Biology of Chamaesphecia schizoceriformis (Lep.: Sesiidae), a biocontrol agent of Euphorbia boissieriana (Euphorbiales: Euphorbiaceae) in north west of Iran

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Abstract

The genus Euphorbia L. (Euphorbiales: Euphorbiaceae) typically have a poisonous white sap in all plant parts. Weedy spurge, Euphorbia boissieriana Prokh., is a toxic deep-rooted herbaceous and perennial weed that is native to the north west of Iran. The biology of spurge clear-wing moth Chamaesphecia schizoceriformis Kolenati as a biocontrol agent of E. boissieriana was studied at field and laboratory conditions (23 ± 2ºC, 60-70% RH, 14L: 10D h) during 2002-2004 in Orumieh region. A field and laboratory observation showed that spurge clear-wing moth was a univoltine species feeding on a single host plant, E. boissieriana. The flight period extended from mid June to the beginning of August. Females, after mating, laid their eggs singly on vegetative stems, mostly on the upper part of the older plants. Females laid an average of 205 ± 29 eggs and potential fecundity was 223 ± 27. The larvae of C. schizoceriformis hatched after 7.90 ± 0.23 days at mean daily temperature of 24.2 ºC. The young larvae penetrate into the stem a few centimetres above the ground and then move into the pith and down into the root. Based on the measurements of head capsules, this moth has seven larval instars and reaches the 5th or 6th instar before winter. In the spring, the larvae mined up to the stem base and prepared an emergence hole a few centimetres above the ground and then pupated within the stem. At mean daily temperature of 20.2 ºC, the pupal period was 13.43 ± 0.27 days. Study on parasitoids of C. schizoceriformis revealed that the larvae and pupa of this moth were parasitized by Villa sesivora Greathead & Karimpour (Dip.: Bombyliidae), Bithia glirina (Rondani) (Dip.: Tachinidae) and Phaenolobus saltans (Gravenhorst) (Hym.: Ichneumonidae) in Orumieh region.

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