Interspecific competition between two generalist parasitoids that attack the leafrollerEpiphyas postvittana(Lepidoptera: Tortricidae)

2015 ◽  
Vol 105 (4) ◽  
pp. 426-433 ◽  
Author(s):  
Y. Feng ◽  
S. Wratten ◽  
H. Sandhu ◽  
M. Keller
Keyword(s):  
Larval Development ◽  
Interspecific Competition ◽  
The Other ◽  
Native Vegetation ◽  
Epiphyas Postvittana ◽  
Host Discrimination ◽  
Natural Habitats ◽  
Behavioural Responses ◽  
Interspecific Differences ◽  
Light Brown Apple Moth

AbstractTwo generalist parasitoids,Dolichogenidea tasmanica(Cameron) (Hymenoptera: Braconidae) andTherophilus unimaculatus(Turner) (Hymenoptera: Braconidae) attack early instars of tortricid moths, including the light brown apple moth,Epiphyas postvittana(Walker) (Lepidoptera: Tortricidae). The two parasitoids co-exist in natural habitats, whileD. tasmanicais dominant in vineyards, whereasT. unimaculatusoccurs mainly in adjacent native vegetation. This difference suggests possible competition between the two species, mediated by habitat. Here, we report on the extent of interspecific differences in host discrimination and the outcome of interspecific competition between the two parasitoids. The parasitoids did not show different behavioural responses to un-parasitized hosts or those that were parasitized by the other species. Larvae ofD. tasmanicaout-competed those ofT. unimaculatus, irrespective of the order or interval between attacks by the two species. The host larvae that were attacked by two parasitoids died more frequently before a parasitoid completed its larval development than those that were attacked by a single parasitoid. Dissection of host larvae parasitized by both species indicated that first instars ofD. tasmanicaattacked and killed larvalT. unimaculatus.

Behavioural responses to alarm cues by free-ranging rainbow darters (Etheostoma caeruleum)

Behaviour ◽  
2009 ◽  
Vol 146 (11) ◽  
pp. 1565-1572 ◽  
Author(s):  
◽  
◽  
Keyword(s):  
The Other ◽  
Antipredator Behaviour ◽  
Alarm Cues ◽  
Natural Conditions ◽  
Natural Habitats ◽  
Behavioural Responses ◽  
Alarm Cue ◽  
Chemical Alarm Cues ◽  
Free Ranging ◽  
Etheostoma Caeruleum

AbstractResponses of fishes to chemical alarm cues have been well-documented in the laboratory, but relatively few taxa have been tested under free-ranging conditions in natural habitats. While snorkeling in a stream, we exposed rainbow darters (Etheostoma caeruleum) to skin extracts from conspecifics (alarm cue), skin extracts from heterospecifics (no alarm cue) and a blank control. Darters showed a significantly longer latency to move ('freezing') in the presence of the alarm cue relative to the other two stimuli. These results indicate that rainbow darters can detect chemical alarm cues under natural conditions and respond with appropriate antipredator behaviour.

scholarly journals A new Synbranchus (Teleostei: Synbranchiformes: Synbranchidae) from ilha de Marajó, Pará, Brazil, with notes on its reproductive biology and larval development

2005 ◽  
Vol 3 (3) ◽  
pp. 319-328 ◽  
Author(s):  
Sandra E. Favorito ◽  
Angela M. Zanata ◽  
Maria I. Assumpção
Keyword(s):  
New Species ◽  
Larval Development ◽  
Reproductive Biology ◽  
Color Pattern ◽  
The Other ◽  
Larval Stages ◽  
Marajó Island ◽  
Northern Brazil

Synbranchus lampreia, new species, is described from rio Goiapi, Marajó Island, Pará, northern Brazil. It differs from the other two described species of the genus by its color pattern, which consists of large roundish black blotches scattered over a light brown or yellowish ground pigmentation and presence of inconspicuous brown small spots distributed among the large dark spots. The species is further distinguished from S. marmoratus by a higher number of vertebrae and from S. madeira by a shorter postanal length. Information about reproductive aspects is provided and larval stages are described and illustrated.

scholarly journals Predicting behavioural responses to novel organisms: state-dependent detection theory

2017 ◽  
Vol 284 (1847) ◽  
pp. 20162108 ◽  
Author(s):  
Pete C. Trimmer ◽  
Sean M. Ehlman ◽  
Andrew Sih
Keyword(s):  
Environmental Change ◽  
Signal Detection Theory ◽  
Novel Species ◽  
Detection Theory ◽  
The Novel ◽  
Natural Habitats ◽  
Behavioural Responses ◽  
State Dependent ◽  
Optimal Thresholds ◽  
Adaptive Thresholds

Human activity alters natural habitats for many species. Understanding variation in animals' behavioural responses to these changing environments is critical. We show how signal detection theory can be used within a wider framework of state-dependent modelling to predict behavioural responses to a major environmental change: novel, exotic species. We allow thresholds for action to be a function of reserves, and demonstrate how optimal thresholds can be calculated. We term this framework ‘state-dependent detection theory’ (SDDT). We focus on behavioural and fitness outcomes when animals continue to use formerly adaptive thresholds following environmental change. In a simple example, we show that exposure to novel animals which appear dangerous—but are actually safe—(e.g. ecotourists) can have catastrophic consequences for ‘prey’ (organisms that respond as if the new organisms are predators), significantly increasing mortality even when the novel species is not predatory. SDDT also reveals that the effect on reproduction can be greater than the effect on lifespan. We investigate factors that influence the effect of novel organisms, and address the potential for behavioural adjustments (via evolution or learning) to recover otherwise reduced fitness. Although effects of environmental change are often difficult to predict, we suggest that SDDT provides a useful route ahead.

Embryonic and larval development of the caridean shrimp Palaemon argentinus (Decapoda, Caridea): effects of salinity and diet

Crustaceana ◽  
2021 ◽  
Vol 94 (1) ◽  
pp. 45-62
Author(s):  
Carolina Tropea ◽  
Liane Stumpf ◽  
Laura S. López Greco
Keyword(s):  
Larval Development ◽  
Artemia Salina ◽  
Culture Conditions ◽  
Nutritional Requirements ◽  
Larval Performance ◽  
Larval Rearing ◽  
Caridean Shrimp ◽  
Natural Habitats ◽  
Larval Stages ◽  
Wide Range

Abstract The caridean shrimp Palaemon argentinus is a species of commercial and ecological interest. Its numerous larval stages, the lack of knowledge on their nutritional requirements, and their ability to survive in a wide range of salinities raise questions on the optimum conditions for larval rearing in captivity. The present study was aimed at evaluating embryonic development under different salinities and larval development under different combinations of salinities and diet regimes, in order to define alternative, cheaper culture conditions. We tested salinities usually encountered by the species in natural habitats (0.1, 1 and 5 ppt) and a highly protein-inert diet (Tetracolor®) as a potential replacement for live food (nauplii of Artemia salina). The incubation period and fecundity were similar among salinity treatments. Overall, the number of survival days and percentage of zoeae that moulted two, three and four times were higher when embryogenesis occurred at 5 ppt and when larvae were exposed to 5 ppt. These results suggest that the conditions experienced by embryos affect the performance of the first larval stages, and probably reflect the lower energetic requirements of zoeae to osmoregulate as water and haemolymph osmolarity become closer. On the other hand, larval performance was better when fed A. salina nauplii than Tetracolor®. The latter may not cover the nutritional requirements of zoeae or may have low digestibility due to insufficient enzymes in the undeveloped larval digestive system. Based on the present results, we conclude that a salinity of 5 ppt combined with a diet consisting of Artemia sp. nauplii is optimal for larval culture at early stages.

Larval development of Petrolisthes tuberculatus (Guérin, 1835) (Decapoda, Anomura, Porcellanidae) reared in laboratory

Zootaxa ◽  
2019 ◽  
Vol 4623 (2) ◽  
pp. 364-380
Author(s):  
MARIA EUGENIA GONZALEZ-CANALES ◽  
JOSE A. CUESTA ◽  
JUAN IGNACIO GONZÁLEZ-GORDILLO
Keyword(s):  
Larval Development ◽  
The Other ◽  
Larval Stages ◽  
First Time

The complete larval development of Petrolisthes tuberculatus (including two zoeal stages and the megalopa) is described and illustrated in detail for the first time, based on laboratory-reared material. In order to allow the differentiation of specimens from plankton samples, the larval stages of P. tuberculatus are compared with those known for other porcellanid crabs from Chilean waters (Allopetrolisthes angulosus, Petrolisthes granulosus, P. laevigatus and P. violaceus). As expected, this comparison lead to the inclusion of P. tuberculatus within the “sección Porcellanina” together with the other Chilean species of porcellanids. 

Seed storage behaviour and seed germination in African and Malagasy baobabs (Adansonia species)

2006 ◽  
Vol 16 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Juvet Razanameharizaka ◽  
Michel Grouzis ◽  
Didier Ravelomanana ◽  
Pascal Danthu
Keyword(s):  
Seed Germination ◽  
Moisture Content ◽  
Seed Storage ◽  
The Other ◽  
Arid Zones ◽  
Physical Dormancy ◽  
Interspecific Differences ◽  
Wet Forests

The Adansonia (baobab) genus comprises seven species in Africa, six of which are endemic to Madagascar. Depending on the species, baobabs develop in widely varying ecosystems, including arid zones and savannahs, as well as dry and wet forests. Seeds from all species exhibited orthodox behaviour, tolerating dehydration to a moisture content of around 5%. There was no physical dormancy in the two species belonging to the Brevitubae section, A. grandidieri and A. suarezensis. Their seeds germinated without any prior scarification. The five other species, belonging to Adansonia and Longitubae section, have seeds with water-impermeable coats. In the case of A. digitata and A. za, the proportion of water-impermeable seeds was around two-thirds, whereas with A. rubrostipa, A. madagascariensis and A. perrieri, the proportion was >90%. Treatments allowing for the removal of physical dormancy needed to be markedly more severe with A. madagascariensis than with the other species. None the less, it seems impossible to link these characteristics and the interspecific differences to a strategy for adaptation by these species to their environment.

Influence of Environmental-Conditions on Flight Duration of Epiphyas-Postvittana (Walker) (Lepidoptera, Tortricidae)

1992 ◽  
Vol 40 (5) ◽  
pp. 477 ◽  
Author(s):  
W Danthanarayana ◽  
H Gu
Keyword(s):  
Body Weight ◽  
Relative Humidity ◽  
Air Temperature ◽  
Environmental Conditions ◽  
Epiphyas Postvittana ◽  
Atmospheric Humidity ◽  
Flight Duration ◽  
Reduced Body ◽  
Light Brown Apple Moth ◽  
Honey Solution

Flight responses of the light brown apple moth, Epiphyas postvittana (Walker), to changes in air temperature, atmospheric humidity, feeding and mating activities were studied under controlled conditions. Flights occurred within the air temperature range from 10 to 30-degrees-C, with the longest flight duration at 20-degrees-C for both sexes. A change of atmospheric humidity significantly influenced flight duration of females, but not of males, at 20-degrees-C. The longest flight duration of the female moths occurred at a relative humidity of 60%. Provision of honey solution or water improved flight duration of the moths aged three days or older. Mating increased flight duration of females from the age of three days onwards, presumably as a result of reduced body weight associated with oviposition.

Sign in / Sign up

Export Citation Format

Share Document