摘要:

Monitoring of long-term biological impact of the Navy's Project Sanguine/Seafarer extreme low frequency (ELF), low energy communications system continued in summer, 1975, at the Wisconsin Test Facility with population analyses of soil arthropods and a floral survey of 9 exposed and 6 control plots. After 6 yr of exposure to ELF the ratio of Cryptostigmata to Collembola in the original Hazleton test plot is almost exactly the same as in 1969, before antenna turn-on. Since 1972, the average annual production of Collembola in the Main test and control subplots has been practically the same—1488 in the former and 1432 in the latter. Surveys taken 3 or 4 yr apart suggest normal vegetational changes and succession in exposed plots and environs. These and other data do not support the hypothesis that Sanguine/Seafarer electromagnetic fields have had a demonstrable impact on populations of soil arthropods and surrounding flora after 6 yr of exposure.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1033

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

The relationship between the parasite,Microctonus aethiopoides, and its host, the alfalfa weevil, was studied in Ontario during 1974 and 1975. In the field, the populations of the 1st generation adults of the parasite were synchronized well with those of the overwintered weevils, resulting in parasitism of 76–82%. The 2nd generation of the adult parasites and the summer adult weevils overlapped for about 2 wk and parasitism of the diapausing host was 41–60%. Some adults ofM. aethiopoideswere present in the field before the summer adults emerged and the significance of this with respect to the establishment and carry over of the parasite from one year to the next is discussed. Parasitism byM. aethiopoidesdid not significantly affect the mortality of the diapausing alfalfa weevil either in the field or during low temperature storage in growth cabinets.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1040

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

The western corn rootworm (WCR),Diabrotica virgiferaLeConte, demonstrated strong affinities for aggregation and feeding on the foliage of certain wildCucurbitaspecies with relatively high concentrations of cucurbitacin “bitter principles.” Most preferred were xerophytic species of the Digitata group—C. digitataGray,C. cylindrataBailey andC. palmataWats. and mesophytic species of the Lundelliana group—C. lundellianaBailey,C. okeechobeensisBailey andC. ecuadorensisCutler and Whitaker. Xerophytic species were more susceptible to injury and seldom survived continuous 24-h exposure to natural infestations. The spotted cucumber beetle (SCB),D. undecimpunctata howardiBarber, exhibited similar aggregation and feeding responses to wild mesophyticCucurbitaspecies with high cucurbitacin foliage but showed a more consistent feeding preference for cultivated species than the WCR. Both species preferred fruits of feralC. texanaGray andC. andreanaNaud. with high cucurbitacin over non-bitter fruits of their cultivated relatives,C. pepoL. andC. maximaDuchesne, respectively. The combined plant and insect factors which interact to bring about the SCB-WCR/Cucurbitaassociations observed here are discussed.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1043

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

The hemipteran predator,Orius insidiosus(Say) plus sprays of chlordimeform [N′-(4- chloro-o-tolyl)-N,N-dimethylformamidine] reduced the effect ofTrichogramma pretiosumRiley on a caged population of the tobacco budworm,Heliothis virescens(F.). The predator consumed both parasitized and unparasitized tobacco budworm eggs and fed readily on young larvae. The sprays decreased the viability of tobacco budworm eggs, influenced the fecundity of the adult budworms, and reduced emergence of adultT. pretiosumfrom parasitized eggs, but they did not directly affectO. insidiosus. The combination of spray, parasites, and predators prevented populations of tobacco budworm larvae from exceeding 2400/acre for ca. 2 months.AlthoughT. pretiosumparasitized relatively large numbers of tobacco budworm eggs when the density ofO. insidiosuswas low and chlordimeform sprays were not bemg applied, the predator had more effects on the tobacco budworm than the parasite through most of the test period. However, when the population of the cotton leafperforator,Bacculatrix thurberiellaBusck, was reduced with chlordimeform, the population ofO. insidiosusdeclined steadily despite a relatively high density of tobacco budworms. The population of cotton leafperforators, therefore, appeared to have great mfluence on the population ofO. insidiosus.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1049

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Three insecticides (chlorpyrifos, parathion, and carbofuran) and 2 herbicides (propanil and molinate) were tested in laboratory and field to determine their toxicity against mosquitofish,Gambusia affinis(Baird&Girard), and green sunfish,Lepomis cyanellusRafinesque. In laboratory tests, green sunfish were more susceptible than mosquitofish to all pesticides tested except molinate. Parathion and chlorpyrifos were the most toxic compounds to green sunfish with comparable LC50'S. The most toxic compound to mosquitofish was parathion. Carbofuran was the least toxic insecticide to both species. Propanil was substantially more toxic than molinate which was the least toxic pesticide tested. In almost all instances the greatest mortality was observed between 24 and 48 h with very slight changes generally occurring between 48 and 72 h.All pesticides with the exception of parathion at 72 hand chlorpyrifos at 24, 48, and 72 h killed less than 10.0% of all fish tested when applied at recommended field dosages. Parathion produced 16.7% mortality to mosquitofish in cage tests 72 h posttreatment. Mortality from chlorpyrifos was 74.4% at all observation intervals against green sunfish in free-release studies. Propanil applied as much as 6-fold the recommended field dosage against green sunfish resulted in no mortality.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1053

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

An average of 33% more almond moths,Cadra cautella(Walker), remained unmated during a 24-h period under absolute dark conditions compared to those moths mated under a light cycle with dim night illumination. Air permeation with synthetic sex pheromone carried out at various moth densities decreased the mean level of mated female moths at 24 h by 51%. When they were combined, darkness and pheromone effects appeared to be additive, suppressing mating by 85% after 24 h and 71% after 48 h. Both dark and pheromone effects were moth density dependent. Darkness combined with pheromone would enable practical population suppression at a moth density two to three times that possible with pheromone alone.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1057

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Xylocoris flavipes(Reuter) was shown to have the potential of being an effective predator of the red flour beetle,Tribolium castaneum(Herbst). Under all test conditions the predator killed more eggs than larvae or pupae of the red flour beetle. The mean maximum numbers killed during the lifetime of the predator were 539 eggs, 34 larvae, or 14 pupae when the stages of prey were available separately; the mean minimum numbers on which at least 46% of the predators survived to adulthood were 40 eggs, 9 larvae, or 6 pupae. When all stages ofT. castaneumwere available,X. flavipeskilled a maximum of 405 eggs, 4 larvae, and 8 pupae; the minimum numbers killed were 6 eggs, 2 larvae, and 6 pupae.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1059

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

A timed trapping devise which utilizes the trap that was the most effective for capturing male oriental fruit moth,Grapholitha molesta(Busck), lesser appleworm,Grapholitha prunivora(Walsh), and pecan bud moth,Gretchena bolliana(Slingerland), and was also one of the most effective for capturing male lesser peachtree borer,Synanthedon pictipes(Grote and Robinson), and peachtree borer,Sanninoidea exitiosa(Say), was designed and constructed to study response of each species to their respective pheromone sources in the field at different times in the day. Details on the design and construction of the timed trapping device are described.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1062

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

A radioisotope-tagging technique for tracing the dispersal of the southern pine beetle from one host tree to another proved satisfactory in laboratory and field-cage tests. Phosphorus 32 (32P) was applied in an aqueous glycerine suspension to the bark before beetles emerged. Emerging beetles picked up and carried the radio-tag, and left the major portion in the pitch tube of the new host bolt.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1065

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

No significant differences were found among 8 grasses as sites for oviposition by female moths of the grass webworm,Herpetogramma licarsisalis(Walker). Differences were found in total amount of larval feeding injury and the rate at which feeding injury developed on the different grasses. Common bermudagrass [Cynodon dactylon(L.) Pers.] and Tifway bermudagrass (C. dactylon ×C. transvaalensisBurtt-Davey) showed the least feeding injury. Feeding injury developed faster on fine textured grasses than on coarse textured ones. Differences were also found in number of adults emerging from different grasses.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1068

出版商:Oxford University Press    

年代:1976

数据来源: OUP