scholarly journals The entomofauna on the leaves of two forest species, Fagus sylvatica and Corylus avelana, in Menoikio Mountain of Serres

2017 ◽  
Vol 23 (2) ◽  
pp. 65
Author(s):  
M. G. Stoikou ◽  
P. P. Karanikola

The insect species composition and their abundance were investigated on the leaves of beech (Fagus sylvatica, Fagaceae) and hazel trees (Corylus avelana, Betulaceae) in the mixed forest located in Menoikio Mountain of Serres. For that purpose from April to June 2011 leaves were collected from the two forest species at weekly intervals and the insects found were reared in the laboratory under outdoor conditions and checked every day till their pupation and adult emergence. A total of 27 insect species was recorded. These insects belonged to seven orders. Fifteen Coleoptera species, 4 Hemiptera species, 3 of Lepidoptera species, 2 of Hymenoptera species and 1 species to the orders Diptera, Neuroptera, and Ephemeroptera were found. The results disclose that the number of insect species found on leaves of hazel trees was fewer than the insect species on beech trees. On hazel trees the population of Lymantria dispar (Lepidoptera: Lymantriidae) was much higher than in beech trees. The species of Coleoptera collected from hazel trees were Phyllobius pyri (Coleoptera: Curculionidae), Rhynchaenus populi (Coleoptera: Curculionidae) and Agiotes acuminatus (Coleoptera: Elateridae). In beech trees the insect species found more frequently were Rhynchaenus fagi (Coleoptera: Curculionidae), Phyllobius pyri (Coleoptera: Curculionidae) and Anobium punctatum (Coleoptera: Anobiidae). The largest population of insects was observed at the end of spring, because the life cycle of the foliage insects were synchronized with leaf- flushing of the foliage.

2017 ◽  
Vol 147 (2) ◽  
Author(s):  
Pallieter De Smedt ◽  
Sam Van de Poel

Sand mining strongly alters the existing landscape, transforming an area into a mosaic of native (sand deposits) and foreign soils, strongly influencing biotic development. The method of restoration of such excavated areas is often debated: natural succession or active restoration. We investigated how natural succession shapes harvestman communities, as part of the soil-dwelling community. We sampled harvestmen over a continuous period of 14 months in 25 plots in an abandoned sand quarry in Belgium using pitfall traps. We found significant increases in harvestman activity-density, species richness and diversity with time since abandonment of the various sections of the quarry. After about 15 years, a drastic change in species composition was observed with the establishment of forest species that more strongly depend on humid conditions to complete their life cycle. Colonisation of harvestmen closely followed vegetation succession despite their limited mobility. We argue that natural succession could be a good management tool for restoring harvestman communities as well as those of other soil-dwelling invertebrates in abandoned sand quarries.


1984 ◽  
Vol 32 (5) ◽  
pp. 481 ◽  
Author(s):  
RS Hill ◽  
J Read

An area of rain forest burnt in the Zeehan fire of 1981 is regenerating toward pure rain forest. This fire was small and patchy and therefore many trees survived to provide a seed source for a major germination of rain forest species after the fire. However, several seral stages are expected to precede the climax vegetation. In contrast, an area of mixed forest burnt in the Savage River fire of 1982 has undergone a major change in species composition because of the proximity of a sclerophyll seed source. The Eucalyptus nitida overstorey is likely to be maintained, but sclerophyllous species will probably increase in dominance in the understorey at the expense of the pre-fire rain forest dominance. Given a long, fire-free interval, this forest may undergo succession to the climax rain forest, but this is unlikely due to large amounts of fuel, the drying effect of the forest edge, and the nearby road which allows access for human-caused fires.


Author(s):  
Kirsten Höwler ◽  
Torsten Vor ◽  
Peter Schall ◽  
Peter Annighöfer ◽  
Dominik Seidel ◽  
...  

AbstractResearch on mixed forests has mostly focused on tree growth and productivity, or resistance and resilience in changing climate conditions, but only rarely on the effects of tree species mixing on timber quality. In particular, it is still unclear whether the numerous positive effects of mixed forests on productivity and stability come at the expense of timber quality. In this study, we used photographs of sawn boards from 90 European beech (Fagus sylvatica L.) trees of mixed and pure forest stands to analyze internal timber quality through the quality indicator knot surface that was quantitatively assessed using the software Datinf® Measure. We observed a decrease in knot surface with increasing distance from the pith as well as smaller values in the lower log sections. Regarding the influence of neighborhood species identity, we found only minor effects meaning that timber qualities in mixed stands of beech and Norway spruce (Picea abies (L.) H. Karst.) tended to be slightly worse compared to pure beech stands.


1973 ◽  
Vol 105 (8) ◽  
pp. 1091-1099 ◽  
Author(s):  
I. D. Hodkinson

AbstractThe four larval instars and the pupa of Ptychoptera lenis lenis Osten Sacken are described. Instars 2 to 4 are very similar morphologically but instar 1 is markedly different. Both a pharate pupal and a pharate adult stage were observed. Larvae are found in stagnant marginal areas of ponds where water depth does not exceed 4 cm and where benthic deposits of plant detritus exceed 8 cm. Fourth instar larvae, under experimental conditions, survived up to 45 days without contact with atmospheric oxygen but development was arrested. P. lenis has a 1 year life cycle with an extended adult emergence season from late May to the end of July.


Author(s):  
Alec R. Lackmann ◽  
Malcolm G. Butler

Except for one unconfirmed case, chironomid larvae have been reported to pass through four larval instars between egg and pupal stages. We have observed a fifth larval instar to be a standard life-cycle feature of the podonomine Trichotanypus alaskensis Brundin 1966 in tundra ponds on the Arctic Coastal Plain near Barrow, Alaska. T. alaskensis has a one-year life cycle in these arctic ponds. Adults emerge in June ~2-3 weeks after pond thaw, then mate and oviposit; most newly-hatched larvae reach instar IV by October when pond sediments freeze. Overwintering larvae complete instar IV within a few days of thaw, then molt again to a fifth larval instar. Imaginal discs, normally seen only during instar IV in Chironomidae, develop across both instars IV & V prior to pupation and adult emergence. While monitoring larval development post-thaw in 2014, we noticed freshly-molted T. alaskensis larval exuviae a week or more prior to any pupation by that species. In 2015-16 we reared overwintering instar IV larvae from single pond sources, individually with daily monitoring, through molts to instar V, pupa, and adult. Some overwintering instar II and III larvae were reared as well, but were few in number. During 2016 we also reared T. alaskensis progeny (from eggs) through instar II, thus documenting head capsule size ranges for all five instars in a single pond’s population. Without individual rearings, the fifth larval instar was not readily apparent for two reasons: 1) The molt itself occurs immediately after thaw and is so synchronous it is difficult to discern in daily field samples. 2) The head capsule size increment between instars IV-V is much lower than the ratio predicted by the Brooks-Dyar Rule. Up through instar IV, the Brooks-Dyar ratio for T. alaskensis ranged 1.30-1.61, but during the IV-V molt head capsule dimensions (sexes pooled) increased by a ratio of 1.09 – comparable to the magnitude of sexual dimorphism in head capsule size within each of the final two larval instars. Individual rearings coupled with 2014-2016 field surveys in nine other ponds suggest that five larval instars is an obligatory trait of this species at this location. As this is the first confirmed case of five larval instars in a chironomid, the phylogenetic uniqueness of this trait needs further investigation.


2012 ◽  
Vol 44 (3) ◽  
pp. 12 ◽  
Author(s):  
Marah Ahmad Dardar ◽  
Hamzeh Mouhammad Ramadan Belal ◽  
Abedlnabi Mouhammad Basheer

<em>Cicadatra persica</em> Kirkaldy, 1909 (Hemiptera: Cicadidae) is regarded as a potential constraint to the productivity of apple fruit orchards in Erneh (33&deg;21&rsquo;N, 35&deg;52&rsquo;E), near Damascus, Syria. However, no research has been conducted on this pest. This study examined adult emergence, egg laying, and hatching periods. Adults emerged in early June, with an emergence peak in the fourth week of June 2011, and started laying eggs in mid-June. Egg development was approximately 40 days, with the first eggs hatching on 1<sup>st</sup> August 2011 and the final hatch on 17<sup>th</sup> August 2011. The simple and relatively successful method of monitoring egg development reported here may be useful for studying the nymphal ecology and life cycle of this species.


1964 ◽  
Vol 54 (4) ◽  
pp. 797-803 ◽  
Author(s):  
Jean M. Taylor

A description is given of the life-cycle in Britain of Theocolax formiciformis Westw. (Pteromalidae), a parasite of Anobium punctatum (Deg.) (Anobiidae). Adults emerge from infested wood in large numbers from April to June. Eggs are laid through the wood surface and use was made of this habit as a means of rearing this parasite under observation in the laboratory. Anobium larvae were placed individually in channels gouged in the surface of 3-inch squares of plywood. They were covered with tracing paper and the parasites were caged on this by means of a glass ring covered with a glass plate. Development from egg to adult at 22 and 25°C., and 75 per cent, relative humidity, averaged about five and six weeks, respectively, compared with 12 weeks outdoors in summer. The number of progeny per female was highest (approximately five) at 22°C., at which the ratio of males to females was 1:3. Only about one per cent, of the adults reared were winged. The use of Theocolax as a biological-control agent is not considered practical.


Biologia ◽  
2017 ◽  
Vol 72 (7) ◽  
Author(s):  
Mária Petrášová-Šibíková ◽  
Igor Matečný ◽  
Eva Uherčíková ◽  
Peter Pišút ◽  
Silvia Kubalová ◽  
...  

AbstractHuman alteration of watercourses is global phenomenon that has had significant impacts on local ecosystems and the services they provide. Monitoring of abiotic and biotic changes is essential to mitigating long-lasting effects, and the 23-year dataset from the Gabčíkovo Waterworks provided a rare opportunity to assess the impact of groundwater regimes on vegetation. The main aim of this study was to describe the effect of the Gabčíkovo Waterworks on vegetation structure and species composition of the adjacent riparian floodplain forests over the past 23 years. The results are based on studies of three permanent monitoring plots (PMPs) located in the Danube inland delta – two outside (PMP 1 and 3) and one (PMP 2) fully under the influence of the artificial supply system. Our results demonstrate that the Danube inland delta was negatively affected by the Gabčíkovo construction, particularly for sites outside of the artificial supply system. There was a significant decrease in soil moisture and increase in nitrogen at both external PMPs (1 and 3). Alter soil conditions were accompanied by negative changes in plant species composition demonstrated by decreases in the number of typical floodplain forest species that are characteristic for the alliance


Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1017
Author(s):  
Sarayut Pittarate ◽  
Julius Rajula ◽  
Afroja Rahman ◽  
Perumal Vivekanandhan ◽  
Malee Thungrabeab ◽  
...  

Fall armyworm Spodoptera frugiperda is a major pest of corn, rice, and sorghum among other crops usually controlled using synthetic or biological insecticides. Currently, the new invention of nanotechnology is taking root in the agricultural industry as an alternative source of pest management that is target-specific, safe, and efficient. This study sought to determine the efficacy of commercial Zinc Oxide (ZnO) nanoparticles (NPs) towards S. frugiperda under laboratory conditions. ZnO NPs were diluted into different concentrations (100–500 ppm), where the baby corn used to feed the S. frugiperda larvae was dipped. The development of the insect feeding on food dipped in ZnO solution was significantly (p < 0.05) affected, and the number of days that the insect took to complete its life cycle had a significant difference compared to the control. There was a significant difference in the adults’ emergence in all the concentrations of ZnO NPs compared to the control, with over 90% of the eggs successfully going through the life cycle until adult emergence. Additionally, several body malformations were observed throughout the lifecycle of the insect. Also, the fecundity of the females was greatly affected. The findings of this study suggest the possibility of exploitation of ZnO nanoparticles not only to manage S. frugiperda but to significantly reduce their population in the ecosystem through body deformations, reduced fecundity, reduced oviposition, and hatchability of eggs. It will be a valuable tool in integrated pest management regimens.


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