Title: Effects of a fruit and host-derived compound on orientation and oviposition in Utetes anastrephae, a little studied opiine braconid (Hymenoptera) parasitoid of Anastrepha spp. fruit flies (Tephritidae:Diptera) Authors
Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 8, 2014
Publication Date: N/A
Interpretive Summary: Tephritid fruit flies attack hundreds of fruits and vegetables and cause trade restrictions wherever they occur. One means of their control is the mass-rearing and augmentative-release of natural enemies. Unfortunately, some otherwise promising candidates require special chemical cues from plants and hosts to reproduce and this makes their production expensive and laborious. In addition there are no synthetic-compound based traps to monitor the survival and dispersal of released fruit fly parasitoids. Scientists at the USDA- ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida with Colleagues from EMBRAPA (Brazil) and the Universidade Estadual de Montes Claros (Brazil) examined two synthetic compounds derived from fly larvae and fruit as egg-laying stimulants and attractants for two species of wasp-natural enemies. The fruit-odor chemical attracted males and females of both species, while the host-odor stimulated egg-laying in only one. These results considerably enlarge what is known about the chemicals that orient/guide fruit fly natural enemies and may be components of future blends used in parasitoid production and the monitoring of augmentative biological control programs.
Technical Abstract: Augmentative biological control of tephritid fruit flies would benefit from: 1) synthetic attractants to monitor the survival and dispersal of released parasitoids and 2) synthetic oviposition stimulants to more economical to produce parasitoid species that are now prohibitively costly to mass-rear. Utetes anastrephae (Viereck) is a wide-spread and sometimes common opiine braconid parasitoid of several pest Anastrepha spp. Despite its range and abundance it has attracted relatively little research and little is known of its chemical ecology. Its orientation was determined towards two chemical cues hypothesized to be useful at two spatial scales: 1) limonene derived from fruit is presumably abundant and widely dispersed and might identify from a distance patches of potentially host-containing fruit; and 2) para-ethylacetophenone (PEA) a volatile emitted by a number of tephritid larvae, presumably in relatively small amounts, and which could serve as short-range cue or oviposition stimulant. Various concentrations of limonene proved attractive to both females and males, perhaps to the later as a means of locating females accumulated in the vicinity of limonene-emitting host plants. PEA at the concentrations tested did not influence oviposition in U. anastrephae, although it did so for Diachasmimorpha longicaudata (Ashmead), another opiine tephritid parasitoid, previously known to respond to PEA and included in the experiment as a positive control. Limonene at the concentrations tested had no effect on oviposition in either species. These results advance efforts to synthesize attractants and oviposition stimulants for alternative candidates for augmentation such as U. anastrephae.