摘要:

The number of prey consumed daily in the laboratory at 20, 25, 30, and 35°C byGeocoris punctipes(Say) was found to vary by several hundred percent, depending on an individual predator's sex, developmental stage, and the temperature. Nymphs in successively later instars tended to eat more prey daily than did those in earlier instars. Nymphs and adult males consumed greater numbers of prey daily at each higher experimental temperature; the same was true for adult females, except that they consumed fewer prey daily at 35 than at 30°C. Prey were eggs of the soybean looper,Pseudoplusia includens(Walker).

ISSN:0046-225X    

DOI:10.1093/ee/4.4.531

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Patterns of subadult gypsy moth,Porthetria dispar(L.), occurrence within a sparse, numerically stable population that was studied in 1965 were modelled as functions of insect stage and certain components of environmental structure. Our results imply the following. (1) Once newly hatched larvae find suitable foliage, they tend to stay on or near it until after they have molted into instar III. (2) These insects begin to wander sometime before reaching instar IV, and continue to do so until suitable daytime resting locations are found. These locations are usually in the litter at the tree base, but the insects will aggregate under bark flaps on dead limbs or on the dead boles of trees in clumps in preference to the litter if these are available. (3) Most of the insects pupate in the locations used earlier for resting sites, but some eventually pupate in objects that may be many feet away from the closest living host tree. (4) Bark flaps may have provided less hazardous resting sites for the growing larvae and pupae than other potential resting locations within the environment.

ISSN:0046-225X    

DOI:10.1093/ee/4.4.535

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Eggs ofLissorhoptrus oryzophilusKuschel were exposed in the laboratory to constant water temperatures of 25°, 30°, 35°, and 40°C. None hatched at the high temperature. The average number of days to hatch were 9, 6, and 4 when exposed to the 3 lower constant temperatures, respectively. The response of eggs of different ages held at 25°C but exposed to 45°C for different periods of time indicated little mortality resulted from 1–3-h exposure. Mortality occurred when eggs were exposed to 45°C for 6, 9, or 15 h, but eggs midway in their development seemed more tolerant than 2–3 day old eggs or those in the last stages of development. The rate of development was slower by ca. 1 day when eggs were exposed to 45°C, regardless of the time of exposure.

ISSN:0046-225X    

DOI:10.1093/ee/4.4.543

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Attraction of adultHylemya platura(Meigen) to germinating seeds was studied. Results indicated that Tendercrop snaps, Fordhook 242 limas, and Butternut squash seeds in contact with moist sand at 21°C for 2–3 days attracted more female flies than did Ashley cucumber, Wando peas, or moist sand. Most of the oviposition occurred near germinating squash, snap bean, and cucumber seeds; aqueous extracts of squash and snap bean also stimulated oviposition. An apparent gustatory preference for lima bean seed extracts was also observed. However, there was no correlation between these responses suggesting that attraction, oviposition, and gustation were operating independently. Oviposition stimulants from squash seeds were nondialyzable, nonlypholyzable, and unextractable with diethyl ether. Field studies showed that germinating snap beans attracted more female flies than did lima beans or unplanted areas.

ISSN:0046-225X    

DOI:10.1093/ee/4.4.545

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Approximately 43% of the larval bagworm population in the Athens, Ga., area were killed by naturally occurring biotic factors during the period July through Sept., 1970. About 71% were killed in 1971 and 66% in 1972. Nineteen insect species including parasitoids, hyperparasites, and scavengers were reared from dead bagworm larvae and pupae. The bagworm is a new host record for 9 of these insects. Bagworm pathogens included bacilliform bacteria, a polyhedrosis virus, and fungi belonging to the generaAspergillus, Penicillium, Geotrichum, Paecilomyces, Hirsutella, Beauveria, Cordyceps, Scopulariopsis, andPestalotia.An inverse relationship existed between the levels of fungal disease and parasitism in larval populations. During 1971 a high level of fungal disease (51%) and a low level of parasitism (10%) were recorded. In 1970 and 1972, high levels of parasitism (29% and 46%, respectively) and low levels of fungal disease (13% and 17%, respectively) were recorded. It appears that fungi contributed most heavily to bagworm mortality during wet periods and that insect parasitoids were the predominant mortality factor during dry periods.

ISSN:0046-225X    

DOI:10.1093/ee/4.4.549

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Bioassays in 12×17×3-m field cages showed an airborne chemical was released from the hairpencils of the maleHeliothis virescens(F.) before mating. When receptors on the female antennae detected the pheromone during courtship, release of female sex pheromone ceased. Emission of the female sex pheromone was effectively terminated if the females were exposed to 50 male equivalents of hairpencil extract or to untreated 2-day-old (virgin) male tobacco budworms. Extracts of hairpencils made with ethyl ether were almost as effective as live males, but extracts made with carbon disulfide did not successfully suppress the production of the sex pheromone.

ISSN:0046-225X    

DOI:10.1093/ee/4.4.555

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

The two-spotted spider mite,Tetranychus urticaeKoch, was identified as the mite pest attacking cotton in 194 of 195 samples taken from 10 counties in the Mississippi Delta. A pathogenic fungus,Entomophthorasp., was found attackingT. urticae(females only) in 92.8% of the samples. Four species of predaceous mites in the family Phytoseiidae were associated with 33 samples. These species wereAmblyseius fallacis(Garman),Galendromus longipilis(Nesbitt),Galendromus pomi(Parrott), andNeoseiulussp. The sex ratio of the tetranychid mites was 1.58 females to 1 male.

ISSN:0046-225X    

DOI:10.1093/ee/4.4.559

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

FemaleOrthogalumna terebrantisWallwork oviposited only on their natural host plant, waterhyacinth—Eichhornia crassipes (Mart.) Solms, in group tests with 22 species of plants. The nymphs fed on waterhyacinth and only slightly on 3 other test plants. In the field,O. terebrantiswas common and often abundant on waterhyacinth, occasionally was found onEichhornia azurea(Swartz) Kunth, and rarely onPontederia lanceolataNutt. In laboratory tests, adults survived longer on waterhyacinth when the leaves bore feeding spots of weevils of the genusNeochetinaor had patches of epidermis removed manually, or on algae than on waterhyacinth leaves with unbroken epidermis; adults did not penetrate the unbroken epidermis of waterhyacinth to feed.

ISSN:0046-225X    

DOI:10.1093/ee/4.4.561

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

In field cage and isolated field tests the response of virgin female boll weevils,Anthonomus grandisBoheman, to male-baited traps was from 2 to 9 times greater than that of mated females. Females that had mated as long as 1 wk prior to release were still not as responsive as were virgins. The interval after the last mating may be important in determining whether or not a mated female will remate. Response of mated females is also influenced by male density. The fact that some mated native females will respond to males a second time should be beneficial to a boll weevil eradication program. In field cage tests the response of sterile female boll weevils to male-baited traps was approximately the same as that of fertile females. If eradication of the boll weevil is attempted, the release of sterile females along with the sterile males may contribute to premature sperm depletion of the sterile males, unless an effective pheromone trapping system is devised to remove these females from the field after release.

ISSN:0046-225X    

DOI:10.1093/ee/4.4.566

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

No consistent deleterious effects directly attributable to the nuclear polyhedrosis virus,Baculovirus heliothis, were observed when rhesus monkeys,Macaca mulattaL., were exposed to the virus once or weekly for 26 weeks by subcutaneous injection, inhalation, or oral gavage. A greater frequency of lymphoid hyperplasia in lymph nodes was observed in treated monkeys, but infective virus was not found in these nodes. Body-weight gains, temperature, hematology, blood chemistry, and histopathology of treated monkeys were similar to those of untreated monkeys. Infective virus, viral antibodies, or viral antigens were not found in blood drawn from treated monkeys.

ISSN:0046-225X    

DOI:10.1093/ee/4.4.569

出版商:Oxford University Press    

年代:1975

数据来源: OUP