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Stomachs of 12 species of Neotropical bats were examined grossly and histologically. Those of stenodermines (family Phyllostomatidae) were highly variable in configuration between species, and even congeneric kinds were distinguishable. The stomachs of stenodermines varied in elongation of the caecum or elongation of the pyloric region, both of which provided for accommodation of large quantities of food. Structural peculiarities, especially in the stenodermines, were considered with respect to their possible relationship to diet.

Chlorella has two mechanisms of K uptake, depending on concentration. Mechanism 1 operates at low concentration and may be responsible for net transport. Mechanism 2 is dominant at high concentration (above 1 × 10−3M) and may be attributed to the K/K exchange system. In either case, Rb, which has a more favourable radioisotope, substitutes for K. Both mechanisms are temperature sensitive, dependent on metabolism, and carrier-mediated. At low Rb concentration (3 × 10−5M), γ-irradiation (60 krad) reduced Rb uptake at 30 °, but increased it at 10 °. At high concentration (3 × 10−3M) uptake was stimulated by irradiation at both temperatures. With K-deficient cells the Rb net transport contributed to a higher degree to total Rb influx, compared with normal cells. On γ-irradiation of K-deficient cells, at low concentration a decrease of the uptake was observed at both 30 ° and 10 °, and at high concentration the stimulation was less pronounced than with normal cells at both temperatures. It is suggested that the K/K exchange system is stimulated, but the K (Rb) net transport system is injured by irradiation. The increased K efflux after irradiation is about equal to the stimulated K (Rb) influx via the exchange system. Thus it is not necessary to assume enlarged membrane permeability to explain the increase of the K efflux after γ-irradiation.

Seven hyperparasites were discovered in Wyoming in 1972. Four species were widely distributed and abundant in the state. Three of the 4 species, Eupteromalus albopilosus Graham, Sceptrothelys grandiclava (Walker), and Sceptrothelys intermedia Graham, were apparently recent European introductions. E. albopilosus was a new species for North America, first collected in March 1972 at Pine Bluffs, Wyo. The 3 species were extremely prolific, adapted well to Wyoming ecology with little environmental resistance, and showed greater biotic potential than their host, Bathyplectes curculionis . These factors point to the possibility of greater detrimental impact on B. curculionis in the future. The data also indicated that the 3 species plus Mesochorus agilis Cresson (a native species) are presently affecting the parasitic efficiency of B. curculionis .

Erythroneura lawsoni Robinson (Homoptera: Cicadellidae), specific to sycamore, was studied in east-central Illinois in 1972, under both laboratory and field conditions. Adult. females laid 4–6 eggs/week during a 4–5 week oviposition period. Eggs hatched within 15 days, and 5 nymphal instars followed, with a mean development time of 3–5 days/instar. Mean generation time was 41 days, and 4 partially overlapping generations occurred in 1972. This species coexists with 4 other leaf-sucking insects on sycamore: Empoasca fabae (Harris), Empoa platana Christian (Cicadellidae), Corythucha ciliata (Say) (Tingidae) and Plagiognathus albatus (Van Duzee) (Miridae); the last 3 species are specific to sycamore. The species show differences in temporal and spatial exploitation of sycamore leaves, so that overlap of feeding niches is small. Empoasca fabae feeds on main viens, Erythroneura lawsoni on the leaf blade close to larger veins, Empoa platana on the leaf blade distant from veins, and the maximum niche overlap seen between these species is 38%. C. ciliata feeds on the whole area of the leaf blade, and thus overlaps other species extensively, 84% for Erythroneura lawsoni and 80% for Empoa platana . But overall overlap, when both time and space are considered, is reduced to a maximum of 63% between C. ciliata and E. lawsoni , and to much less (0–39%) for other species combinations. The sycamore leaf offers a mosaic of microhabitats which allows niche diversification and specialization in the leaf-feeding guild.

Grubs of Ataenius spretulus Harold, a scarabaeid turf pest, were encountered at 2 widely separated locations in New York during 1969–71. All field-collected grubs were infected with a bacillus producing a milky disease similar to that produced by Bacillus popilliae Dutky or B. lentimorbus Dutky in other scarabaeid grubs. This bacillus was noninfective to grubs of the Japanese beetle, Popillia japonica Newman, and northern masked chafer, Cyclocephala borealis Arrow, and only mildly infective to the European chafer, Amphimallon majalis (Razoumowsky). Histological examination of infected Ataenius grubs indicated that sporulation occurred in connective tissue sheaths and possibly also in lobes of the fat-body. Cytological studies showed the general ultrastructure of the spore to be similar to those reported for the other milky disease bacteria. It differed in the smallness of the endospore relative to the size of the whole sporangium, the greater number of ridges formed by the spore coat, and the presence of conspicuous exosporium. The results of our investigations suggest that the etiological agent of the A. spretulus disease is a new milky disease organism.

The mean weight of food items from winter flounder (Pseudopleuronectes americanus) at St. Margaret's Bay, Nova Scotia closely coincided with the mean weight of benthic prey potentially available. Flounder larger than the mean length (29 cm) ate heavier particles. Small particles were consistently disregarded. There were seasonal changes in the weights of food items used and in the proportion of organisms to detritus in stomachs.

The daily and seasonal emergence patterns of Synanthedon pictipes (Grote and Robinson) were determined under field conditions in Door County, Wisc., m 1972 and 1973. Daily emergence occurred during the morning hours at times related to temperature conditions. The earliest emergence was recorded at 5:45 AM. No emergence took place at temperatures below 15°C,. but on fast warming days emergence was not initiated until the temperature was much higher. It is suggested that a certain number of thermal units accumulation followmg sunrise are required for emergence to take place. The observed seasonal emergence extended between 6 June and the week ending 3 August. The ratio of males:total number of adults declined significantly on both daily and seasonal scales.

When the life history functions B (E) and P (E)-fecundity and postbreeding survival-are subject to environmentally induced fluctuations, one of two patterns is selected for: If the functions are concave (iteroparity in constant environments), the optimal population is monomorphic. Variation in B (E) selects for reduced effort in all individuals; variation in P (E) for increased breeding. If functions are convex (semelparity in constant environments) and fecundity is the parameter at issue, the optimal population can be polymorphic, with only a fraction of the population reproducing annually. Increasing the severity of fluctuations reduces the optimal value of this proportion, even if the average rate of reproductive success is not changed.

A population of meadow voles (Microtus pennsylvanicus) 75 mi northeast of Winnipeg, Manitoba, Canada was live-trapped biweekly for two winters. From August to February of each year the mean population weight decreased by 30% to 40%. This decrease was not due to preferential death of the heavier animals because their survival was better than would have been expected if survival and weight were independent. Part of the weight loss was due to the immigration of young animals that failed to gain weight. However, much of the decrease in mean weight was due to that lost by individuals, because many samples of animals released and recaptured 2 wk later had lost significant amounts of weight. Four marked 8 8 trapped from August to February lost an average of 28.6% of their weights while 14 marked 9 9 lost 45.5% in the same time period. In February the mean weights of individuals and the population began to increase. It is suggested that weight loss is not simply a result of lack of food, but is an adaptive response cued by some factor such as day length.

A simple electrophysiological method for the pharmacological investigation of synaptic transmission in insects is described. By means of this technique synaptic potentials and ganglionic polarization can be recorded from the sixth abdominal ganglion of Periplaneta americana L. for long periods. In the absence of stimulation, spontaneous excitatory (EPSP) and inhibitory (IPSP) postsynaptic potentials can be recorded. The mechanical stimulation of cereal receptors demonstrates the summation of EPSPs leading to spike generation. Electrical stimulation of the cereal nerves (X, XI) enables the recording of a monosynaptic EPSP (XI) and a bisynaptic IPSP (X). The action of acetylcholine on synaptic transmission, including a dose-response curve, is described. The potential of this technique as a tool in pharmacological research is discussed.

A 3-year study was conducted on a population of Nicolea zostericola (Oersted: Grube, 1860) at Nahant, Massachusetts (USA), which indicated that this species has a life span of about 1 year. Spawing occurred from mid-April to early July, after a rise in sea-water temperature to about 6°C. Pair formation occurred between sexually mature adults prior to and during spawning. Eggs were deposited in cocoons, where development occurred in 14 to 22 days. Larval develomment is described along with juvenile and adult substrate preferences and behavior. The entire intertidal population disappears following the spawning season in late June, and reappears in September as a result of migration of worms from the sub-littoral zone. Oogenesis consists of 3 phases: a short gonadal and follicular phase, followed by a longer vitellogenic phase during which oocytes are free-floating in the coelomic fluid.

The Sediment of Lake Kummerow. Investigations on the Chemism and the Diatom Flora The paper deals with the distribution of chemical parameters and of diatoms in the deposits of the eutrophic Lake Kummerow (GDR), produced during about the last 3500 years. The sediment consists of a calcareous gyttja with a very low content of sand and clay. The results indicate a relatively constant trophic state of the lake in former times and an increased production within the last five centuries. Stephanodiscus astraea and its variety minutula is by far the most constant diatom species; in the uppermost parts of the sediment small sized planctonic taxa are increasing, in the main Stephanodiscus hantzschii var. pusillus, Melosira granulata var. angustissima, Asterionella formosa and Synedra acus var. angustissima and var. radians.

Le developpement larvaire des ouvrieres comprend trois stades caracterises par la forme des poils, des mandibules, ainsi que la dimension des stigmates. La differenciation visible des larves de soldats intervient a la fin du troisieme stade. Ces larves de soldats n'ont pas de mue supplementaire. La differenciation au niyeau des proteines de l'hemolymphe n'est effective qu'a partir du stade prenymphe. Le determinisme semble etre de nature trophique. L'orientation dans le sens soldat est favorisee par une nourriture riche en debris d'insectes et une temperature superieure a 24°. La production de soldats obeit a un phenomene de regulation sociale qui maintient ou retablit le nombre de soldats au voisinage d'un pourcentage donne.

Field cage studies using cotton plants were conducted to test the hypothesis that laboratory-reared Trichogramma deteriorate in their effectiveness as biological control agents. The results of these studies presented evidence that a deuterotokous Trichogramma stock deteriorated. No reduction in effectiveness could be demonstrated for arrhenotokous stocks. These studies also showed that Trichogramma rapidly lose their effectiveness in field cages and that parasitization of hosts occurs during the day rather than at night.

The bacterium Serratia marcescens is pathogenic for the pea aphid, Acyrthosiphon pisum. When S. marcescens cells are inoculated into the hemocoel of the aphid, there is a variable lag period of 2–3 hr duration. This phase is followed by a rapid increase in pathogen numbers causing a general septicemia and the death of the aphid. The LD50 for fourth-instar pea aphid nymphs was estimated as 190 viable S. marcescens cells (95% confidence limits, 123–288). It is suggested that being sucking insects aphids are protected against infection by bacterial pathogens in the field.

The annual reproductive cycle and the cyclical changes in the gonad of the New Zealand rock oyster, Crassostrea glomerata (Gould, 1850), during the breeding period of 1970–71 and 1971–72 have been described. The gonad passes through an intermediate phase, after a post‐spawning period, when sex is indeterminate. Gametogenesis begins in July and August, but follicles ripen mostly during the spring months of October and November. Maximum development is seen in November, and nearly all oysters are in spawning condition in December and January. Major spawning takes place in January or February depending upon water temperature, and spawning continues until the end of March. Larvae may be found in the‐ plankton until late in the season, to the end of April or even May. Following spawning, gonadial regression sets in, with leucocyte infiltration and phagocytosis of residual gonial cells. A greater percentage of oysters more than 1 y old are females. The majority of oysters of age 1 y and below are males.

The chronological and geographical distributions of immature and adult orthopteroids were compared in a semi-isolated abandoned crop field in Michigan. Seven general plant associations within the 1.8-acre field were sampled by sweeping and pit-trapping, and the relative numbers of orthopteroids within each association were determined. Thirty species of orthopteroids were captured with the following distribution by families: Acrididae 16, Gryllidae 5, Conocephalidae 3, Phaneropteridae 1, Gryllacrididae 1, Tetrigidae 2, Manteidae 1, Phasmatidae, 1.

Eight study-sites were chosen on road margins in the alpine tundra of Rocky Mountain National Park, Colorado. Seven of the sites were located about the middle of slopes created by filling, below the roads. The remaining site was above the road, and flat on bedrock. Mosaics of pioneer vegetation types are present on roadcut slopes. These appear to be correlated with altitude, exposure, substrate texture, and degree of slope. Forty to fifty years after denudation, succession plays only a minor role on roadcut slopes. Plant coverage after that time is approximately one-half that of cushion-plant communities on natural tundra. The most important pioneer plants under these conditions are ‘bunch type’ Gramineae, especially Agropyron scribneri and Poa fendleriana .

A suspension of Bacillus thuringiensis was inoculated at 24 and 72 hr into the oral cavity of Galleria mellonella larvae following exposure to 20, 50, and 70 Kr of gamma radiation, respectively. The cytopathology was conducted after B. thuringiensis had developed for 3, 5, and 7 hr and after radiation damage had developed for 27, 29, 31, 75, 77, and 79 hr in the larvae exposed to 20, 50, and 70 Kr, respectively. B. thuringiensis spores appeared in the midgut lumen from 3 to 7 hr after inoculation of 20 Kr irradiated larvae. At 7 hr after B. thuringiensis infection, and 79 hr after 20 Kr irradiation, the following changes were seen: B. thuringiensis rods appeared adsorbed onto the walls of epithelial cells, a few spores appeared in hemolymph, epithelial cells developed vacuoles, and villi appeared detached from the basement membrane. Within a period ranging from 3 to 5 hr after infection, B. thuringiensis rods attacked vacuolated epithelial cells of most of the 50 and 70 Kr irradiated larvae. At 7 hr after infection and at 31 hr after 70 Kr irradiation, the spores reached the interior of some epithelial cells and were also seen concentrated near the basement membrane. In general, the midgut epithelial cells of the 70 Kr-irradiated groups of larvae appeared highly vacuolated, badly disrupted, and in most cases undistinguishable as a result of attack of B. thuringiensis . In short, B. thuringiensis did not show a characteristic pattern of pathology on 20 and 50 Kr-irradiated midgut cells. The problem of permeability of B. thuringiensis toxin into the irradiated cells needs further investigation.

The behaviour of the lesser sandeel, Ammodytes marinus (Raitt), has been investigated at 5, 10 and 15° C, using a photographic method of recording activity. The activity patterns at 10 and 15° C were very similar, there being a high level of swimming activity during the light period, which fell to a low level at 5° C. It was also lower at 10° C at the end of the experiment than at the beginning and it is suggested that this might have been due to an increase in the fat contents of the fish. The feeding rate of the fish was measured and showed a Q10 of 2.08 for the temperature range 5–15° C. The annual cycle of activity of A. marinus is discussed in relation to seasonal changes in food availability, light and temperature, and in the fat content of the fish. It is concluded that after spawning in the December–January period the fish remain buried in the sand until April, because of the limiting effect on swimming and feeding activity of the environmental factors in the intervening period. The proportion of fish available for capture at the start of the fishery in April is related mainly to temperature, but food (as measured by numbers of copepods) light intensity and photoperiod are by then increasing rapidly. After July the fishery ceases and it is thought that this is because the fish have entered an overwintering stage, during which they remain buried in the sand. This phase is also thought to be associated with the maturation of the gonads in readiness for the winter spawning. The factors causing the fish to enter this stage are as yet undetermined but may be related to the attainment of a certain level of fat content.

Serum and blood samples from 86 wolves taken in northern Canada were examined for neutralizing antibodies to canine distemper, infectious canine hepatitis and canine herpesvirus. The tests were performed on eluates prepared from paper discs previously saturated with serum or blood from wolf carcasses. Canine distemper and infectious canine hepatitis antibodies were demonstrated in two and eleven samples respectively. No reactors were detected for canine herpesvirus. These findings indicate the existence of the viruses of both CD and ICH in free-living wolves in northern Canada. However, their significance in these animals is not known.

Les regimes alimentaires d'un insecte parasite entomophage,Phanerotoma flavitestacea, sont identifies par examen histologique du contenu du mesenteron, au cours de ses 2 modes de vie larvaire successifs, endoparasite, puis ectoparasite. Lors de sa phase endophage, la larve se nourrit uniquement de l'hemolymphe des chenilles d'Anagasta kuehniella. Il n'y a pas de phase steatophage. Au cours de sa phase ectophage, elle ingere tous les organes de son hote, sans ordre apparent et sans choix. La digestion, commencee des le repas acheve, est completement terminee lorsque le cocon est tisse.

Dans ce travail, nous etudions la biologie et l'ecologie d'une Fourmi savanicole d'Afrique tres repandue:Crematogaster impressa Emery.

During 1966 and 1967, the spawning runs of an anadromous population of alewives, Alosa pseudoharengus (Wilson), were studied in Bride Lake, Connecticut. Alewives entered the lake from Long Island via Bride Brook from March to June. The number of fish entering the lake each day varied and was not related to water temperature or amount of moonlight. Males predominated among early migrants, whereas a 1:1 sex ratio existed through the later part of the migration. The average size of adults decreased as the migration progressed. Adults spent from several days to 3 months on the spawning grounds, the males outnumbering the females. Counts of the number of fish entering and leaving the lake indicated that high mortalities occurred. Females spawned from 48,000–360,000 eggs. The total number of eggs spawned in the lake was estimated to be 2.0 X 1010. Young alewives migrated seaward from June to October and increased water flow was thought to be a major stimulant. One young alewife migrated seaward for eve...

Strongwellsea castrans is a parasite of the adult cabbage maggot, Hylemya brassicae, in Canada. Laboratory cultures of H. brassicae became infected when exposed to infected, field-collected flies. Infected flies lived a maximum of 5–7 days after the appearance of the characteristic abdominal hole through which the conidia are discharged. Attempts to culture the fungus on artificial media were not successful. Under field conditions, infection rate varied considerably within a season and between years; a high rate of infection was associated with a high relative humidity and possibly a comparatively low temperature.

Hamsters maintained in isolation boxes for 4–7 weeks were allowed to select their own lighting regimens by pressing levers, and to be active in running wheels. Three hamsters expressed circadian rhythms of light preference and of wheel-running activity (Figs. 1–3). Light tended to be selected during the inactive phase, and darkness was selected during wheel-running activity. By such a circadian rhythm of self-selected lighting, these hamsters are behaving in a way which may maintain those metabolic cycles that depend upon a 24-hour oscillation of light and darkness.

Cyrtophora moluccensis (Doleschall) in New Guinea and C. citricola Forskal in the Mediterranean and Africa form persistent aggregations of individuals of all ages. Characteristic of this “communal” organization (as defined by Wilson, 1971) in C. moluccensis are low level aggressive interactions during prey capture and during web repair and renewal. Such interactions may serve as a spacing mechanism, ensuring an adequate fool supply for each individual Disadvantages resulting from conspicuousness and persistence of C. moluccensis colonies are a high incidence of parasitism and a large degree of colony avoidance by flying insects (potential prey). Advantages of communal organization postulated for C. moluccensis includes increased protection of egg-cases and young, greater web building efficiency, greater prey capture efficiency, and the ability to exploit habitats that are unavailable to solitary species. Evidence is presented for the first and last of these hypotheses. It is suggested that due to its durable, 3-dimensional web Cyrtophora species could invade grassland habitats exposed to frequent and heavy wind and rain (Lubin, 1973). Colony formation then evolved in the larger species, C. moluccensis and C. citricola, as a means for exploiting large, open spaces that are rich in flying insects and poor in competing araneids. Under such optimal conditions, low level aggression occurring during prey capture and web construction may be interpreted as instances of reciprocal altruism among related colony members.

Heligmosomoides johnsoni sp. nov. is described from the cecum of the heather vole, Phenacomys intermedius Merriam, from the Olympic Mountains, Washington. The absence of longitudinal cuticular ridges dorsally separates H. johnsoni from species of Heligmosomoides other than H. hudsoni (Cameron, 1937), which occurs in varying lemmings, Dicrostonyx spp., and from which H. johnsoni is distinguished by its longer spicules, form of the dorsal ray, and other characters. Both Phenacomys and Dicrostonyx have a specialized cecum, with long villi around which the nematodes are found tightly coiled. The zoogeography of heligmosomid nematodes in Phenacomys is briefly discussed.

The existence of variability in the cereal cyst nematode, Heterodera avenae Woll. in India is confirmed. Tentatively five biotypes have been identified using an assortment of cereals and grasses; the distribution of the biotypes in the light soils of Rajasthan and Haryana is plotted. These biotypes do not appear to be identical to those in Denmark, The Netherlands, Britain, Germany and Australia. They have been designated as 1, 2, 3, 4 and 5 of which biotype 3 is the most common in India. The possibilities of the existence of more biotypes is also indicated.

The Manini is a widely distributed surgeonfish that is often abundant on reefs. It has two modes of existence, scattered individuals or dense column-forming schools, which may be seen on the same day at different places on the reef. In Hawaii schooling is a tactic used for getting to the bottom to feed when the bottom is held by territory-holding food competitors. Mixed-species “flocks” are an extension of this tactic. In atoll situations habitat partitioning exists, with the Maninis feeding in the intertidal area away from competitors; there, schooling is anti-predator behaviour.

Intracardial injection of chicken red blood cells (RBC) into the oyster, Crassostrea virginica, at 15–19°C elicited ingestion, digestion, and removal of the cells by the leukocytes. A rapid response of fibroblastlike cells and characteristic cell aggregates were also detected as early as 1 hr post-injection. While the former was engaged in an unsuccessful attempt to encapsulate red blood cell laden leukocytes intravascularly, the function of the latter cell type was undetermined. The process of disposing the red blood cells in the oysters under running seawater conditions was not noticeably different from that observed in the oysters under standing water conditions. In oysters previously sensitized with red blood cells, response to a challenge injection was similar to that observed following the first injection, and there was no indication that the activities of the leukocytes were enhanced. However, it was demonstrated that oyster leukocytes remained functionally viable for at least 22 days. There is evidence indicating that the number of the characteristic cell aggregates increases considerably after a secondary injection of red blood cells, although the specificity of this response is yet to be determined. At 6°C, although phagocytosis of the blood cells occurred quite extensively, leukocytes exhibited considerably low digestive and migratory activity which resulted in far less effective disposal of the blood cells. Preliminary observations also revealed possible adhesion of oyster leukocytes to the wall of blood vessels following the inoculation at this temperature.

Zbadano tarczyce 265 myszy wielkookich leśnych, pochodzących z wylowow prowadzonych w roznych porach roku, w Bialowieskim Parku Narodowym w latach 1966-1969. W podziale na grupy uwzgledniono plec, wiek i aktywnośc plciową, a u samic takze okres ciązy i laktacji.

An absolute requirement for sugar could not be shown but laboratory rearing experiments using artificial diets have demonstrated a definite increase in weight of adult spruce budworm (Choristoneura fumiferana (Clem.) Freeman) with increasing dietary levels of certain sugars. Males exhibit a threshold of 0.9% soluble sugars above which higher sugar levels produce no further increases in size. Females respond with an increase in size up to 4.0%, the highest level tested. Generally, faster development rates accompany greater mature weights on diets with higher nutrient levels.Maltose, raffinose, glucose, sorbitol, sucrose, and fructose are all good sugar sources. Galactose and trehalose are only slightly inferior. Lactose, ribose, melibiose, xylose, mannose, arabinose, and melezitose in the diet are little different from the sugarless control. Sorbose is somewhat inhibitory.Results of transfer experiments confirm the importance of sugar particularly during late larval development. They also indicate that a high protein diet during early instars has a significant effect on development rates. These results suggest that departure from the normal synchrony of development in the insect and its host can affect both rate of development and mature size of the insect.

The electrophoretic patterns of the general proteins, esterases, creatine kinase and phosphoglucomutase of white muscle from Lough Neagh pollan, Lough Erne pollan, Lake Bala gwyniad, Loch Lomond powan, Haweswater schelly and Bassenthwaite vendace are consistently of three types. It is therefore suggested that the coregonids examined are three distinct species: the pollans; gwyniad, powan and schelly; vendace. Vendace is genetically closer to the gwyniad group than to the pollans.

Bushflies emerging into a cage which has separate sources of water, sugar and protein placed on its floor, usually do not feed on the protein for about 2 days. Newly emerged flies will feed on protein, however, if brought into contact with it by response to another environmental factor, such as moving upwards or towards the light. After such feeding there is no delay in the development of eggs by the female. Smaller flies, which arise from unfavourable larval feeding conditions which leave them with a relatively greater protein deficit to make up, develop an interest in protein sooner than larger flies. Zusammenfassung PROTEIN-ANNAHME UND EI-ENTWICKLUNG BEI DER AUSTRALISCHEN BUSCHFLIEGE, MUSCA VETUSTISSIMA IN ABHANGIGKEIT EINIGER FAKTOREN Erwachsene Fliegen-Weibchen, Musca vetustissima, die in einem Kafig geschlupft sind, wo Wasser, Zucker und Protein auf dem Boden gestellt ist, ruhren in den beiden ersten Lebenstagen das Protein wahrend eines 5-Minuten Tests nicht an. Die Ei-Entwicklung ist dadurch verzogert. Frisch-geschlupfte Fliegen fressen dagegen von dem Protein, wenn es so gestellt ist, dass die Fliegen es finden, wenn sie auf andere Umgebungs-Einflusse reagieren, wenn sie gegen das Licht in die Hohe fliegen. Nach einer so herbeigefuhrten Protein-Mahlzeit findet keine Verzogerung in der Ei-Entwickelung statt. Kleinere Fliegen, die bei ungunstigen larvalen Futterungs-Verhaltnissen entstehen und deshalb an einem relativ grosseren Protein-Mangel leiden, entwickeln ein Interesse fur Protein fruher als grosse Fliegen.

Three formulations of Bacillus thuringiensis Berliner, preparation Thuricide® were evaluated against a commonly occurring leafroller, Archips rosanus (L.), on filberts. In the laboratory at 26.7 ± 1 °C, all larvae died within 7 days after feeding for 48 h on filbert leaves treated with dust and wettable formulations. With aqueous concentrate, the mortality was slightly less. Insect susceptibility was markedly reduced when the length of feeding exposure period was decreased. In the field, the infestation of A. rosanus was significantly reduced within a week after treatment in almost all the treated plots. Larval mortality continued for about 4 weeks. Under western Oregon conditions, dust treatments were slightly better than wettable or aqueous concentrate formulations.

Under laboratory conditions, females of Eurytoma amygdali were attracted to almond fruit, whereas males were not. Females changed their position twice as often as males, in the absence of fruit. Almond leaves had little, if any, attraction for females; moisture had none. Outdoors, free wasps were active in and around almond trees in sunny and in overcast weather, during the morning mainly on the eastern side, and in the afternoon mainly on the western side of trees. Males were often “dancing” horizontally in a plane parellel to the periphery of trees. Courting and mating were observed on fruits only. 527 wasps which emerged on three focus trees equally distributed in an otherwise uninfested orchard damaged an average of about 25.8 fruits per female. 70.9% of the damaged fruits were on the focus trees, 17.4% on trees directly facing them, and 12.8% on further removed trees. In some cases, trees bordering on open spaces were more heavily infested than those between them and the focus trees. No correlation was found between the number of infested fruits and fruit load of individual trees. Zusammenfassung STUDIEN ZUM VERHALTEN, ZUR AUSBREITUNG UND ZUM SCHADPOTENTIAL DER MANDELWESPE, EURYTOMA AMYGDALI In Kafigen im Laboratorium wurden Weibchen, Mannchen jedoch nicht von Mandelfruchten angezogen. Mandelblatter und Feuchtigkeit ubten kaum bezw. keine Anziehungskraft auf Weibchen aus. In Abwesenheit von Fruchten anderten Weibchen ihre Position ungefahr doppelt so oft wie Mannchen. Frei lebende Wespen waren in sonnigem und bewolktem Wetter aktiv, morgens an der ostlichen, nachmittags an der westlichen Seite der Baume. Mannchen “tanzten” oft nahe der Peripherie der Baumkronen. Vor dem Beginn der Aktivitat am Morgen sasen Mannchen und Weibchen auf der Oberseite der Blatter. Werben und Kopulation wurden auf Fruchten beobachtet. In einer vorher nicht befallenen Mandelanlage wurden in den Kronen von drei gleichmasig verteilten Baumen insgesamt 527 Wespen zum Schlupfen gebracht. Diese beschadigten im Durchschnitt pro Weibchen 25.8 Fruchte. 70.9% der befallenen Fruchte waren auf die 3 Focusbaume, 17.4% auf die Baume, welche die Focusbaume direkt umgaben, die restlichen 12.8% auf die ubrigen Baume der Anlage verteilt. In einigen Fallen waren Baume, die an offenes Feld grenzten, schwerer befallen als die Baume zwischen ihnen und den Focusbaumen. Eine Korrelation zwischen Fruchtmenge und Befall pro Baum konnte nicht festgestellt werden.

Microscopic examination of scales from lesions on the ear of a white-tailed deer (Odocoileus virginianus) revealed the presence of fungal structures, gross appearance of which was consistent with the morphology of a dematiaceous mold. Nutrient agar cultures inoculated with such scales yielded Alternaria alternata. No other fungus was seen or isolated. Hyphalike elements were also noted in thin sections of the connective tissue of the ear. These data indicate a subcutaneous infection initiated by Alternaria.

The dynamic quantitative balance between prey and predator invertebrate species inhabiting the same shallow-shelf (sublittoral level bottom) benthic communities was first discussed by Thorson (1953). Thorson considered the exact timing of larval settlement of prey and predator species possessing pelagic development and temporal supression of the adult predators' feeding activities during reproduction at the time of the preys' settlement to constitute the major factors which facilitate survival of the prey species in such communities. However, information obtained demonstrates that Thorson's “mechanism of balance between predator and prey species of benthic communities” is not always effective in securing survival from predation not only of the prey's spat but even sometimes of the predator's spat also. Because of this, the “mechanism” can not be rated as universally effective in all situations. Analysis of the data so far published demonstrates that, in marine benthic communities, especially in shallow-shelf waters, it is not uncommon for gametes, larvae, or early juveniles of different prey species to pass alive through suspension (filter)-feeding and deposit-feeding adult invertebrates preying on them. Sometimes development can even continue after excretion by predators. The hypothesis of Voskresensky (1948) and Goycher (1949) of the importance of this phenomenon for the maintenance and recruitment of the mussel Mytilus edulis and other filter-feeding lamellibranchs of nearshore waters preying on their own and other lamellibranch pelagic larvae must be rejected on the basis of accumulated data on their feeding and general biology and on the adverse influence of the mucous of their faecal pellets and pseudofaeces on the larvae excreted by them alive. The data considered here demonstrate that, although the passing alive of larvae and spat of benthic invertebrates through benthic predators is not uncommon in shallow-shelf bottom-communities, it plays no important role in the processes of maintenance and recruitment of the species and communities involved nor of the marine benthos as a whole. The actual ecological significance of predation on pelagic larvae and bottom spat of benthic invertebrate prey species by all three main trophic groups of marine benthos (suspension or filter-feeders, deposit-feeders, carnivores) and its importance to predator-prey dynamics in marine benthic communities remains open to debate until more reliable quantitative data become available.

Prepupae from a population of P. forficalis larvae reared at 16 h photoperiod and 20°C produced a continuous distribution of emerging adults; no clear distinction between diapause and non-diapause was evident. At 16-h photoperiod adult emergence distributions from the progeny of individual pairs having different prepupal lengths varied widely. Under photo-periods of 20 and 24 h all individuals emerged within a few days of each other, following a short prepupal period, and pupal stage of 14 days. At 14 and 12 h photoperiods emergence was protracted and rarely began before 40 days after the start of the prepupal stage. Emergence before 40 days was therefore taken as the criterion for non-diapause. Under 16 h at 20° pre-40-day emergence varied from 10% to over 80%; this photoperiod must therefore be near to critical for P. forficalis. Selections for tendency to diapause and rapid emergence, based on time of emergence at respectively long and short photoperiods, were successful. There was a significant correlation between F1% emergence at 16 h and that of the male parental family at 16 h photoperiod. When the rearing photoperiod, % emergence and prepupal length of both parents and grandparents were examined for their effects on F3 emergence, a multivariate regression analysis showed that all these factors together accounted for 46% of F3 emergence variance at 16 h. All those partial regressions of factors associated with the male parent were significantly correlated with F3 emergence. Possible causes for these relationships were examined and the nature of diapause in P. forficalis and the significance of its intrinsic variation are discussed. Resume NATURE HEREDITAIRE DE LA DIAPAUSE ET SON INDUCTION PAR LA PHOTOPERIODE CHEZ PIONEA FORFICALIS (LEPIDOPTERA PYRALWAE) Dans une population naturelle de larves de P. forficalis elevees sous une photoperiode de 16 a a 20°, l'emergence des adultes se produit a un rythrne continu, presentant d'abord un maximum apres une duree d'enviroo 3 semaines de la period pre-nymphale et nymphale, et s'achevant par quelques eclosions sporadiques etalees sur plus de 30 semaines. II n'y a done pas ici de distinction nette entre individus a diapause et individus. sans diapause. La descendance de couples eleves a 16 h montrait une grande variation, dans la proportion des emergences precoces et dans la distribution de ces emergences; celle-ci tendait Dependant a etre parfois bimodale. Pour une photoperiode de 20 et 24 b, tous les adultes sont eclos dans un delai de 30 jours apres le debut du Stade pre-nymphal, alors qu'avec une photoperiode de 12 et 14 h il n'y a pas ou tres peu d'emergence d'adultes avant 40 jours. Avec une photoperiode de 16 h la proportion d'emergence avant 40 jours varie de moins de 10% a plus de 80%; cette photoperiode represents done une valeur critique. La duree d'emergence avant on apres 40 heures servira done de enTEre pour distinguer lee conditions de non diapause ou de diapause. Il a eTE possible de selectkmner la tendance a la diapause ou le developpement sans diapause, a partir d'adultes a eclosion tardive ou a eclosion precoce dans les conditions d'une photoperiode empechant ou induisant la diapause. On a trouve une correlation significative (r = 0.51) entre le pourcentage d'emergences d'imagos de la F1 apres une photoperiode de 16 h et celui existant dans les memes conditions chez les ascendants du pere. Dans une tentative d'explication, 2 generations successives ont eTE elevees a differentes photoperiodes et on a examine sur la F3 (emergence apres une photoperiode. de 16 h), I'influence de la photoperiode subie par les grands-parents et parents ainsi que les caracTEres relatifs a la duree du Stade pre-nymphal et au pourcentage d'emergence de ces memes ascendants. Une analyse de regression a alors confirme la transmission de la tendance a la diapause par le mâle. II semble que ce caracTEre soit de nature polygenique, et il est diseuTE de l'avantage adaptatif confere a l'espece par la grande variation de ses reponses a la photoperiode, ce qui peut expliquer sa large distribution geographique.