Target pest: Coleophora spissicornis (Lepidoptera: Coleophoridae), banded clover casebearer
Agent introduced: Chelonus contractus (Hymenoptera: Braconidae) = Microchelonus contractus (Nees)
1961?, 1968?, 1969
1961, 1968 Avignon, France via DelÃ©mont, Switzerland; 1961, 1969 near Freiburg, Germany
Cameron et al. (1989) - Chelonus was imported as parasitised Coleophora spp. host larvae; either C. frischella collected from Avignon, France (and reared in DelÃ©mont, Switzerland prior to shipment) or C. deauratella from near Freiburg, Germany. Shipments in 1961 contained an estimated nearly 1,000 Chelonus sp. nr contractus larvae in C. deauratella larvae and another eight to 10 in C. frischella larvae. None emerged before the shipment was destroyed because of an infestation of the mite Pyemotes zwoelferia. A 1968 shipment of C. frischella contained â€˜some Cheloninae, but only three females emerged and there is no record of their fate. In October and November 1969 shipments of C. deauratella there were an estimated 270 Chelonus contractus. â€˜Small numbersâ€™ emerged and were released.
Cameron et al. (1989) - â€˜small numbersâ€™ were released in 1969, although it was not recorded where.
Cameron et al. (1989) - there have been no recoveries of C. contractus/Chelonus sp.
Cameron et al. (1989) - Chelonus was imported under the names Chelonus sp. [see database entry under this name] and Chelonus contractus, but it is probable these are the same species. Chelonus sp. in Europe is most numerous in the host Coleophora deauratella. A Chelonus sp. common in C. spissicornis has identical larvae but no adults have been obtained, so verification of the identity has not been possible. However, adults identical to those obtained from C. deauratella were obtained from C. frischella (in which it occurs only rarely).
Cameron PJ, Hill RL, Bain J, Thomas WP (1989). A Review of Biological Control of Invertebrate Pests and Weeds in New Zealand 1874-1987. Technical Communication No 10. CAB International Institute of Biological Control. DSIR Entomology Division. 424p.