Host-Acceptance Behavior of Dinocampus coccinellae (Hymenoptera: Braconidae)

Abstract

Dinocampus coccinellae (Schrank) spent >80% of a 300-s observation period in host-handling activities (orienting toward, pursuing, and attacking hosts) when exposed to individual adult Coleomegilla maculata (DeGeer) or Coccinella septempunctata (L.). When D. coccinellae was exposed to two populations of Hippodamia variegata (Goeze) from Canada or France and Propylea quatuordecimpunctata (L.) from Canada or Turkey, host-handling activities decreased to <70% of 300 s. D. coccinellae oriented toward and attacked C. maculata and C. septempunctata in 10-12 s, compared with 18-38 s for H. variegata and P. quatuordecimpunctata. Additionally, C. maculata and C. septempunctata were attacked more frequently (mean = 3.3 and 2.6 in 300 s, respectively) than H. variegata or P. quatuordecimpunctata (mean = 2 and 1.5 in 300 s, respectively). No differences in D. coccinellae behavior were observed in response to the two H. variegata and two P. quatuordecimpunctata populations. D. coccinellae successfully emerged from 58% of C. maculata, 47% of C. septempunctata, 7-15% of H. variegata, and 1% of P. quatuordecimpunctata. Total mortality of adults exposed to D. coccinellae was 80% for C. maculata, 76% for C. septempunctata, 50% for H. variegata (France), 38% for H. variegata (Canada), and 11% for both P. quatuordecimpunctata populations. Based upon our observations, we expanded the description of D. coccinellae selection behavior to include orientation, which precedes forward motion toward a host.

Impact of host behavioral defenses on parasitization efficacy of a larval and adult parasitoid

“…When first encountering a potential host, D. coccinellae female examine it with its antennae, the wasp then bends its abdomen with the ovipositor directed toward the host. In a rapid movement, the female inserts its ovipositor inside the host's abdomen and either accepts the host and lays an egg or rejects it and removes its ovipositor without depositing an egg (Richerson and DeLoach 1972;Orr et al 1992). Behavioral recordings were initiated when the parasitoid female was released in the Petri dish (10.5 cm diameter) and lasted for a period of 30 min.…”

“…In addition, H. axyridis shows aggressive behaviors against heterospecific coccinellids in intraguild interactions (Michaud 2002;Sato et al 2005;Snyder et al 2004;Yasuda et al 2001Yasuda et al , 2004 but whether it displays such defensive behaviors against parasitoids has not been documented. Previous studies that looked at choice tests between different hosts by D. coccinellae females never considered defensive behaviors as a factor influencing parasitism success (Koyama and Majerus 2008;Obrycki 1989;Orr et al 1992).…”

Natural Enemies of Ladybird Beetles

“…Perilitus rutilus or Microctonus spp. (Jackson 1928, Barratt & Johnstone 2001, D. coccinellae most frequently parasitizes its hosts when they are mobile (Bryden & Bishop 1945, Walker 1961, Richerson & DeLoach 1972, Orr et al 1992. Pre -oviposition and oviposition behaviour of the parasitoid may be categorized as a sequence of the following activities: (i) pursuit and investigation of the host without extending the ovipositor, (ii) ovipositional stance with the ovipositor extended ventrally and forwards between the legs, and (iii) ovipositional attack, i.e.…”

“…Its reported values vary greatly, even within the same species and development stage of host (Table 8.6 ). Such variability may be a result of different methods used by different authors to determine the rates, but it may also refl ect real differences in suitability, related, for example, to the physiological state of the hosts, their colour morphs (Berkvens et al 2010 ), or the origin of parasitoid (Koyama & Majerus 2008 ) and host populations (Orr et al 1992 ;Koyama & Majerus 2008 ).…”

Natural enemies of the Coccinellidae: Parasites, pathogens, and parasitoids

“…As a solitary endoparasitoid of adults, D. coccinellae prefers larger species of Coccinellinae (Ceryngier and Hodek, 1996). Coccinellids vary in their suitability as hosts for D. coccinellae (Orr et al, 1992;Firlej et al, 2006;Koyama and Majerus, 2008), but the mechanisms that influence realized rates of parasitism of various coccinellid species are unknown for many species. Comparing primary and secondary parasitism rates suggests that at least some coccinellids are able to overcome parasitoid larvae (Hoogendoorn and Heimpel, 2002;Koyama and Majerus, 2008).…”