摘要:

The side effects of candidate mosquito control agents against nontarget organisms were investigated in the laboratory and outdoors in artificial containers, intermittent ponds, and irrigated pastures. The compounds used were TH 6040 [1-(4-chlorophenyl)- 3-(2, 6-difluorobenzoyl)-urea], H 24108 [3-butyn-2 ylN- (p-chlorophenyl) carbamate], and Altosid® [isopropyl 11-methoxy-3, 7, 11-trimethyl-2, 4 dodecadienoate].In the laboratory, crustaceans, especially the tadpole shrimp,Triops longicaudatusLeConte, clam shrimp,Eulimnadiaspp., and water fleas,DaphniaandMoinaspp., were susceptible to TH 6040 at levels below 0.01 ppm. Copepods,CyclopsandDiaptomusspp., showed some tolerance at 0.01 ppm, whereas seed shrimp,CypricerusandCypridopsisspp., were tolerant to as much as 0.5 ppm. Among aquatic insects tested, mayfly nymphs,Callibaetisspp., and chironomid midge larvae,Goeldichironomus holoprasinus(Goeldi), were sensitive. However, beetles,Thermonectus basillaris(Harris),Laccophilusspp.,Hydrophilus triangularisSay, andTropisternus lateralis(F.), demonstrated a strong tolerance. Mosquitofish,Gambusia affinis(Baird and Girard), also showed no effect at high dose levels.In artificial containers, TH 6040 suppressed the cladocera and copepod populations, but they recovered again. There was no effect on seed shrimp and the sideswimmer,Hyalella azteca(Saussure). TH 6040 also suppressed reproduction of the backswimmer,Notonecta unifasciataGuerin. There was no adverse effect on the backswimmer and mosquitofish colonies when the SR-1O formulation of Altosid was applied.In field tests, TH 6040 suppressed populations of tadpole shrimp, clam shrimp, water fleas, and copepods; but these recovered soon. Adult emergence of mayflies and aquatic midges was affected by TH 6040 treatments. Some affected midge pupae were noticed when Altosid was applied.

ISSN:0046-225X    

DOI:10.1093/ee/3.4.631

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

The planarian,Dugesia dorotocephala(Woodworth), was studied in the laboratory and field as a predator of all developmental stages ofCulex peusSpeiser. Reproduction by transverse fission was accelerated by higher feeding rates and probably by crowding. Decreased feeding in culture could be offset by increasing the density ofDugesia. Experimental field populations ofCulexlarvae were reduced by 90+% in 26 days during July and August, 1973. Mucus secretions effectively immobilized prey larvae and their body fluid was consumed. Mucus was also used to produce cemented sand anchors for attachment to larvae and pupae. Group feeding without internecine activity was observed whereby as many as 12Dugesiacollectively ensnarled a single prey. Field and laboratory observations indicated optimum temperatures for feeding and reproduction were 20–26°C. Feeding ceased above 29°C; mortality ensued at 30°C.

ISSN:0046-225X    

DOI:10.1093/ee/3.4.637

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

The effect of a preplanting application of phorate onTetranychus urticaeKoch, associated predators, and aphids on strawberry was investigated in southern California in 1969–70. The spider mite population was significantly lower in the phorate plot from March 3–April 28, reaching a peak averaging 226.8 active stages per leaflet on May 5, compared to 445.5/leaflet in the check on April 28. Except for March 24 and April 14, the predator population was significantly higher in the check plot from March 17–May 12.Scolothrips sexmaculatus(Pergande) andGeocorisspp. were the most common predators present. The seasonal mean number of spider mites and predators was significantly lower in the phorate plot and the mean fruit yield (g/plant) was significantly higher. The aphid population never exceeded an average of 0.3 aphids per leaflet in the phorate plot compared to a peak of 59.2/leaflet in the check on March 24. The strawberry aphid,Chaetosiphum fragaefolii(Cockerell), comprised 96% of the aphid population. The use of phorate in an integrated control program for strawberry pests is discussed.

ISSN:0046-225X    

DOI:10.1093/ee/3.4.642

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

When maleLaspeyresia pomonella(L.) were exposed to 0 or 38 krad of gamma irradiation within 24 h posteclosion and caged at ages 1, 2, 3, 4, or 5 days for 24 h with a 24-h-old virgin female, a significantly higher percentage of unirradiated males passed spermatophores than did irradiated males in each age group. Also, when similar males were caged with a similar female each day for 5 successive days, the untreated males passed a significantly greater number of spermatophores.

ISSN:0046-225X    

DOI:10.1093/ee/3.4.645

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

The spatial distribution of attack around release sites in cotton fields was measured for the parasiteTrichogramma pretiosumRiley attacking eggs of the cabbage looper,Trichoplusia niHübner. The host eggs were presented 20/plant at equidistant “stations” in a cross pattern centered on the release site. Random diffusion theory predicts that the pattern should be a normal distribution in which the variance is a linearly increasing function of time. Out of 24 attack patterns, 14 were found to deviate significantly from a normal distribution. The deviations from normality tended toward a bimodal distribution. In addition, the time-trend of the variance showed a significant deviation from linearity. It is proposed that the deviations from normality may be due to time-varying drift and diffusion rates. In addition, saturation of the environment with parasites can cause a flattening of the attack pattern near the release site.

ISSN:0046-225X    

DOI:10.1093/ee/3.4.647

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

The effect of age, starvation, host plant, and photoperiod on flight activity of female spined stilt bugs,Jalysus spinosus(Say), an important predator of tobacco pests, was studied using tethered and free flight techniques. Stilt bugs reared at a photoperiod ⋝ 14 h and confined with prey and tobacco (standard females) showed no consistent agerelated variation in flight activity other than a postmolt teneral period of 3–5 days. Rearing and holding females at a photoperiod<13 h resulted in a greater proportion flying and longer flights. Also, females held with no prey or no host plant showed significantly more flight activity than standard females. The results are discussed in the context of the observed seasonal migrations of spined stilt bugs and the control of flight activity during mass release experiments.

ISSN:0046-225X    

DOI:10.1093/ee/3.4.653

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

From 1971 to 1973, 36Solenopsis invictaBuren colonies were examined monthly in Orangeburg County, S. C. Marked and randomly selected mounds were opened and the various forms present were visually identified and recorded.This study indicated that all forms (adult and immature) of the fire ant could be found in some colonies throughout the year. The occurrence of asexual immatures varied greatly throughout the year. They were observed in the largest number of mounds from the last of June until the first of August. A considerable decline was noticed in September. A cyclic trend was not evident in the frequency of occurrence of these immatures.The sexual immatures and adults showed a definite cyclic trend in frequency of occurrence. This cycle apparently began sometime between December and January and reached its peak between July and August. Only a small percentage of active colonies contained these forms during the colder months.

ISSN:0046-225X    

DOI:10.1093/ee/3.4.656

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

The collapse of the elm spanworm outbreak in Connecticut was caused primarily by anOoencyrtussp. previously determined asO. clisiocampae(Ashmead), but now thought to be an undescribed species. This parasitoid decimated the egg population in southwestern Connecticut in 1971 and in central and eastern Connecticut in 1972.In 1972 weekly collections of elm spanworm eggs from the infested area showed an increase in the amount of parasitism as summer progressed. At the western edge of the infestation, virtually all eggs were parasitized by July 25. Near the center of the infestation almost all eggs were parasitized by Sept. 5 and at the eastern edge of the infestation by Sept. 19. We attribute this eastward increase in part to the movevement of adult parasitoids into areas where they had previously been absent or rare.Superparasitism of elm spanworm eggs was common in dense populations of the parasitoid. At sites where parasitism was high and superparasitism prevalent, many host eggs were dead and were supporting growth of fungi.

ISSN:0046-225X    

DOI:10.1093/ee/3.4.659

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

The behavior and pollination effectiveness of honey bees,Apis melliferaL., were studied in an enclosed environment.Four groups of melon plants,Cucumis meloL., were grown in an inflated polyethylene greenhouse and exposed for variable times to bee pollination. Blooms were shielded from bee visits with gelatin capsules.Plant blooms shielded from bees during the entire experiment produced no edible melons. The production of plants with blooms exposed for various times did not vary significantly. Seed counts, percent soluble solids, and weights of melons indicated adequate pollination. Variable carbon dioxide concentrations within the greenhouse appeared to affect the soluble solids percentages in mature melons. Bee activity was enhanced by the presence of supplemental pollen cake.

ISSN:0046-225X    

DOI:10.1093/ee/3.4.664

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

The soil excavated from nest chambers ofTrachymyrmex septentrionalisMcCook is placed in crescent-shaped heaps to one side of the entrance hole. The crescents occupy a mean arc of about 75° (but this increases somewhat with time) at a mean distance of 8.0 cm from the hole; a new mound is built at the same orientation and distance if the original mound is removed. The immediate orientational cue which the excavating ants use is a visual image, perhaps landmarks, but not simply a positive or negative phototaxis. If the local slope is altered the mound will be gradually reoriented to a downslope direction over a period of many days. Mound orientation is highly individualistic for each nest, and the compass orientations often appear to be random among nests of a local population.

ISSN:0046-225X    

DOI:10.1093/ee/3.4.667

出版商:Oxford University Press    

年代:1974

数据来源: OUP