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United States Department of Agriculture

Agricultural Research Service

Research Project: BIOLOGICALLY-BASED TECHNOLOGIES FOR MANAGEMENT OF CROP INSECT PESTS IN LOCAL AND AREAWIDE PROGRAMS

Location: Insect Behavior and Biocontrol Research Unit

Title: Intrinsic competition and competitor-free-space influence the coexistence of parasitoids (Hymenoptera: Braconidae: Opiinae) of neotropical tephritidae (Diptera)

Authors
item Paranhos, Beatriz -
item SIVINSKI, JOHN
item STUHL, CHARLES
item Holler, Tim -
item Aluja, Martin -

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 15, 2013
Publication Date: August 1, 2013
Citation: Paranhos, B.J., Sivinski, J.M., Stuhl, C.J., Holler, T., Aluja, M. 2013. Intrinsic competition and competitor-free-space influence the coexistence of parasitoids (Hymenoptera: Braconidae: Opiinae) of neotropical tephritidae (Diptera). Environmental Entomology. 42(4):717-723.

Interpretive Summary: Parasitoid larvae may compete by physical or physiological means. The opiine braconids Doryctobracon areolatus (Szepligeti) and Utetes anastrephae (Viereck) are among the most common native parasitoids of frugivorous Tephritidae in the Neotropics and subtropics. Utetes anastrephae wins in interactions with D. areolatus, but the later has a longer ovipositor and may find a competitor-free-space in larger fruit whose hosts are beyond the reach of U. anastrephae. An Asian opiine species, Diachasmimorpha longicaudata (Ashmead) has been introduced throughout much of the Americas. Its ovipositor is longer than that of D. areolatus and if it is a superior intrinsic competitor it should be able to cause local extinctions of D. areolatus. Scientists at the USDA Agriculture Research Service, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida, along with colleagues at the Instituto de Ecologia, Xalapa, Veracruz, Mexico, found that Diachasmimorpha longicaudata suppressed D. areolatus and this denial of competitor free space may account for the gradual replacement of D. areolatus by D. longicaudata in Florida where both species were introduced ~ 40 years ago. The displacement of already established parasitoids should be considered when Introductions of D. longicaudata are planned.

Technical Abstract: Endoparasitoid larvae may eliminate heterospecific competitors by physical or physiological means. The outcomes of these intrinsic competitions are often predictable with one species typically eliminating the other. The opiine braconids Doryctobracon areolatus (Szepligeti) and Utetes anastrephae (Viereck) are among the most common native parasitoids of frugivorous Tephritidae in the Neotropics and subtropics. Utetes anastrephae is typically the victor in intrinsic interactions with D. areolatus, but the later has a longer ovipositor and may find a competitor-free-space in larger fruit whose hosts are beyond the reach of U. anastrephae. An Asian opiine species, Diachasmimorpha longicaudata (Ashmead) has been introduced throughout much of the Americas. Its ovipositor is longer than that of D. areolatus and if it is a superior intrinsic competitor it should be able to cause local extinctions of D. areolatus. The outcomes of sequential ovipositions by D. longicaudata and D. areolatus and U. anastrephae found that D. longicaudata significantly suppresses development of D. areolatus. However, competitions between D. longicaudata and U. anastrephae were more equal. The denial of competitor free space may account for the gradual replacement of D. areolatus by D. longicaudata in Florida where both species were introduced ~ 40 years ago. Diachasmimorpha longicaudata and D. areolatus continue to co-exist in Mexico and this could be due to greater abiotic and biotic environmental complexity that allows for separate niches. Establishment or augmentative releases of D. longicaudata could result in elimination of native parasitoids and this should be considered prior to its introduction.

Last Modified: 7/28/2014
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