摘要:

AbstractOxygen consumption was measured in fifth and sixth instar larvae ofSpodoptera exempta(Walker) (Lepidoptera, Noctuidae) at 25d̀C using Warburg manometry. The mean rate of oxygen consumption while feeding on maize or sorghum leaves was approximately twice that at rest. The increment in oxygen consumption attributable to feeding was 583±207 μlg‐1h‐l(mean±95% confidence limits) or, for maize, 6.1±3.5 μl O2per mg of l

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00890.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00891.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractThe courtship ofMeraporus graminicolaWalker is described and compared with that of other Pteromalinae. The sequence of courtship movements is characteristic of each species, and in all species studied the male's mating attempt is made not during a sequence of courtship movements but at the end of the sequence. Then the male extends its mouthparts, an action common to all species, and if there is no contact with the female's antennae a mating attempt follows.

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00892.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00893.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractDiapause in fully grown larvae of Ephestia elutella and Plodia inferpunctella was induced by low temperature and short photoperiods. Light intensities below 1 lx affected the induction of diapause in both species. At 20 and 25d̀C, the critical photo‐period for E.elutella wasc.14 h, and forP.interpunctella c.13 h. The sensitive phase in both species occurred at about the time of the fourth larval moult. InE.elutellaabout seven short photoperiods were required for larvae to enter diapause. InP.interpunctellahigh population density during larval development increased the proportion of larvae entering diapause.The conditions inducing diapause in laboratory stocks, and in stocks collected from the field, were different. Laboratory stocks of both species did not enter diapause at 25d̀C and required short photoperiods for diapause at 20d̀C. Some larvae of the field stock ofE.elutellaentered diapause in constant darkness at 30d̀C, the number being increased at low R.H., and almost all did in short photoperiods at 25°C. At 20T, most larvae of this stock entered diapause regardless of photoperiod, and at 15°C all did. InP.interpunctellaup to one‐third of larvae of the field stock entered diapause in short photoperiods at 25d̀C, and all did if transferred to short photoperiods at 20d̀C.In unheated premises, falling temperatures normally induce diapause inE.elutellaeach autumn, photoperiod only being important if temperatures are high. InP.interpunctella, photoperiod is a more important factor because it can override the effect of falling temperature to a greater extent than inE.elutella.In both species, however, different field populations may respond in dif

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00894.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractThe influence of environmental factors on the duration of diapause in Plodia interpunctella larvae reared in short photoperiods at 20 or 25° C was examined, Diapause terminated most rapidly in long photoperiods at high temperatures. Pupation was more delayed, and mortality was higher, in darkness than in the presence of light. At 20° C, LD 16: 8 hastened diapause termination only slightly in unchilled samples. Chilling for 10 weeks at 10° C greatly reduced the duration of diapause at 20 or 25° C in constant darkness, and rendered LD 16:8 effective in terminating diapause at 20° C. In addition, the quite short duration of diapause under LD 16:8 at 25° C was further shortened by holding for 6–10 weeks at 10° C or below, or by holding in an outbuilding during winter. Holding diapausing larvae at 15 or 20° C proved less effective. Temperature rises from 20 to 25 or 30° C proved effective in terminating diapause. In one stock, the temperature at which diapause was induced influenced its subsequent duration. Lighting conditions during induction had less influence on duration than had temperature, and no difference occurred between pupation times of larvae reared at different population densities, Under all conditions tested, diapause lasted longer in a recently collected field stock than in a labora

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00895.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractThe term ‘chirp’ as defined by Broughton (1952) and varied by him (1963a, b) is shown to be both inadequate and potentially misleading, particularly in the light of the principles of measurement of the time‐parameters of insect song, which are reviewed. It is important to include, in the measured duration of a given element, not only the durations of its constituent sub‐elements plus the intervals between them, but also an estimate of the interval that would have followed the last sub‐element, had the emission been prolonged further.‘Chirp’ should be totally restricted to initial, empirical descriptions of sounds that appear undivided to the human ear (or ultrasonics of corresponding length). For a first‐order assemblage of syllables, the term ‘echeme’ with a highly relevant etymology, is proposed.In early insect‐acoustics studies, Broughton (e.g. 1963a), seeking mainly to follow the admirable German terminology of Faber (e.g. 1953) and Jacobs (e.g. 1953), and to combine it with accepted physical terms, proposed certain English equivalents, many of which (such as ‘pulse’, ‘syllable’, ‘sequence’) have proved adequate in the years since then.The term ‘chirp’, however, had been rather loosely and inappropriately used in still earlier studies (Broughton, 1952, 1953; Chavasseet al., 1954) as the equivalent of Jacobs'Silbe(syllable = sound or ultrasound corresponding to one stroke of the singing apparatus). This was in direct conflict with the dictionary usage of ‘chirp’ as a sound that appears unitary and undivided to the unaided human ear (M. Duijm, personal communication in 1962).This is why, in the 1963 revision, Broughton abandoned the use of chirp as equivalent ofSilbe, in favour of the direct translation, syllable; and proposed restricting ‘chirp’ to usage as a term for the first‐stage description of a unitary‐sounding element of an animal emission, regardless of its composition in terms of physical units (pulses) or physiological units (syllables). Thus, the song ofChorthippus brunneus(Thunberg)(Orth., Acrididae) sounds unitary to the human ear, but consists of a rapid series of sounds each corresponding to one stroke of the apparatus: it is therefore, according to the 1963 system, a ‘polysyllabic chirp’ (Fig. 1)‐a chirp that happens to be a first‐order assemblage of syllables. By contrast, the song ofChorthippus parallelus(Zetterstedt) is a clear series of unitary sounds each visibly produced by one movement, and is

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00896.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractRhipicephalus pulchelluswas observed to aggregate on the tips of grass stems in the field in Kenya. Laboratory studies of this behaviour, using simulated glass ‘stems’ in sand‐trays, showed that this aggregation was not due to responses to either (a) chemical marks placed on the stems by climbing ticks, or (b) other stimuli transmitted down the stems by ticks already at their tips. Instead, the aggregation on stems appeared to be an adventitious result of the ticks aggregating on the ground (in the lab., under filter paper covering the sand substrate of the apparatus) and then climbing the nearest stem in due course. Briefer, comparative observations on R.appendiculatusindicated that it was much more mobile on the stems, spending less time at their tips, and not obviously aggreg

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00897.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractFractionation of methanolic extracts of haemolymph on Sephadex LH‐20 made possible the measurement of the titre of adipokinetic hormone in the haemolymph of locusts. Experimentally produced high concentrations of haemolymph carbohydrate caused a delay in the mobilization of lipid during flight, and very low titres of the hormone were present in the haemolymph of locusts injected with trehalose immediately before a 25 min flight. In these locusts flight speed was higher than saline‐injected controls. Although delayed lipid mobilization during flight was also seen in locusts injected with sucrose, sucrose is not utilized for flight metabolism and flight speed was not increased by the injection. Tentative estimates of the release rate (c.1000pg/20min flight) and half life (c.20 min) of adipokinetic hormone during flight are made. The results described suggest that during flight the rate at which trehalose disappears from the haemolymph does not play a major role in the initiation of the release of adipokinetic horm

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00898.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractThe behavioural rhythms of three species of nocturnal insects were studied: locomotion in a cockroach, luminescence in a firefly and luminescence in a glow‐worm. The behaviour was released at the change from light to dark in all cases. In continuous dim light, a circadian rhythm was apparent with a period of from 22.5 to 27 h in the cockroach, and from 19 to 23.5 h in the glow‐worm.In constant dim light, the cockroach shifted the phase of its rhythm when subjected to a change of temperature. A temperature step down some time prior to the expected onset of locomotion generated a phase advance, whereas a temperature step up generated a phase delay; the greater the step up, the greater the phase delay.By advancing the change from light to dark, it was found that glow‐worms could synchronize immediately to advances of up to about 6 h only. At greater advances an increasing phase angle difference between onsets of darkness and activity occurred. However, if a temperature step down was applied at the light change, immediate synchronization occurred up to 9–12 h before the normal onset.A theory is propounded which assumes that the onset of rhythmic behaviour is determined by the interaction of a circadian process of sensitization and a threshold for release of the behaviour. The threshold is high at high temperatures and light intensities, and low at low values of these. A temperature step up raises the threshold and delays the activity while a step down lowers the threshold and advances the a

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00899.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY