How does the ectoparasitoid wasp Euplectrus separatae (Hymenoptera: Eulophidae) recognize a suitable oviposition site on the host larva Pseudaletia separata (Lepidoptera: Noctuidae)?

Abstract

The larval ectoparasitoid of Pseudaletia separata, Euplectrus separatae oviposits exclusively on the dorsolateral surface from the 3rd thoracic to the 2nd abdominal segment of the host. Larval parasitoids are well known to be exposed to risks from aggressive defense behavior when they attempt to parasitize a host. E. separatae female sting the host to inject a venom prior to oviposition. At this time the female wasp is exposed to a serious risk from aggressive host behavior. However, the female avoids the risk by moving to a specific segment of the host. The question arose as to how the female wasp recognizes the specific segments of the host. The female wasp mounted the host larva from the posterior dorsal part and moved forward on the host. The female used chemical cues to recognize the posterior part of the host body. Diethyl ether extracts from the last abdominal segments of the host were more attractive to females than extracts from the head. Motionless behavior in the host after the female wasp mounted did not induce the forward movement of the female wasp. Once the female was on the host she used crawling of the host body (peristaltic movement) as a stimulus to move forward on the host. Another key stimulus to cause the parasitoid to cease movement forward on the specific segments of the host was examined. When a host head was attached to the 3rd abdominal segment, the female wasp shifted the oviposition site adequately behind the head on the host body, suggesting that the head is used as a visual cue to pinpoint a suitable oviposition site.

Does the aggressiveness of the prey modify the attack behavior of the predator Supputius cincticeps (Stål) (Hemiptera, Pentatomidae)?

“…Additionally, S. cincticeps touch their prey with their antennae and legs, supporting the idea that predatory stink bugs also use tactile clues in prey selection. Similar observations have been made by others to support the conclusion that predators may use tactile (Lemos et al 2005), visual (Haynes et al 2002;Nakamatsu & Tanaka 2005) and chemical clues (Haynes et al 2002;Mendel et al 2004;Mochizuki & Yano 2007) to locate and recognize their prey. We noticed that initial recognition of the prey may directly influence the attack behavior of S. cincticeps, suggesting that it is able to adapt its behavior according to the prey being offered (Wignall & Taylor 2009).…”

“…The parasitoid Euplectrus separatae Kamijo (Hymenoptera, Eulophidae) oviposits in areas of the body of the prey Pseudaletia separata (Walk.) (Lepidoptera, Noctuidae), which are less susceptible to defense reaction, thereby avoiding the removal of eggs and young stages of the parasitoid (Nakamatsu & Tanaka 2005).…”

Defensive behaviors of the Oriental armywormMythimna separatain response to different parasitoid species (Hymenoptera: Braconidae)

“…Thrashing can be a powerful counterattack to avoid contact with ovipositors, and may even result in dislodging or injuring parasitoids in some larvae ( Myers & Smith, 1978 ; Stamp, 1982 ; Heinz & Parrella, 1989 ). On the other hand, remaining motionless can also be an effective defense against parasitoids ( Richerson & Deloach, 1972 ; Rotheray, 1981 ), for in some parasitoid species visual cues from moving larvae are necessary for a successful oviposition ( Nakamatsu & Tanaka, 2005 ; Yamamoto, Chau & Maeto, 2009 ). Our observation that M. pulchricornis spent longer host-handling time and had an overall lower likelihood of stinging than did M. mediator The suggestion that M. separata is more effective to defense against attacks by M. pulchricornis than by M. mediator may partly explain why M. separata is less often parasitized by M. pulchricornis ( Jiang et al, 2011 ) than by M. mediator ( Li et al, 2006b ; Luo et al, 2013 ).…”

Host movement initiates oviposition behavior of Meteorus pulchricornis, a braconid parasitoid of free-living lepidopteran larvae

“…Among many parasitoid wasps of free-living insects living on foliage, the necessity of host movement for oviposition behavior has been firmly demonstrated in a braconid parasitoid (Dinocampus coccinellae) of aphidophagous coccinellid adult beetles (Richerson and De Loach, 1972) and in an eulophid parasitoid (Euplectrus separatae) of Mythimna larvae (Nakamatsu and Tanaka, 2005). Host motion is not essential to the oviposition behavior of many braconid aphid parasitoids Mackauer, 1994, 1995), and is less important than chemical cues in an ichneumonid parasitoid (Campoletis sonorensis) of Heliothis larvae (Wilson et al, 1974).…”

“…Host motion has been well demonstrated to be essential for host searching and successful oviposition in polyphagous tachinid parasitoids, i.e., Exorista spp. (Stireman, 2002;Yamawaki et al, 2002;Yamawaki and Kainoh, 2005); however, only a few studies have suggested the necessity of host movement for oviposition behavior in hymenopteran parasitoids (Richerson and De Loach, 1972;Nakamatsu and Tanaka, 2005). Host motion seems to be less important or not necessary in many parasitoid wasps, even when attacking exposed-living hosts (Wilson et al, 1974;Sato, 1988;Mackauer, 1994, 1995;Demas et al, 2002).…”