摘要:

We describe a method that permits tracking and quantifying the movement patterns of insects in three dimensions under seminatural conditions. We released individualRhagoletis pomonellaflies onto an apple tree and recorded all movements and behavior of the foraging insect. The type information obtained included: measurement of relative distance flown (net and gross displacement, average distance between stops), relative directness of flight from the fly release point to any point within the tree, relative speed of flight, relative angle and vector information for individual and total displacements, and time spent performing individual behaviors. All these parameters were calculated over the total time the insect spent on the tree and for specific time and spatial windows of particular interest. We also describe a computer program that processes and partially analyzes the gathered data. The usefulness of 3-D analysis is illustrated by providing results that show a trend for reduction in the relative distance flown and for an increase in the directness of flight by flies that searched for and landed on fruit models that released synthetic apple odor compared with models that did not.

ISSN:1754-5692    

DOI:10.1093/ee/18.1.1

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

Effects of weather on infestation levels of grasshopper assemblages in the shortgrass prairie regions of Montana, Wyoming, Colorado, and New Mexico were examined using correlation and multiple regression analyses. Fifty-three years of population and monthly weather data were analyzed to estimate the effects of temperature, precipitation, and a heat/precipitation (H/P) drought index on extent of infestation of grasshoppers. Regressions and correlations indicated that effects of weather varied with latitude. Infestation levels in both northern states (Montana and Wyoming) were positively associated with 3-yr mean July-August temperatures. Significant terms in regressions for the southern states (Colorado and New Mexico) were spring and summer H/P ratios; infestation was negatively associated with H/P. These results suggest that grasshoppers in more northern states are favored by warm, dry summer conditions, whereas grasshoppers of southern areas appear to require spring and summer moisture. Results are compared with similar analyses done for grasshoppers in Canada and for Old World locust populations. Impact of insecticides on long term infestation trends was analyzed using 25–30 yr of grasshopper suppression program data. There was little evidence that grasshopper suppression activities interfered with our perception of weather–population relationships. Regression analyses indicated that number of hectares sprayed the previous year was significantly and negatively associated with infestation in Colorado and New Mexico.

ISSN:1754-5692    

DOI:10.1093/ee/18.1.8

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

Development ofPlatynota flavedanaClemens andP. idaeusalis(Walker) on a meridic diet was observed at constant temperatures in the laboratory. Lower developmental threshold values for egg, larval, and pupal stages ofP. flavedanawere 10.6, 8.6, and 9.0°C, respectively. Lower developmental threshold values of 9.7, 7.0, and 8.5°C were estimated for egg, larval, and pupal stages ofP. idaeusalis, respectively. Averages of 101.5 DD10.6, 379.6 DD8.6, and 126.0 DD9.0were required for development of egg, larval, and pupal stages ofP. flavedana, respectively.P. idaeusalisrequired 104.7 DD9.7442.7 DD7.0, and 132.2 DD8.5to complete development in the egg, larval, and pupal stages, respectively. Differences in rate of development were observed between food sources for both species.

ISSN:1754-5692    

DOI:10.1093/ee/18.1.15

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

Several field trials were conducted in likely activity sites in Iowa to determine how chronological age and laboratory propagation affect the ability of black cutworm (BCW),Agrotis ipsilon(Hufnagel), females to attract male BCW moths. The effects of seasonality also were studied. In 1978, initial experiments were conducted to ascertain the factors that might contribute to variability in trap catches. Trap location and night of capture were identified as highly variable factors. In experiments conducted from 6 July to 13 July 1978, there were no significant differences in the attractancy of BCW female moths reared for one or multigenerations in the laboratory.In 1979, only the seasonal trends in reproductive behavior for 2-, 4-, 6-, and 8-d-old virgin female BCW were analyzed. In general, neither 4- nor 6-d-old virgin female BCW were significantly more attractive at any time during the year; however, a trend favoring the attractancy of older females (up to 6 d) early in the season seems evident. A reduction in sexual responsiveness of male BCW was noted during late July and early August in Iowa.

ISSN:1754-5692    

DOI:10.1093/ee/18.1.19

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

The oral toxicity of thePenicilliummycotoxins, alone and in combination, toHeliothis zea(Boddie) andSpodoptera frugiperda(J. E. Smith) at naturally occurring levels was evaluated. Ochratoxin A and citrinin were the most toxic alone to both insect species and caused abnormalities in the Malpighian tubules. The combination of ochratoxin A and penicillic acid was synergistically most toxic toH. zea, whereas the combination of ochratoxin A and citrinin was synergistically most toxic toS. frugiperda. The production of frequently found combinations of mycotoxins byPenicilliumfungi likely to be encountered by these insects is discussed in relation to the results obtained.

ISSN:1754-5692    

DOI:10.1093/ee/18.1.24

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

Spider populations were studied in three peanut fields in the Texas West Cross-Timbers region during the 1981 and 1982 growing seasons. Hunting species made up 85.8 and 91.7% of the spider fauna during 1981 and 1982, respectively; the remainder were webbuilders. Three hunting families, Oxyopidae, Lycosidae, and Thomisidae, were dominant, constituting 74.6% of the total spider fauna for the two study years. Each family in turn was dominated by a single species.Oxyopes salticusHentz (Oxyopidae) constituted 37.3% of the total spider fauna in 1982 and 16.2% in 1981. The Lycosidae were dominated byPardosa pauxillaMontgomery and, as a family, were 31.0% of the fauna in 1981 and 26.6% in 1982. The Thomisidae were dominated by theMisumenopsspp., mostlyM. celer(Hentz). TheMisumenopsspp. were 14.0% and 14.1% (If the spider fauna in 1981 and 1982, respectively. Spider abundance generally increased as the growing season progressed and plant size and structure increased. Lycosids were dependent on a closed plant canopy and were most successful in irrigated fields. Populations of most species, especially lycosids, declined in drought-stressed rain-fed fields, exceptMisumenopsspp., which were most successful under rain-fed conditions. Ballooning activity of spiders was determined from suction trap samples in 1982; results showedO. salticusto be the most numerous aeronaut. The Araneidae and Linyphiidae were next most abundant in suction trap collections, although these and other web-building species constituted only 11.3% of the peanut spider fauna for the two study years. Identification of spider prey revealed a preference for Hemiptera (32.7%), with Lepidoptera and other Araneae constituting 17.3% each. Pest species taken as prey includedHeliothisspp.,Stegasta bosqueella(Chambers), leafhoppers, and thrips (Frankliniellaspp.). Entomophagous species constituted about one-half the spider diet.

ISSN:1754-5692    

DOI:10.1093/ee/18.1.30

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

Using captive birds, two aspects of bird predation on gypsy moth,Lymantria dispar(L.), larvae were examined: whether birds are more likely to attack and consume early rather than late larval instars, and whether birds will attack gypsy moth larvae in the presence of alternative prey. Of 37 individuals of nine passerine bird species offered second-instar gypsy moth larvae, 27 individuals of seven species accepted them. Of 22 individual birds of six species offered third- to sixth-instar larvae, 15 individuals of five species accepted them. Birds given a simultaneous choice between gypsy moth larvae and alternative prey (two nonhairy types and one hairy type) preferred the nonhairy alternatives. We conclude that birds may be important sources of mortality for early (first and second) as well as late (third to sixth) instars. Most field studies of gypsy moth population dynamics have documented bird predation primarily on the latter, but our results indicate that bird predation on early instars must also be taken into account in analyses of gypsy moth population dynamics.

ISSN:1754-5692    

DOI:10.1093/ee/18.1.43

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

Population biology ofHyadaphis tataricae(Aizenberg) on honeysuckle,Loniceraspp., was examined. Aphid populations exhibited a bimodal seasonal abundance pattern. Watered and pruned honeysuckle had a significantly higher number of aphids than either watered and unpruned or unwatered and unpruned plants. These cultural practices produced more of the succulent, actively growing terminals which were preferred byH. tataricae. ApterousH. tataricaehad a significantly higher fecundity (29.15 nymphs) and significantly longer reproductive period (14.31 d) than alatae (16.21 and 9.78, respectively).

ISSN:1754-5692    

DOI:10.1093/ee/18.1.46

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

Five species of house fly pupal parasitoids,Nasonia vitripennisWalker,Muscidifurax raptorGirault and Sanders,Pachycrepoideus vindemiae(Rondani),Spalangiasp., andApanteles carpatus(Say), were recovered from house fly pupae exposed in controlled-environment, caged-layer poultry facilities during a 17-mo New York statewide survey. Overall, rates of parasitism were low, ranging from 0.2% in early spring to 14.0% in the fall. The number of fly pupae attacked byN. vitripenniswas significantly higher than those killed by the other parasitoid species. Of all parasitized pupae collected in 1981, 76.9% were killed byN. vitripennis. In 1982,N. vitripenniswas responsible for killing nearly 94.8% of all parasitized pupae.N. vitripenniswas also the most abundant parasitoid, accounting for 95.5 and 99.2% of all parasitoids emerging from sentinel pupae during 1981 and 1982, respectively. In addition,N. vitripenniswas the only parasitoid species observed to actively parasitize fly pupae in these facilities during cold winter months when temperatures in the first-floor manure pits ranged from 12 to 16°C. All the other parasitoid species generally were active only during warm summer months.

ISSN:1754-5692    

DOI:10.1093/ee/18.1.51

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

The alfalfa seed chalcid,Bruchophagus roddi(Gussakovsky), is a host-specific insect that lays eggs in the developing seeds of alfalfa. In laboratory bioassay, females made in-flight evaluations of olfactory stimuli that emanated from an array of host and nonhost flowers. The outcome of choice tests depended on pretest conditions that varied in sequence and time of exposure to host and nonhost plants. Specific flight and landing behavior was elicited or inhibited by conditions that prevailed before the choice test. When females were confronted with a choice of different species of legume flowers (including alfalfa), they made more in-flight visits to the species to which they were exposed just prior to the test. Then, after in-flight evaluation of test flowers at close range, females made more landings on alfalfa. In addition, females made about the same number of direct landings on host and nonhost alike but without close-range evaluation of the flowers.

ISSN:1754-5692    

DOI:10.1093/ee/18.1.56

出版商:Oxford University Press    

年代:1989

数据来源: OUP