Annals of the Entomological Society of America (1997) 90, 604-618
John Sivinski, Martin Aluja and Maurilio Lopez (1997)
Spatial and temporal distributions of parasitoids of Mexican Anastrepha species (Diptera: Tephritidae) within the canopies of fruit trees
Annals of the Entomological Society of America 90 (5), 604-618
Abstract: In Veracruz State, Mexico, the temporal and spatial distributions of 5 species of parasitic Hymenoptera attacking larvae of 5 Anastrepha species in 7 species of fruit tree canopies were examined. Parasitism by Doryctobracon areolatus (Szepligeti) (Braconidae), Diachasmimorpha longicaudata (Ashmead) (Braconidae), and Utetes anastrephae (Viereek) (Braconidae) was higher in 3 of 4 significant cases in the lower portions of the canopies. U. anastrephae was more abundant in the interior of canopies (2 cases), whereas D. areolatus was more common in the margins (1 case). In 6 of 7 instances the mean sizes of fruits containing parasitoids were smaller than those of infested fruits without parasitoids. U. anastrephae attacked larvae in a narrow range of smaller host-fruit species relative to other parasitoids. The efficiency (proportion of larvae attacked in a fruit) of D. longicaudata compared to that of other parasitoids increased with fruit size. D. longicaudata may be better able to locate or attack hosts in larger fruits. In all of 17 instances there were on average more host larvae in fruits containing parasitoids than in fruits without parasitoids. In all of 18 significant instances the larval density (larvae per gram weight of fruit) was higher in fruits that contained parasitoids than in fruits that did no. Parasitism by D. areolatus, Doryctobracon crawfordi (Viereck), D. longicaudata, and U. anastrephae often changed over time during the fruiting period, but was as likely to decrease as increase. D. areolatus had a pattern of decreasing parasitism during the fruiting periods of individual trees as the season changed from rainy to dry. There were only a few instances of significant relationships between parasitism and local differences in the canopy with respect to fruit numbers, host numbers, and host density. In 2 instances there were significant negative relationships between parasitism caused by the commonly cooccurring D. areolatus and U. anastrephae. In 2 other cases, parasitism by D. crawfordi and D. longicaudata was positively correlated. D. longicaudata is a recent introduction to Mexico and the positive relationships may indicate a niche overlap not present between the 2 native species, D. areolatus and U. anastrephae. Fewer than expected numbers of fruits containing both D. areolatus and U. anastrephae together was further evidence of niche differences. This pattern did not occur in fruits containing D. crawfordi and D. longicaudata. Information on the distribution of parasitoids at levels ranging from within canopies to across regions may guide biological control efforts, allowing the match of candidate species to locations.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Martín Aluja
Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
population dynamics/epizootiology
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Diachasmimorpha longicaudata (parasitoid) | Mexico | |||
| Doryctobracon areolatus (parasitoid) | Mexico | |||
| Utetes anastrephae (parasitoid) | Mexico | |||
| Doryctobracon crawfordi (parasitoid) | Mexico |
