A study of the spectrum and the degree of establishment of wheat aphid parasites was conducted during 1978 in three localities of the 5TH Region, Chile (32° - 33°S): Lo Campo, in San Felipe; Rinconada, in Los Andes, and Quebradilla, in ·La Ligua.
The introduced parasites, Aphidius ervi (Haliday) and the "complex Aphidius rhopalosiphi- uzbekistanicus" were established in the aboye mentioned localities. Both showed preference for Metopolophium dirhodum (Walker) and less for Sitobion avenae (Fabr.) At the begining of the wheat season they were also found on Alyzus persicae (Sulzer) which is a new host to the "complex A. rhopalosiphi-uzbekistanicus".
A third introduced parasite, Monoctonus nervosus (Haliday) although released in various localities so far has not been recovered.
Among the endemic parasites, Aphidius colemani Viereck was fmind in higher numbers in Lo Campo and Rinconada, and Praon volucre (Haliday) in Quebradilla, the later species parasiting S. avenae. In a less degree Lysiphlebus testaceipes (Cresson) was recorded in the three mentioned localities while Diaeretiella rapae (M'Intosh) was found only in Rinconada and Quebradilla.
The following secondary parasites or hyperparasites were collected: Alloxysta sp., Asaphes rufipes Brues, Asaphes vulgaris Walker, Dendrocerus sp., and Pachyneuron Slphonophorae (Ashm.). Their hosts remain to be ascertained.
|1Experto Entomólogo, Subestación Experimental La Cruz, Instituto de Investigaciones Agropecuarias (INIA), Casilla 3, La Cruz, Chile. |
2Ing. Agr., Subestación Experimental La Cruz, Instituto de Investigaciones Agropecuarias (INIA), Casilla 3, La Cruz.