摘要:

The native parasitesChelonus insularisCresson,Temeluchasp., andApanteles marginiventris(Cresson) were the primary species attacking the fall armyworm (FAW),Spodoptera frugiperda(J. E. Smith), in unsprayed field corn in South Florida from 25 March to 30 June 1980. Parasites destroyed 63% of each of the first four FAW instars, andC. insularisemerged from 71% of the parasitized larvae. Generally, parasitization rates followed closely the increase or decrease in FAW larval populations.Eiphosoma vitticoleCresson was not recovered from any of five study plots.Chelonus insularisandTemeluchasp. did not emerge from larvae having head capsule widths greater than 1.8 mm, andA. marginiventrisdid not emerge from larvae with head capsule widths greater than 1.2 mm. Larvae not producing parasites were classified as nonparasitized; 53% of these became adult moths, 23% did not feed on the diet and therefore starved, and 24% fed on the diet but died from unknown causes before pupation.

ISSN:0046-225X    

DOI:10.1093/ee/11.4.833

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

An overwintering population ofCardiochiles nigricepsViereck (Hymenoptera: Braconidae) was studied in Central Texas in 1979–1980 in a plot of pigeon peas infested by a large, late-season population of the tobacco budworm,Heliothis virescens(F.). Emergence from overwintering started in early June, and no adults emerged after late June 1980. OverwinteringC. nigricepscocoons were collected from December 1979 through June 1980 and incubated at 26.7°C to determine the number of days required for adult emergence. Results indicated that adults had the potential to emerge from overwintering throughout the summer. In the field, however, predation of the cocoons by imported fire ants, coupled with an extremely dry summer that caused the soil to get extremely hard, interfered with the emergence of adult parasites over an extended period.

ISSN:0046-225X    

DOI:10.1093/ee/11.4.838

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Sticky, white pyramid traps set at 20 to 23 sites in each of four Maryland cattle pastures were used to monitor dispersal and dispersion of face flies,Musca autumnalisDe Geer. The greatest number of flies of both sexes were caught in valleys near water and cattle resting sites. However, the largest number of males was caught near intersecting forest borders. whereas the largest number of females was caught near scattered trees. Fly dispersal routes appeared to be along valleys. particularly those which had a stream and trees. Face fly trap sites are described and ranked on the basis of ecological factors.

ISSN:0046-225X    

DOI:10.1093/ee/11.4.843

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Predispersal seed predation of the native Platte thistle,Cirsium canescensNutt. (Compositae), byParacantha culta(Wiedemann),Orellia occidentalis(Snow) (both Diptera: Tephritidae), andHomoeosoma stypticellumGrote (Lepidoptera: Pyralidae), was quantified and compared with other causes of seed mortality at three Nebraska sites. Damage to capitulae ranged from 16 to 25%; however, biotic agents damaged only 1 to 7% of the developing capitulae. Although non-biotic agents damaged 18 to 31% of the developing seeds, the three insect species damaged at least 21 to 54% of the seeds. The predominant insect species varied between sites. Only 9 to 24% of the total number of developing seeds per plant matured. Seed predation of the Platte thistle is expected to reduce its colonization of new habitats and its subsequent population growth.

ISSN:0046-225X    

DOI:10.1093/ee/11.4.847

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Infected periodical cicadas,Magicicada cassini(Cicadidae: Homoptera), that are developing resting spores of the fungusMassospora cicadina(Entomophthorales) invade new habitat (nearby young trees) about as readily as do uninfected cicadas, although this may not be true for another periodical cicada species,M. septendecim. Proportions of the two sexes infected by the fungus are variable in different situations. Infected females do not oviposit, although they readily mate. Mated females tend to disperse. InM. cassini, males may also disperse en masse, especially if crowded. This may help certain individuals to escape infection in the current generation, but it also serves to spread the resting spores to newly invaded habitat, where they will infect emerging cicada nymphs of the following generation.

ISSN:0046-225X    

DOI:10.1093/ee/11.4.852

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Three chemicals significantly reduced the mating success of female tobacco budworms (TBW),Heliothis virescens(F.) (Lepidoptera: Noctuidae), and disrupted courtship behavior of males when deployed separately or in paired combinations at the rate of 1 g/0.4 ha. These chemicals were (Z)-11-hexadecenal, (Z)-9-tetradecenal (Z-9-TDAL), and (Z)-11-hexadecen-1-ol (Z-11-HDOL). Four other chemicals [(Z)-9-hexadecenal, (Z)-7-hexadecenal, hexadecanal, and tetradecanal] were deployed separately at the same 1-g rate in the test plots but showed little or no effect on TBW courtship behavior, as indicated by catches in traps. Amounts of the chemicals that actually dissipated during 60-htreatment periods varied between chemicals from ca. 23 to 84%. Based upon actual quantities dispensed and relative biological effects, Z-11-HDOL was the most potent chemical assayed. MaleH. zea(Boddie) moths were caught in traps baited with virgin TBW females when Z-9-TDAL was deployed at 1 g/0.4 ha in different 4-ha cotton fields in 1978 and 1979. MaleH. zeawere also captured in the traps in 1979 when Z-11-HDOL was deployed at 1 g/O.4 ha and again in 1981 when only 0.7 g was dispersed in 60 h. This interspecific response did not occur when the other five chemicals were deployed separately at the same rate, even thoughH. zeamales were in the fields.

ISSN:0046-225X    

DOI:10.1093/ee/11.4.859

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

The seasonal abundance of the three most important stink bug (Hemiptera: Pentatomidae) pests of soybean were studied weekly between 1977 and 1978 on both cultivated and uncultivated host plants by using a sweep-net. The sequence of black cherry,Prunus serotinaEhrhart, and elderberry,Sambucus canadensisL., in the study area allowed large populations of the green stink bug,Acrosternum hilare(Say), to develop before entering soybean,Glycine max(L.) Merrill. Populations ofA. hilarein soybean peaked during September and early October. Fourteen other breeding hosts were identified but were considered unimportant. The control of black cherry and elderberry would drastically reduce the importance ofA. hilarein soybean. Populations of the brown stink bug,Euschistus servus(Say), were sampled during the fruiting cycles of several hosts, including sowthistle,Sonchus oleraceousL., wheat,Triticum aestivaleL., peppergrass,Lepidium virginicumL., vetch,Viciaspp., partridge pea,Cassia faseiculataMichaux, wild lettuce,Lactuca canadensisL., and horseweed,Erigeron canadensisL. The availability of preferred hosts throughout the season may account for comparatively low populations in soybean. Important hosts of the southern green stink bug,Nezara viridula(L.), were wild radish,Raphanus raphinistrumL., and wheat in spring; soybean, cowpea,Vigna unguiculata(L.) Walpers, and showy crotalaria,Crotalaria spectabilisRoth, during summer and fall. Coffee senna,Cassia occidentalisL., was highly attractive to adults of bothAcrosternum hilareandNezara viridula. Several hosts ofThyanta accerraMcAtee,T. calceata(Say), andEuschistus tristigmus(Say) were also identified. Mark-recapture studies showed that adult populations ofAcrosternum hilareon black cherry andEuschistus servuson mullein,Verbascum thapsusL., frequently move among individual plants.

ISSN:0046-225X    

DOI:10.1093/ee/11.4.867

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

The aphelinid endoparasiteProspaltella perniciosiTower was collected on sticky traps baited with synthetic pheromones and virgin females of the San Jose scale,Quadraspidiotus perniciosus(Comstock). Right of overwintered parasites in central California correspond closely with spring flights of male scale and maturity of female scale. Subsequent flights ofProspaltellaare not as closely synchronized with mature scale populations, and show a general decline through the remainder of each season. If the parasites are using the sex pheromones produced by mature female scales in host-finding behavior, this asynchrony of summer populations could help explain the decline of parasite populations.

ISSN:0046-225X    

DOI:10.1093/ee/11.4.876

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Response of the deodar weevil,Pissodes nemorensisGermar (Coleoptera: Curculionidae), to traps containing slash pine bolts and males, females, males with females, or no adults was studied in northern Florida in each of two studies. Significantly more weevils were caught at traps containing males than at any other treatment. Approximately equal numbers of male and female weevils responded to all treatments in both studies. Peak response to male-baited traps was observed in November, and a small peak was observed in February.

ISSN:0046-225X    

DOI:10.1093/ee/11.4.881

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Seasonal activity of male flies peaked in mid-July during 1976 and 1977. Activity was based on total weekly collections of 19,620 male flies trapped on sticky screen discs stapled to the tops of fence posts. During 1976 to 1978, male face flies became active in the spring when a minimum of 20 day-degrees had been accumulated above a base 4.4°C. Use of day-degrees to predict when male activity ceased in the fall was inconclusive. Flies were active 5 weeks before cattle left overwintering areas to be pastured near the study area. Sunlit and wind-protected areas were favored resting sites. Activity was reduced on cool, cloudy, or rainy days.

ISSN:0046-225X    

DOI:10.1093/ee/11.4.884

出版商:Oxford University Press    

年代:1982

数据来源: OUP