摘要:

A microencapsulated pheromone formulation for the grape berry moth,Paralobesia viteana, was used at the rate of 25 g pheromone/ha. A schedule of 20 sprays over a 103-day period gave ca. 95% disruption of ♂ orientation to pheromone traps. Grape berry injury was reduced by 87% compared to the check plot. Each application of microencapsulated pheromone was found to be effective in disrupting ♂ orientation for ca. 5–7 days.Hollow fibers were found to be very steady and efficient releasers of pheromone, giving excellent ♂ orientation disruption for at least 70 days. The results obtained withP. viteanaalso are supported by data simultaneously collected withEpisimus argutanus, which is attracted to the same chemical, (Z)-9-dodecenyl acetate.

ISSN:1754-5692    

DOI:10.1093/ee/5.4.688

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Phytophagous insects ofCarduus nutansL. (Compositae) in South Dakota are reported. Ninety-eight species are noted, including 3 which have endophagous habits; i.e.,Papaipema nebrisGuenée (Lepidoptera: Noctuidae),Platyptila carduidactlysRiley (Lepidoptera: Pterophoridae) andHomoeosoma ellectellumHulst (Lepidoptera: Pyralidae). Nearly half of the species were collected only once in the samples and are therefore considered rare or transient. Comparisons with European thistle insects indicate musk thistle in South Dakota has not been thoroughly exploited by native insects.

ISSN:1754-5692    

DOI:10.1093/ee/5.4.692

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Egg traps were used to study populations of the navel orangeworm,Paramyelois transitella(Walker) in almond orchards in the San Joaquin Valley of California in 1974 and 1975. Seasonal variations in moth emergence and flight as indicated by egg laying patterns were readily identified in both years. Egg deposition curves closely followed ♂ moth flight patterns during the early season but did not correlate as well from midsummer through fall. Differences in moth and egg populations could be detected with egg traps in orchards that received varying levels of post-harvest sanitation. Sticky traps baited with the egg trap attractant showed a sex ratio of responding navel orangeworm moths of ca. 11 ♀:1 ♂. Attractant odors given off by the egg trap bait are not specific for navel orangeworm but also attract the raisin moth,Cadra figulilella(Gregson). However, only eggs of navel orangeworm were found on the egg traps in the field.

ISSN:1754-5692    

DOI:10.1093/ee/5.4.697

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Effects of the insect growth regulating compound, Dimilin [1-(4-chlorophenyl)-3-(2,6,-difluorobenzoyl)-urea], on reproduction in brine shrimp,Artemia salina, were investigated using pair mating experiments. Reproductive performance was compared for 5 groups of 15 mated pairs each, exposed to one of 5 test solutions (1, 2, 5, 10 ppb Dimilin and a control). Significant reduction in reproductive lifespan was evident in adults exposed to 2, 5, and 10 ppb; in addition, males consistently outlived females in all Dimilin exposures. Survivorship of nauplii produced viviparously by mated pairs was comparable to controls, except in the 10 ppb exposed group. Cysts, produced oviparously by treated pairs at all Dimilin concentrations, displayed significantly lower mean hatchability (<4.8%) than controls (22.6%) upon rehydration. Newly hatched nauplii (24 h old) were exposed to concentrations of Dimilin (10,000 ppb, 1000 ppb, 100 ppb, 10 ppb, 1 ppb and a control) for a l2-day period. Nauplii exposed to concentrations greater than 10 ppb died within 3 days or less, while survival of nauplii exposed to 10 ppb and 1 ppb was comparable to controls.

ISSN:1754-5692    

DOI:10.1093/ee/5.4.701

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Epizootics of an undescribedHowardulasp. nematode (family Sphaerulariidae) occurred in tobacco fields among larval populations of the tobacco flea beetle,Epitrix hirtipennis(Melsheimer), at Oxford, NC in 1974 and 1975, and Clayton, NC in 1975. The parasitic adult ♀ nematode produced juveniles in about 70% of the parasitized flea beetle larvae. The potentially infective juveniles were able to exit from the parasitized larvae. Also, from 0 to over 50% of the adultE. hirtipenniswere parasitized which resulted in greatly reduced fecundity among afflicted ♀ beetles.

ISSN:1754-5692    

DOI:10.1093/ee/5.4.707

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

The daily oviposition rhythm ofS. pictipeswas determined in the laboratory. Mated females were kept for 4 days under 2 constant temperatures and 3 thermoperiods, and a 16:8 L:D photoperiod. In all regimes, the oviposition occurred during photophase, with the mean in the late photophase.The mean time of oviposition at the thermoperiod 26.7:16.7°C was advanced compared to that at a constant temperature (26.9°C) about equal to thermophase temperature. A small 2nd peak of oviposition occurred at the very end of photophase under all thermoperiods.

ISSN:1754-5692    

DOI:10.1093/ee/5.4.712

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Regression equations for predicting diameter outside bark (DOBx) and bark thickness (BTx) as functions of height and diameter or bark thickness class were developed from data collected as part of aDendroctonus frontalispopulation dynamics study. The 2 equations were combined and integrated over height to provide estimates of the phloem area and bark volume infested by the insect.A graphic analysis using the BTxmodel showed that eggs/cm3of bark increase with height, indicating that factors other than BTxcontrol the egg density per unit area. An example is presented showing the use of the phloem area model to estimate the total number of insects inhabiting a tree.

ISSN:1754-5692    

DOI:10.1093/ee/5.4.714

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Biotype C of the greenbug,Schizaphis graminum(Rondani), was cultured in the greenhouse on resistant sorghum entries for ca. 2 years. About every 4 mo the components of resistance of the plant were measured to determine whether new biotypes had occurred. Although non-preference and tolerance did not change significantly within an entry, the fecundity of aphids on the resistant entries decreased. This reduction persisted when the greenbugs were transferred directly to susceptible “Wheatland” and then tested, but it did not persist when they were left on Wheatland 4 mo before testing. Thus the reduced reproduction was probably a conditioning effect and not a mutation.

ISSN:1754-5692    

DOI:10.1093/ee/5.4.720

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Nymphs and adults ofMelanoplus femurrubrum(DeGeer) in a 1.8 acre mixed grassforb field were collected and analyzed for food plants and parasites for 3 years. The most common foods in the crops of the grasshoppers were normally those most abundant in the field, although the less common hoary alyssum (Berteroa) was profusely selected. Feeding trials indicated that a mixture was needed for increased fecundity. Ground cherry (Physalis) made up 6% of the crop contents but when fed alone it caused nymphal mortality. The nematode,Mermis nigrescens, accounted for up to 71% mortality when analyzed using the seasonal index of parasitism.Eutrombidium rostratus,Perilampus hyalinusand aSarcophagasp. had a negligible effect on mortality. Nematode parasitism and suboptimal nutrition appeared to be major factors in maintaining a stable grasshopper population.

ISSN:1754-5692    

DOI:10.1093/ee/5.4.724

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Samples ofHarpalus pennsylvanicusDeGeer,Pterostichus chalcitesSay, andScarites substriatusHaldeman taken from Iowa cornfields were analyzed for chlorinated hydrocarbon insecticide residues. Results are reported in ng of insecticide/g of beetle (ppb). The principal residues occurring in these field-collected carabids were dieldrin andp,p′-DDE. Smaller quantities of aldrin,p,p'-DDT, heptachlor, heptachlor epoxide, and lindane were detected. Although from the same field,H. pennsylvanicusandS. substriatuscontained significantly (P=0.05) different levels of aldrin, dieldrin, andp,p′-DDE.P. chalcitescontained the highest level ofp,p′-DDE (913.5μg/g). No significant differences (P=0.05) were found in the amounts of insecticide residues present between male and female beetles.FemaleP. chalciteswere dosed topically with 2 μl of an acetone solution of dieldrin. Five concentrations were used, varying from 10–250 μg of dieldrin/beetle. Mortality counts were made 48 h after application of the insecticide. The computed LD50was 3357 μg of dieldrin/g of beetle (ppm). This far exceeded the residue levels of dieldrin reported herein. Clearly,P. chalciteshas an extremely high resistance to dieldrin.

ISSN:1754-5692    

DOI:10.1093/ee/5.4.729

出版商:Oxford University Press    

年代:1976

数据来源: OUP