摘要:

ABSTRACT.The male bushcricket,Requena verticalis, calls with a signal containing two predominant frequencies, 16 kHz and 28 kHz. A synthesized call, made from a template of the natural call, was played to females under conditions of a two‐speaker trial on a flat arena. Orientation pathways to a speaker emitting only a 16 kHz signal were more circuitous than the pathways made by females orientating to a speaker emitting only a 28 kHz signal. Females preferred a signal with both carrier frequency peaks present within the song to a signal with only a 16 kHz or 28 kHz carrier frequency, when the signal containing a double peak was kept at equivalent absolute intensity to that with a single peak. Females chose signals containing a more powerful high frequency peak over a signal in which both peaks were balanced. For the higher peak, they were able to differentiate between frequencies with a separation of 8 kHz but not of 4 kHz. They were unable to differentiate between frequencies with a separation up to 8 kHz in the lower peak when one frequency was held at 16 kHz; however, when this frequency was held at 18 kHz, females were able to distinguish between frequencies with a difference of 4 kHz. (N.B.18 kHz is 2 kHz above the mean value for this frequency within the natural population.) We conclude that females are choosing males on the amount of power in the higher frequency range of their song and that this may be equivalent to a close calling male in the fiel

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1988.tb01118.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT.Pnigalio soemius(Hymenoptera, Eulophidae) is a polyphagous ectoparasitoid of the apple leafminerPhyllonorycter cydo‐niella(Lepidoptera, Gracillaridae). The tracks of females searching on the unmined leaf lamina and on the mine were segmented into 2 mm steps and analysed for angle distributions and correlations between successive steps. The movements on the mine are characterized by a higher mean and higher variance of turn angles compared to the turn angles on the leaf (kinesis‐reaction family). Both klinokinesis and schemakinesis, for which a more precise definition is proposed, are present. Varying the step length has a great influence on the result and can be used to identify different orientation reactions within one track. The insect turns sharply once the mine border has been reached, a behaviour shown to be a crude taxis. An ecologically related species,Sympiesis sericeicornis(Hymenoptera, Eulophidae), moves in the same way. For this species a taxis towards the host could also be observed. A complex mixture of these orientation behaviours allows the parasitoid to remain on the mine and to localise the h

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1988.tb01119.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT.A simple modification of the Ramsay method is described for the isolationin vitroof Malpighian tubules fromAcheta domesticus.Isolated tubules continue to secrete for many hours in a simple Ringer solution. The rate of secretion is linearly related to the length of tubule within the bathing fluid.Secretion rates during the immediate post‐equilibration period relate to the physiological state of the donor insect. Highest rates are recorded in tubules removed from animals during the scotophase when the crickets are most actively feeding. Starvation reduces the rate of secretion and when previously starved insects are given access to food the rate increases. These results are consistent with variations in the haemolymph titre of DH that are induced by feeding.Tubule fluid secretion is stimulated by either CC extract (1 gland pair/50 μ1) or dibutyryl cAMP (10‐3M). CC extracts increase the rate of fluid secretion by c. 200 pl/mm/min for up to 6 h after the tubules have been isolated. The response varies little with the age or physiological state of the donor insect. However, tubules from newly moulted insects secrete at very low rates and respond poorly to CC extract, although they are stimulated by cAMP. The significance of these results is discussed with particular reference to the use ofAchetatubules as a bioassay preparation fo

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1988.tb01120.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

PHEROMONE BIOCHEMISTRY. Edited by Glenn D. Prestwich and Gary J. Blomquist.ADVANCES IN INSECT PHYSIOLOGY. Volume 20. Edited by P. D. Evans and V. B. Wigglesworth.INSECT DEVELOPMENT. PHOTOPERIODIC AND TEMPERATURE CONTROL. By A. Zaslavsky. Translated from the Russian by B. Vasilyev.

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1988.tb01121.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT.The tortuosity of mite trails was characterized by their fractal dimension, which is the non‐Euclidean dimension varying between 1 (completely straight) and 2 (so tortuous that the complete two‐dimensional space is used). This index was shown to be a good, discriminative index for mite trails, which is a completely new use of the fractal dimension. The value of this index is compared with other tortuosity indi

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1988.tb01122.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT.In no‐choice tests, larvae of the Colorado potato beetle,Leptinotarsa decemlineata(Say) (Coleoptera: Chrysomelidae), avoided contact with, and were less frequently observed feeding on, excised foliage of the resistant wild potatoSolanum berthaultiiHawkes than on leaves of the cultivated potato,S.tuberosumL. For older larvae, reduced feeding was a consequence of less frequent contact withS.berthaultiileaves. However, first instars appeared unable to penetrate the adhesive barrier presented by glandular trichomes ofS. berthaultii, and those that remained on the leaflets fed less often than did first instars onS. tuberosum.Removal of the trichome barrier by wiping leaflets with tissue paper did not attenuate the apparent repellent effect ofS. berthaultifoliage, but led to increased incidence of feeding by first instars. Inhibition of larval feeding may therefore rely on a mechanical barrier provided by the glandular trichomes ofS.berthaulti

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1988.tb01123.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT.Effects of egg availability on daily ovipositional activity were determined forCoccophagus atratusCompere (Hymenoptera: Aphelinidae). Females were observed for 6 h per day for their entire adult lives. Observed ovipositional activity was analysed in relation to egg maturation before and after emergence, egg depletion during oviposition and egg replenishment after oviposition. Ovipositional activity, including oviposition, inconsequential probes and searching for hosts, occurred predominantly in the first 30 min of exposure to hosts on the 2nd, 4th, 7th, 10th and 13th days after emergence. The remaining time was spent on non‐ovipositional activities (preening, drinking honeydew and sitting on the glass of the experimental arena). Peaks of ovipositional activity were associated with high numbers of mature eggs in the ovaries. Eggs that remained in the ovaries after a bout of oviposition were apparently not mature even though they had attained their maximum size. Non‐ovipositional activity continued until females had built up a reserve of about eighteen mature eggs. After each successive bout of oviposition, the rate of oogenesis slowed down. Consequently females took longer to accumulate a supply of eggs and periods of non‐ovipositional activity increased.We conclude that (1) the availability of eggs and the tendency of females to store mature eggs influences ovipositional activity, (2) full‐sized eggs are not necessarily mature, (3) future experiments withC.atratuscould be restricted to days of high ovipositional activity, and (4) the terms syn‐ and pro‐ovigenic formulated by Flanders (1950) to describe apparent differences in oogenesis between various parasitic Hymenoptera do not apply toC. atratusand are therefore not universally

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1988.tb01124.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT.The potencies of seventeen analogues of ATP as gorging inducers forGlossina palpalis palpaliswere evaluated. The ranking for effective dose that induced half the flies to gorge (ED50) was: A tetra P 5 ATP=2'd ATP ADP=2'd ADP>AMP‐PNP>3'd ATP 2'3′dd ATP>AMP‐PCP>adenosine 5′ triphosphate 2′,3'dialdehyde AMP‐CPP » AMP. Females detect ATP and its analogues better than males. The ED50of ATP was 5 × 10‐7M for teneral females and 1.5 × 10‐6M for males. According to the potency order of the ATP analogues, theG.p.palpalisgustatory receptors recognizing ATP can be classified a

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1988.tb01125.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT.The effect of (flS)‐hydroprene treatment (2, 20, 200μg) on JH release was assessed in virgin females ofD. punctata(Eschscholtz) during the first 10 days of adult life as was basal oocyte length and number of cells in the CA. At a dose of 2μg hydroprene, JH release was stimulated slightly and, on days 4 and 6, oocyte growth was significantly greater than that of acetone‐treated controls. A similar but more striking enhancement of JH release and basal oocyte growth was observed at a dose of 20μg and a significant inhibition of JH release, in concert with a rapid growth of basal oocytes, was observed at a dose of 200μg. During the observation period, the mean number of cells in the CA decreased in a dose‐dependent fashion, with a highly significant reduction in numbers in 20 and 200μg‐treated animals. Reimplantation of vitellogenic ovarioles (three or six) into ovariectomized virgin females also resulted in an enhancement of JH release; this indicates that virgin female CA can respond to the stimulatory action of the ovary and is consistent with a model for (RS)‐hydroprene action in which the ‘positive feedback’ effect (stimulation of JH release) observed with low doses of the analogue occurs as a consequence of the action of the analogue on the ovary. (RS)‐hydroprene treatment stimulates basal oocyte growth to the point at which the previously unstimulatory virgin oocytes are able to enhance JH release by a feedback loop involving the CA an

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1988.tb01126.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT.The acoustic properties of the clicks emitted in response to male courtship pheromone by femalePyrrharctia Isabella(J. E. Smith) (Lepidoptera: Arctiidae) have been investigated. Extracts of male scent organs or synthetic male pheromones can be applied to a glass rod and used to stimulate females to produce these sounds. Power spectra, sound pressure readings, and oscillographic analyses show that the acoustic signals elicited by male extracts or synthetic male pheromones are not distinguishable from those produced in response to disturbance (handling). This is the first reported example of a sound produced by a female moth in a sexual context, and is the first reported example in moths of an acoustic response to a pheromonal stimulus.

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1988.tb01127.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY