Dittrichia viscosa andRubus ulmifolius as reservoirs of aphid parasitoids (Hymenoptera: Braconidae: Aphidiinae) and the role of certain Coccinellid species

Abstract

The role of the self-sown shrubs Dittrichia viscosa (L.) W. Greuter and Rubus ulmifolius Schott as reservoirs of aphid parasitoids was investigated. In the field studies conducted, D. viscosa grew adjacent to crops of durum wheat and barley and R. ulmifolius grew adjacent to cotton. The relative abundance of the parasitoids of (a) Capitophorus inulae (Passerini) on D. viscosa, (b) Rhopalosiphum padi (Linnaeus) on durum wheat and barley, (c) Aphis ruborum (Börner) on R. ulmifolius, and (d) Aphis gossypii Glover on cotton in various parts of Greece, was assessed during the years 1996-2000. In 2000, the fluctuation of parasitization of the above four aphid species was recorded and the action of the aphidophagous predators of the family Coccinellidae was studied. It was observed that Aphidius matricariae Haliday predominated on C. inulae and R. padi in all sampling cases. In contrast, Lysiphlebus fabarum (Marshall) was the dominant species parasitizing A. ruborum on R. ulmifolius and A. gossypii on cotton in Thessaly (central Greece) and Macedonia (northern Greece), whereas Lysiphlebus confusus Tremblay et Eady and Binodoxys acalephae (Marshall) were the dominant parasitoid species in Thrace (northern Greece). Coccinella septempunctata Linnaeus was the most abundant coccinellid species on durum wheat, whereas Adonia variegata (Goeze) predominated on cotton. However, coccinellid individuals were scarce on both D. viscosa and R. ulmifolius. The present study indicated that these two shrubs can be regarded as useful reservoirs of aphid parasitoids.

Aphid parasitoids (Hymenoptera: Braconidae: Aphidiinae) in cultivated and non-cultivated areas of Markazi Province, Iran

“…Similar results between crop and non-crop habitats have been reported by Tomanović et al (2009). Aphids occurring on noncultivated plants have been considered as important reservoirs of common aphid parasitoids (Starý 1970(Starý , 1986bStarý & Pike 1998;Kavallieratos et al 2002;Havelka et al 2012). This situation is evident in the present study in the case of Aphis spp.…”

“…However, further investigation is required in order to support this hypothesis in the Markazi province. The knowledge on pattern of distribution and the identity of the member of parasitoid guild, as well as the management of the non-crop habitats are the critical points in the improvement of conservation of biological control (Starý 1986a;Kavallieratos et al 2002;Havelka et al 2012). Furthermore, the effect of agricultural intensifications on the diversity, i.e., species richness and species evenness should not be ignored (Tscharntke et al 2005).…”

Aphids (Hemiptera: Aphidoidea) on cultivated and self-sown plants in Greece

“…In the present study we recorded 32 economically unimportant aphid taxa (Table 1) which should be examined from this point of view. In a previous study in Greece, Kavallieratos et al (2002) supported the recommendation of the self-sown shrubs Dittrichia viscosa (L.) W. Greuter and Rubus ulmifolius Schott, colonized by Capitophorus inulae (Passerini, 1860) and Aphis ruborum (Börner, 1932), respectively, as useful reservoirs of aphid parasitoids.…”

“…Self-sown plants contribute to the diversity of the plant cover in cultivated or non-crop areas (Starý 1986;Sarlis 1998) and may harbor aphid species that could be pests or are economically unimportant (Starý 1974;Kavallieratos et al 2002;Tomanović et al 2006). The latter can be attacked by parasitoids and/or predators, which may disperse to the neighboring crops and attack a target aphid pest there (Starý & Lyon 1980;Kavallieratos et al 2002). In the present study we recorded 32 economically unimportant aphid taxa (Table 1) which should be examined from this point of view.…”

Cereal aphids (Hemiptera: Aphidoidea) in Serbia: Seasonal dynamics and natural enemies

“…Samples in 2004-2006 were collected weekly, from May till July at Surcin and Galovica from 10 preselected sites, 20 m apart, within each field (two rows with five sites in each row). From each site, 10 stems, 20 cm long (Kavallieratos et al, 2002), were collected on each sampling date at least 50 m from the field edge. All fields were approximately 5-6 ha, quadrate or subquadrate, not sprayed with insecticides and with 500-600 plants/ m 2 .…”