Studies on the dispersal behaviour of apterous pea aphids acyrthosiphon pisum (Harris)
Notice bibliographique
Résumé
The dispersal behaviour of apterous pea aphids, Acyrthosipon pi sum (Harris) was studied in the laboratory and field. In the laboratory, aphids exhibited two types of behaviour while on the ground, after dropping from plants in response to predators. Most aphids showed a high frequency of turning and tended to return to the plant they left, while a smaller proportion walked in straight lines and did not return to the plant they left. Adults and older nymphs had the highest proportion of individuals which showed the second type of behaviour and adults showed the greatest tendency to disperse to plants more distant than the nearest available plants. Young instar aphids were less successful at locating a host than older nymphs and adults. Aphids were placed on the central bean seedlings within plots, inside large field cages. Adult coccinellids were released into two of the cages while the other cage remained predator-free. Aphids in the cages with predators frequently moved between plants, while aphids in the predator-free cage did not. Adult aphids colonized more plants and had a lower mortality while on the ground than all other instars. Aphids did not show a preferred dispersal direction and the distance dispersed by aphid nymphs was proportional to the density of aphids on the plant they left. The importance of emigrating apterae in the exploitation of new resources and the regulation of aphid populations is discussed. Bean plants infected with an aphid transmitted virus were transplanted into the central position of bean plots in the field cages. Aphids were placed on the central infected plants and adult coccinellids were released into two of the three cages for three days. Aphids frequently moved to other plants from the centre infected plant in the two cages with predators but not in the predator-free cage. When plants were examined two weeks later, significantly more plants were infected with virus in the cages with predators than in the predator-free cage. New virus infections were correlated with plants that were visited or colonized by aphids from the central infected plant. The influence of predators in the spread of aphid transmitted diseases is discussed. In laboratory experiments, pea aphids from Vancouver were presented with alarm pheromone from irritated conspecifics. Adult and fourth instar aphids responded to the pheromone by either dropping, running or backing up. Instars one, two and three responded to the pheromone only when a vibratory stimulus accompanied it. A high proportion of all instars responded to the double stimulus by dropping. When adult aphids from Vancouver and Kamloops were presented with alarm pheromone, the Kamloops adults exhibited a more conservative reaction to alarm pheromone. Kamloops adults also were more conservative about leaving their plant when confronted by a coccinellid predator. A hypothesis is presented, which accounts for the differences in escape reactions between instars and biotypes. The hypothesis takes into consideration predation risk, escape behaviour repertoire and survival on the ground. Pea aphid adults resisted heat paralysis longer than first instars when subjected to high temperature treatments. All aphids succumbed to paralysis sooner at 42°C than at 37.5°C, but there appeared to be no difference in aphid survival in dry compared to moist conditions at high temperatures. Kamloops aphids were not more resistant to high temperatures.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».