摘要:

We elaborate on methods described by Turchin, Odendaal&Rausher for quantifying insect movement pathways. We note the need to scale measurement resolution to the study insects and the questions being asked, and we discuss the use of surveying instrumentation for recording sequential positions of individuals on pathways. We itemize several measures that may be used to characterize movement pathways and illustrate these by comparisons among severalEleodesbeetles occurring in shortgrass steppe. The fractal dimension of pathways may provide insights not available from absolute measures of pathway configuration. Finally, we describe a renormalization procedure that may be used to remove sequential interdependence among locations of moving individuals while preserving the basic attributes of the pathway.

ISSN:1754-5692    

DOI:10.1093/ee/22.4.709

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Significant spatial or temporal variability (or both) is shown in the physiological time (degree-days) needed for males of the tufted apple bud moth,Platynota idaeusalis(Walker), redbanded leafroller,Argyrotaenia velutinana(Walker), codling moth,Cydia pomonella(L.), and spotted tentiform leafminer,Phyllonorycter blancardella(F.) to complete one generation. For the four insect species at all geographic locations (North Carolina, West Virginia, Pennsylvania, and Michigan), the degree-day requirement for a generation is significantly smaller if the requirement is measured between the beginning of flight periods rather than between flight peaks. The degree-day requirement per seasonal generation significantly increases from spring to autumn for redbanded leafroller and spotted tentiform leafminer. Latitudinal effects on generation time for the tufted apple bud moth and redbanded leafroller show that the insects develop significantly faster and exhibit more synchronized flight periods with increasing latitude. Similar elevational effects are shown for tufted apple bud moth. Laboratory data do not give developmental parameter estimates that yield accurate phenology model predictions for three of the four species, and tufted apple bud moth developmental data from field cage rearings likewise give inaccurate parameter estimates for phenology model predictions. Model predictions of seasonal male flights are most accurate if model developmental parameters are estimated from monitoring field populations and these parameters are specific both spatially and temporally.

ISSN:1754-5692    

DOI:10.1093/ee/22.4.716

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

The influence of temperature and vapor pressure deficit (VPD) were determined on larval, pupal, and adult stages of nonfeedingFrankliniella occidentalis(Pergande) under controlled laboratory conditions and on first instars confined to cucumber leaves under controlled greenhouse conditions. The influence of temperature and VPD on sanitation clean-up for control of thrips at the end of the growing season in the greenhouse was also determined. In laboratory trials, the larval stages exhibited the lowest percentages of survival under the range of temperatures and VPDs tested. The adult stage had>80% survival except with high VPDs at 25, 30, and 35°C. Pupae had 100% survival at all temperatures except 35°C, at which survival decreased to ≍60%at the higher VPDs. A quadratic model was fitted to the response surfaces of the larval and adult stages. By using the quadratic model, it is possible to predict the response of the different stages ofF. occidentalisto a range of hygrothermal conditions. Cage trials of first instars on cucumber leaves in the greenhouse also showed that high temperature and VPD will decrease the percentage survival ofF. occidentalis. Sanitation trials demonstrated that 40°C and VPD ≥ 4.76 kPa will controlF. occidentalisat the end of the crop season when the greenhouse is being prepared for the next crop.

ISSN:1754-5692    

DOI:10.1093/ee/22.4.726

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Counts of grasshoppers from Wyoming and New Mexico were related to the proportion of O.1−m2samples that contained grasshoppers through binomial sampling models. Three models were investigated. One was based on the Poisson probability density function and two were based on the Nachman and logit binomial regressions. The Nachman and logit regressions were tested extensively for an influence of predominant instar, sampling year, and location on the estimated parameters. Results indicated that instar and sampling year did not influence the parameter estimates, but location did. All models were then tested to determine which provided the smallest error for predicting densities from incidence and vice versa. Results showed that no differences occurred between models. Based on this finding, the Poisson sampling model was selected for use in wide-scale surveys because it is simple and easy to use. An independent data set from Montana was used to validate this model. Implications of this and other findings in context of using binomial sampling as a management and research tool are discussed.

ISSN:1754-5692    

DOI:10.1093/ee/22.4.733

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Studies were conducted using sticky traps and corn rootworm traps in fields of maize (Zea mays L.) after silking had occurred to determine effect of trap color, olfactory attractants, and type of toxic bait dispenser on captures of adult corn rootworm beetles (Diabrotica barberiSmith&Lawrence andDiabrotica virgifera virgifera LeConte). Capture ofD. barberi(each sex) on sticky traps varied with color but not with the presence or absence of attractant (4-methoxyphenethanol [MPE]). Yellow traps captured the greatest numbers ofD. barberi. Capture ofD. v. virgifera(each sex) on sticky traps varied both with color and attractant (4-methoxycinnamaldehyde [MCHO]); interaction between color and attractant was also significant. Saturn yellow and aluminum foil traps, each baited with MCHO, captured the greatest numbers ofD. v. virgifera. Tests comparing commercial brands of sticky traps showed that Multigard traps captured more maleD. barberithan did Pherocon AM traps. Unbaited Multigard traps captured the greatest number of maleD. v. virgifera, whereas most femaleD. v. virgiferawere captured on Multigard traps baited with MCHO. Capture ofD. barberiin corn rootworm traps (vial-type traps baited with toxin and feeding stimulant) did not vary with color or attractant (MPE). Both color and attractant affected capture ofD. v. virgifera: traps painted Saturn yellow and baited with MCHO captured the greatest numbers ofD. v. virgifera. Capture of femaleD. barberivaried with the type of toxic-bait dispenser: mean capture was greatest in traps with tray-type dispensers. Implications are discussed for trapping of adultD. barberiandD. v. virgifera.

ISSN:1754-5692    

DOI:10.1093/ee/22.4.743

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Scavenging of arthropod tissue by grasshoppers has been hypothesized to be an important aspect of their diet selection and an important route of pathogen transmission. By placing grasshopper cadavers in the field, we determined that the frequency distributions of nymphs and adults of different species observed scavenging differed from that in the local grasshopper community. Only four of the 10 species present in sweep samples were observed scavenging grasshopper cadavers. The largest species,Melanoplus packardiiScudder tended to be present among scavengers in proportions much greater than its representation in the community. The most abundant species at the two research sites,Melanoplus sanguinipesF. andAulocara elliotti(Thomas) tended either to be underrepresented in the scavenger samples or to be present in proportions equal to those in the community. Access to the cadavers was strongly related to success in aggressive interactions among grasshoppers congregating at feeding sites. We observed both intra- and interspecific competitive interactions among grasshoppers. Using a logistic regression model that took into account the size differences among contestants and the species involved in each interaction, we found a good match between the observed and expected number of fights won by each species/sex/developmental stage class.M. packardiiandM. sanguinipestended to win fights when they were matched against smaller opponents, butA. elliottilost more fights than expected from their size alone. Neither sex nor status of the contestants as resident and intruder at a cadaver had a significant effect on the outcome of interactions.

ISSN:1754-5692    

DOI:10.1093/ee/22.4.751

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Leptinotarsa decemlineata(Say) from the central Mexican state of Morelos was studied to see whether exposure toSolanum tuberosumL. in the egg, larval, pupal, or adult stages would induce feeding.S. tuberosumis not native in the range ofL. decemlineatain Morelos and is rejected as food by Morelos larvae. No evidence was found for induction of feeding on potato when the parents had been fed potato in their larval stage, nor did the percentage of Morelos first instars feeding on potato increase after exposure of eggs or newly hatched larvae to potato. There was no difference in pupal weight between larvae that fed on potato and those that would feed only on the native host,Solanum angustifoliumMill., but first-instar mortality was 18.9% higher on potato. Neither encasement of Morelos pupae with pupal exuvia ofL. decemlineatafrom Rhode Island nor preovipositional feeding significantly affected larval feeding in the next generation. Larval feeding on potato was induced when Morelos larvae were exposed to potato frequently in earlier instars. This induction was independent of larval age. Previous feeding as larvae or preovipositional feeding increased feeding on potato by mature adults.

ISSN:1754-5692    

DOI:10.1093/ee/22.4.759

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Nicrophorus vespilloidesHerbst was reared with and without its phoretic mitePoecilochirus carabiG.&R. Canestrini in the laboratory. Clutch and brood size ofN. vespilloidesinP. carabi-infested (P+) cultures were smaller than inP. carabi-free (P−) cultures, but only brood size differed significantly. The number of eggs per clutch that failed to hatch was significantly higher and mean larval weight was greater in P+ than in p− cultures. FemaleP. carabiare oophagous and have been observed to consumeNicrophoroseggs; the differences between treatments may result from consumption or damage or both toNicrophoruseggs byP. carabi.

ISSN:1754-5692    

DOI:10.1093/ee/22.4.766

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Interspecific predation and cannibalism and associated rates of oviposition were assessed for adult femaleMetaseiulus occidentalis(Nesbitt) andTyphlodromus pyriScheuten when provided nonlimiting amounts of either eggs, larvae, protonymphs, or deutonymphs. Tests with all four stages of phytoseiids and larvae ofTetranychus urticaeKoch were carried out at 25°C. At 15 and 12.5°C, only larvae of phytoseiids and larvae ofT. urticaewere prey items. Predation byT. pyriwas higher than byM. occidentalisat 12.5 and 15°C but more similar at 25°C.M. occidentalisdid not feed appreciably on phytoseiid larvae at 15 and 12.5°C. Neither phytoseiid oviposited at 12.5°C when fed phytoseiid larvae, butT. pyridid at 15°C. We concluded thatT. pyriwas a more active predator at low temperatures. Early-season predation onM. occidentalisimmatures byT. pyricould contribute to displacement ofM. occidentalisfrom apple orchards in western Oregon.

ISSN:1754-5692    

DOI:10.1093/ee/22.4.770

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Colonies ofChironomus tepperilarvae derived from wild and laboratory strain egg masses were cultured at 17.5 and 25°C with a 15:9 (L:D) h. Morphometric analysis of sequential larval samples identified four larval instars which can be identified reliably even if populations are reared at different temperatures or derived from different genetic lineages. Fourth instars show a bimodal frequency distribution for cephalolabial length, reflecting prepupal sexual differentiation. Third and fourth instars raised at 17.5°C had significantly larger head capsules (based on cephalolabial length) than those reared at 25°C. Larval growth obeys Dyar's Law, with a regression ofy= −1.339 + O.223x, wherex= instar andy= log10cephalolabial length (in mm). Culturing larvae at 25°C is recommended for the rapid production of fourth instars for use in bioassays. When younger larvae are required, culturing at 17.5°C is more appropriate because early instars last much longer at the lower temperature.

ISSN:1754-5692    

DOI:10.1093/ee/22.4.776

出版商:Oxford University Press    

年代:1993

数据来源: OUP