Host stage preference, functional response and mutual interference of Aphidius matricariae (Hym.: Braconidae: Aphidiinae) on Aphis fabae (Hom.: Aphididae)

Abstract

Host stage preference, functional response and mutual interference of Aphidius matricariae (Haliday) (Hym.: Braconidae: Aphidiinae), parasitoid of the black bean aphid, Aphis fabae Scopoli (Hom.: Aphididae) were investigated in a growth chamber at a temperature of 25°C, 65% relative humidity and a photoperiod of 16 h light : 8 h dark on the PP8 variety of sugar beet. Nicholson's model and linear regression were used to determine per capita searching efficiency and interference coefficient, respectively. The highest parasitism percentage was observed on the third instar nymphs of A. fabae in both choice and no-choice preference tests. There was significant difference between rates of parasitism on different stages of A. fabae (P < 0.01). Using logistic regression, a type II functional response was determined for A. matricariae. The Holling and Rogers models were used for estimating searching efficiency (a) and handling time (Th). The data was fitted by the Rogers equation better than by the Holling disc equation based on the R 2 values. The estimated values of searching efficiency and handling time were 0.040 Ϯ 0.013/h and 3.439 Ϯ 0.383 h, respectively. The per capita searching efficiency decreased significantly from 0.272 to 0.139 as parasitoid densities increased from one to five. Therefore, different host-parasitoid ratios could affect the efficacy of A. matricariae.

Foraging Behavior ofPraon volucre(Hymenoptera: Braconidae) a Parasitoid ofSitobion avenae(Hemiptera: Aphididae) on Wheat

“…Our finding was consistent with Diaeretiella rapae (M'Intosh) preferring second-instar nymphs of Brevicoryne brassicae (L.) for oviposition [29]. By contrast, Aphidius matricariae (Haliday) preferred to oviposit into third-instar nymphs of Aphis fabae (Scopoli) [30]. Hagvar and Hofsvang [31] demonstrated the parasitism of an aphid nymphal instar influenced the development and fecundity of the aphids as well as their parasitoids.…”

“…Aphidius uzbekistanicus (Luzhetzki) showed a type II functional response to Metopolophium dirhodum (Walker) [38]. Also type II functional response has been reported by Zamani et al [39] for A. matricariae and A. colemani on Aphis gossypii Glover, for A. matricariae on A. fabae [30], and for D. rapae on B. brassicae [29]. Praon near occidentale showed a type II functional response on Macrosiphum euphorbiae (Thomas) at 18, 20 and 25…”

“…The significant reduction of host parasitization per parasitoid with increasing parasitoid density suggests that interference amongst parasitoids also increased at higher parasitoid density. This is probably due to a closed experimental arena and limited time for parasitization and a high probability of mutual interference [30]. In nature, parasitoids may be more attracted to patches of high host density than to patches of low host density [51].…”

Host instar preference and functional response of Aphidius transcaspicus, a parasitoid of mealy aphids (Hyalopterus species)

“…Under these controlled conditions Lysiphlebus testacipes exhibited a Type I response (Jones et al 2007), A. ervi, A. matricariae, A. rhopalosiphi, and A. sonchi exhibited Type II responses (Hughes et al 1992;Ives et al 1999;Tahriri et al 2007), and A. colemani and A. salicus provided evidence of a Type III response (Hughes et al 1992;van Steenis and Elkhawass 1995;Jones et al 2003;Byeon et al 2011). However, Fernandez-Arhex andCorley (2003) examined the functional responses of parasitoids, including some Aphidius species, that have been used in classical biological control programs and found no correlation between the type of response and parasitoid success.…”

“…In this context, the upper asymptote of 64.3 aphids day -1 for A. transcaspicus places this species among those with the greatest daily parasitism potential (58-70 aphids day -1 ) as found for Aphidius colemani (Jones et al 2003;Byeon et al 2011), Diaeretiella rapae (Bernal et al 1994), Ephedrus cerasicola (Hofsvang and Hagvar 1983), Lysiphlebus testaceipes (Hughes et al 1992;Jones et al 2003), and Lysiphlebia mirzai (Tripathi and Singh 1991). Most other Aphidius species that have been studied have lower upper asymptotes from seven to 30 aphids day -1 (Hughes et al 1992;Zamani et al 2006;Tahriri et al 2007), and from five to 46 aphids day -1 for Trioxys and Aphelinus species, and Lysiphlebus fabarum (Collins et al 1981;Hughes et al 1992;Rakhshani et al 2004;Mahmoudi et al 2010).…”