摘要:

AbstractThe effect of artificial host odour on the landing responses of males ofGlossina m.morsitansWest, and on their reaction to visual targets has been investigated in a wind tunnel. Landing was induced in flies that traversed steep odour gradients as they flew upwind and downwind across the edge of an odour plume, irrespective of whether visual targets were present or not; the landing response could be elicited over a wide range of odourconcentrations. When targets were present such odour gradients also tended to increase the proportion of landing flies which alighted on or near the targets; and the bigger the target, or the hungrier the flies, the greater was the propensity for target landing. In air which was more uniformly permeated with odour, the propensity to land on targets was increased only at high odour concentration.

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1990.tb00525.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe relationship between corpus allatum (CA) regulation of copulatory behaviour and the CA's influence on the development of the accessory reproductive glands was studied in the male grasshopper,Melanoplus sanguinipes(Fabr.). Allatectomy slowed the development of copulatory behaviour; ≤80% of control males 7 days and older mated with females, but allatectomized males did not show comparable levels of copulation until day 19. In a 3 h observation period, the time taken for 50% of males to initiate copulation wasc.60 min for allatectomized males and onlyc.10 min for controls. At the age when 50% of males copulated, the accessory glands of allatectomized males were less developed than those of controls; the accessory gland weight was 65%, soluble protein was 72% and reserves of long hyaline protein I were 40% those of controls. Treatment with Juvenile Hormone III on day 2 stimulated accumulation of long hyaline protein I in 9‐day‐old allatectomized males to the level found in untreated 19‐day‐old allactec‐tomized males, but did not elicit heightened copulation. No positive feedback from the accessory glands appeared necessary to elicit copulation since vasectomy, ablation of the accessory glands or isolation of the terminal abdominal ganglion by ventral nerve cord transection did not inhibit copulatory behaviour in 7‐day‐old males. Because allatectomy inhibited copulatory behaviour in 7‐day‐old males in which the accessory glands were removed but not in 19‐day‐old males without accessory glands, the increased tendency of older allatectomized males to mate with females was not due to release of inhibition caused by continued growth of the access

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1990.tb00526.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractElectromyographic recordings were made from muscles that extend the trochanter/femur of each of the six legs of American cockroaches,Periplaneta americana(L.), while the insects swam in water. The recordings showed two novel features. (1) During swimming, muscle activity in different legs was coordinated in the alternating tripod pattern commonly seen during free walking on land, not in the pattern of synchronous leg pairs common to other large terrestrial insects in water. (2) Fast axons were usually recruited along with slow axons, even when the insect swam at a moderate pace. Fast axon activity always started after the middle of the slow axon burst in intact insects, but vanished from most bursts in the stump of the leg after amputation of the femur. The alternating tripod pattern was maintained even after amputation. Possible causes of fast axon recruitment are discussed.

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1990.tb00527.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractCircadian rhythms of activity in four societies ofOecophylla longinoda(Latreille) have been studied. Activity is continuous, but diurnal activity is greater than the nocturnal activity. This species is characterized by a strong sense of territoriality and the workers occupy: central territories, trees and immediate surroundings occupied by the society; secondary territories, used for hunting purposes, in natural conditions located on the ground; and intermittent territories in the forest zone (diurnal), scarcely used for hunting, but mainly in relation to the tending of homopterans.The circadian rhythm of activity can be reversed by artificially lighting certain territories at night (reinforcement by attraction of numerous prey). This reversal can only be obtained progressively. By permanent surveillance of the territories and efficient recruitment, the societies rapidly adapt to fluctuations in the quantity of prey. There is a close correlation between agressive territoriality and predation.

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1990.tb00528.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe ichneumonid endoparasitoidCampoletis sonorensisCameron (Hymenoptera: Ichneumonidae) injects a polydnavirus when it oviposits into a host. We compared the development ofHeliothis virescens(F.) (Lepidoptera: Noctuidae) larvae parasitized in the penultimate (fourth) stadium with those parasitized in the last (fifth) stadium byC.sonorensisand show that hosts stung in the fifth stadium exhibited arrested or delayed development compared to the controls. Parasitoids developed normally to the point of emergence in larvae stung in the fifth stadium but most did not successfully emerge from the host. The prothoracic glands in all successfully parasitized fifth stadium hosts and most unsuccessfully parasitized fifth stadium hosts showed some degree of virally‐induced degeneration. Larvae stung in the fourth stadium developed more slowly than controls and either did not moult or developed to a fifth and sometimes a supernumerary sixth stadium before parasitoid emergence. Unsuccessfully parasitized hosts were delayed in their development but eventually moulted to the fifth and, in some cases, a supernumerary sixth stadium before pupating. Hosts stung in the fourth stadium showed no signs of prothoracic gland degeneration whether successfully parasitized or not. In addition, calyx fluid injections into early fourth stadium hosts did not cause prothoracic gland degeneration even after these hosts moulted to the fifth stadium, suggesting that degeneration induced by polydnavirus is specific to the last stadium of the hos

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1990.tb00529.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractMeasurements of residual haematin in males ofGlossina morsitans morsitansWestwood reared in the laboratory at 25oC suggest that blood meal digestion is completed in 4 or 5 days after feeding. However, a high proportion of haematin is present as faecal matter 2 days after feeding and it is concluded that digestion is completed sooner than indicated by the regression of logio haematin on time. Therefore, low levels of residual haematin in field‐caught tsetse provide no indication of the frequency with which they feed. For this reason the effects of feeding frequency upon various reproductive parameters in the laboratory have been examined. It is concluded that the best performance is achieved byG.m. morsitansfemales which ingest four blood meals per inter‐larval period and that for a similar performance inG.pallidipesfive blood meals are required. The extent to which such feeding frequencies are a reflection of feeding activity in the field are discussed in terms of the biochemical requirements to maintain a reproductive adult female tsetse in positive energy bala

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1990.tb00530.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractPheromone production in virgin females ofHeliothis virescens(F.) (Lepidoptera: Noctuidae) peaked between the fourth and seventh hours of scotophase on the second, third, fourth and fifth days following eclosion. The highest peak (186 ng) occurred on day 3 after eclosion. Z‐11‐Hexadecenal comprised the highest proportion of seven components in the pheromone glands. Disproportionately higher amounts of hexadecanal and Z‐11‐hexadecenol occurred during photo‐phase and other periods when low quantities of total pheromone were recorded.Mating suppressed pheromone production which remained low until 48 h after mating. Coupling females with males mated three times previously or with 6‐day‐old males was less effective in causing a drop in pheromone content which peaked again 24 h after mating. This suggests the transfer of a male factor, a pheromonostatic factor, that suppresses pheromone production in mated females and that the factor from older and previously mated males is l

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1990.tb00531.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe liquid diet and high metabolic water production during flight in the carpenter beeXylocopa capitataSmith 1854 (Hymenoptera, Anthophoridae) causes a water excess, and this is exacerbated by a low dietary intake of ions. The nectar and pollen of the preferred food‐plants,Virgilia divaricataAdamson andPodalyria calyptrataWilld., and other Fabaceae had low levels of sodium. Analyses of the bees and their body fluids showed that the bees have an exceptionally low Na content, and Na homeostasis seems to depend on recycling almost all Na which enters the rectum. The copious dilute urine (137 mOsm) had Na and K concentrations of only 3.4 and 7.0 ITIM, respectively. Isolated preparations ofXylocopaMalpighian tubules secreted a fluid with a K concentration 10 times that of the haemolymph. This means that recycling of K is as important as that of Na, and the bulk of K resorption probably occurs passively in the ileum. This study is the first to examine hymenopteran Malpighian tubules. Their stimulation by cAMP is indicative of the presence of a diuretic hormone inXylocop

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1990.tb00532.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe respiratory metabolism of workers ofMessor capitatus(Latreille) was measured using standard micro‐Warburg techniques on single individuals. The experiments were carried out at 10, 20, 25, 30 and 40oC, and the respiratory quotient (RQ), measured for the same individuals at 30oC, was found to be 0.77. The specific respiratory rate(y, in μl O2/mg dry weight/h) could be described by the following equation:Iny =‐2.24 + 0.098r ‐0.258 InW;whereTis temperature andWis the dry weight in mg. The Q10forM. capitatusin the temperature interval 20–30oC was 3.4, a higher value than for other ants.The energy costs of movement and carrying were determined by using the RQ to convert the continuous measurement of CO2produced at 30oC by Enfiuran anaesthetized workers (‘resting metabolism’), by running workers and by workers loaded with a 20 mg weight to units of energy. The resting metabolism was 10.0±1.0 mJ/mg fresh weight/h. The cost of running (Yin joule per km) could be described by:Y =3.865 + 0.363Wf, whereWfis fresh weight in mg. The cost of transport for all experiments could be expressed as 0.64 × the c

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1990.tb00533.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe preference in seed selection byMessor capitatus(Latreille) was studied with artificial seeds (weighted styropore spheres) in the laboratory and with natural seeds in the field. The laboratory experiments showed no strong preference for size of the artificial seeds in the range 3–8 mm (diameter). A mass of about 400 mg was selected when artificial seeds of 5‐5.5 mm were offered at different distances from the nest.In the field experiments, crushed seeds were placed 2 m from the nest and ants showed a clear preference for the size class 2.0–3.0 mm in diameter, which is much smaller and lighter than the preference for the artificial seeds. The preference of seeds from different plants showed very big variability. There was no correlation between the preference and any of the following variables of the seeds: fresh mass, dry mass, water content, energy content, and nitrogen content. No evidence for energy optimizing in food selection inMessor capitatuswas found.The energetic reward of bringing any seed back to the nest will, under all normal conditions, be much higher than the energetic expenditure. For example, the energetic content in a wheat seed is about 650 Joule, which is sufficient energy for a worker ant ofMessor capitatusto carry the seed for a distance of 6.5 km at a temperature of

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1990.tb00534.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY