Notes on the Biology of Chelonus Texanus Cress

Abstract

In this paper we describe the very peculiar life-history2 of Chelonus texanus Cresson. In brief the adult Chelonus deposits its eggs in the eg!!;sof its hosts but the parasite emerges not from the egg, but from the larva developed therefrom. Oviposition in the host's egg' and retarded development of the parasite to permit the host to hatch and grow to considerable size has been pointed out by Marchal (Summarized by Bugnion, 1907. Smithsonian Report for 1906. pp. 310-314) with reference to the Encyrius fuscicollis Dalman which oviposits in the eggs of Hyponomeuia malinella, etc., and by Silvestri (Biologia del Liiomastix irt/llcaicUus (Dalm.). Portici, pp. 4, 5, 10. 1906) with reference to Litomastix iruncateUus Dalman. which oviposits in the eggs of Plusia gamma Limucus and other Lepidoptera .. Litomastix truncatellus is polyemhryonic and possibly prndogenetic in alternate generations; Encyrtus fuscicollis is also polyembryonic, hut the Chelonus we have observed is a single and simple parasite. The Litomastix adult measures only 1.9 mm: in length and the egg of Plusia measures 0.6 mm. in diameter. Chelonus measures fully 5 mm. and the eggs of Heliothis measure about 0.5 mm. in diameter, while those of Laphygma are still smaller. Thus the contrast is much more striking when one observes Chelonus ovipositing than it would be in observing Litomastix.

Biology and temperature responses ofChelonus KellieaeandChelonus phthorimaeae(Hymenoptera: Braconidae) and their host, the potato tuberworm,Phthorimaea operculella(Lepidoptera: Gelechiidae)

“…The female then resumed her search for more host eggs. This behavior is similar for other species of Chelonus as observed by Pierce and Holloway (1912), Loginbill (1928), andVance (1932)…”

Natural Enemies of the Fall Armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in Ghana

“…Chelonus spp. are typical of egg-larval solitary koinobiont endoparasitoids that attack Noctuidae and Pyralidae (Marsh 1978;Virla et al 1999;Murúa et al 2009) by ovipositing into host eggs (Pierce & Holloway 1912;Rechav & Orion 1975). The parasitized host larvae exhibit reduced growth rates and weight compared to unparasitized larvae (Ables & Vinson 1981;Ashley et al 1983).…”

Parasitoids attacking fall armyworm (Lepidoptera: Noctuidae) in sweet corn habitats

“…Chelonus insularis is typical of egg-larval solitary koinobiont endoparasitoids that 245 oviposit into host eggs (Pierce and Holloway, 1912;Rechav and Orion, 1975) and 246 survive through several molts until emerging from either 4th or 5th instar Spodoptera 247 spp. host larvae that are actually developmentally arrested precocious prepupae (Ashley, 248 1983;Soller and Lanzrein, 1996;Pfister-Wilhelm and Lanzrein, 2009).…”