ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1996.tb00850.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract.The adipokinetic hormone (AKH‐I and AKH‐II) content of the corpora cardiaca from adult males of crowded (gregarious) and isolated (solitary)Locusta migratoria migratorioides(Reiche&Fairmaire) was quantified by reverse‐phase high‐performance liquid chromatography.Significantly less total hormone was found in the corpora cardiaca of crowded locusts than in those glands of isolated locusts at the age of 12–19 days after fledging.The ratio of AKH‐I/AKH‐II was higher in crowded than in isolated locusts at this age.From the age of 12–19 days to that of 25–30 days, AKH content increased significantly in the corpora cardiaca of crowded locusts, but no such increase was found in the glands of isolated locusts, and at 25–30 days there were no significant differences in the AKH content of the glands from crowded a

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1996.tb00851.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract.The Senegalese grasshopper,Oedaleus senegalensis(Krauss) (Orthoptera: Acrididae), is periodically a devastating pest of subsistence crops in the sahelian zone of West Africa.Egg diapause has been suggested as an important component of the mechanism acting to generate outbreaks and therefore diapause duration, egg survival in relation to desiccation and egg‐pod morphology were investigated in this study.Three months after oviposition, 50% of initially diapausing egg pods maintained in the laboratory exhibited ‘partial emergence’ and produced hoppers.No difference in diapause duration was evident between egg pods maintained at a constant 30 ± 1°C and those maintained under alternating temperature conditions of 23 ± 1°C and 35 ± 1°C.Laboratory maintained eggs showed significant variation in diapause duration with diapause lasting between 2 months and 4 years.Diapause duration was shorter in the field with onlyc.1.4% of eggs remaining in diapause after a single dry season (6–7 months).Survival of eggs in relation to desiccation was high in the field and low in the laboratory, and field eggs lost onlyc.20% of their body weight over the dry season.Survival of diapausing and non‐diapausing egg pods in the laboratory was similar, indicating that diapause in this species is primarily a mechanism for preventing emergence at an inappropriate time of year, rather than conferring any additional resistance to desiccation.Egg pods oviposited under diapause‐inducing conditions (LD 14:10 h, 25°C) were significantly shorter than those laid under non‐diapausing conditions (LD 10:14 h, 40°C).These results are discussed both in relation to possibleO.senegalensis‘bet‐hedging’ strategies and to the probable mechanism operating behind majo

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1996.tb00852.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract.The effects of age, sex, mating status, pre‐exposure to pheromone, resource (diet) quality, and starvation on the response ofProstephanus truncatus(Horn) (Coleoptera: Bostrichidae) to its male‐produced aggregation pheromone were investigated.Age was an important factor determining the level of response to pheromone: young adults were more responsive than older adults.The suitability of the resource in whichP.truncatusis present affected its dispersal tendency, but not its sensitivity to pheromone perse.Sex, mating status, brief prior exposure to pheromone, and starvation did not influence the response of the larger grain borer to pheromone.The orientation behaviour of the beetle is described, and it is proposed that the pheromone primarily functions as a ‘suitable resource location and colonization si

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1996.tb00853.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract.Data are presented on the development from egg to adult of a wild‐type and an albino strain of the spider miteTetranychus urticaeon a semi‐synthetic liquid diet.The diet is a modification of the diet developed by Van der Geestet al.(1983).Apart from the standard diet without added carotenoids, diets supplemented with either β‐carotene or vitamin A were tested.A high incidence of diapause was found in the wild‐type strain under short‐day conditions on all three diets.No diapause was found in the albino mutant under short days on the standard diet.Partial restoration of the photoperiodic response was obtained after addition of β‐carotene to the diet, and full restoration was found after the addition of vitamin A.Diapause could be terminated in diet‐reared diapausing females of both strains after a cold rest of 3 weeks at 4°C.The results lead to the conclusion that vitamin A or a derivative of vitamin A probably functions as the photoreceptor pigment for the photoperiodic induction of diapause in

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1996.tb00854.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract.Using heterologous and conspecific bioassays, two peptides have been isolated from methanolic extracts of corpora cardiaca from the pyrgomorphid grasshopperPhymateus morbillosusL.The structures of both peptides were elucidated by a combination of Edman degradation, after deblocking the N‐terminal pyroglutamic acid residue, and mass spectrometric techniques.One peptide is an octapeptide (pGlu‐Leu‐Asn‐Phe‐Ser‐Thr‐Gly‐TrpNH2) which also occurs in other insects and is code‐named Scg‐AKH‐II.The second peptide is a novel decapeptide member of the AKH/RPCH family (pGlu‐Leu‐Asn‐Phe‐Thr‐Pro‐Asn‐Trp‐Gly‐SerNH2code‐named here Phm‐AKH.It is the first example of a different peptide in the same genus.The analysis of changes of metabolites in the haemolymph, fat body and flight muscles of maleP.morbillosusduring a 30 min flight and rest after flight reveal an overall picture of flight metabolism similar to that ofLocusta migratoria.Carbohydrate‐fuelled metabolism is pronounced during the first 15 min of flight, whereas lipid‐based metabolism is mainly used thereafter.By analogy with work onL.migratoria, it is concluded that the endogenous peptides

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1996.tb00855.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract.MarkedGlossina pallidipesAusten were released downwind of an odour source in the field in Zimbabwe and the percentage recaptured at the source on the same day was measured.In the absence of odour, 1.3% of the marked tsetse released from a box or refuge were recaptured, independent of the distance between release point and odour source.The distance was varied from 10 to 100 m.When natural ox odour or a blend of carbon dioxide, acetone, octenol and phenols was dispensed, untransformed recapture percentages of box‐released tsetse decreased from 18% for tsetse released at 10 m to 2% for tsetse released at 100 m.Recapture percentages were significantly higher than in the absence of odour at all release distances for ox odour and for release distances up to 75 m downwind for the artificial odour.When a combination of acetone, octenol and phenols or carbon dioxide on its own was dispensed, recapture percentages decreased from 6% for tsetse released at 10 m to 0% for tsetse released at 100 m.With these odours, recapture percentages were higher than in the absence of odour when tsetse were released at 20 m from the source, but were lower than recaptures in the presence of ox odour or the artificial mixture with carbon dioxide.Recapture percentages of flies spontaneously leaving refuges were higher than those of box‐released tsetse.Proximity of source had no effect on the recapture percentage of refuge‐leaving tsetse and host‐location efficiency was close to 100% when host odour was detected at 30 m or less.The results are discussed in relation to the host location strategy of

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1996.tb00856.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract.We determined standard metabolic rate at 25°C in forty‐eight species of millipede from southern Africa and compared these data with confident measures of standard metabolic rate previously published for other arthropod groups.Metabolic rate in millipedes was not significantly different from that in beetles, ants or spiders once body mass effects had been accounted for, but was significantly higher than that in ticks.The exponent for the mass scaling of metabolic rate did not vary significantly between the five arthropod orders.Our best estimate for the relationship between standard metabolic rate (μl O2h‐1) and body mass (mg) in non‐tick arthropods was 0.86 m

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1996.tb00857.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract.High percentages of naiveCadra cautella(Walker) (Lepidoptera: Pyralidae) males not pre‐exposed to pheromone flew upwind to sources containing 50 ng (83%) and 500 ng (97%) of pheromone, but not to sources containing 5 μg (23%) and 50 μg (4%).Of the naive males that flew upwind in response to 50 ng sources, 67% located and landed on the source, whereas fewer than 19% of the naive males that flew upwind in response to higher doses located and landed on the sources.A 2‐minute pre‐exposure ofC.cautellamales to a spray cloud containing 50 ng, 500 ng, 5 μg or 50 μg of pheromone, induced shifts in response levels such that in wind‐tunnel bioassays performed 1 h later, there was an increase in the doses that optimally elicited upwind flight and landing on the source that was proportional to the pre‐exposure dose.Few of the pre‐exposed males flew upwind to (10–43%) and landed on (0–33%) 50 ng sources, whereas they now perferentially flew upwind to(58–81% and 52–73%) and landed on (33–68% and 55–60%) pheromone sources of doses of 500 ng and 5 μg, respectively.Therefore pre‐exposure to pheromone promoted a shift of threshold for response, and not an overall reduction

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1996.tb00858.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract.Ventilatory motor patterns were recorded from abdominal muscles in crickets,Gryllus campestrisL.andTeleogryllus commodus(Walker), at rest and during three types of stridulatory motor activity; calling, courtship and aggressive song.Increases in ventilatory period were almost exclusively due to an increase of the pause between expiratory bursts, whereas abdominal ventilatory bursts remained constant at 200 ms.Ventilatory patterns depended on the stridulatory motor pattern and indicated that the same basic respiratory oscillator exists in both cricket species.InG.campestristhere was a strict 1:1 coupling between chirps and ventilatory bursts.InT.commodussuch a relationship was also observed for the chirp part of the songs, but less strictly for the trill part of the calling song and not for the courtship song.In both species the onset of the ventilatory burst was within ± 100 ms of a stridulatory chirp.Ventilatory burst lasted longer the earlier they began before a stridulatory chirp.This suggests strongly that the stridulatory motor pattern terminates the expiratory burst, and thus influences the ventilatory motor pattern

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1996.tb00859.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY