摘要:

Females ofApanteles melanoscelus(Ratzeburg), a braconid parasite of the gypsy moth,Lymantria dispar(L.) (Lepidoptera: Lymantriidae), responded to silk deposited on leaves or artificially wrapped on filter paper by examining such areas intensely with their antennae. This examination behavior increased the parasite's chances of finding hosts. As few as 10 silk strands could be detected, and active silk components were not destroyed by aging or heating. Silk from other lepidopterous species was not nearly as effective as was gypsy moth silk. Water deactivated silk but organic solvents did not. Smears and water extracts of host silk glands released examination behavior especially when combined with water-deactivated silk. Conclusions are that water-soluble silk chemicals (kairomones) are important in the response of the parasite to silk, but water-insoluble chemicals and/or physical properties of the silk also influence the parasite's behavior.

ISSN:0046-225X    

DOI:10.1093/ee/5.6.1128

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

A new description of temperature-dependent, rate phenomena was deduced to describe developmental time and ovipositional data for the McDaniel spider mite,Tetranychus mcdanieliMcGregor. The derived equation accounted for asymmetry about optimum temperature and was of particular utility for description of systems operating at or above optimum temperatures. Ovipositional and developmental rate functions were used in a temperature-driven, discrete-time, simulation model describing McDaniel spider mite population dynamics. Temperature dependence of the instantaneous population growth rate was determined by fitting the derived rate-temperature function to data generated through simulation at various fixed temperatures. The functional relationship of important population parameters to temperature provided the mechanism for inclusion of phenological effects on mite populations in a synoptic apple pest management model.Two derived functions were fit to several published rate-temperature data sets. Adequacy of description (as indicated by R2values) indicated general applicability of both functions for description of temperature-controlled, biological processes. Further, it was concluded that the singular perturbation method of matched asymptotes has potentially wide application in ecology, and an Appendix detailing the application of this method is included.

ISSN:0046-225X    

DOI:10.1093/ee/5.6.1133

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Populations of the dark tussock moth,Dasychira basiflava(Packard), reached outbreak levels in eastern Connecticut between 1973 and 1975. Various stages of dark tussock moths were sampled between 1974 and 1975 from 5 sites to ascertain the natural enemies and their effects on the populations. The reason for the population collapse at 2 sites (Voluntown and Chaplin) is unknown. In Mansfield, a nuclear polyhedrosis virus (NPV) was important in causing the population collapse. The population collapse in Brooklyn was attributed in large part to larval parasitism and NPV and in Eastford primarily to larval parasitism.Eleven primary parasites, 3 hyperparasites, and 1 parasite of uncertain status were isolated in Connecticut. The total number of primary parasites now known to attack the dark tussock moth is 15. Seven pathogens were recovered of which the host specific NPV was the most prevalent.

ISSN:0046-225X    

DOI:10.1093/ee/5.6.1141

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

The larvae of 7 lepidopterans were parasitized in the laboratory with maggots of a tachinid,Lixophaga diatraeae(Towns.). Parasitism of all species occurred, ranging from 18.5% for the fall armyworm,Spodoptera frugiperda(J. E. Smith), to 90.0% for the principal host ofL. diatraeae, the sugarcane borer,Diatraea saccharalis(F.). Survival of maggots placed onDiatraealarvae exceeded 33%, while less than 15% survived when placed on other larval hosts. The time required for parasites to penetrate hosts was similar for all species. Most maggot penetrations occurred at the intersegmental membranes of host larvae; however, a few penetratedD. saccharalislarvae at the mid area of body segments.

ISSN:0046-225X    

DOI:10.1093/ee/5.6.1146

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Phlebotomine sand fly populations were studied over a one year period by light-trap collections along a 200 m transect at Empire Range, Panama Canal Zone. The zoophilic speciesLutzomyia carpenteri(Fairchild and Hertig) was dominant during the dry season while the anthropophilic speciesL. panamensis(Shannon) was dominant during the wet season. Sand fly populations were strongly correlated with the degree of development of the forest cover, increasing from grassy to secondary forest biotopes and from secondary forest to mature forest biotopes.

ISSN:0046-225X    

DOI:10.1093/ee/5.6.1149

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Carbofuran, a systemic insecticide, was studied for its effect on two predators of the twospotted spider mite,Tetranychus urticae(Koch);Amblyseius fallacis(Garman) andOrius tristicolor(White). Both predator species showed high mortality when caged on systemically-treated excised lima bean seedlings. The presence of prey had little effect on mortality of the 2 predator species indicating that ingestion of poisoned plant sap was a likely mode of poisoning. These results were substantiated on strawberry plants grown in carbofuran-treated soil in greenhouse tests.Side-dressed field applications of carbofuran 10 G at 1.1 and 4.5 kg AI/ha to strawberry plants significantly (P = .05) reduced populations ofOriusandNabisspp. nymphs one week after treatment.T. urticae,Amblyseiusspp., and spider populations were not significantly changed.Field applications of carbofuran 4 FC at 1.1 and 4.5 kg AI/ha to the crowns of raspberry plants, which provided systemic and contact action, significantly reduced populations ofOriusspp. adults and nymphs, andNabisspp. nymphs. Spider populations were not significantly reduced.

ISSN:0046-225X    

DOI:10.1093/ee/5.6.1155

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

The comparative efficacy of 4 predators against 3 different stages of the cotton bollworm,Heliothis zea(Boddie), or the tobacco budworm,Heliothis virescens(F.), was studied in the laboratory. The species studied wereChrysopa carneaStephens,Geocoris punctipes(Say),Coleomegilla maculata(DeGeer), andPodisus maculiventris(Say). Two of these predators were also evaluated for control of the tobacco budworm on cotton in field cages.Under limited searching requirements,C. maculatawas generally the most efficient predator ofHeliothiseggs and 1st stage larvae. However, when the 1st stage predators were compared,C. carneawas the most efficient predator on 1st instars. Third stage nymphs and adults ofP. maculiventriswere the most efficient predators of the 3rdstage larvae. Under expanded searching requirements,C. carnealarvae were the most efficient of the immature stages of predators onHeliothiseggs and 1st instars. As adults,C. maculatawere the most efficient predators on eggs whileG. punctipeswere the most effective predators on 1st stage larvae. Third instars and adults ofP. maculiventrisconsumed more 3rd instars ofHeliothisthan the other predators studied.Releases ofC. carneaandP. maculiventrisat rates of 100,000/acre in field cages resulted in substantial reductions in the number of tobacco budworm larvae. The reductions effected byC. carneawere more evident in the egg and small larva numbers while the reductions attributed toP. maculiventrisoccurred mainly when the tobacco budworm larvae were larger.

ISSN:0046-225X    

DOI:10.1093/ee/5.6.1160

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Analyses of volatiles from hindguts ofD. adjunctusrevealed the presence of frontalin withtrans-verbenol in feeding females andexo-brevicomin in emergent males. In field tests, both frontal in andexo-brevicomin were attractive, whereas no response totrans-verbenol could be shown. Males were more responsive to frontalin than toexo-brevicomin, and females were more responsive toexo-brevicomin.

ISSN:0046-225X    

DOI:10.1093/ee/5.6.1165

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Phytophagous insects representing 7 orders, 36 families, and 113+ species are reported as comprising the insect fauna ofAmbrosia psilostachyaDecandolle (Compositae) in southern California. Most insects found attacking this native ragweed were euryphagous, ectophagous, sap- and foliage-feeding species. About ½ reproduced on this plant. Seventeen (18%) of the 95 associates identified to species were stenophagous, their hosts apparently confined to the tribe Heliantheae. Thirty (32%) of these were minor or major pests of cultivars.Prospects for biological control of ragweeds in North America and abroad are discussed.

ISSN:0046-225X    

DOI:10.1093/ee/5.6.1169

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

The influence of hydroprene (Altozar®), a juvenile hormone mimic (JHM), on parasitized and unparasitized cabbage looper,Trichoplusia ni(Hübner), was studied. Larvae were reared on standard wheat germ diet until early 4th stadium then on diet containing 0.1, 1, 2 and 4 ppm of hydroprene. Larval development from the 4th to the 5th stadium was essentially the same for all treatments. A decided influence was found in the development of the unparasitized 5th stage larvae at the 1, 2 and 4 ppm treatments of the JHM. Longer time intervals were required to spin, for pupation and adult eclosion. No adults were obtained from 2 and 4 ppm hydroprene treatments and only 2.5% survived from the 1 ppm treatment.T. nilarvae parasitized byHyposoter exiguae(Viereck) developed the same on JHM and control diets. Parasites emerged from hosts on both diets at the same time and immediately began to spin cocoons. Adult eclosion and survival was no different as a result of host diet. When JHM was topically applied at 2 and 20 micrograms prior to insect parasite emergence, development was extended and adult mortality ranged from 5–95%.JHMs generally disrupt insect development prior to the larval pupal molt. Since the parasite's last larval molt occurred after the host ceased feeding, apparently the hydroprene was not available in sufficient quantity during the parasite's last instar to influence its development. Topical application of the JHM near the time of parasite emergence allowed sufficient material to reach the parasite during its last instar and influenced development. These data indicate the importance of knowing developmental patterns of beneficial insects to determine the potential impact of a JHM applied for insect control.

ISSN:0046-225X    

DOI:10.1093/ee/5.6.1178

出版商:Oxford University Press    

年代:1976

数据来源: OUP