摘要:

ABSTRACT.The presence of an aggregation pheromone was studied in two species of milkweed bugs. The nymphs, young adults and old adults ofOncopeltus fasciatuswere tested for their aggregation in response to acetone extracts of themselves and each other. TheO. fasciatusnymphs were also tested for their response to odour from liveO. fasciatusnymphs, as well as toLygaeus kalmiinymphal extract, and the response ofL. kalmiinymphs towardsO. fasciatusnymph extract was tested. It was found that there is an aggregation pheromone in the nymphs and young adults and that there may be an alarm pheromone in the old adultO. fasciatus.A preliminary chemical analysis performed on the aggregation pheromone revealed it probably to be a polar non‐aromatic compound of high molecular weigh

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00619.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.A light microscope study of the endocrine and ovarian systems ofLucilia sericataunder two diets revealed that in young females fed on sugar and water, medial neurosecretory cells (MNC) synthesized and stored neurosecretory material (NSM) as the flies matured. The MNC remained filled with NSM as long as the diet was maintained. Following a small increase immediately after emergence, the size of the corpora allata (CA) showed little further change, and the nuclei of nurse cells remained small. However, rapid changes occurred in these tissues soon after a meat meal: NSM was discharged from the MNC, and the CA increased in size. These changes were at a maximum 20 h after a meat meal. 4h later, vitellogenesis was well established and the nurse cell nuclei had increased in size 20‐fold. Growth of the nurse cell nuclei continued until approximately 6 h before the completion of vitellogenesis when they are resorbed. Oögenesis took about 48 h at 25°C. When 100 μg of each of three different juvenoids were applied topically to different sugar‐fed flies, the nuclei of both MNC and nurse cells became enlarged, whereas the CA were somewhat reduced in size. The relationship between protein ingestion and oogenesis is discussed, and the results obtained withL. sericataare compared with those of other species, especially the blowflyCalliphora erythroc

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00620.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.The innervation of the locust head hairs was investigated by filling the sub‐cuticular neurones with cobalt and by recording antidromic spikes at individual hairs when the circumoesophageal and cervical connectives were stimulated. The central projections from most head hairs (c.80%) terminate in the suboesophageal ganglion, whereas about 20% extend into the thoracic ganglia. Sensilla with projections to the thoracic ganglia are structurally no different from those whose fibres terminate in the suboesophageal ganglion and they are scattered throughout the hair fields with no consistent positions in different individuals. We have re‐investigated the ‘accessory response’ (Camhi, 1969) and conclude that it is not indicative of a separate afferent or efferent system but is simply cross‐talk from adjacent axons. We relate our findings to the fibre composition of the dorsal tegument

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00621.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.Observations on the nature and control of spontaneous flight activity in tsetse flies have so far been made only onG. m. morsitansWestw. This paper reports preliminary observations of the same kind on two other species:G. p. palpalis(R.‐D.) andG. austeniNewst. The flight pattern of all three species consisted of short bursts of activity (usually lasting<1 min) separated by long intervals of rest, changes in activity level occurring exclusively as changes in the frequency of these flight bursts. In constant conditions in LD 12:12,G. palpalisandG. austeniwere almost totally diurnal, with strongly predominant afternoon activity peaks, but a slight tendency to decrease activity around noon as occurs to a much greater extent inG. morsitans.This rhythm persisted in constant darkness (DD), but whereas in mostG. morsitansonly the morning peak was retained in DD, inG. palpalisandG. austeniit was only the afternoon peak. The loss of the afternoon peak inG. morsitansmay be due to the very low activity levels in DD. Food deprivation led to increased activity in all three species, most markedly so inG. palpalisandG. austeni, in which the amount of activity per day increasedc.ten‐fold over three days' post‐emergence starv

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00622.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.Using theGalleriabioassay, no difference could be found between the JH titre of diapausing and developingNasonialarvae. Compared to the values found in some Lepidoptera, the JH titres inNasonialarvae are low,c.14Galleriaunits/g live weight. Induction of diapause could not be brought about by topical application of JH I, JH analogues, precocene, or ecdysterone to the maternal generation, nor by treating eggs or larvae with compounds with JH activity. Diapause was easily terminated by topical application of ecdysterone, however. If ecdysterone treatment was preceded by JH‐treatment, the percentage of larvae terminating diapause was reduced: JH II seems to be more potent than JH I or JH III in this effect if the interval between JH and ecdysterone treatment is 72

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00623.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.DuringDrosophilacourtship ‘pulse song’, muscle potentials occur at two points during the cycle of neuromuscular events which result in a sound pulse being produced. The dorsal longitudinal, second and third dorsal ventral and axillary muscles show potentials 18 ms before each sound pulse while the first dorsal ventral, basalar and sternobasalar muscles fire 3 ms after the onset of each pulse. The timing of these events remains unaltered in animals with the antennae removed, indicating that acoustic feedback is not an important factor. Courting vestigial flies, in the absence of detectable wing base movements, produce indirect muscle potentials at the appropriate song inter‐pulse intervals. Thus proprioceptive feedback is also unimportant in determining the intervals between pulses. During putative ‘sine song’, ‘pulse song’ and flight in vestigial flies, however, the timing of basalar muscle potentials is abnormal. Also, if the wing is driven externally at a frequency different from that of normal flight, basalar and, to a lesser extent, first dorsal ventral muscles, are phase locked to the driving frequency. These two results suggest that the timing of those muscles which fire at the beginning of the sound pulses is set by proprioceptive feedback. A model of song production is proposed which takes into account the data from this and from previously pub

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00624.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.Techniques for investigating pheromones responsible for clustering inApis melliferaare described. Stable queenless clusters were formed in response to synthetic Nasonov pheromone mixed with (E)‐9‐oxo‐2‐decenoic acid. This mixture plus the addition of (E)‐9‐hydroxy‐2‐decenoic acid was less potent in initiating cluster formation than it was without this addition, but the clusters once formed sometimes grew larger. Other unknown components from the queen's mandibular glands encouraged cl

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00625.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.The pattern of circadian flight activity in femaleCulex pipiens quinquefasciatuswas modified after insemination or injection with an extract of male accessory glands. The changes were linked with an apparent alteration in the timing of one of the major components of the rhythm. In LD 12:12, virgin females were highly active at ‘dusk’ and ‘dawn’ and in the latter part of the dark phase; inseminated females were less active at ‘dusk’ and ‘dawn’ and were active in the first half of the dark phase. In DD, there were two peaks in each cycle, the initial (evening) peak occurring at the same time after all treatments; the peaks were approximately 12 h apart in virgin females, but only 6–7 h apart in females which had been inseminated or injected with accessory gland extract. The accessory gland substance (pheromone) also appeared to cause a progressive increase in activity. These induced changes are consistent with a switch to host‐seeking behaviour, which, under natural conditions, leads to a peak of biting in the

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00626.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.The responses of third instar carrot fly larvae,Psila rosae, to plant metabolites were studied in a moving air olfactometer. Directed responses over distances greater than 7.5 cm were obtained to both host and non‐host plant odours, to CO2and methyl eugenol, a volatile secondary metabolite of carrot roots. Larvae also oriented to gradients of contact‐chemostimuli. The role of both olfactory and contact‐chemostimuli in the host plant finding behaviour ofP. rosaelarvae is discussed, and observational evidence for the behavioural mechanisms involved pres

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00627.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.Running activity was filmed at high speed in two species of phorid fly,Megaselia scalarisandPuliciphora borinquenensis, which differ in weight by about one order of magnitude. Under all experimental conditions, activity consisted of brief runs regularly interrupted by short halts when the insect was completely immobile. Runs and halts were approximately equal in duration and occurred five to eight times a second. In crowded conditions the flies made longer stops and usually also shorter runs. Maximum instantaneous velocities during running were 0.2 m s‐1inM. scalarisand 0.09 m s‐1in maleP. borinquenensis.Maximum relative velocities were 80 and 112 fly‐lengths s‐1respectively. InM. scalaris, step frequencies reached at least 57 Hz and this rate can probably be exceeded. Fast running was accompanied by small side‐to‐side oscillations of the body at the step frequency. Fast turns were normally made at the start of runs and only rarely at other times. Painting the compound eyes or removing the antennae did not disrupt the stop—go pattern of running, although flies so treated were reluctant to run. Possible visual and chemosensory functions for stop—go runnin

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00628.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY