Spatially patterned guild structure in larval parasitoids of cyclically outbreaking winter moth populations

2010 ◽  
pp. no-no
Author(s):  
OLE PETTER LAKSFORSMO VINDSTAD ◽  
SNORRE B. HAGEN ◽  
TINO SCHOTT ◽  
ROLF A. IMS
Keyword(s):  
Guild Structure ◽  
Winter Moth ◽  
Larval Parasitoids

scholarly journals Forest defoliator pests alter carbon and nitrogen cycles

2016 ◽  
Vol 3 (10) ◽  
pp. 160361 ◽  
Author(s):  
Anne l-M-Arnold ◽  
Maren Grüning ◽  
Judy Simon ◽  
Annett-Barbara Reinhardt ◽  
Norbert Lamersdorf ◽  
...  
Keyword(s):  
Climate Change ◽  
Leaf Litter ◽  
Soil Microbial Activity ◽  
Quercus Petraea ◽  
Oak Forests ◽  
Operophtera Brumata ◽  
Winter Moth ◽  
Carbon And Nitrogen ◽  
Soil Microbial ◽  
C And N

Climate change may foster pest epidemics in forests, and thereby the fluxes of elements that are indicators of ecosystem functioning. We examined compounds of carbon (C) and nitrogen (N) in insect faeces, leaf litter, throughfall and analysed the soils of deciduous oak forests ( Quercus petraea  L.) that were heavily infested by the leaf herbivores winter moth ( Operophtera brumata  L.) and mottled umber ( Erannis defoliaria  L.). In infested forests, total net canopy-to-soil fluxes of C and N deriving from insect faeces, leaf litter and throughfall were 30- and 18-fold higher compared with uninfested oak forests, with 4333 kg C ha −1 and 319 kg N ha −1 , respectively, during a pest outbreak over 3 years. In infested forests, C and N levels in soil solutions were enhanced and C/N ratios in humus layers were reduced indicating an extended canopy-to-soil element pathway compared with the non-infested forests. In a microcosm incubation experiment, soil treatments with insect faeces showed 16-fold higher fluxes of carbon dioxide and 10-fold higher fluxes of dissolved organic carbon compared with soil treatments without added insect faeces (control). Thus, the deposition of high rates of nitrogen and rapidly decomposable carbon compounds in the course of forest pest epidemics appears to stimulate soil microbial activity (i.e. heterotrophic respiration), and therefore, may represent an important mechanism by which climate change can initiate a carbon cycle feedback.

Distribution, abundance and natural enemies of the invasive tomato leafminer, Tuta absoluta (Meyrick) in Kenya

2021 ◽  
pp. 1-16
Author(s):  
G. Kinyanjui ◽  
F. M. Khamis ◽  
F. L. O. Ombura ◽  
E. U. Kenya ◽  
S. Ekesi ◽  
...  
Keyword(s):  
Natural Enemies ◽  
Sustainable Management ◽  
Management Strategies ◽  
Tuta Absoluta ◽  
Macrolophus Pygmaeus ◽  
Larval Parasitoids ◽  
Parasitism Rates ◽  
Nesidiocoris Tenuis ◽  
Sentinel Plants ◽  
Open Fields

Abstract Tuta absoluta (Meyrick) has become a serious menace to sustainable production of tomato in Kenya. A survey was conducted between April 2015 and June 2016 to determine its distribution, abundance, infestation, and damage levels on tomato, and associated natural enemies. Trap counts of T. absoluta moths were recorded in all surveyed 29 counties, which indicated its nationwide distribution irrespective of altitude. Tuta absoluta was present in both open fields and greenhouses. The highest moth/trap/day was 115.38 ± 15.90. Highest leaf infestation was 92.22% and the highest number of mines and larvae per leaf were 3.71 ± 0.28 and 2.16 ± 0.45, respectively. Trap captures in terms of moth/trap/day were linearly and positively related to leaf infestations in open fields (R2 = 0.81) and greenhouses (R2 = 0.61). Highest fruits’ infestation and damage were 60.00 and 59.61%, respectively, while the highest number of mines per fruit was 7.50 ± 0.50. Nesidiocoris tenuis (Reuter) and Macrolophus pygmaeus (Rambur) were identified as predators of T. absoluta larvae. Nine species of larval parasitoids were recovered from infested foliage, with a combined parasitism of 7.26 ± 0.65%. Hockeria species was the most dominant (31.25%) and accounted for 12.88 ± 1.47% parasitism. Two species of larval parasitoids, Hockeria and Necremnus were obtained from sentinel plants with an average parasitism of 1.13 ± 0.25. The overall abundance and parasitism rates of recovered natural enemies were low to effectively control the field populations of T. absoluta. These findings form the basis of researching and developing effective and sustainable management strategies for the pest.

scholarly journals The impact of Sosnowsky’s Hogweed on feeding guilds of birds

2021 ◽  
Author(s):  
Emilia Grzędzicka ◽  
Jiří Reif
Keyword(s):  
Negative Impact ◽  
Bird Community ◽  
Plant Invasions ◽  
Bird Communities ◽  
Feeding Guilds ◽  
Guild Structure ◽  
Feeding Guild ◽  
Potential Impact ◽  
Underlying Mechanisms ◽  
The Impact

AbstractPlant invasions alter bird community composition worldwide, but the underlying mechanisms still require exploration. The investigation of feeding guild structure of bird communities can be informative in respect to the potential impact of invasion features on the availability of food for birds. For this purpose, we focused on determining the influence of the invasive Sosnowsky’s Hogweed Heracleum sosnowskyi on the abundance of birds from various feeding guilds. In spring and summer 2019, birds were counted three times on 52 pairs of sites (control + Heracleum) in southern Poland, at various stages of Sosnowsky’s Hogweed development (i.e. sprouting, full growth and flowering, all corresponding to respective bird counts). We have shown that the presence of invader negatively affected the abundance of birds from all feeding guilds. However, a closer examination of the invaded sites uncovered that responses of particular guilds differed in respect to development stages expressed by a set of characteristics of the invader. Ground and herb insectivores were more common on plots with a higher number of the invader, while the abundance of bush and tree insectivores was negatively correlated with hogweeds’ height. Granivores were not affected by the invader’s features, while the abundance of omnivores was negatively related to the number of flowering hogweeds. Besides showing the general negative impact of the invader on different feeding guilds, our research has shown that certain aspects of Sosnowsky’s Hogweed invasion may support or depress occurrence of different birds on invaded plots. Knowledge of these aspects may facilitate our capacity for coping with challenges the invasive plants put in front of bird conservationists.

scholarly journals Potential host ranges of three Asian larval parasitoids of Drosophila suzukii

2021 ◽  
Author(s):  
Kent M. Daane ◽  
Xingeng Wang ◽  
Brian N. Hogg ◽  
Antonio Biondi
Keyword(s):  
Body Size ◽  
Host Species ◽  
Classical Biological Control ◽  
Developmental Time ◽  
The Body ◽  
Phylogenetic Position ◽  
Egg Load ◽  
Drosophila Suzukii ◽  
Larval Parasitoids ◽  
Female Body Size

AbstractAsobara japonica (Hymenoptera: Braconidae), Ganaspis brasiliensis and Leptopilina japonica (Hymenoptera: Figitidae) are Asian larval parasitoids of spotted wing drosophila, Drosophila suzukii (Diptera: Drosophilidae). This study evaluated these parasitoids’ capacity to attack and develop from 24 non-target drosophilid species. Results showed that all three parasitoids were able to parasitize host larvae of multiple non-target species in artificial diet; A. japonica developed from 19 tested host species, regardless of the phylogenetic position of the host species, L. japonica developed from 11 tested species; and G. brasiliensis developed from only four of the exposed species. Success rate of parasitism (i.e., the probability that an adult wasp successfully emerged from a parasitized host) by the two figitid parasitoids was low in hosts other than the three species in the melanogaster group (D. melanogaster, D. simulans, and D. suzukii). The failure of the figitids to develop in most of the tested host species appears to correspond with more frequent encapsulation of the parasitoids by the hosts. The results indicate that G. brasiliensis is the most host specific to D. suzukii, L. japonica attacks mainly species in the melanogaster group and A. japonica is a generalist, at least physiologically. Overall, the developmental time of the parasitoids increased with the host’s developmental time. The body size of female A. japonica (as a model species) was positively related to host size, and mature egg load of female wasps increased with female body size. We discuss the use of these parasitoids for classical biological control of D. suzukii.

scholarly journals How rapidly do invasive birch forest geometrids recruit larval parasitoids? Insights from comparison with a sympatric native geometrid

2013 ◽  
Vol 15 (7) ◽  
pp. 1573-1589 ◽  
Author(s):  
O. P. L. Vindstad ◽  
T. Schott ◽  
S. B. Hagen ◽  
J. U. Jepsen ◽  
L. Kapari ◽  
...  
Keyword(s):  
Birch Forest ◽  
Larval Parasitoids

Predator release from invertebrate generalists does not explain geometrid moth (Lepidoptera: Geometridae) outbreaks at high altitudes

2013 ◽  
Vol 145 (2) ◽  
pp. 184-192 ◽  
Author(s):  
Tino Schott ◽  
Lauri Kapari ◽  
Snorre B. Hagen ◽  
Ole Petter L. Vindstad ◽  
Jane U. Jepsen ◽  
...  
Keyword(s):  
Carabid Beetles ◽  
Birch Forest ◽  
Generalist Predators ◽  
Tree Line ◽  
High Altitudes ◽  
Lower Altitude ◽  
Rove Beetles ◽  
Northern Norway ◽  
Winter Moth ◽  
Underlying Mechanisms

AbstractOutbreaks of geometrid defoliators in subarctic birch forest in Fennoscandia often occur at high altitude in a distinct zone along the tree line. At the same time, moth larvae may not have an impact on the forest at lower altitude. Directly adjacent outbreak and nonoutbreak areas offer unique opportunities for studying the underlying mechanisms of outbreaks. Within two altitudinal gradients in coastal northern Norway, we investigated whether altitudinal outbreaks might be caused by release from pupal predation by ground-dwelling invertebrates such as harvestmen (Opiliones), spiders (Araneae), rove beetles (Coleoptera: Staphylinidae), carabid beetles (Coleoptera: Carabidae), and other beetles (Coleoptera). We predicted a consistently higher abundance of such generalist predators at low versus high altitudes. Our results did not support this prediction. There was no consistent altitudinal variation in the abundance of predators that could be related to zonal moth outbreaks in the birch forest slopes. In addition, none of the predator groups investigated showed any numerical response to a distinct outbreak of winter moth that took place during the course of the study. Consequently, localised moth outbreaks at the altitudinal tree line in northern Norway cannot be explained by the release from pupal predation by the predator groups examined here.

Changes in Numbers in the Parasitoid Complex Associated With the Diamond-Back Moth, Plutella Xylostella (L.) (Lepidoptera), in Victoria.

1979 ◽  
Vol 27 (6) ◽  
pp. 981 ◽  
Author(s):  
S Goodwin
Keyword(s):  
High Temperatures ◽  
Plutella Xylostella ◽  
Winter Period ◽  
Parasitoid Species ◽  
Primary Parasitoid ◽  
Parasitoid Complex ◽  
Larval Parasitoids ◽  
Pesticide Treatment ◽  
Drought Conditions ◽  
Rate Of Recovery

Between 1972 and 1974, a study was made of parasitoids of P. xylostella naturally infesting four successive crops of cabbages which had not received any pesticide treatment. Parasitism fluctuated in each crop, averaging 49% during the study. The major parasitoid species were Diadegma cerophaga, Thyraeella collaris and Diadegma rapi, which averaged 93% of parasitism over the study period. Six minor primary parasitoid and one hyperparasite species were also recorded. Parasitoid activity was high during spring and summer, although extremely high temperatures during summer reduced numbers of both the host and its parasitoids. Drought conditions accentuated this. Parasitism in autumn depended upon the severity of this depletion and on the ensuing rate of recovery. The more important larval parasitoids were closely synchronized with host numbers, with a distinct lag during the winter period.

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