Abstract: Adults of the damselfly Pyrrhosoma nymphula (Sulzer) were to a great extent found to have their midgut infected with a eugregarine Hoplorhynchus oligacanthus (Siebold). Heavy infestation seriously damaged the gut epithelium, and the viability of the host was estimated to be reduced. Marking experiments have revealed that individuals which attained great adult age were either lightly infected or non-infected, or they were thought to have been infected late in their adult life. The conclusion is that the eugregarine infestation apparently reduces the longevity of adults when other conditions are sub-optimum.

Abstract: During the period I966-69 entomological investigations on the dipterous fauna of grazing cattle in Denmark were carried out with a view to recording potential vectors of the disease "summer mastitis" Some I200 biting midges (Culicoides Latr) were collected from grazing piebald heifers in 3 field and meadow localities 8 species of biting midges were represented in the material Most of the species are known as blood-suckers on domestic animals About 50 % of the material consisted of C obsoletus, while C punctatus, C chiopterus, and C subfasciipennis accounted for 24 %, I4 %, and I0 % respectively Midge activity was extremely high on the belly, especially in the umbilical region and on the udder, much lower on the back and flanks, and considerable on the legs Several species were present on the belly, however C obsoletus, C punctatus, and C subfasciipennis being dominant These species could be suspected of participating in the transmission of "summer mastitis", when co-operating with non-biting flies, eg Hydrotaea irritans Fall; they are therefore deserving of special attention On the back and flanks, C obsoletus and C punctatus were the main species, and on the legs, C chiopterus

Abstract: Populations of Ischnura elegans, Coenagrion puella and Enallagma cyathigerum were studied in order to determine sex ratios, mating frequencies and mating expectancies. As the true imaginal sex ratio is unknown in these Odonata attempts were also made to determine the larval and final instar exuvial sex ratios. The larvae of I. elegans showed a small but nonsignificant excess of males, and males constituted 62 percent of imaginal samples. Estimates of total season's imaginal population sizes tend to suggest that the real sex ratio was near to I:I. Larval samples of C. puella indicated a significant excess of males and males constituted 76 percent of imaginal samples. Samples of final instar exuviae of E. cyathigerum showed that the sex ratio at emergence was exactly unity but male imagines constituted 84 percent of the population samples. Only 5 percent male and I2 percent female I. elegans were seen to mate despite a high persistence at water and that this species has a long copulation time. Sexual maturation is rapid in I. elegans and both sexes mate well into old age. The mating frequencies of male C. puella and E. cyathigerum were low, but females of these species showed very much higher values than for I. elegans. The data suggest that some males of I. elegans and E. cyathigerum are not successful in achieving mating.

Abstract: The European species of the Nepticula ruficapitella group are revised on the basis of authentic material. Four new species, svenssoni, dorsiguttella, roborella and eberhardi, are established. Three species, atricapitella Hw., ruficapitella Hw. and samiatella Z., formerly not satisfactorily defined, are redescribed. N. cerricolella Klim. is reduced to a subspecies of basiguttella Hein. N. ilicivora Peyer. is considered synonymous with the older name suberivora Stt. Five lectotypes are designated, some of these specimens have previously been labelled "Type" or "Lectotype" but as far as known without publication. These lectotypes are here published in accordance with the rules of zoological nomenclature. A list of the Scandinavian and British Nepticulidae was compiled and the species are arranged into groups consisting of allied species. The definition of Stigmella Schrank 1802 is disagreeing with the structural characters distinguishing the family Nepticulidae. Consequently, the generic name Stigmella has to be rejected and the younger but better known and satisfactorily defined name Nepticula Heyden I843 has been used in this paper.

Abstract: In I968 and I969 noctuids were caught by means of a light trap at Bunkeflo, south of Malmo (prov. Scania). Hourly catches were separated. Sex differences in the diel distribution of catch were found. In summer, the males showed their highest activity around midnight. The females then showed a bimodal catch curve with the highest catch before, and a second weaker peak after midnight. In summer, light was found to be the factor governing the nocturnal distribution of catch, in autumn temperature. In I970 observations and experiments on captured moths were performed. Start of flight in the twilight period was found to be induced by the decreasing light. The moths started at higher light values if the temperature during this period was high. In actograph experiments it was found that moonlight has a depressing effect on the activity of noctuids.

Abstract: In. the spring of I97I, Neoaplectana bibionis Bovien was re-isolated from larvae and pupae of Bibio hortulanus L. and other bibionids from 3 localities in Denmark. Third stage infective larvae were recovered and used to initiate laboratory cultures. When nematodes were injected into the mouth of the greater wax moth larvae, Galleria mellonella L., they quickly penetrated into the hemocoel of the living insects and brought about their death. Successive nematode generations also occurred on artificial media used for rearing Neoaplectana carpocapsae Weiser. A specific rod-shaped bacterium was isolated from the intestine of infective stage larvae and probably has the same relationship to the nematode as N. carpocapsae has to its symbiotic bacterium, Achromobacter nematophilus. This nematode may make an excellent candidate for biological control programs involving soil insects.

Abstract: Two new species and one new genus are described and placed within the Tribe Tachyini. A discussion of hypothetical relationships is given for these species. And, a synonymy among names applied to extant groups of tachyines is pointed out and corrected.

Abstract: The activity of the cockroach Ectobius lapponicus was found to differ in males and females in the field, the males being active during the afternoon, the females after sunset. The difference was thought to be due to an inhibition by low temperatures in the males, displacing the activity towards an earlier period of the day. This is in accordance with a theory concerning sensitization, and different thresholds of release dependent on light and temperature as established for the stridulation in Orthoptera Ensifera and the locomotion in a domestic cockroach. A relationship between the amount of activity and the relative humidity was found in the nymphs. Laboratory experiments showed that the activity at constant temperature was released by a change from light to darkness. If low temperatures were applied during the dark period, the activity was displaced to the latter half of the light period. The influence of illumination on the activity was investigated, a faint illumination being more favourable than total darkness.

Abstract: The distribution and ecology of Tardigrada in interstitial habitats in northern Europe is discussed. Known results point only to species of the genera Macrobiotus and Hypsibius (fam. Macrobiotidae) as being psammophilous. Fourteen species were found; of these six belong to the genus Macrobiotus and eight to Hypsibius. Three species from each genus are new. Adaptations of true freshwater Tardigrada are discussed, the major aspect of which is the development of prehensile claws.

Abstract: A survey of the 46 aphid species known from the Canary Islands is given, including 13 species new to the islands. The geographical relations are discussed.

Abstract: The author has had the opportunity to study some type specimens of species of the genus Chrysopa Leach, I8I5. The species in question were mostly described in a way that does not allow sure identification. Redescriptions have therefore been prepared, when necessary, and lectotypes have been selected in cases when the descriptions were based on more than one single specimen. Some cases of new synonymy have been discovered.

Abstract: Benthic animal communities in streams with varying environmental conditions in a national park in northern Swedish Lapland were analysed. Dominant taxa were Ephemeroptera, Plecoptera, Trichoptera and Diptera Simuliidae. Northeasterly or very widely spread species make up the fauna. Intrariverine distribution patterns were found to differ between taxa, and great variations of standing crop values between adjacent sampling sites were the rule. Day-to-day fluctuations of drift rate were unsynchronized between taxa. Some ecological properties of Brachyptera risi (Plec.) are discussed. Some lake shores and streams affected by hydroelectric exploitation appeared virtually devoid of macroscopic animals.

Abstract: Four European species of Limnellia Malloch are recognized, one of which, L. surturi, is described as new on material from Iceland. Wings, male abdomina, and male genitalia of the four species are figured. For L. quadrata (Fall.) and L. stenhammari (Zett.) lectotypes are designated. L. surturi n.sp. is recorded as new to the British Isles and L. fallax Czerny as new to Sweden. A simplified key to the species is given.

Abstract: J. W. Zetterstedt described between I8I9-I850 thirty-seven species of the Empidid subfamily Tachydromiinae in combination with Tachydromia Meig. (30), Tachypeza Meig. (5), Drapetis Meig. (I) and Empis L. (I). A revision of these species has been based on a study of Zetterstedt's Collection at Lund, Sweden. Lectotypes or holotypes for thirty-six of Zetterstedt's species are designated and a further two lectotypes for Platypalpus pallipes (Fall., I8I5) and Platypalpus boreoalpinus Frey, I943 have been selected. Five species are redescribed, viz., Platypalpus brevicornis (Zett., I842)—the male sex is described for the first time—, Crossopalpus curvinervis (Zett., I842), comb.nov., Platypalpus sordidus (Zett., I838), Platypalpus unguiculaws (Zett., I838) and Platypalpus boreoalpinus Frey, I943. The following species are described as new: Platypal pus confiformis sp.n., Platypalpus zetterstedti sp.n., and Platypalpus alpinus sp.n. Some new synonymy is established: Symballophthalmus scapularis Collin, I96I is a synonym of Symballophthalmus fuscitarsis (Zett., I859), Tachydromia gilvipes Coquillett, I900 and Platypalpus xanthopodus Melander, I928 are synonyms of Platypalpus unguiculatus (Zett., I838), Platypalpus extricatus (Collin, I96I) is a synonym of Platypalpus Iongiseta (Zett., I842), Drapetis nigripes Zett., I859 is a synonym of Drapetis pusilla Loew, I859, Tachydromia parvicornis Zett., I859 is a synonym of Crossopalpus nigritellus (Zett., I842). A new name Platypalpus anomalinervis nom.nov. is proposed for Tachydromia curvinervis Collin, I94I (nec Zett., I842), described from Ussuri. Platypalpus candicans (Fall.) is still known only from the female sex, the recorded males are represented in Zetterstedt's Collection by males of Platypalpus longiseta (Zett.) (syn. extricatus Coll.) and Platypalpus stabilis (Coll.). Also Lundbeck (I9I0) described the male sex of P. candicans (Fall.) and P. major (Zett.) by mistake.

Abstract: Several amber collections have been surveyed for Trichoceridae and the two specimens, one male and one female, mentioned by Loew (I850:37) are here described under separate species in a new genus, Oligotrichocera. The systematic position of the family within the Tipuloidea is stressed. The characters for generic assignment in the subfamily Trichocerinae are tabulated. Some wing vein characters, such as the shape of the discal cell (IstM2), the position of sc 1 and sc 2 , and the variation in the medial field are discussed in relation to fossils of tipulid stock and the wing venation of Kawasemyia. The rarity of trichocerids in Baltic amber may not merely be accidental, since the occurrence of adults may not have coincided with the highest amber production during the annual temperature cycle.

Abstract: Laboratory breeding of the polymorphic African butterfly, Acraea encedon, has established the dominance relationships of most of the common colour forms It is not yet certain if the forms are determined by a series of multiple alleles at a single locus, and alternative interpretations involving more than one locus are suggested Evidence for the possibility of linkage between two of the forms is discussed The widespread white form, lycia, occurs in most populations and it may be the universal recessive comparable to the widespread black and white form of the African swallowtail, Papilio dardanus

Abstract: Trechus flavolimbatus ferrarius Jeann. and T. palmensis Mateu are regarded as synonyms of T. flavocinctus gomerae Jeann. and T. flavocircumdatus Jeann., respectively. The significance for the biogeography of the Canary Islands of the remaining taxa of the T. flavolimbarus complex as well as some other endemites is discussed.

Abstract: Aricia artaxerxes (allous G.-Hb.) ssp. vandalica Kaaber and Hoegh-Guldberg flies for such a long period, almost 3 months, that it might be regarded as two generations, just as is the case with the sibling species, A. agestis Schiff. Experiments with simultaneous rearing of the two species, under identical conditions, exhibited a great difference (I) in the rate of growth of the larvae and (2) in the dispersion in time of the larval stage. On examination of previous experiments these findings were confirmed and must be considered as permanent specific differences. The consequence is that eggs of artaxerxes from a single experimental day of oviposition may result in imaginal emergence spread over a long period (3-4 weeks); in nature the dispersion will be so much greater that the long flying time can be explained without assumption of the presence of two broods. The larvae of agestis grow more equally and rapidly, enabling this species to produce 2 (or 3) generations.

Abstract: A fossil specimen of Longistigma caryae (Harris) has been found in tuff from Iceland, locality: Hrutagil i Mokollsdal in northwestern Iceland, age: Upper Miocene or Lower Pliocene. In the present time the species lives exclusively in the region of the Eastern Deciduous Forests of North America on several genera of deciduous trees, a.o. Carya and Fagus. The find certifies paleobotanical evidence indicating that Iceland once belonged in the region of deciduous forests with a flora more like the modern eastern North American flora than any other modern flora region. The recent aphid fauna of Iceland contains only palaearctic, holarctic, cosmopolitic, and endemic species and species common with Greenland and arctic Canada.

Abstract: In Scandinavia there are at present I7 known posed to be conspecific with ratisbonensis Stt., a species of the genus Bucculatrix. A short descrip- species often confused with artemisiae HS. Instead tion of each species and figures of wings and male of boyerella Dup. the older name albedinella Z. and female genitalia are given. They are arranged should be used, and merei P.-C. is stated to be a according to these characters and also according to synonym of capreella H. Krog. food-plants. The American leptalea Braun is sup-

Abstract: The morphology of the abdomen of the mayfly, Povilla adusta Navas (Polymitarcidae) has been studied from dissections of muscles and nerves in male and female imagines and in a female nymph and a number of apparently very primitive traits have been disclosed. The findings have been compared to similar structures in other mayflies and, as a result, a revised interpretation of the genital and postgenital segments of Ephemeroptera is proposed.

Abstract: The life-history of Aeshna viridis Eversm. has been studied at a peat-pit in southern Sweden by means of regular sampling. Larvae from some samples from late summer to early spring have been experimentally subjected to constant artificial day-lengths of I3, I4.5, I6 and I9.5 hours at a temperature of 20°C. The results of experiments suggest that the rapid transition of photoperiod in autumn and spring is most important in the regulation of the life-cycle, which in the population studied had a duration of 2-3 years. A comparison is made between the seasonal regulation in Aeshna viridis and that in some other species. The causes of the phenological differences between certain types of spring and summer species and the differences in life-history of Aeshna species at different latitudes are discussed.