摘要:

Aedes atropalpus(Coquillett) prefers to oviposit on clean water used to hold larvae or pupae in the laboratory for a short period (24 hours). The attractant does not filter out, and the filtrate remains effective for several weeks. Repeated utilization of certain pools in nature is undoubtedly aided by this attractant.

ISSN:1754-5692    

DOI:10.1093/ee/2.5.729

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

Metepa-sterilized males ofDacus oleae(Gmelin) mixed at different ratios with normal males were allowed to compete for normal females. Sexual competitiveness of sterile males was compared with that of normal males based on mating activity and egg hatch. The effect of competition stress on the mortality of insects also was examined.Mortality of sterile males was lower than that of normal males when competition stress was absent. Mortality of sterile males competing with normal males at 1:1 and 2:1 ratios respectively, is higher than that of normal males. At the 4:1 ratio sterile males show the same low mortality as irradiated males caged alone. Mortality of normal males was not affected by competition stress. Mortality of normal females which were introduced into the male cages every week for mating was the same for all experiments during the first two weeks. During the following weeks mortality was higher when females mated with normal males or when they were outnumbered by males by a factor of at least 5.Mating competitiveness of sterile males was the same as that of normal males. On average, more than 72% of total matings of both sterile and normal males caged separately occurred during the first day of their contact with females. The percentage of sterile males caged alone which mated was lower than that of normal males caged alone during the first week and higher during the third week.Competitiveness of sterile males based on egg hatch was the same as that of normal males in all cases except during the first week and only when they occurred in a 1:1 ratio.

ISSN:1754-5692    

DOI:10.1093/ee/2.5.731

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

The chronological and geographical distributions of immature and adult orthopteroids were compared in a semi-isolated abandoned crop field in Michigan. Seven general plant associations within the 1.8-acre field were sampled by sweeping and pit-trapping, and the relative numbers of orthopteroids within each association were determined. Thirty species of orthopteroids were captured with the following distribution by families: Acrididae 16, Gryllidae 5, Conocephalidae 3, Phaneropteridae 1, Gryllacrididae 1, Tetrigidae 2, Manteidae 1, Phasmatidae, 1.

ISSN:1754-5692    

DOI:10.1093/ee/2.5.737

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

Orchard studies clearly demonstrated that sexually mature female and maleRhagoletis pomonella(Walsh) respond positively to the odor of fresh-picked apples of susceptible varieties in a stage suitable for oviposition and larval development. Evidence suggests that the nature of the flies' response is one of attraction (in the loose sense of the word). No response was detected to the odor of fresh-picked fruits of a nonsusceptible apple variety or a nonhost species, choke cherry (Prunus virginianaL.). We discuss the potential utility of the unidentified attractive component(s) of the fruit odor in development of improved devices for monitoring fly populations and new, integrated methods of population management.

ISSN:1754-5692    

DOI:10.1093/ee/2.5.743

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

The influence of 70 compounds on the attractant activity of the synthetic sex pheromones ofAdoxophyes orana(Fischer von Röslerstamm) was investigated in the field. Six. compounds, 8-n-butoxyoctan-l-ol acetate; 11-methoxy-; 11-ethoxy-; and ll-n-pro-poxyundecan-1-ol acetate; cis-7- and cis-l0-tetradecen-1-ol acetate had strong inhibitory effect. 11-Chloroundecan-1-ol acetate and some other compounds seemed to have a synergistic effect. Other compounds had no obvious influence on moth captures.

ISSN:1754-5692    

DOI:10.1093/ee/2.5.751

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

Marked adultRhagoletis pomonella(Walsh) were released in an 8-tree abandoned orchard and were recaptured on baited traps. Of 3080 marked adults released, 71% were recaptured on yellow sticky-board traps and on traps that combined a red sphere and a yellow board. Of the 2188 flies recaptured, 67.3% were caught on the combination traps.

ISSN:1754-5692    

DOI:10.1093/ee/2.5.757

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

Effects of age ofTrichoplusia ni(Hübner) on rate of development ofHyposoter exiguae(Viereck), a solitary endoparasitoid, and the relationships of parasitism to growth and developmental patterns of the host were determined.Hosts parasitized prior to the sixth day of age initially developed similarly to nonparasitized individuals, but from the 6th day parasitized larvae grew slower. The maximum weight of these larvae was about one-seventh that of nonparasitized individuals. Growth patterns of larvae parasitized after the sixth day of age are almost immediately observable. Parasitized individuals gain little or no weight as compared with normally developing larvae. The maximum weights of these larvae were one-fifth to one-third the weights of nonparasitized larvae.Parasitoid development time was significantly negative when correlated with host age. Those starting their development in 1-day-old hosts required 13.85 days to complete development, whereas parasitoids starting development in 10-day-old hosts required only 7.4 days to complete development. Developmental rate changes most dramatically from one- to four-day-old hosts, by more than four days. In hosts five-ten days old development differed by approximately one day.

ISSN:1754-5692    

DOI:10.1093/ee/2.5.759

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

Nuculaspis californica(Coleman) occurs on several species of pine and on Douglasfir with dense populations of outbreaks causing defoliation, discoloration of foliage, and reduced growth. All known outbreaks of this scale are caused by reducing the population ofProspaltellaparasitoid that normally keeps the scale populations at very low densities. Abnormal mortality ofProspaltellais caused either by presence of sorptive dusts or by drift of insecticides. The scale is excluded from many areas by rapid onset of freezing and in other areas it is regularly reduced in numbers by such freezing. In areas where the scale is cold-conditioned annually before freezing occurs it persists without significant winter reduction.Prospaltellaand winter freezing are the only factors that reduce the populations of scales to acceptable levels on forest or ornamental trees. Some reduction of numbers occurs through predation by the coccinellids of the generaChilocorusandMicroweisiaand by snakeflies. At extreme population densities scales die either because of crowding or because they kill host tree twigs or whole trees. Scale populations apparently become adapted to specific host individuals, and population densities can become high only with genetic fitness of the population to the host species and individual. Nymphs have the greatest chance of survival on the parent tree, less chance on other trees of the same species, and little chance when transfer is made to another host species. Hence scale outbreaks are largely confined to one host species even when several known host species occur in the area. No known causal relationships exist between atmospheric fluorides and black pineleaf scale population density. Infestations may be reduced with insecticides, but environmental improvement to conserve theProspaltellaparasitoids is the most effective control.

ISSN:1754-5692    

DOI:10.1093/ee/2.5.765

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

Fluorescent pigment-marked male and femaleMusca domestieaL., heterozygous for a reciprocal translocation between chromosome II, III, and V (that reduced their fertility to 32.5% in outcrosses), and for 2 recessive mutant marker genesbwb(brown body color-III) andoera(ocra eye color-V), were released into a native population for 7 generations at a pig-rearing installation near Gainesville, Florida. Males and females homozygous for the mutant markersbwbandoerawere also released. All released females had mated before release with one of the two types of males. The releases were startcd (July 6, 1970) after the native population had reached its initial seasonal peak. The mixed population, measured by grid counts and estimated to be 20,000 flies before the releases were started, remained at a fairly consistent density throughout the entire release program, even though an average of 1500–5000 marked flies were released at the site each day. The number of released flies recovered by netting never exceeded 1% of those released, and no mutant homozygotes (bwb; ocra) were ever recaptured. The low rate of recovery of translocation or mutant-bearing pupae collected near the release site indicated that most of the released flies migrated from the release area, probably because the incipient population had saturated the existing environment. For whatever reason, the number of translocation-bearing males and females that remained in the vicinity of the release site and that participated in the reproductive cycle was not large enough to cause a very significant reduction in fertility of the native females.

ISSN:1754-5692    

DOI:10.1093/ee/2.5.779

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

The effects of larval competition on rate of development, carrying capacity of an apple, ovarian development, head-capsule width and O2uptake were examined forLaspeyresia pomonella(L.). A laboratory strain of codling moth, originating from Yakima, Washington, was used, although it may not be typical of wild populations. Experiments were conducted at 26°±2°C and a 16-hour photoperiod, except that oxygen measurements were carried out under dark conditions.Rate of development decreases at higher competitive levels. The carrying capacity for a 4-cm-diameter apple is approximately three larvae per apple. The mean number of eggs developing per moth is reduced at higher competitive levels. The head-capsule width for second and fourth instars decreases with increased competition.Third and fourth instars have a linear relationship between O2uptake and body-weight. There was a reduction in O2uptake for competing third instars. Fourth and fifth instars did not show differences in O2uptake due to competition. Fifth instars displaced from the competing arena decreased their O2uptake. Precompetitive O2uptake rates for displaced and nondisplaced larvae were greater than the postcompetitive rates.

ISSN:1754-5692    

DOI:10.1093/ee/2.5.783

出版商:Oxford University Press    

年代:1973

数据来源: OUP