less toxic to natural enemies, e. g., A. plutellae, E. graminicola and C. septempunctata, final decreasing ratios being 47.68, 17.84, 27.81 %, than methomyl, with 90.94, 80.80, 74.55 %, in comparison to the populations in the control plots, respectively. So, because of the low toxicity of GCSC-BtA to the natural enemies, it is recommended that, on one hand, its application should be carried out after mass migration of the pests to the fields, on the other hand, the alternative agent GCSC-BtA should be used with the aim of minimizing the harmfulness to the natural enemies in the whole program of integrated pest management in cabbage fields.

Storehouses and mills in the Magdeburg region are known to be infested with black (ore house) rats. In residential buildings, however, house rats (Rattus rattus L.) have not been detected for at least 20 years. Therefore, it was of much interest for the expert to note that this rat species had been seen in two occupied residential buildings (a refurbished old building and a terraced house). It has been suspected for a longer time that black rats can be found in certain residential buildings in towns or even cities.

Field experiments with the synthetic insecticides, Methomyl and Carbaryl, alone and in combination with the biological control agents, Bacillus thuringiensis (Bt) and Trichogramma evanescens, were conducted to control pests in yardlong beans, Vigna sesquipedalis, during the dry season 1998/1999. The experimental area was located at the Central Luzon State University in the province of Nueva Ecija on the Philippine main island Luzon. Carbaryl was applied against bean flies 5 days after plant emergence. Methomyl was sprayed against pod sucking insects and the bean podborer, Maruca vitrata, 45 days after plant emergence. The biological control agents were applied with the beginning of the flowering stage of V. sesquipedalis, when plants were first attacked by M. vitrata.

Methods using the reactions of beneficial arthropods to stimuli of prey and habitats are becoming more and more important in the biological control of pests. Especially olfactory cues, which are measurable with so called 'olfactometers' are of great importance. In the present study, a modified four-armed airflow olfactometer is described by explaining these modifications. As an example, the results obtained for the predatory ladybeetle Coccinella septempunctata are explained in detail. Various odour sources caused evident differences in the reactions of the predator, especially comparing the reared beetles and the individuals collected in the field. The volatiles emitted by the odour source 'bean plant + aphids' were attractive to 28 % of the reared and to 38 % of the field-collected test individuals. These values were clearly higher than in the cases of the odour source 'aphids' with 18 % for both groups. About 15 % of the reared and 13 % of the field-collected coccinellids reacted to the olfactometer chamber without an odour source. On the other hand, it became obvious in test series with groups of adult beetles that group tests were not so suitable because the test individuals diverted each other so that the reactions to the odours were reduced. In the case of the group tests, 68 % of the reared and 60 % of the field-collected individuals did not react to one of the offered odour sources. In further surveys, the most favourable pre-experiment starvation period of the tested individuals and optimal duration for a single experiment were determined. For adults of C. septempunctata, the most favourable starvation time was 6 hours and the most suitable duration of a single experiment 30 minutes. In two further experiments, it was investigated whether there were differences between males and females or between beetles of different ages. There were slight differences between males and females reacting to distinct odour sources and also in the case of coccinellids of different ages but in both cases without clear tendencies.

The Australian cockroach (Periplaneta australasiae [Fabricius, 1775]) is a roach species that is scarcely found in Germany. On the territory of Saxony-Anhalt it has only been detected twice, these observations dating back more than 60 years. In early 2001, a mass appearance of the Australian cockroach was recorded in a greenhouse of the Magdeburg Zoological Gardens. The author is not aware of any other current appearance of the Australian cockroach in the land of Saxony-Anhalt.

The polyphagous gypsy moth (Lymantria dispar) is able to feed on about 400 different woody plant species. In general, oak species are preferred – on the other hand some other groups of plants are avoided on account of the presence of toxic substances. These unfavoured hosts are, for example, most of the Papilionaceae, like locust (Robinia pseudoacacia). We compared survival rate and development of two populations of different origin with long-term habituation to oak and locust, respectively. Larvae from the population habituated to oak proved unable to develop on locust food. There must be a lack of detoxification systems to modify the toxic alcaloids and flavenoids produced by Robinia pseudoacacia. On the other hand, larvae isolated from an locust stand were able to feed on oak leaves without problems in larval development or eclosion of adults. Gypsy moth larvae specialized on locust as host showed increased mortality (up to 27 %) in the early larval instars, but the surviving animals, especially female individuals, reached significantly higher pupal weights and showed better fecundity: 40 % higher egg numbers/egg mass compared to those feeding on oak. These results indicate that the gypsy moth population originating from the locust forest had achieved a high level of metabolic adaptation to this host plant and formed a 'biotype' of Lymantria dispar with optimal reproductive conditions in this special habitat.

The distribution of microsporidian infections of browntail moth (Euproctis chrysorrhoea L.) populations in Bulgaria was studied. Of the 72 browntail moth populations in the regions of Balkan, Sredna Gora, Sakar Mountains, and Rodope Mountains, 21 were infected by Microsporidia. The Microsporidia belong to two genera – Nosema (Dihaplophasea, Nosematidae) and Endoreticulatus (Haplophasea, Encephalitozoonidae). Microsporidial infections caused by a Nosema were found in 14 populations, by an Endoreticulatus in 8 populations, and mixed infections of Nosema and Endoreticulatus were recorded from 3 populations. Endoreticulatus was present in Balkan, Sredna Gora, and the Sakar Mountains. Nosema infections were found in Sakar Mountains and Rodope, and mixed infections were recorded only from the Sakar Mountain populations.

Modes of passive dispersal of the grape rust mite Calepitrimerus vitis (Eriophyoidea) were investigated in a vineyard of South-Western Germany. More than 200 Eriophyoidea per month were trapped in a wind chamber during summer (32,1 % C. vitis) suggesting long-distance dispersal by air currents. Rain washed part of the adult C. vitis population from the foliage. SE micrographs suggest that quiescent nymphs are affixed to the leaf by a substance of unknown nature. However, the role of rain in C. vitis colonisation of uninfested vineyards is still unclear, as is the role of phoretic transport by arthropods. For the first time, evidence of rust mite dispersal by human activity is presented. A large number of C. vitis was found adhering to clothes and hands of workers carrying out customary cultural practices in the vineyard. Other arthropods, including Typhlodromus pyri, the main predator of C. vitis, were also passively transported by wind, rain and human activity.

Concerns regarding the potential of pesticides to harm terrestrial non-target arthropod populations have led to the increased use of ecotoxicological test systems for terrestrial Non-target Arthropod risk assessment. Whilst some useful guidance on terrestrial invertebrate test systems is available, there are significant gaps in guidance for terrestrial non-target arthropod exposure estimates. The typical exposure in the standard test systems is by application of the test substance at the field rate (i. e. gram substance per hectare field) on to a two dimensional surface. However, under field conditions such a spray deposit will be diluted over the total available 3-Dimensional plant and soil surface. The recommendation is to use published leaf area index and crop interception values to standardize terrestrial dilution factors, which can then be used to predict exposure on a 3-Dimensional plant surface. Based on average crop/time specific LAI data for 26 crops, a surrogate off-crop dilution factor of 12 was calculated which can be used to convert 2-Dimensional spray drift exposure to 3-Dimensional off-crop plant surface exposure. Another significant terrestrial exposure guidance gap is how to calculate predicted environmental concentrations (PECs) for multiple application products. Based on spray interval and half-life data from 32 representative multiple application plant protection products, the typical worst-case PECs for accumulation of residues were calculated after up to 8 applications. These data showed that Multiple Application Factors (MAFs = accumulated PEC/initial PEC), increased from 1 to 3.5 after 1 to 8 applications, respectively. Finally, overall 90th percentile spray deposit values have been proposed for deriving off-crop multiple applications PECs (1 to 8 applications) based on published spray drift data. The recommended equations for terrestrial exposure assessment include the use of:-application rate, the 90th percentile drift value, the multiple application factors (MAF) and the standard dilution factor (for 3-Dimensional plant surface). This proposed terrestrial non-target arthropod exposure scheme is comparable with other first tier exposure assessment schemes eg aquatic exposure assessment.

This paper is a guidance document for side-effect testing with plant protection products on non-target arthropods under semi-field and field conditions. The principles, methods, endpoints and interpretation of non-target arthropod semi-field and field trials which should be conducted for registration of plant protection products in the European Union are presented and discussed. The recommendations presented reflect the opinions of the experts from authority, academia, industry and consulting which participated at the IOBC (International Organisation of Biological Control), BART (Beneficial Arthropod Regulatory Testing) group and EPPO (European Plant Protection Organisation) Joint Initiative workshop held in Versailles (France) on the 25–26 October, 1999.

In Germany, the dusky cockroach (Ectobius lapponicus [Linné, 1758]) lives in woodland. Dwelling of these insects which are not considered a pest, in buildings is an extremely rare observation. In early summer of 2000, several areas of a forest hospital were found to be infested withEctobius lapponicus. In contrast, the German cockroach (Blattella germanica [Linné, 1767]) had not been found in that, hospital for years. In the light of the literature available, an attempt is made to provide a survey of infestation of buildings with the dusky cockroach.

Studies were made in 1998 and 1999 In an oak forest (“Meuenburger Holz”) in Northern Germany for the purpose of testing the effect of some insecticides on the soil fauna. The preparations “Fastac” (active agent:a-Cypermeth-rin) and “Foray 48 B” (active agent:Bacillus thuringiensis var.kurstaki) were used for the control of winter moths (Operopbthera brumata). The insects and spiders were caught using the following methods: soil samples, pitfalls and net sweeps. There were differences In the spectrum of species and In the density of individuals between the three experimental areas, but these did not depend on effects of the used insecticides.

The EU Plant Protection Product Directive 91/414/EEC recommends the EPPO/CoE Arthropod Natural Enemies Risk Assessment Scheme for guidance on how to conduct risk assessments for terrestrial non-target arthropods. This scheme is currently in the process of being revised by EPPO/ CoE. A major change will be the recommendation for the generation and use of ’Dose Response’ toxicity data instead of limit test data. In addition, the revised EPPO/CoE Non-target Arthropods Risk Assessment Scheme will replace the current arbitrary 30% threshold trigger value applied to limit test data, with a Hazard Quotient (HQ; = Ratio Application Rate/LC50 on Glass)), comparable to the successful approach adopted in the EPPO/CoE ’Honeybee Risk Assessment Scheme’. However, in order for this new approach to be implemented under 91/414/EEC, an appropriate regulatory HQ trigger value needs to be derived. Such an HQ trigger value has been established by calculating HQ values for the 2 recommended sensitive indicator species (T pyri andAphidius) for a wide range of products and validating opposite robust semi-field/field data. This validation indicated that an HQ trigger value of ≥ 12 forT pyri and ≥ 8 forAphidius spp., should be used to trigger higher-tier risk assessment and/or higher-tier testing for non-target arthropods. As these trigger values were validated with realistic semi-field/ field data they apply for both lethal and sub-lethal effects as well as single and multiple application scenarios. Due to the worst case assumptions used in this HQ validation analysis, no further uncertainty factors need to be applied for in-crop risk assessment. Whilst a small amount of uncertainty exists regarding the comparative sensitivity ofT pyri andAphidius spp. for off-crop non-target arthropod guilds of arthropods, this is balanced by the fact that the off-crop exposure assessment used in the HQ derivation, is at least an order of magnitude higher than that realistically likely in the field. This HQ approach and trigger value is an appropriate and conservative tool for tier 1 risk assessment, which should reduce the number of false positive results leading to unnecessary higher-tier testing.

Evidence of the brown-banded cockroach (Supella longipalpa [Fabricius, 1798]) in Saxony-Anhalt In the past, evidence of the brown-banded cockroach in the Land of Saxony-Anhalt was based on reports furnished by pest control businesses to the extent that brown-banded cockroaches had been traced on the premises of two Magdeburg companies in 1985. A specimen of brown-banded cockroach was recently detected in the Land of Saxony-Anhalt (March 2000). The roach was found in the office of a smallsized business in the town of Wolmirstedt north of Magde burg. The route along which the pest had entered the premises, or been brought in, could not be elucidated.

Data of a pest control business was used to study infestation with the brown, or Norway rat (Rattus norvegicus Berkenhout, 1769]) in the City of Magdeburg for the year 1999. Swarms of rats were found to live all over the territory of the city. Blocks of residential buildings erected during G. D. R. times and, more specifically, their basements were noted to be focal sites of infestation with rats. The problem of rats living in the sewerage system of the city turned out to be unresolved. Detailed reference is made to rodenticides and active substances as well as to control strategies. The priority given to economical issues over the application of scientific findings is considered to be the decisive factor which accounts for the needs in the extermination of rats.

In an agroecosystem, catches of epigeal invertebrate predators obtained by pitfall traps were compared to absolute population densities estimated by ground photoeclectors in two different habitats, a field and an adjacent set-aside land. In general, abundance of Carabidae and Lycosidae were overestimated by pitfalls, while Staphylinidae and Linyphiidae were underestimated, and beetle larvae showed no obvious trend. The overestimation of Carabidae and Lycosidae by pitfalls had its maximum in spring and summer. Numbers collected by pitfalls did represent actual population densities better in the field than in the set-aside. This is probably caused by the higher vegetation diversity and complexity of the set-aside land which additionally influenced the catches. Pitfalls recovered higher numbers of animals and species, and species composition differed significantly between pitfalls and photoeclectors, in the field as well as in the set-aside. Body size seemed to be the main factor in determining the catch, the relatively larger species being more frequently caught by pitfall traps. In sum, the relationship between pitfall trap catches and actual population densities appeared to be either absent, weak or highly variable among taxa, habitat and time of the season. Thus numbers caught in pitfall traps cannot be considered as reliable indices of “real” abundance nor do they reflect the relative abundance within a given predator community correctly. Therefore, in most cases absolute density estimates should be preferred for the study of epigeal invertebrates in arable land. However, I suggest a combination of both pitfall traps and standardised area samples, because the two approaches possibly provide information of different qualities equally important for the evaluation of epigeal predator species, namely searching activity and population density.

In den Jahren 1992 und 1993 wurden 24 schwarzeTheysohn-Schlitzfallen mit Kombinationen von synthetischen Borkenkäferlockstoffen, Pheroprax, Chalcoprax, Linoprax und Cembrax, auf ihre Fängigkeit getestet. Zum Vergleich wurden Fallen mit Einzelbestückung und Zweifachkombinationen von Pheroprax+Cembrax und Linoprax+Cembrax sowie zwei Fallen ohne Lockstoff in einem 24 ha großen Forstgebiet aufgestellt. Mit den Fallen wurde die Flugaktivität der angelockten Scolytiden ermittelt. Die erhaltenen Fangzahlen vonIps typographus, Pityogenes chalcographys, Xyloterus lineatus undX. domesticus wurden wöchentlich registriert und in Verbindung mit der unterschiedlichen Pheromonbestückung der Fallen diskutiert. Von den drei letztgenannten Arten wurde der Fang von Männchen und Weibchen getrennt bewertet. In einzeln mit Pheroprax bestückten Fallen fanden sich die meisten Buchdrucker pro Falle. Ihr Anteil nahm 1993 um 9% gegenüber dem Vorjahr zu. Für den Kupferstecher waren die vierfach kombinierten Pheromonfallen etwas fängiger als die einzeln mit Chalcoprax bestückten Fallen. AuchXyloterus-Arten bevorzugten die vierfach kombinierten Pheromonfallen gegenüber solchen, die nur Linoprax enthielten. Die Anzahl der gefangenen Ambrosiakäfer wurde im Verlauf von 5 Jahren stark reduziert. In beiden Untersuchungsjahren wurden neben den gezielt geköderten Scolytiden 252 Käferarten aus 49 Familien registriert, von denen 10 Arten eine Pheromonpräferenz erkennen ließen. Der Beifang betrug jährlich 0,6–0,7% der Gesamtzahl an gefangenen Käfern. Zu 85–87% war der Kupferstecher am Gesamtfang beteiligt. Der Buchdrucker hatte einen Anteil von 11–14% an der Gesamtausbeute.

In the present study, the distribution of the Horse Chestnut Scale insectPulvinaria regalis Canard in Germany in the years 1996 to 1998 and tendencies in the variation of infestation levels during the past three years were investigated by a survey. A questionnaire was sent to the offices for green areas and environmental affairs of 121 cities in Germany with a population exceeding 75.000 citizens. Additional observations by the authors were also taken into consideration. A comparison to data from 1995 was conducted. In the year 1998, this arboricultural pest occurred in 34 cities (15 in 1995) and could be found in the areas of the Rhineland and the Ruhr-Valley, from Bonn in the south up to Münster (Westphalia) in the north and from Aachen in the west to Hagen and Dortmund in the east.P. regalis could also be detected in Offenbach and Frankfurt a. M., It also occurred southward along the rivers Rhine and Neckar in the cities of Mainz, Ludwigshafen, Freiburg and Stuttgart. The most southern point whereP. regalis was detected in July 1998 was Zürich in Switzerland. The first occurrence of the 19 new observed infestations withP. regalis took place in six instances before 1995, eight in 1995, three in 1996, and one each in 1997 and 1998. The investigations about tendencies in the variation of infestation levels revealed a decrease in scale numbers only in the cities where Horse Chestnut Scales have been observed first in Germany. On the other hand, almost every place located further away from these infestation sites showed a population increase ofP. regalis. Constant infestation levels over the past three years could be found in only two cities. In most cases lime, maple and horse chestnut trees were the host plants of this scale insect.

Die aktuelle Befallsituation (1998/1999) bei den Hausratten-beständen (Rattus rattus [L.]) in der Stadt Magdeburg wurde in Zusammenarbeit mit Schädlingsbekämpfern und Objektbesitzern ermittelt. Dabei wurden 10 Objekte bekannt, in denen der Nager nachgewiesen werden konnte. Es handelte sich um Kornmühlen, Silos und Lebensmittelgroßbetriebe. In mehreren dieser Gebäude siedelte die Dachratte seit Jahrzehnten. Bekämpfungsaktionen verliefen schon immer erfolglos. Zur Zeit wird aus Kostengründen kein Vorkommen mit Konsequenz bekämpft.

The present paper deals with developmental duration, emergence, longevity and fecundity ofAleurotuberculatus takabashi David & Subramaniam at different temperatures and humidity levels. The developmental time from egg to adult was 81.8, 56.9, 39.6, 29.9, 20.6 days at 15±1, 20±1, 25±1, 30±1, 35±1°C under constant relative humidity (RH) of 70±5%, respectively. At 25±1°C, the total developmental time was slightly affected by humidity, ranging from 46.4 days at 40±5% RH to 39.2 days at 90±5% RH. The developmental threshold and the thermal constant for the stage from egg to adult were 10.1°C and 542.8 day-degrees. It was estimated that the whitefly has about 10 generations a year in Fuzhou region in southeastern China. Lowest mortality rates of 12.4% for the egg, 6.8% for the nymph and 3.1% for the puparium were obtained at 15±1°C, while they were highest with 92.1% for the egg, 48.2% for the nymph and 36.3% for the puparium at 35±1°C. The mortality rates were slightly affected by humidity, ranging from 17.6% at 40±5% RH to 27.9% at 90±5% RH for the egg, 11.2% at 40±5% RH to 19.6% at 90±5% RH for the nymph, and 6.4% at 40±5% RH to 11.6% at 90±5% RH for the puparium. The emergence rate of adults decreased as temperature increased, ranging from 89.1% at 15±1°C to 21.5% at 35±1°C, so did the longevity of adults, ranging from 9.6 days at 15±1°C to 2.9 days at 35±1°C. The number of eggs per female was significantly affected by temperature (P.01), valuing 29.4 eggs per female at 15±1°C, 36.7 at 20±1°C, 52.4 at 25±1°C, 42.9 at 30±1°C, and 6.1 at 35±1°C. The optimal temperature for reproduction was about 25°C.