摘要:

(Z)-11-Hexadecenal was identified from heptane washes of ovipositors of female artichoke plume moths,Platyptilia carduidactyla(Riley), by using glass open-tubular capillary chromatography, combined capillary chromatography-mass spectrometry, and microchemical degradation. The washes were free of detectable quantities of any other pheromone-like compounds (C12to C18olefinic acetates, alcohols, or aldehydes). In the field, insect traps baited with 100 μg of (Z)-11-hexadecenal captured artichoke plume moth males at a greater rate than traps baited with virgin female moths. The chemical and field results together indicate that the long-range female sex pheromone of this species is a single component.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.763

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Surveys from 1965 to 1977 of the native wild and introduced naturalized flora of the delta of Mississippi for F1generation larvae of the overwintered population ofHeliothis zea(Boddie) andH. virescens(F.) showed thatH. zealarvae occurred at least 1 week earlier thanH. virescenslarvae. Eight plant species supported populations of bothHeliothisspecies. Both crimson clover andGeranium dissectumL. were major hosts ofH. zea. Although brief high populations ofH. virescensoccurred on several plant species,G. dissectumwas the only early-season host that supported high populations ofH. virescensover an extended period of time.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.766

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

An intensive sampling program was conducted during 1977 and 1978 in central Iowa to determine the faunal composition and seasonal occurrence of the predatory arthropod community in soybeans. Although a complex of more than 80 species was recorded, the majority of predators was infrequently collected.Orius insidiosus(Say),Nabisspp., and Araneida accounted for ca. 90% of the foliage-inhabiting fauna. Carabidae, Staphylinidae, and Formicidae were the most common litter-dwelling predators.Predator densities varied greatly in magnitude between years, but population trends were similar each season. In general, predators were most abundant during soybean podfill stages (R5 and R6). Phenological and density relationships between predatory arthropods and larval green cloverworms,Plathypena scabra(F.), indicated that predators contribute to larval mortality, particularly late in the season. However, predation alone is not sufficient to halt larval outbreaks that occur earlier in the season.Extensive predator surveys in 1978 showed that the faunal composition of predatory arthropod communities throughout Iowa was similar to the complex observed in central Iowa.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.771

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Parasitism studies from 1961 to 1974 of field-collected European corn borer (ECB),Ostrinia nubilalis(Hübner), larvae showed thatLydella thompsoniHerting (=L. stabulans grisescensRobineau-Defvoidy) was no longer present in Delaware. Weekly releases of this parasitoid were made in 1975 and 1976 in an attempt to reestablish it in the state. The first recoveries of the parasitoid were in 1978, and it was recovered from ECB larvae collected during the winter of 1979–1980 from corn fields throughout the state.The parasitism rate of ECB larvae byMacrocentrus grandiiGoidamich has noticeably increased during the last decade, and the data indicate thatNosema pyraustaePaillot is an important, consistent mortality factor of its host the ECB.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.779

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Parasitization of the Mexican bean beetle (MBB),Epilachna varivestis, by the waspPediobius foveolatuswas monitored in five urban vegetable gardens in Washington, D.C., in 1979 and 1980. We innoculated all five gardens withP. foveolatusin 1979 and one of these gardens in 1980. This wasp is an exotic, non-overwintering biocontrol agent that is used in Maryland soybean fields. Our innoculative releases,P. foveolatusthat probably came from Maryland, or both parasitized from 97 to 100% of the MBB larvae in each garden by late summer. Therefore, most of the MBB damage m these urban gardens probably could be eliminated by making innoculative releases of adequate numbers ofP. foveolatusthroughout gardens at appropriate times.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.782

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Efficiency and reliability of a suction device for assessingRhinocyllus conicuspopulations were determined and compared with current visual research techniques. A suction machine collected a greater proportion of weevils from thistles ranging in height from 6 cm to 1 m but was less efficient than visual searches on rosettes or plants in excess of 1 m. A single, 2-sec suction sample was as efficient as multiple samples with durations up to 6 sec. Horizontal approaches were superior to up-sweep or vertically oriented suction samples and collected 98.6 ± 1.3% of adult weevils in recapture tests.R. conicuspopulation density increased with plant height; correlation coefficients were highest (r = 0.95) when plant height variability was greatest and all thistles except rosettes were sampled. Although ca. 15% of the potentially viable eggs per primary bloom may be dislodged during suction sampling, removal of old, dried-out egg casings resulted in counts of eggs remaining on thistle blooms which were generally more indicative of actual weevil populations.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.787

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

The southern masked chafer,Cyclocephala immaculataOlivier, and the northern masked chafer,C. borealisArrow, are serious pests of turfgrass in central Kentucky. The temperature threshold for pupation of overwinteringC. immaculatagrubs was determined experimentally as 10.8°C. Trapping studies during 1979 and 1980 indicated that first emergence and peak flight of males occur approximately 1 to 2 weeks earlier forC. borealisthan forC. immaculata. Thermal unit accumulations in air and soil were closely correlated with the first emergence of beetles, but they were less useful for predicting the date of 50 and 90% flight. Once emergence has begun, activity of masked chafers is more closely related to rainfall patterns than to temperature.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.793

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

The objective of this study was to determine the effects of moisture, temperature, organic matter, pH, and interspecies competition on stable fly populations under field conditions.Statistical analysis did not detect a correlation of stable fly populations to the four physical factors. However, statistical analysis detected a significant effect for competing insects which increased when a pH factor was added. Populations of Syrphidae and organic matter significantly influenced stable fly populations in a stepwise regression analysis.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.798

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

When polyhedra ofAutographa californicapassaged several times inSpodoptera exiguawere passaged inTrichoplusia ni, the size of the polyhedra increased considerably. In addition, these polyhedra contained more virions per cross section of polyhedral inclusion body (PIB), contained a greater mean and mode of nucleocapsids per virion, and were more virulent to neonateT. ni. The polyhedra ofT. niafter several passages inT. niwere not altered in size when passaged inS. exigua. However, these polyhedra had more virions per cross section of PIB, had a greater mean and mode of nucleocapsids per virion, and were more virulent to neonateT. nithan were PIBs ofT. niproduced inT. nilarvae.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.801

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Vertebrate-host-seekingCulicoides melleusandC. hollensiswere captured from 0930 to 2030 h in salt marshes and woodlands, dissected to determine stage of follicle development and panty, and were analyzed by an anthrone test for nectar sugars. Of the total 1,783 midges examined, 99.3% had completed the first gonotrophic cycle More than 65% of 1,022C. melleusand 61% of 743C. hollensishad stage I follicles. The remainder had stages I-II or stage II terminal follicles. The predominance of parous midges suggests autogeny in the first ovarian cycle. Anthrone tests detected fructose or sucrose in 66% of 1,078C. melleusand in 64% of 773C. hollensis; sugar positivity approached or exceeded 50% for each species regardless of diel period or sampling site. Although definitive diurnal patterns of sugar presence were indiscernible, it is believed that these carbohydrates are important dietary supplements and are probably the chief energy sources for flight and maintenance activities.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.807

出版商:Oxford University Press    

年代:1981

数据来源: OUP