SEASONAL HISTORY, ADULT FLIGHT ACTIVITY, AND DAMAGE OF THE OBLIQUEBANDED LEAFROLLER, CHORISTONEURA ROSACEANA (LEPIDOPTERA: TORTRICIDAE), IN FILBERT ORCHARDS

1986 ◽  
Vol 118 (4) ◽  
pp. 351-359 ◽  
Author(s):  
M.T. AliNiazee

AbstractSeasonal history, adult flight activity, and damage of the obliquebanded leafroller, Choristoneura rosaceana (Harris), on filbert were studied during a 7-year period between 1976 and 1984. Data from periodic field counts and moth catches in sex-attractant traps indicated two generations per year. The first-generation adult capture peak was generally higher than the second, except in 1978 when about an equal number of moths were trapped from both generations. A physiological time scale, using degree-days (DD), was devised for predicting emergence of obliquebanded leafroller adults. The first adults from overwintering larvae emerged at approximately 374 DD above a threshold of 10 °C starting 1 March. A total of 1172 DD were required between the first and the last adult emergence during the first generation and about 519 DD during the second generation. The obliquebanded leafroller causes both foliar and nut damage in filbert orchards of Oregon. Foliar damage was insignificant, but nut damage, caused exclusively by the first-generation larvae during June and early July, was highly destructive. Larval feeding on nuts caused staining and premature drop of infested nuts resulting in substantial yield reduction in heavily infested orchards.

2002 ◽  
Vol 134 (3) ◽  
pp. 303-309 ◽  
Author(s):  
I. Pronier ◽  
J. Paré ◽  
J-C Wissocq ◽  
C. Vincent

AbstractA virus isolated from obliquebanded leafroller, Choristoneura rosaceana (Harris), larvae collected in an apple, Malus domestica Borkh. (Rosaceae), orchard of Saint-Joseph-du-Lac (Quebec, Canada) was studied. Microscopic studies revealed that it was a uninucleocapsid nucleopolyhedrovirus from the family Baculoviridae. Larval mortality was approximately 75% (0% mortality in control group) in larvae infected as third instars immersed in a suspension of 1.7 × 108 occlusion bodies/mL. The average time for larval mortality was 23 ± 3 d after treatment. The majority (95.5%) of infected larvae died as fifth or sixth instars. Infection was observed primarily in fat body cells, and occasionally in the tracheal matrix and epidermis. Mean larval development time of infected larvae surviving to pupae was 20 ± 3 d, significantly greater than the 18 ± 3 d observed in control larvae. Adult emergence was significantly lower in pupae of treated larvae (73.6%) than in the control group (93.5%). Our work constitutes the first baseline study of naturally occurring virus of the obliquebanded leafroller.


2015 ◽  
Vol 30 (2) ◽  
pp. 85-90
Author(s):  
Draga Graora ◽  
Ivan Sivcev ◽  
Lazar Sivcev ◽  
Wolfgang Bьchs ◽  
Vladimir Tomic ◽  
...  

The Brassica pod midge (Dasineura brassicae Winn.) is an important pest in oilseed rape (Brasica napus L.). It develops two generations per year and overwinters in the larval stage in cocoons in soil. Immigration of the first generation adults lasted from the beginning of April until the end of May. Larvae developed in pods from mid-April to mid-June, causing pod deformation and cracking, which resulted in premature falling out of seeds and yield reduction. Pod damage amounted to 11.6%. The emergence of the second generation adults was detected at the end of May and in the first ten days of June. D. brassicae was found to lay eggs in healthy pods and no correlation was found with the cabbage seed weevil, Ceutorhynchus assimilis Paykull.


1989 ◽  
Vol 121 (9) ◽  
pp. 745-756 ◽  
Author(s):  
J. Maltais ◽  
J. Régnière ◽  
C. Cloutier ◽  
C. Hébert ◽  
D.F. Perry

AbstractThe braconid parasitoid Meteorus trachynotus Vier. was found in overwintered larvae of the obliquebanded leafroller, Choristoneura rosaceana (Harr.), on foliage of a variety of deciduous species, well before the parasitoid’s attack on the spruce budworm, Choristoneura fumiferana (Clem.). In the spring, percentage parasitism of C. rosaceana by M. trachynotus was 8.0 and 18.8% in 1986 and 1987, respectively. Maximum parasitism on C. fumiferana (35 and 4% in 1986 and 1987, respectively) was reached in late June, at a time when over 50% of M. trachynotus cocoons found on deciduous vegetation had emerged. Twenty days later, parasitoids produced on C. fumiferana reached 50% adult emergence. The catches of adult parasitoids on sticky traps placed on deciduous trees and on conifers showed two periods of adult activity. Based on the sex ratio of captured parasitoids, male M. trachynotus were active at emergence sites, whereas females were found mostly in the habitats of available hosts. The phenology of C. rosaceana was observed in 1987. As indicated by light-trap captures, males fly sooner than females. Eggs were laid in July, and so the early larval stages were available to female M. trachynotus as overwintering hosts. Several parasitoids common to C. rosaceana and C. fumiferana were identified.


1984 ◽  
Vol 116 (12) ◽  
pp. 1659-1664 ◽  
Author(s):  
H. F. Madsen ◽  
J. M. Vakenti ◽  
A. P. Gaunce

AbstractThe distribution and adult flight activity of obliquebanded leafroller, Choristoneura rosaceana (Harris) and threelined leafroller, Pandemis limitata (Rob.) were studied in the Okanagan and Similkameen valleys of British Columbia using traps baited with the sex pheromone of each species. Adult activity began in early June and continued through September and the two species were distributed throughout the apple-growing region of the Okanagan and Similkameen valleys. In the northern Okanagan and in uncultivated areas at higher elevation, the trap captures indicated that both species are univoltine. In the southern Okanagan and the Similkameen Valley, large numbers of both species were captured throughout the season which may indicate more than one generation. Traps captured similar numbers of adults in orchards with known infestations and in orchards lacking infestations, suggesting that males are attracted to traps in orchards from native hosts in uncultivated sites.


1995 ◽  
Vol 127 (2) ◽  
pp. 271-273 ◽  
Author(s):  
S.Y. Li ◽  
S.M. Fitzpatrick ◽  
M.B. Isman

In recent years, the obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae), has become a major pest of raspberries in the Fraser Valley, British Columbia (Anonymous 1994). Overwintering C. rosaceana larvae begin feeding on raspberry leaf buds in early April. Heavy infestation causes serious damage to raspberry plants. Larvae of the first generation hatch in late June to early July, and feed on growth terminals and berries. The occurrence of this generation usually coincides with berry harvesting time. Because the larvae are shaken from the plants by the harvesting machine, C. rosaceana can be a major contaminant of machine-harvested berries.


2019 ◽  
Author(s):  
Zac Wylde ◽  
Foteini Spagopoulou ◽  
Amy K Hooper ◽  
Alexei A Maklakov ◽  
Russell Bonduriansky

Individuals within populations vary enormously in mortality risk and longevity, but the causes of this variation remain poorly understood. A potentially important and phylogenetically widespread source of such variation is maternal age at breeding, which typically has negative effects on offspring longevity. Here, we show that paternal age can affect offspring longevity as strongly as maternal age does, and that breeding age effects can interact over two generations in both matrilines and patrilines. We manipulated maternal and paternal ages at breeding over two generations in the neriid fly Telostylinus angusticollis. To determine whether breeding age effects can be modulated by the environment, we also manipulated larval diet and male competitive environment in the first generation. We found separate and interactive effects of parental and grandparental ages at breeding on descendants’ mortality rate and lifespan in both matrilines and patrilines. These breeding age effects were not modulated by grandparental larval diet quality or competitive environment. Our findings suggest that variation in maternal and paternal ages at breeding could contribute substantially to intra-population variation in mortality and longevity.


2020 ◽  
Vol 54 (s41) ◽  
pp. 89-115
Author(s):  
Einat Gonen

Abstract This paper presents a diachronic study of Modern Hebrew agreement between numerals and their quantified nouns. This research is possible thanks to the discovery of two rare collections of recordings from the 1950s and 1960s, which document four generations of speakers and have become important sources of spoken Early Modern Hebrew. On the basis of these two corpora, I compare numeral agreement in the first two generations of speakers with present-day usage and analyze trends of change and conversation in Modern Hebrew. The study shows that the first generation of speakers (“Gen1”) largely acquired the gender distinction of cardinals. However, in contrast to other agreement issues that educated Gen1 speakers realized fully, numeral use showed variation and absence of agreement in a small set of cases. Moreover, some linguistic features of Gen1 Hebrew found in this study no longer characterize Present-Day Hebrew; among these features is prosodic conditioning, which led to a Gen1 tendency to use the feminine form of the numeral ‘four’ with masculine nouns more frequently than was the case with other numerals.


1995 ◽  
Vol 127 (4) ◽  
pp. 577-586 ◽  
Author(s):  
Y. Carrière ◽  
S. Paré ◽  
B.D. Roitberg

AbstractThe daily pattern of oviposition, the rank order of oviposition preference for three potential hosts, and the effect of experience on oviposition preference were investigated under natural abiotic conditions in the obliquebanded leafroller, Choristoneura rosaceana. Females from the two adult cohorts occurring seasonally oviposited between 0400 and 2400 hours, with peak oviposition around 2000 hours. Both non-choice and choice oviposition trials revealed that the apple and snowberry hosts were preferred over wild rose. Oviposition preference resulted in delays in laying on the less preferred host, but seemed to have no effect on clutch size. Females caged with exclusive access to one of the three hosts appeared to have similar lifetime fecundity or longevity. A first oviposition on wild rose resulted in a delay in laying a second clutch on that host, which suggests the presence of aversive learning that could function to reduce the liklihood of laying successive clutches on a less preferred host. A first oviposition on the apple host, however, seemed to have no effect on further oviposition preference. Hence, it appears that learning would not function specifically to concentrate foraging of the females within apple orchards.


2013 ◽  
Vol 47 (1) ◽  
pp. 438 ◽  
Author(s):  
I. Thabet ◽  
A. Kilias ◽  
A. Koroneos ◽  
S. Kamh

The study deals with the petrography of the granitoid rocks intruding the five (A to E) domes of Hafafit Culmination. The morphological characteristics of zircon crystals are also examined, in order to elucidate the genesis of zircon and their host Hafafit granitoids. The granitoid rocks are tonalites, granodiorites and quartz diorites, all exhibiting gneissic texture. The zircon crystals from all the rock types intruding each one of the domes are examined in detail for colour, inclusions, crystal length, crystal width, elongation ratio, crystal form and habit, degree of roundness and corrosion, and are distinguished in groups on the basis of the previous characteristics. Two generations of zircons have been recognized; the first generation with magmatic features and the second one with post magmatic features. The first generation of zircon is attributed to the subduction, magmatic and deformation events while the second generation of zircon is attributed to metamorphism.


2021 ◽  
Vol 29 ◽  
pp. 41-46
Author(s):  
V. A. Katsan ◽  
A.I. Potopalsky ◽  
B.O. Zadorozhnii

Aim. The investigation of the influence of the constituents of Izatison, DMSO and PEG400, on the oat growth and its grain productivity during 2 generations after the seed treatment became the aim of this study for the elucidation of mechanism of Izatison stimulant influence. Methods. The broad scale of the concentrations of the solvents composition in the proportion, to be as in Izatison, was used. The plants were grown in the field. The growth processes were evaluated by the stem height on the tubing stage. The grain productivity was characterized by the panicle length, the grains number in the panicle and of theirs weight. Results. The dependence of influence of the solvents composition on the stem growth from its concentration was detected in the first generation. In some variants the negative influence was revealed on the grains number in the panicle and on theirs weight. The stimulation of the growth regardless from the solvents concentration was observed in the second generation and the more pronounced negative effect on the grain productivity. Conclusions. The solvents DMSO and PEG400 are able to influence on the oat growth and its productivity, and that effect was manifested also in 2 generation after the seed treatment. Keywords: Izatison, DMSO, PEG400, oat growth and grain productivity.


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