scholarly journals Distribution of Population of Immature Stages of Pear Psylla, Cαcopsyllα pyri, within the Tree and Development of Sampling Strategy

2017 ◽  
Vol 10 ◽  
pp. 5 ◽  
Author(s):  
E. T. Stratopoulou ◽  
E.T. Capatos
Keyword(s):  
Second Generation ◽  
Sampling Strategy ◽  
Tree Canopy ◽  
Oviposition Period ◽  
Immature Stages ◽  
Flower Buds ◽  
Uniform Pattern ◽  
Cacopsylla Pyri ◽  
Pear Psylla ◽  
Oviposition Sites

The distribution of Cacopsylla pyri (L.) (Homoptera-Psyllidae) infestation within the tree canopy and in the varions organs of the tree was investigated in the region of Magnesia (Greece) during 1988 and 1989. The upper parts of the tree canopy and the sections ori­entated to South and west were infested heavier during winter and spring. Later in the scason the infestation was diffused within the tree canopy and at the end of the season a rather uniform pattern of distribution was observed. During the first oviposition period (February-March), the preferred oviposition sites were flower buds white during spring (second generation) they were the leaves of flower buds and young shoots. Sampling strategy for the study of populations of immature stages of pear psylla is discussed on the oasis of these findings.

scholarly journals Phenology of Population of Immature Stages of Pear Psylla, Cαcopsyllα pyri, in the Region of Magnesia (Greece)

2017 ◽  
Vol 10 ◽  
pp. 11 ◽  
Author(s):  
E. T. Stratopoulou ◽  
E.T. Capatos
Keyword(s):  
Population Density ◽  
Overlapping Generations ◽  
First Generation ◽  
Immature Stages ◽  
Basic Pattern ◽  
Environmental Pressure ◽  
Cacopsylla Pyri ◽  
Pear Psylla ◽  
Low Levels

The phenology of the population of immature stages of pear psylla, Cacopsylla pyri (L.), was studied in Greece (region of Magnesia), during the period 1988-1991 and it was found to follow a basic pattern. Pear psylla produces 5-6 gencrations per year. The first generation develops during the period February-middle April and it is quite discrets. Three overlapping generations are developed during the period front middle April until middle August but the amount of overlapping varies front year to year. Front middle August until the end of the season pear psylla produces 1-2 generations, i.e. only a part of the firth generation complotes the sixth one. Population density is generally low during the first generation but during May-June reaches verty high levels. During sommer, strong environmental pressure, supresses the population of pear psylla to low levels but it recovers again during September-October.

Selection for monocrotophos resistance in pear psylla,Cacopsylla pyri(L.) (Hom., Psyllidae)

1995 ◽  
Vol 119 (1-5) ◽  
pp. 507-510 ◽  
Author(s):  
S. Berrada ◽  
T. X. Nguyen ◽  
D. Merzoug ◽  
D. Fournier
Keyword(s):  
Cacopsylla Pyri ◽  
Pear Psylla ◽  
Selection For

Effect of Rate and Timing of Biorational Materials for Control of Second Generation White Apple Leafhopper Nymphs, 1995

1996 ◽  
Vol 21 (1) ◽  
pp. 6-7
Author(s):  
E. H. Beers
Keyword(s):  
Second Generation ◽  
Apple Orchard ◽  
Tree Canopy ◽  
Single Tree ◽  
Tree Fruit ◽  
Pre Treatment ◽  
Experimental Treatments ◽  
Extension Center ◽  
Mature Apple

Abstract The test was conducted in a mature apple orchard (several strains of ‘Delicious’) at the Tree Fruit Research & Extension Center, Wenatchee, WA. Treatments were replicated 4 times, with each replicate consisting of a single tree. The experimental design was a RCB, using pre-treatment WALH populations as the blocking factor. The experimental treatments (three types of horticultural mineral oil and Neemix, a neem product) were applied at various rates and timings. The timings were selected based on previous experience of WALH phenology. The late Jul timing (27 Jul) coincides with the appearance of the 4th instars, while the mid-Aug timing (14 Aug) coincides with the first appearance of adults of the second generation. Pesticides were applied with a handgun sprayer to the point of drip. WALH populations were sampled ca. weekly by counting in situ all live nymphs on 20 leaves per tree, distributed throughout the tree canopy.

INFLUENCE OF HUMIDITY ON THE PREDACEOUS MITE MELICHARES DENTRITICUS (BERLESE) (ACARINA : ACEOSEJIDAE)

1962 ◽  
Vol 40 (5) ◽  
pp. 761-766 ◽  
Author(s):  
I. Rivard
Keyword(s):  
Food Product ◽  
Prey Population ◽  
Oviposition Period ◽  
Predator Population ◽  
Immature Stages ◽  
Tyrophagus Putrescentiae ◽  
Adult Females ◽  
Rate Of Increase ◽  
Predaceous Mite

The predaceous mite Melichares dentriticus (Berlese) was reared individually on larvae and protonymphs of the stored food product mite Tyrophagus putrescentiae (Schrank) at 68.0° F and 70, 80, 90, and 100% R.H. Survival and speed of development of the immature stages increased slightly with the humidity. Longevity of adult females was similar at different humidities, though the oviposition period was much shorter at 70% R.H. More eggs were laid at 100% R.H., but then the peak of laying occurred later in the oviposition period. The rate of increase of the predator population was altered very little by different humidities in comparison with that of the prey population and thus, assuming that these rates are an accurate guide to the outcome of the interaction, the population of the prey should be better controlled at lower humidities.

The biology of Nanophyes sp. (Col., Curculionidae) infesting Jussieua repens in India

1967 ◽  
Vol 57 (3) ◽  
pp. 337-341 ◽  
Author(s):  
T. Sankaran ◽  
K. Krishna
Keyword(s):  
Larval Period ◽  
Aquatic Weed ◽  
Immature Stages ◽  
Flower Buds ◽  
Pupal Period

Nanophyes sp. nr. nigritulus Boh. infests the aquatic weed, Jussieua repens (Onagraceae) in India, its larvae feeing and developing inside the fruits. Adults feed on the leaves and also on the pollen and nectar of flowers. Eggs are laid singly in the interior ovaries of flower buds or blossoms. The ovaries hypertrophy and develop into deformed fruits which, when severely infested, are also completely seedles. The number of eggs laid by six females was found to vary from 89 to 410. The female that laid 410eggs distributed them in as many as 167 flowers, 7 being the maximum number of flwers in which eggs were laid and 13 the maximum number of eggs laid per day. In the laboratory, one of the females lived for 207 days and one of the males for 93 days. The period hatched in 4–8 days, the larval period occupied 7–16 days and teh pupal period, 3–6 days. The larvae moulter three times and pupated in separate chambers that they formed before pupating. Adults emerged by biting holes in the wall of the fruit. The egg and immature stages of the weevil are briefly described. Three species of Pteromalid wasps belonging to Habrocytus, Trichomalopsis and an unidentifies genus, and a species of Eupelmus (Eupelmidae) attacked the larvae.

scholarly journals Comparative biology of two congeneric stinkbugs, Chinavia impicticornis and C. ubica (Hemiptera: Pentatomidae)

2015 ◽  
Vol 50 (5) ◽  
pp. 355-362 ◽  
Author(s):  
Cleonor Cavalcante Alves Silva ◽  
Raul Alberto Laumann ◽  
Maria Carolina Blassioli Moraes ◽  
Michely Ferreira Santos de Aquino ◽  
Miguel Borges
Keyword(s):  
Population Size ◽  
Life Table ◽  
Egg Production ◽  
Oviposition Period ◽  
Demographic Parameters ◽  
Comparative Biology ◽  
Immature Stages ◽  
Survival Curves ◽  
High Fecundity ◽  
Time Required

The objective of this work was to compare the biology of Chinavia impicticornis and C. ubica (Hemiptera: Pentatomidae), two species of stinkbugs that occur as secondary pests in soybean. Life table procedures were used for evaluating nymphs, and fecundity tables for evaluating adults, in order to establish the demographics of the two species. The two species have similar demographic parameters, and the development of immature stages, from egg to adult, had similar duration periods of approximately 30 days. In both species, eggs and second-instar nymphs were the stages with higher mortality. Total egg production did not differ between females of both species. Fecundity and survival curves for adults showed similar trends in both species. However, C. ubica had greater potential to increase its populations, since its fecundity parameters were significantly higher than those of C. impicticornis. Moreover, the generational time and the time required to double the population size were shorter in C. ubica. Prolonged longevity, long oviposition period, high fecundity, and the ability to rapidly increase their populations indicate that both species can become potential pests in favorable environments.

scholarly journals Efficacy of Spirotetramat in the Control of Pear Psylla (Cacopsylla Pyri L.) on Pear Trees in Poland

2012 ◽  
Vol 20 (2) ◽  
pp. 91-106 ◽  
Author(s):  
Krystyna Jaworska ◽  
Remigiusz W. Olszak ◽  
Barbara H. Łabanowska ◽  
Mirosław Korzeniowski
Keyword(s):  
Field Experiments ◽  
Early Stage ◽  
Single Application ◽  
Pest Population ◽  
Total Reduction ◽  
Cacopsylla Pyri ◽  
Summer Generation ◽  
Pear Psylla ◽  
Pear Trees ◽  
Very High

Abstract The effectiveness of spirotetramat in the control of pear psylla (Cacopsylla pyri) on pear trees was investigated in five field experiments, carried out in years 2009- 2011. One or two treatments were applied in June; the first treatment in the early stage of larvae hatching from eggs deposited by females from the summer generation, whilst the second application was carried out about two weeks later. In all the experiments, spirotetramat as Movento 100 SC applied at a dose of 2.25 l/ha effectively reduced the pest population after only a single application (total reduction of larvae after one week post-treatment 75.3-91.4%, and 83.7-97.6% at two weeks posttreatment). Movento 100 SC applied after a single application at a lower dose of 1.8 l/ha had a slightly worse effect (the total reduction of larvae at one week posttreatment was at the level of 58.4-91.3%, and two weeks after application at the level of 56-92.6%) - but in this case only a few larvae at stages L4 and L5 were found on pear shoots. The effectiveness of spirotetramat at both doses after two applications was very high.In comparison with standard insecticides the efficacy of spirotetramat was higher or not significantly different. In two experiments the application of standard compounds such as diflubenzuron and novaluron was not effective in controlling pear psylla and therefore did not prevent damage to pear trees. This may suggest that local populations of the pest are resistant to these measures, especially since they have been used for many years to control other pests of pear trees

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