Laboratory and field studies to evaluate the potential of an open rearing system of Lysiphlebus testaceipes for the control of Aphis craccivora in Argentina

TAVELLA, JULIA; ZUMOFFEN, LETICIA; SALVO, ADRIANA; SIGNORINI, MARCELO

BIOCONTROL (DORDRECHT)

SPRINGER

Lugar: Berlin; Año: 2016 vol. 61 p. 23 - 33

1386-6141

The aim of this work was to examine, bothin the field and in the laboratory, ecological aspects ofselected plant?aphid?parasitoid interactions to evalu-ate their potential for the open rearing of the parasitoidLysiphlebus testaceipes(Cresson) (Hymenoptera:Aphidiinae) for the control ofAphis craccivora(Koch)(Hemiptera: Aphididae) in alfalfa agroecosystems. Tothis end quantitative samplings of parasitoids andaphids were made fortnightly in three alfalfa cropfields and their spontaneously vegetated edges, inRafaela (Santa Fe, Argentina), during three years(2009?2011). Three sink webs based onL. testaceipes,on a per-year basis, were constructed to assess thestrength of the interactions established by aphids andparasitoids, the host ranges of alternative aphidspecies, and the tendencies in parasitoid host useacross years. In the laboratory, emergence rates,parasitism rates, larval and pupal development times, and adult lifespan ofL. testaceipeswere analyzed bymeans of choice tests, including the alternative and thetarget aphid species in the assays. About 84 % ofadults ofL. testaceipesobtained in the samples camefromAphis nerii(Boyer de Fonscolombe), an innocu-ous aphid species only associated with plants of thegenusAraujiaBrotero (Apocynaceae). Based on ourresults, the system proposed has many features thatsupport its feasibility to be used as an open rearingsystem ofL. testaceipes: unrisky alternative aphid,easy reproduction of the banker plant and similarsuitability of innocuous and pest aphid species for theparasitoid to oviposit and complete their developmentwithout noticeably preference for specific hosts.