摘要:

AbstractThe sex attractant of the female redbanded leafroller moth,Argyrotaenia velutinana(Walker), is a blend of seven compounds. Specialized olfactory receptor neurones had been found for only two of the compounds, (Z)‐11‐tetradecenyl acetate (Z11‐14:Ac) and (E)‐11‐tetradecenyl acetate (E11–14:Ac). These receptor neurones were always found in pairs within the long trichoid sensilla, which are the most abundant multi‐pored sensilla on the male antenna. A systematic survey of all regions of the male antenna with standard extracellular recording techniques was undertaken to find receptor neurones responsive to the remaining five minor components of the female pheromone. Of the 113 long trichoid sensilla sampled, all contained two receptor neurones, one specialized for Z11–14:Ac and a second specialized for Ell –14:Ac. A comparable number of recordings were then obtained from the less abundant classes of multi‐pored sensilla. Two new receptor neurone types were found, responsive to the minor pheromone components (E)‐9‐dodecenyl acetate (E9‐12:Ac) and (Z)‐9‐dodecenyl acetate (Z9‐12:Ac). Scanning electron micrographs indicated that these recordings were obtained from shorter, narrower trichoid sensilla. The majority of these sensilla appeared to contain three neurones capable of spontaneous action potential production. In each sensillum, only one receptor neurone appeared to respond to stimulation with a minor component of the female blend. The remaining two neurones did not respond to

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1991.tb00538.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractBrief exposure to low (0oC) or high (40oC) temperature elicits a protective response that prevents injury when the flesh fly,Sarcophaga crassipalpisMacquart, is subjected to more severe cold (‐10oC) or heat (45oC). Both the low and high temperature responses were found in all developmental stages of the fly, but were most pronounced in the pupal and pharate adult stages. The protective responses generated by brief exposure to 0 or 40oC appear similar in that both result in a rapid acquisition of cold or heat tolerance and a loss of protection after the flies are returned to 25oC. The protection generated by chilling is obvious within 10 min of exposure to 0oC while a 30 min exposure to 40oC is required to induce the high temperature protection. High temperature protects against cold shock injury within a narrow range (around 36oC) but we have no evidence that low temperature can protect against heat injury. We previously demonstrated that the rapid increase in cold tolerance correlates with concomitant increases in glycerol concentration, but in this study we found no significant elevation in glycerol in heat‐shocked flies. Thus the physiological and biochemical bases for the rapid responses to cold and heat appear to be differ

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1991.tb00539.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe cabbage seed weevil (Ceutorhynchus assimilisPayk.) lays eggs singly into pods of oilseed rape (Brassica napusL.) through punctures bored with the mouthparts, preferring pods not recently used for oviposition. A simple new choice test has been used to test individual components of egg‐laying behaviour for their effect on oviposition site selection. It is confirmed that an oviposition‐deterring pheromone (ODP) is deposited during abdomen brushing of the pod which follows egg‐laying. Neither pin punctures, weevil feeding punctures, oviposition punctures nor eggs had any deterrent effect. Pods walked on by female weevils were not avoided by those laying eggs. Observations suggest that the ODP is sensed by contact chemoreceptors on the antennae. The deterrent effect lasted only 1–2 h. The implications of these findings on the adaptive significance of the pheromone and its possible use in pest control are di

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1991.tb00540.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractWild caught female horseflies,Tabanus nigrovittatusMacq. (Diptera: Tabanidae), were fed solutions containing either sucrose or ATP as a phagostimulant. The sucrose diets were presented as free liquids at room temperature. The ATP in the other diets was dissolved in 0.15 M NaCl, or in 0.3 M or 1 M cellobiose and was presented covered with a Parafilm membrane at 38oC. The content of dissolved solids in some diets was adjusted with added cellobiose, which had no phago‐stimulatory effect. Diets of 1 M or 0.6 M sucrose were ingested in large amounts and were directed to the crop. Diets of 0.3 M or 0.1 M sucrose induced lower levels of ingestion, and the diet was directed to the midgut. The addition of cellobiose to give a 1 M total concentration of dissolved solids in these sucrose diets induced many insects responding to the lower concentrations of sucrose to direct the diet to the crop. Diets of ATP in saline or in 0.3 M cellobiose were directed to the midgut. ATP in 1 M cellobiose caused many of the insects to put the diet in both the crop and the midgut. Two behavioural models are presented that integrate interactions between the level of phagostimulation, the concentration of dissolved solids, and an endogenous feeding factor. The dissolved solids effect is most likely a response to osmotic pressur

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1991.tb00541.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractFree‐flying wild tsetse flies (Glossina pallidipesAust. andG. m. morsitansWestw.) were video recorded in Zimbabwe as they flew within an artificial host odour plume at 3, 7 or 15 m from the source, or in no odour, with and without a 0.75 m2vertical, black visual target present aligned with the wind. With no visual target present, flights in odour were strongly biased upwind, and in the absence of odour strongly biased downwind. With the target present, between 16% and 40% of the upwind approaching flies responded visually as they passed the target, by circling it, in proportion to the proximity of the source (taken to be proportional to the mean odour concentration). Crosswind approaching flies (for whom the target will have been visible for some metres away) circled more frequently (34–56%), but without obvious correlation with the odour concentration. Circling flies also responded orthokinetically, by slowing down as they passed the target. The departure directions relative to the wind of flies leaving the target were significantly affected by the odour concentration. At 3 m they left the target in all directions, except possibly avoiding due upwind. At 7 m they left with an obliquely upwind bias, but at 15 m and also in no odour, they left with a strong crosswind b

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1991.tb00542.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractFood consumption and reproduction were compared through two gonotrophic cycles in female brown‐banded cockroaches,Supella longipalpa(F.), fed a standard rat food diet which had been serially diluted with methyl cellulose, alpha cellulose or dextrin. Females did not increase daily intake to compensate for dilution, and reproductive rate was highly dependent upon the degree of dilution of the diet. With increasing dextrin concentrations, digestibility increased, but reproductive rate, size and mass of oothecae, and efficiency of food utilization progressively decreased.On diets containing 75% rat food and 25% methyl cellulose, females consumed minimal amounts of food and 80% of the females did not mate or produce oothecae within 30 days. On identical diets containing 25% alpha cellulose, food digestibility decreased and females ate significantly more than females fed 25% methyl cellulose, but less than females fed rat food. Many (65%) females fed 25% alpha cellulose produced oothecae which were smaller and took longer to form than in control females fed on rat food. At concentrations higher than 50% of either methyl or alpha cellulose daily intake was further reduced and females died rapidl

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1991.tb00543.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe paths of Colorado beetles (Leptinotarsa decemlineataSay) in a featureless environment are circular, like those of other species studied. The turning velocity may reach 35o/s and is due to an internal asymmetry, which may change spontaneously. Normally, all control loops of the insect, like fixation or optomotor responses, must work against this asymmetry to stabilize the insect's path. Stationary vertical patterns damp this turning tendency, but their effect is not strong enough to induce a straight path. Only 70% of the turning tendency can be so eliminated. This reaction is termed optomotor response because it can be adequately described with the parameter turning velocity alone. The insect's path was stabilized more effectively when pattern wavelengths were greater than 60o. The insects seemed to fixate these wider stripes. This reaction is termed fixation because the correlation between pattern components and insect's course becomes prominent.A comparison was made between these reactions to stationary patterns and to turning patterns. No differences could be found in the behavioural reactions to the different situations. This suggests that the insect does not use an internal representation of its spontaneous turning tendency to discriminate between the type of turning of the optical environment. These results can be explained by a simple feedback control loop with an additive interaction between the internal turning command and feedback signals from the eyes.

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1991.tb00544.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractA wind tunnel and video equipment are used to study the long‐range and close‐range responses of gravid females ofCulex quinquefasciatusSay to a synthetic pheromone,eryrthro‐6‐acetoxy‐5‐hexadecanolide. In response to water and acetoxyhexadecanolide, together or independently, in the presence of wind, females follow meandering flight paths upwind. Females have a higher rate of turning and a lower flight‐speed when landing at a site containing pheromone than at a comparable site without pheromone. Females stay longer at oviposition sites containing the attractant than at sites with

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1991.tb00545.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractA comparative study of the olfactory responses to pheromone compounds was performed in twenty‐four species of Hadeninae. Electroantennograms (EAG) were recorded on male moths in response to thirty compounds and the response profiles of each species were analysed by factorial correspondence analysis. A limited number of molecules were found active and the most effective stimuli were Z9 tetradecenes and Z11 hexadecenes. The species of theMythimnagenus were most sensitive to aldehydes.Tholera decimalisdid not respond to any of the molecules tested. The species belonging to theMamestraand theOrthosiagenera responded to a variety of molecules and no simple correlation was found between the genus and the EAG sensibility. Pheromone reception is discussed in relation to the taxonomy and the evolution of olfactory communication in Hadenina

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1991.tb00546.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractDilution of an artificial diet with water or cellulose to nutrient levels of 32% (undiluted), 19% and 10% fresh weight (fw) resulted in increased fw and dry weight (dw) food consumption (both absolute amounts and weight‐relative rates) by velvetbean caterpillars,Anticarsia gemmatalisHübner. Despite these increases, the absolute amount and relative rate of nutrient intake by the caterpillars declined with dilution, as did their dw gain and dw (% fw) and lipid (% dw) contents. The proportion of consumed food (dw, including cellulose) that was digested and absorbed declined with increased dietary cellulose; however, the proportion of consumed nutrients (dw, excluding cellulose) that was digested and absorbed was not affected by the presence of cellulose, although it increased slightly (but significantly) with dietary water. The efficiency with which the absorbed nutrients were converted to biomass energy showed a negative relationship with the various measures of food consumption and thus a positive relationship with dietary nutrient level.The compensatory increases in feeding mitigated the deleterious impact of dietary dilution on growth, which would have declined further without the increased feeding. These data suggest that food consumption is regulated primarily through an evaluation of food nutrient level, and that the metabolic costs associated with the increased consumption and processing of food may be substantial, especially on the most diluted diets. Another hypothesized cost of increased feeding, reduced efficiency of digestion and absorption as food presumably passes more rapidly through the gut, was not detect

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1991.tb00547.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY