摘要:

Adults of the locustChortoicetes terminiferawhich had been deprived of water for 24 h took larger ‘meals’ of water than insects which had been deprived for 2 h. Water or dilute solutions of NaCl injected into the kaemcoel reduced the amount of water ingested by 24‐h, deprived locusts. Injections of more concentrated solutions of NaCl (0.5 m) or glycerol (1.0m) increased the water intake of 2‐h deprived locusts. Water injections into 24‐h deprived locusts did not reduce their responsiveness to sucrose and it is concluded that haemolymph osmotic pressure plays an important role in determining the specific responsiveness ofC. terminiferato water. The time course of the effects of injection indicates that the effects of haemolymph osmotic pressure on water responsiveness are mediated neurally. Injections of water into 24‐h deprived insects caused a marked reduction in the sizes of their meals of seedling wheat. It is suggested that the mechanisms responsible for the regulation of water intake might limit total intake when locusts have access only to fresh vegetation of high wa

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00957.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.tb00958.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

The influence of environmental factors on the duration of diapause was evaluated in larvae ofEphestia elutella(Hübner) reared in short photo‐periods at 25d̀C or below. Termination of diapause was hastened by long photoperiods, high temperatures, long periods at low temperature, or exposure to fumigants. Diapause terminated rapidly under long photoperiods at 30 or 25d̀C, but not at 20d̀C. The critical photoperiod for the termination of diapause was similar to that for induction, lying between 13 and 16 h at 25d̀C. The longest duration of diapause occurred in constant darkness (DD) at 20d̀C. However, batches of larvae reared at 20d̀C in DD pupated a little sooner than batches reared under LD, if both were transferred at the start of diapause to warm, long‐day conditions. Long exposure to low temperature reduced the number of long photoperiods necessary for the rapid termination of diapause at high temperature. Samples of larvae brought to the laboratory at monthly intervals from an unheated outbuilding in which they were overwintering, required an average ofc.200 days to pupate in DD at 25d̀C when transferred in December, compared with only 32 days when transferred in February or March. By comparison, batches transferred to LD 16:8 at 25d̀C required 39 days when transferred in December and 20–24 days in February and March. Holding at low temperature for long periods also encouraged synchronous emergence of the sexes. Duration of diapause was generally shorter in a laboratory stock than in a stock collected

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00959.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Three modes of self cleaning occur in insects: nibbling by the maxillae, scraping one structure by another in one direction only, and rubbing back and forth while the respective parts are in continuous contact. This paper describes a comprehensive and comparative account of this behaviour in bees, with special reference to the cleaning of or by the forelegs.Bees, like all Hymenoptera, clean various parts of the head, including the mouthparts and the antennae, with the forelegs. Lower Hymenoptera scrape each antenna with either foreleg; in the species of Aculeata that possess the antenna cleaner (strigil) on the foreleg, only the ipsilateral leg is used. The thoracic dorsum of most bees, as in many sphecoid wasps, is scraped in a forward direction by the middle leg;Triepeolusspp., however, use the hind leg, and the Anthophorinae the foreleg.Some beetles and lacewings clean their forelegs in the mouthparts by nibbling and scraping. Most higher Hymenoptera as a rule scrape the foreleg between the ipsilateral maxilla and the labium; bees, however, clamp the foreleg between the flexed ipsilateral middle leg and then scrape it. An evolution of this behaviour is postulated via several intermediate forms derived from original stepping movements.Halictidae and Andrenidae clamp the foreleg for scraping underneath the middle tibia, whereas all other bees nearly always clamp it underneath the middle basitarsus. Very similar movements are used in various species for transferring pollen, oil, or nest materials from the foreleg to the middle leg.It is argued that the original way of pollen carrying in bees must have been by filling the crop through direct eating or by scraping pollen off the foreleg between the ipsilateral maxilla and the labium. The latter movement is widespread among bees and is homologous to the normal foreleg cleaning in the mouthparts of most other Hymenoptera. The efficiency of this behaviour is enhanced in many lower bees by a comb on the galea, which is the homologue of a similar structure widespread among aculeate wasps. In higher bees, Apidae and Anthophoridae, the galeal comb is replaced by an equifunctional stipes comb. Many bees have neither of these types of maxillary combs.

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00960.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Larvae of Antheraea pernyi and Hyalophora cecropia terminate the feeding phase of the fifth instar by purging the alimentary tract. This occurs in the morning under artificial illumination schedules and precedes the initiation of spinning by a species‐specific time interval. Infusion of β‐ecdysone into H. cecropia late in the feeding phase may, under certain conditions, provoke premature gut purging or terminate spinning by causing premature metamorphosis. Experiments in which spinning A. pernyi were stripped of their cocoons at various stages of construction confirmed that caterpillars initiated the spinning of a second cocoon at the same point in the behavioural repertoire where they had been interrupted. The rapid turning involved in cocoon impregnation behaviour was executed only in the confines of a cocoon, and required that the hindgut be both distended by exudate and free to expel it. Severance of the ventral nerve cord anterior to the terminal ganglion also eliminated impregnation behaviour. Cyclic turning of the cat́erpillar in the cocoon persisted after spinneret occlusion or silk gland excision, but at a markedly depressed freq

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00961.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Mating frequency in groups ofDacus tryoniwhich had been either warm‐acclimated or cold‐acclimated were compared in temperature regimes ranging from just above mating‐threshold to optimal. Cold‐acclimation appeared to suppress initial mating ability of mature insects of both sexes to an extent which depended upon the acclimation regime used. The most favourable cold‐acclimation regime produced flies which in certain circumstances were able to mate at an initial frequency similar to that of warm‐acclimated flies. In no mating regime was initial mating significantly more frequent in any cold‐acclimated group than it was in any warm‐acclimated group. In most cases warm‐acclimated flies in a given regime mated at high frequency for 1–2 days, whereas the cold‐acclimated flies mated at low frequency for a greater number of days. In all cases, cold‐acclimated flies accumulated a similar or significantly lower total number of matings than warm‐acclimated groups. In experiments in which both warm‐acclimated and cold‐acclimated males competed for cold‐acclimated females, the warm‐acclimated males always out‐competed the cold‐acclimated males in two mild (near optimal) regimes. In a relatively harsh (near torpor threshold) regime, there was no significant difference in the competitive abilities of cold‐acclimated and warm‐acclimated males. The relevance of these results to possible acclimation procedures used in control campaigns involv

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00962.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

The rate of oocyte development in constant regimes corresponded to the rates predicted by Pritchard's (1970) relationship which indicates that the lower temperature threshold is 13.5dgC. Rates in fluctuating regimes indicated that development occurs at certain temperatures below the constant threshold if these are alternated with higher temperatures on a daily basisIn certain fluctuating regimes, oocyte development occurred at a rate in excess of 3.5% per day and maturation proceeded to completion. In such regimes resorption occurred only if egg laying was prevented; when this happened the terminal oocytes usually remained intact and the penultimate ones were resorbed. In other fluctuating regimes, oocyte development proceeded at a rate of less than 3.5% per day and no maturation was achieved because the most advanced oocytes were resorbed‐either before or during the vitellogenic phase.The 3.5% threshold corresponds to a value of 2 day‐degrees per day (2DDPD) above 13.5d̀C. Resorption, but no development, was observed in partly mature flies around O DDPD, whereas neither occurred in a still colder regime. These results are shown to be in accord with Fletcher's (1975) field data which are also used to discuss the significance of resorption. Finally, the DDPD relationship is used to define those daily temperature profiles which may permit maturation in the f

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00963.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.tb00964.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Final instar larvae and adults of the chrysomelid beetleHaltica lythriAubé were tested for their feeding preferences on young and senescent leaves of their host plantEpilobium hirsutumL., and found to spend most of the time feeding on young leaves when in a free‐choice situation. Females fed senescent leaves laid significantly fewer eggs than females fed young leaves. Feeding on senescent leaves is discussed in an ecological conte

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1976.tb00965.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.tb00966.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY