Effects of physiological condition and experience on oviposition behaviour of Trichogramma australicum Girault (Hymenoptera: Trichogrammatidae) on eggs of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae)

We produced an ethogram for and investigated effects of physiological condition and experience on oviposition behaviour for Trichogramma australicum on Helicoverpa armigera eggs. The data, coupled with the ethogram, have enabled the establishment of standard behavioural categories which can be used to assess acceptability of H. armigera eggs to T. australicum reared in vitro or in eggs of other species. Physiological and experiential conditions were investigated using females of three different ages (0–24, 24–48 and 48–72 h old), two types of sexual states (mated and unmated) and two types of ovipositional experience (naive and experienced). Durations of host finding, host examination, and post-ovipositional re-examination were reduced by oviposition experience and were shorter in younger females (0–48 h old). Oviposition experience reduces the duration of the drilling and percentage of females host-feeding. Being mated and young reduces the host examination time in subsequent oviposition bouts. Only ovipositionally inexperienced females host-feed before oviposition and host-fed more frequently than experienced individuals after oviposition. Host-feeding needs consideration for optimal culture.     

Circadian rhythms of feeding, oviposition, and emergence of the boll weevil （Coleoptera： Curculionidae）

Circadian rhythm of feeding, oviposition, and emergence of boll weevil adults were determined at five different photophases （24, 14, 12, 10, and 0 hours） and a constant 27℃ temperature, 65% RH in the laboratory. Squares from Petri dishes, where they were exposed to boll weevil females, were removed and examined for feeding and oviposition punctures every 4 hours during daylight （0700-1900 h） and every 12 h at night （1900-0700 h） over eight consecutive days. Cohorts of randomly selected egg-punctured squares were sampled from ovipositing females at 0700, 1100, 1500, and 1900 during 24 hours and under different photophase treatments, and maintained in Petri dishes at 27 ＋ I℃, 65% RH. Dishes were observed twice daily （1900 and 0700 h） for adults emerging at day or night. Circadian rhythm of oviposition was not affected by the length of the photophase. The boll weevil has round-the-clock circadian rhythm of oviposition, with a daytime preference. We observed that 82.4%-86.0% of the boll weevil eggs were deposited between 0700 and 1900 h, and 14.0%-17.6% between 1900 and 0700 h during a 24-h period. Feeding of boll weevil females in photoperiods 24：0 h （complete light） and 0：24 h （complete darkness） did not significantly change between 0700-1900 h versus 1900-0700 h, while the d .ally cycle of light and darkness in other photoperiods significantly increased the feeding punctures from 0700-1900 compared with 1900-0700 h. The circadian rhythm of emergence depended significantly on the time of oviposition and the length of the photophase. Investigation of boll weevil circadian rhythm provides a better understanding of boll weevil ecology and reveals potential weak links for improving control technologies targeting their reproductive strategies.     

Evaluation of the Growth of Salmonellae in Rappaport's Broth and in Muller-Kauffmann's Tetrathionate Broth

S ummary . The behaviour of 70 strains of salmonellae belonging to 44 serotypes in Rappaport's broth and in Muller-Kauffmann's tetrathionate broth was examined. With an inoculum of 5–25 cells, 5 strains did not grow in Rappaport's medium, 2 multiplied slowly and 63 grew strongly in 24 h. With an inoculum of 100–500 organisms all but one strain grew readily in 24 h. In Muller–Kauffmann's tetrathionate broth inoculated with pure cultures of salmonellae, growth of many strains was markedly inhibited, in the absence of added faeces, at 37° and 43°. This inhibition was more severe with light inocula at 43°. The addition of 0.05% (w/v) of salmonella-free human faeces to Muller–Kauffmann's tetrathionate broth, did not stimulate growth of salmonellae. In contrast, the addition of 5% (w/v) of human stools to this medium resulted in a heavy growth of the added salmonellae, especially at 43°.     

Differential survival of juvenile sockeye and coho salmon exposed to low dissolved oxygen during winter

Juvenile sockeye salmon (43–78 mm) survived 100% for 24 h in cages in ice–covered Black Lake, Alaska at oxygen saturations >65% (9 mg l^–1), but only 45% at 24% saturation (3·0–3·3 mg l^–1) and none at <17% saturation (2·3 mg l^–1). All juvenile coho (50–120 mm) survived 100% for 24 h down to 21% oxygen saturation (3·1 mg l^–1), and all 50 coho survived 4–5 days at 23–24% saturation (3·2–3·3 mg l^–1).     

The relationship of age and ovarian development to mating of Delia antiqua (Diptera: Anthomyiidae)

Abstract. The relationship between age and sexual receptivity for male and female onion flies, Delia antiqua (Meigen) (Diptera: Anthomyiidae), and factors affecting ovarian development were examined under various conditions. Confinement in small arenas had a significant negative effect on the rate of oogenesis over the first 10 days of adult life and, in some cases, on the percentage of females inseminated. The rate of oogenesis was not affected by male population density, but high density of females in large arenas appeared to have a priming effect. Few males in single-pair mating bioassays conducted over 24 h were sexually mature at 3–4 days post-eclosion, but > 50% mated when aged 6–7 days. Although females first mated at 3–4 days post-eclosion when confined for 24 h with sexually mature males, most females mated at 6–7 days of age when oocytes in the terminal ovariole position comprised 50% of total egg volume (stage 7 or greater on a 10-stage scale). No females aged 3 days were mated in no-choice and two-choice bioassays with sexually mature males over 24 h. Previtellogenic females (stage 3) were not inseminated, and ovarian development was only correlated weakly ( r = 0.48) with mating. Frequency of mating in mixed-sex groups of twenty flies was comparable with that in single pairs. However, more females were inseminated at 3–4 days, probably as a result of multiple matings by a few precocious males. These results do not support the hypothesis that females mate only when ovarioles are mature.     

CORTICOTROPHIN INCREASES CEREBRAL POLYAMINE CONTENT

Abstract— To determine whether changes in cerebral polyamines might mediate previously reported ACTH-induced changes in brain biochemistry and behavior, the cerebral content of polyamines was examined following ACTH treatment. Male CD-1 mice were injected daily for 3 days with long-acting (zinc phosphate) preparations of ACTH_1–24 (1 μg/g) or ACTH_4–10 (0.33 μg/g) and killed 24 h after the last injection. Putrescine, spermidine and spermine contents were determined by high pressure liquid chromatography. Putrescine content was significantly elevated in all brain regions by ACTH_1–24 (approx 50%), and in the telencephalon by ACTH_4–10 At the dose tested ACTH_4–10 was less effective than ACTH_1–24. Telencephalic spermidine was also elevated (10%)by ACTH_1–24, but spermine content was not altered in any brain region. One injection of the long-acting ACTH_1–24 preparation elevated telencephalic putrescine (49%) 24 h post-injection. ACTH_1–24 (1 μg/g) in saline produced a peak elevation of all three telencephalic polyamines 6 h post-injection, while in the liver only putrescine was significantly elevated and reached a peak at 10h. Neither plasma polyamine nor ornithine concentrations were significantly altered by any of the treatments. Corticosterone, in both single and multiple injection regimens, failed to alter telencephalic polyamine content. Adrenalectomy, however, prevented the ACTH_1–24-induced increase in telencephalic polyamines. It is concluded that ACTH acts directly in the brain to increase cerebral polyamine concentrations. The possibility that adrenal hormones exert permissive effects on this action is discussed.     

Behavioural modifications in the early life stages of Siberian sturgeon (Acipenser baerii, Brandt)

Behavioural modifications of Acipenser baeri were studied during early ontogeny at 18 °C by means of specific tests and general observations. During A. baeri ontogeny, several different periods could be clearly distinguished by behavioural patterns. From hatching to 3 days post hatch (p.h.), specimens exhibited swimming-up and drift behaviour. A transition from a pelagic to benthic behaviour occurred between 4–5 days p.h. and specimens were positively rheotactic. At 7–8 days p.h., prelarvae aggregated into schools of different shapes. During prelarval development, specimens were positively phototactic, preferred white bottoms and did not show any preference for bottom concealment. Between 9–10 days p.h. coinciding with the onset of the exogenous feeding, larvae were active bottom swimmers, schooling behaviour disappeared and larvae dispersed. During early ontogeny, changes in body coloration were observed among those specimens who swam over bottoms of different brightness and during the day/night cycle. From 9 to 12 days p.h., larvae were positively phototactic, denied bottom cover and showed preference for white substrates. At 13 days p.h., the percentage of fish exhibiting positive phototactism, preferring open to concealed bottom habitats and white bottoms started to decrease, while at 20 days p.h. specimens showed a clear preference for bottom concealment and black and greyish bottoms. The significance, use and evolution of the former behavioural patterns is deeply discussed.     

Non-invasive corticosterone treatment changes foraging intensity in red-eyed vireos Vireo olivaceus

Corticosterone is thought to play an important role in food caching and foraging behaviour. However, the direct influence of increased plasma corticosterone on feeding behaviour is still unclear. In this study the effect of increased corticosterone on feeding behaviour in migratory active red-eyed vireos Vireo olivaceus was investigated. We hypothesized that if increased corticosterone levels facilitate foraging behaviour, an increased number of visits to the food bowl by corticosterone treated birds would be seen. In addition to ad lib food during the experiment, the vireos were fed every full hour between 09.00–13.00 h with one meal worm injected either with 4 μg corticosterone dissolved in 20 μl DMSO, or with DMSO only as a control treatment. The presence or absence of a bird in the food bowl was recorded by a motion detector between 09.00–15.00 h. The non-invasive corticosterone treatment increased plasma corticosterone levels and caused vireos to visit the food bowl more frequently compared to control treated individuals between 11.00–12.00 h and 13.00–15.00 h. Our data indicate that corticosterone has an effect on feeding behaviour in birds.     

Description of a new Lake Tanganyikan cichlid fish of the genus Cyprichromis(Perciformes: Cichlidae) with a note on sexual dimorphism

Cyprichromis coloratus , a new cichlid species, is described based on 41 type specimens from the Zambian coast of Lake Tanganyika. It differs from Cyprichromis microlepidotus by having fewer scales in the longitudinal line (41–44 v . 59–70 in C. microlepidotus ) and upper lateral line (31–36 v . 47–59), from Cyprichromis leptosoma by more dorsal‐fin spines (14–15 v . 11–13 in C. leptosoma ) and longitudinal line scales (41–44 v . 38–40), from Cyprichromis pavo by fewer dorsal‐fin spines and soft rays (29–31, usually 30, in total v . 30–32, usually 31, in C. pavo ), and from Cyprichromis zonatus by shallower body depth [24·0–28·5 (26·4 ± 1·1)% of standard length v . 24·5–30·5 (28·4 ± 1·3)% in C. zonatus ] and smaller eye [eye length 25·2–30·9 (27·2 ± 1·1)% of head length v . 27·9–33·3 (30·2 ± 1·2)%]. The new species is also separable from C. microlepidotus , C. pavo and C. zonatus by absence of distinct small spots on the body ( v . pearl grey and yellowish small spots along scale rows on body at least in males of C. microlepidotus and C. pavo ), its distinct dichromatism (particularly on the caudal fin) between males of the same population ( v . dichromatism absent in C. zonatus ) and absence of vertical bands ( v . three or four distinct vertical bands beneath dorsal fin base in live males of C. zonatus ). Cyprichromis coloratus n. sp. also exhibits sexual dimorphism, females having a larger head and males having longer pelvic fin, differences which are discussed in relation to reproductive behaviour. A key to the five species of Cyprichromis is included. A lectotype is designated for Cyprichromis leptosoma .     

Mass-rearing biology of Fopius vandenboschi (Hym., Braconidae)

Abstract:   Basic biological information concerning the reproductive activities of Fopius ( Biosteres ) vandenboschi (Fullaway) (Hym., Braconidae, Opiinae) were determined to facilitate insectary mass production. Mean (±SE) progeny production per generation (yield) of 200 ♀♀ F. vandenboschi was 6835.8 ± 433.2 and 3755.8 ± 112.4 parasitoids, with 24-h exposure to second instar Bactrocera dorsalis (Hendel), and Ceratitis capitata (Wiedemann), respectively. Ceratitis capitata as a factitious host was more sensitive to parasitism, producing a significantly higher percentage of uneclosed host puparia frequently containing parasitoid cadavers (22.5 ± 0.8%), than B. dorsalis (3.4 ± 0.2%). The overall mean production of female offspring was ≥50%♀♀ in both host species. Unlike several other opiine parasitoids, young (5-day-old) females of F. vandenboschi produced low proportion of daughters (26–37%♀♀) and significantly shifted production to female-biased offspring (53–71%♀♀) at older age intervals (16–30 days). Based on the parasitoid yield data with a 24-h exposure period to second instar host larvae of B. dorsalis , about 150 cage replicates (of 200 ♀♀ each) may be sufficient to mass produce about 1 million parasitoids of F. vandenboschi during the reproductive period of 5–30 days, with an average of 56% female offspring. A short oviposition exposure period of 6 h was not optimal for mass production of F. vandenboschi . Total yield at 6 h exposure was one-fifth the production at 24-h exposure, using B. dorsalis hosts.     

The control of postharvest decay in table grapes using acetaldehyde vapours

Grapes ( Vitis vinifera L. cv. 'Sultanina') harvested at the end of the 1985–1988 seasons, received postharvest application of acetaldehyde (AA) vapours for 24–40 h. Treatment with AA vapour at 20 °C or 0 °C reduced significantly the decay caused by several fungi: Botrytis cinerea, Rhizopus stolonifer, Aspergillus niger and Alternaria alternata . In grapes treated with 0.5% AA for 24 h, no R. stolonifer was found after 8 days of storage at 20 °C. Treatment with 0.25% AA vapour for 40 h of grapes cv. 'Perlette' inoculated with R. stolonifer reduced the decay by 89%.     

Changes in tissue adenylates and water content of bluegill, Lepomis macrochirus, exposed to copper

Bluegill were exposed to copper (2–0 mg/1⁻¹ unfiltered) for 24, 48, 72 or 96 h at 24° C. This concentration approximated the 96 h LC20. Water content of liver increased 4–8% after 24 h exposure and muscle 4–6% by 48 h. These changes persisted throughout the 96 h experiments. Copper exposed fish exhibited decreases in muscle ATP, ADP, total adenylates, and energy charge by 48 h. There was a trend toward recovery of ATP with further exposure. Liver ATP of exposed fish was lower than controls at all intervals with the greatest difference evident at 48 h. No significant changes in brain adenylates were observed. Muscle and liver lactic acid was unchanged at 48 h exposure, therefore tissue hypoxia was not the cause of the adenylate changes. It was concluded that copper causes decreases in muscle and liver ATP several days before probable death of copper exposed fish and the changes seen are the result of dilution by increased tissue water, and the copper acting on certain cellular enzymes involved in detoxification and energy metabolism.     

A female sex pheromone in Bruchidius atrolineatus (Pic) (Coleoptera, Bruchidae): analysis of the factors affecting production or emission of this pheromone

ABSTRACT. . The females of the tropical Bruchid Bruchidius atrolineatus (Pic) (Coleoptera) produce a sex pheromone that influences male behaviour. This pheromone, tested on males in an olfactometer, triggers characteristic antennal movements followed by a distinct chemo-anemotaxis. Sex pheromone production depends on the age of the females and is partly correlated with their ovarian activity. Females 0–24 h old are not attractive, but they begin to attract males on the second day of adult life. Vitellogenesis seems to correlate with the emission or the production of the pheromone but there is no precise synchrony between the two phenomena which are probably induced by the same endocrine factors. Within 1 h after mating there is a decrease in the females' attractiveness, which lasts at least 48 h. Under our experimental conditions no particular rhythm of production or emission of the sex pheromone in B. atrolineatus could be observed.     

Haul-out and diving activity of male Atlantic walruses (Odobenus rosmarus rosmarus) in NE Greenland

During August-September 1989 and 1990, movements, haul out and dive activity of male Atlantic walruses ( Odobenus rosmarus rosmarus L.) were studied at a terrestrial haul-out site situated in an inshore foraging area in NE Greenland at 76± 30' N. Data were collected from direct observations of a group of about 50 males during August, including walruses that could be individually identified from natural markings, and from tracking of 8 adults equipped with satellite-linked radio transmitters during August-September. In both years, instrumented walruses hauled out for a total of 29.3% of the sampling time. In 1989, when ice floes were available for hauling out, the walruses spent 11% of the time on ice, whereas in 1990, when ice was absent from the study area, they only hauled out on land. Duration of haul-out periods, which did not differ between months or years, averaged 11 h (0.46 d) on ice (S.D. = 5.9, range: 1–29 h, n = 19 periods), and 38 h (1.6 d) on land (S.D. = 11.7, range: 13–64 h, n = 43). The walruses mainly hauled out during the afternoon and evening. Numbers hauling out on land during August were negatively correlated with wind direction, precipitation (rain) and wind-chill. In 1989, the duration of periods of absence from the terrestrial haul-out site (i.e. presumed foraging trips) averaged 206 h or 8.5 d (S.D. = 106.9, range: 48–412 h, n = 13), whereas, in 1990, such trips averaged only 81 h or 3.4 d (S.D. = 37.9, range: 24-156 h, n = 24), reflecting that walruses used the haul-out site more frequently when ice was absent. Direct observations of foraging walruses showed that they were submerged about 81% of the time.     

Seasonal changes in the day and night activity of adult perch, Perca fluviatilis L.

Perca fluviatilis L. were caught by gill nets every 3 h over a 24 h period monthly from February 1975 until January 1976. The numbers caught increased with rise in temperature (correlation coefficient r = 0.86 P < 0.001). During the winter months perch migrated into deeper water although some fish were still caught in shallow water (1–6 m). Perch were active at very low light intensities. However changes in visual surface irradiance (400–700 nm) and water clarity caused inverse changes in activity. Only June did not conform to this pattern and it was presumed that spawning behaviour was of primary importance. It is suggested that increase in eutrophication with its effect on water clarity enables fish to become more active during the day in the summer months. They are thus able to utilise food sources to a maximum at an optimum period for feeding and growth.     

Effects of sucrose concentrations and fly age on feeding responses and survival of female and male western cherry fruit flies, Rhagoletis indifferens

Abstract. The effects of single meals of different sucrose concentrations on feeding responses and survival of 8–24-h-old, 1–2-, 10–12- and 31–36-day-old female and male western cherry fruit flies, Rhagoletis indifferens Curran, were determined. Feeding time and food consumption response patterns in both sexes within age groups were curvilinear. Feeding times increased as sucrose concentrations increased, and were longest when the sucrose concentration was 100% (dry). Consumption of dilute wet sucrose was low, whereas consumption of concentrated wet sucrose was high. However, consumption of dry, 100% sucrose was also low. One to 2-day-old flies of both sexes that had not previously fed consumed more sucrose foods than unfed 8–24-h-old flies and 10–12- and 31–36-day-old flies that had been starved for 16–24 h. Females consumed more than males, but they consumed the same amount as males per mg bodyweight. When fed single 20% and 60% sucrose meals, 1–2-day-old flies survived longer compared to flies in all other age groups, with 31–36-day-old flies surviving shortest. Despite age-related differences in survival, in general, no sex differences in survival were seen in flies fed sucrose within any age groups, or in flies fed sucrose-yeast, cherry juice and honeydew foods. The results suggest that sugar-feeding behaviours and the energy invested in sugar 'seeking' by both sexes of R. indifferens should be the same throughout life.     

Decreased time for detection and quantification of virulent Bacillus anthracis and Yersinia pestis using a BioNanoPore (BNPTM) membrane technology

Many aspects of biodefense research require quantitative growth assessments of the test agent. This study evaluated the BioNanoPore (BNP™) technology to quantitate Bacillus anthracis and Yersinia pestis faster than traditional plate counting methods. The BNP™ technology enabled quantification of B. anthracis and Y. pestis in phosphate-buffered saline and naïve rabbit blood at 6 and 24 h, respectively. After 6 h of growth, counts for B. anthracis ranged from 6·19–6·45 log₁₀ CFU ml⁻¹ on BNP™, while counts after 24 h on tryptic soy agar (TSA) ranged from 6·51–6·58 log₁₀ CFU ml⁻¹. For Y. pestis , counts on BNP™ at 24 h ranged from 6·31–6·41 log₁₀ CFU ml⁻¹ on BNP™ and ranged from 6·44–6·89 log₁₀ CFU ml⁻¹ on TSA at 48 h. This study demonstrates that the BNP™ technology provides a more rapid detection of B. anthracis and Y. pestis , which could aid in the evaluation of potential medical countermeasures and treatments as well as other biological defense applications such as surface sampling or decontamination efficacy.     

Territorial and non-territorial spawning behaviour in the bream

The spawning behaviour of bream Abramis brama was studied in 1993, in a harbour on the River Meuse, Belgium. Fish spawned from 22 to 27 April and from 11 to 14 May, when the water temperature rose to 14.5) C. The reproductive behaviour of the bream was studied within a 15 m long part of the harbour using a video camera. Territorial males with tubercles (33–43 cm total length; >5 years old) defended bank areas of diameter 80–150 cm which included spawning substratum, i.e. roots of alder and willow trees and aquatic plants. Water depth ranged from 25 to 50 cm. Non-territorial males without tubercles (24–33 cm; 3–4 years old), remained 2–4 m away from the bank. Aggressive behaviour between males was frequent and, occasionally, males with tubercles were unable to defend a territory. Mature females (25–43 cm; >3 years old), coming from the deeper water of the surrounding area, were followed by non-territorial males before spawning in territories near the bank.     

Kleptoparasitic interactions of Arctic Skuas Stercorarius parasiticus and Black Guillemots Cepphus grylle in northeastern Hudson Bay, Canada

Kleptoparasitic behaviour of Arctic Skuas was studied at a Black Guillemot colony in northeastern Hudson Bay, Canada. Skuas procured fish in 7-2% and 19-9% of attacks, and Black Guillemots lost fish in 7-2% and 21-2% of chases in 1982 and 1983, respectively. In 1983 chase outcome was related to distance between birds at the end of a chase and number of skuas in pursuit. The skuas' foraging efficiency (energy intake/energy expended during hunting) was estimated at 45 for 1982 and 5–8 for 1983, and total daily energy expenditure was estimated at 2–4 and 2-1 × b.m.r. for these years. Energetic calculations suggested that skuas obtained sufficient food to meet their daily needs in 3–6 h of hunting in 1982 and 2–7 h in 1983. The absence of intensive kleptoparasitic activity by breeding skuas in North America is attributed to the paucity of colonies suitable for both feeding (due to available host species and colony topography) and nesting (due to presence of arctic foxes and/or polar bears).     

Laboratory evaluation of flight activity of the common cutworm, Spodoptera litura (Lepidoptera: Noctuidae)

Abstract  The flight activity of Spodoptera litura in tethered conditions is evaluated using a computer-mediated flight-mill in the laboratory. The 3–4-day-old moths fly longer and farther than those of other ages. Male and female moths exhibit similar flight activity. Mating status does not influence the flight duration and distance of 2-day-old females. However, these two flight parameters with a 6-day-old mated female is significantly lower than that of unmated ones. The optimum temperature for flight ranged from 16–24°C, whereas the optimum RH ranged from 60%–100%. During 72-h period, the total flight duration and distance of 1-day-old male and female moths were 19.6 h (± 5.8) and 83.3 km (± 28.4), and 24.0 h (± 7.0) and 105.4 km (± 37.4), respectively. These results indicate that S. litura has a great potential to undertake long-distance migratory flights.