摘要:

Adult and immature populations ofAgromyza frontella(Rondani) (Diptera: Agromyzidae) were monitored in 2 alfalfa fields in central PA. Four generations per year were found in 1977 and 1978. Two sampling methods, the sweep net and the vacuum net, compared favorably in estimating relative adult abundance. Adult sex ratio ranged between 50–100% female, varying significantly with sample date. Effective population numbers, i.e., the numbers of individuals leaving progeny, were much lower than actual population numbers. Sampling of eggs and larvae showed slight correlation of eggs with plant height, patchy distribution, and seasonal trends. Rearing of field collected pupae showed wide variations in percent emergence, sex ratio, and population abundance from generation to generation. Ten species of parasites were reared, including 3 new host records and 3 possible new species.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.105

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

In olfactometer tests, adult males and females ofEucelatoriasp. deprived of water were strongly attracted to the odor of okra leaves. Okra leaves from plants subjected to short natural photoperiods (late Oct.–early Nov.) and collected at 0800 h were highly attractive to water-deprived flies. The addition of water to olfactometer cages containing water-deprived flies produced an immediate and striking decrease of 99.4 and 99.9% in the attraction of males and females, respectively, to okra volatiles. Water-deprivedEucelatoriaresponded to the airflow from water-saturated paper, but the response was weaker than the attraction to volatile chemicals from okra.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.111

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Seven leafhoppers and a planthopper,Delphacodes campestris(Van Duzee), occurred on all 8 cool-season grasses but densities were significantly different on different hosts.Endria inimica(Say) was the most abundant leafhopper on all grasses but preferredBromus inermisLeyss. and,B. albidusM.B.Psammotettix alienus(Dahlbom) was most abundant onBromusspp. andPhalaris arundinaceaL.P. lividellus(Zetterstedt) andMacrosteles fascifrons(St´l) preferredAlopecurus arundinaceusPoir.Exitanus exitiosus(Uhler) was most abundant onAgropyron intermedium(Host) Beauv. andElymus junceusFisch;Forcipata locaDelong&Caldwell onDactylis glomerataL.,Festuca arundinaceaSchreb. andA. arundinaceus.Balclutha abdominalis(Van Duzee) did not exhibit significant host preferences.D. campestriswas most abundant onA. intermedium,E. junceus, andF. arundinacea. Relative abundance of several leafhoppers varied seasonally on different hosts. Nonpreferred hosts tended to have highest leafhopper populations in the spring.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.114

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Pherocon 1C® traps baited with liveDioryctria disclusaHeinrich females caught more than 900 male moths in loblolly pine seed orchards at Greensboro, GA, and Georgetown, SC, from 28 May-18 June 1979. Up to 25 times as many moths were trapped in the upper than in the lower crowns of trees of 9 to 15m tall. Peak catch occurred on 6 June with an average of 25 moths per trap. Females attracted males between 2400 and 0200 h e.d.t. the first night after emergence. OnlyD. disclusamales were trapped, although otherDioryctriaspp. were active in the orchards. Mating periodicity may be a species isolating mechanism for sympatric populations ofDioryctriaspp. with overlapping moth emergence. Our field data show that femaleD. disclusamoths produce a sex pheromone and provide the first evidence of the usefulness ofDioryctriaspp. pheromones for capturing male moths in the field. Pheromones offer a convenient, inexpensive, and specific survey technique for these forest insect pests.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.119

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

FemaleBlissus leucopterus leucopterus(Say) laid significantly more eggs on sorghum than wheat or corn. More eggs were laid on barley than wheat or corn and less than on sorghum, but numbers were not significantly different. Percentages of eggs hatched and longevity of both sexes on the 4 host plants did not differ. Nymphs developed to the adult stage significantly faster on sorghum than on corn, barley, or wheat, which did not differ significantly from each other. Males developed to the adult stage significantly faster than females but female adults lived significantly longer than males. Last instar nymphs killed seedling sorghum in significantly fewer days than males or females collected from overwintering sites. Overwintering male and female adults with a one week pretest feeding and newly emerged females killed plants in significantly fewer days than newly emerged males or males and females from overwintering sites with no pretest feeding. Chinch bugs collected from the field Sept. 6, Sept. 21, and Oct. 3 and confined to a 16-h photophase actively fed and mated and females laid eggs while those confined to an 8-h photophase did not. This is the first demonstration of a photoperiod induced diapause in this species.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.122

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

The F1progeny of one overwintered female boll weevil,Anthonomus grandisBoheman from a “clumped” emergence pattern were detected in all of seven 2-ha cotton fields with 10 grandlure-baited infield traps/ha but in only 4 of 7 fields with 2.5 traps/ha. The probability of detecting at least one of the F1progeny of one female was calculated with a simple model to be 63.2 and 99.1%, respectively, for 2.5 and 10 traps/ha.With 10 traps/ha, an avg of 5.0 or 71% of the females emerging in test fields were captured during a 21-day period. This capture rate was essentially equal to the expected capture rate of 83.6% of the females when uniform distribution of both traps and boll weevils and equal attraction of mate-seeking females to traps and to males was assumed. These favorable results were attributed to the ability of the synthetic pheromone released by the traps to largely overpower the attractiveness of the males despite the closer proximity of the males to mate-seeking females.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.125

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Sticky panels (7 colored, 1 clear) were placed at 2 heights in a Connecticut forest in the spring and summer of 1979. Of the tachinids captured, 9 species or species groups were analyzed to see whether trap catches could be related to the egg laying habits of each species. Macrotype egg depositors (Parasetigena silvestris(Robineau-Desvoidy),Tachinomyiasp., and possiblyOswaldiasp.) were caught preferentially on white, yellow, and blue panels placed 15 m above the ground in trees. Males greatly outnumbered females. Microtype egg depositors (Patelloa silvatica(Aldrich and Webber),Gonia sagaxTownsend), on the other hand, were caught on panels placed 0.6 m above the ground as abundantly as on those 15 m high and preferred yellow and white panels. Males outnumbered females, but not to the same extent as for the macrotype egg depositors. Comparisons between other tachinid species groups were inconsistent.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.131

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Several insects and spiders collected from thistle flower heads frequented byRhinocyllus conicusFroelich were tested for predation on the weevil. Insects collected during the weevil oviposition period in 1978 did not feed on eggs or adults ofR. conicus. Three species of spiders:Xysticus ferox(Hentz) andX. funestusKeyserling (Thomisidae); andPhidippus audax(Hentz) (salticidae), fed on the 3rd instars and adults. The mean number of larvae or adults consumed per individual predator was less than 7 per wk in 1978 and 1979. Additional field observations and laboratory tests in 1979 showed that besides the spiders,Monomorium minimum(Buckley) (Hymenoptera: Formicidae) fed on larvae; 2 Hemiptera species,Orius insidiosus(Say) (Anthocoridae) andArilus cristatus(L.) (Reduviidae) fed on larvae and adults ofR. conicus, respectively.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.136

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Heliothis virescens(F.),H. sublfexa(Guenëe), and the backcross 8 larval progeny of [(H. subflexa♀ ×H. virescens♂) ×H. virescensmale … 7] produced diapausing pupal populations in the fall that survived the winter and emerged as adults the following year. Emergence curves were unique for each parent species; that of the backcrosses was influenced by the paternal parent. Spring emergence of BC8was in close synchrony with that ofH. virescens. The percentage of BC8insects to survive the winter and emerge the following year was as high as that ofH. virescens. Once infused into the native population, the sterile male trait should be perpetuated through diapause from year to year until the native population is suppressed.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.139

出版商:Oxford University Press    

年代:1981

数据来源: OUP