Laelius pedatus (Say, 1836)

Notton, David G., Popovici, Ovidiu A., Achterberg, Cornelis Van, Rond, Jeroen De & Burn, John T., 2014, Parasitoid wasps new to Britain (Hymenoptera: Platygastridae, Eurytomidae, Braconidae & Bethylidae), European Journal of Taxonomy 99 (99), pp. 1-20 : 14-15

Laelius pedatus (Say, 1836)

Figs 26-28

Identification

This species was provisionally identified by John Burn and confirmed by Jeroen de Rond; it may be identified using the key by Vikberg & Koponen (2005) covering Scandinavian species of Laelius ; they provided a redescription of both sexes and illustrated the wing venation and propodeum of the female and genitalia and apical sclerites of the male. Vikberg & Koponen discussed the steps they took, in the absence of the original type material, to ensure that their interpretation was consistent with previous works such as Evans (1978). The specimens mentioned as plesiotype and plesiallotype by Evans (1978) have no type status as these terms are not recognised by the ICZN; they are merely the specimens on which he based his redescription. The recent specimens mentioned by Vikberg & Koponen (2005) as paratypes are not paratypes; this is an error, since Say’s type(s) are lost.

Material examined

ENGLAND: London, Lewisham, TQ388757, ♀, 19 May 2013, in kitchen, D. G. Notton; London, The Natural History Museum, Entomology Department, TQ265790, ♀, Jul. 1996, A. Polaszek; London, The Natural History Museum, Palaeontology Department, ICZN Secretariat Office, TQ267790, ♀, 2 Oct. 2008, walking across desk, D. G. Notton; London, Streatham Hill, TQ304725, ♂, 7 Jul. 2006, G. Broad; Berks, Ascot, Silwood Park, numerous ♀♀, ♂♂, 1993, in culture, D. Morgan (all BMNH).

THE NETHERLANDS: Leiden University, ♀, cultured on Trogoderma angustum (Solier, 1849) (wasps from this culture originated from Madison University, Wisconsin, U.S.A.), P. Mayhew ( BMNH).

Distribution

Originating from the New World: Canada, United States of America, Mexico and Brazil ( Gordh & Móczár 1990). More recently recorded from Europe: The Netherlands ( Heitmans 1998), Finland ( Vikberg & Koponen 2005) and now Britain. L. pedatus was kept in culture in Britain by David Morgan at Imperial College (probably the Imperial College field station at Silwood Park near Ascot, Berkshire, U.K.) for some time from at least 1993 ( Mayhew 1998), and the possibility of escapees cannot be excluded as a source of the British specimens reported here. Morgan’s culture originated from a culture kept by the United States Department of Agriculture in Hoboken, New Jersey ( Morgan & Cook 1994). An alternative possibility is that wasps were introduced from mainland Europe, where free-living wasps have been present since at least 1987 ( Vikberg & Koponen 2005).

Biology

L. pedatus is a parasitoid of the larvae of various species of carpet beetles ( Coleoptera , Dermestidae ), including those which are pests of stored products and museum collections. In Europe the wasp has previously only been found indoors ( Gordh & Móczár 1990; Heitmans 1998; Vikberg & Koponen 2005), as were the British specimens.

Remarks

The presence of L. pedatus in museums is a matter for concern not because of any problem caused by the wasp itself, but because it may indicate the presence of long standing dermestid infestations upon which they prey. Since the adults of this wasp are quite mobile they might be found on the sticky traps used for museum pest monitoring. Anyone encountering bethylid wasps in these situations is invited to submit the specimens to the senior author in order that the spread of this species can be monitored. One of the localities given above, the old Entomology Building at the Natural History Museum, London, has been demolished and replaced by the new Darwin Centre, which has much improved environmental control and pest management.

Figures

Figs 26–28. Laelius pedatus (Say, 1836), 26–27. ♀, specimen number BMNH(E)968242. 26. Dorsal habitus. 27. Fore wing. 28. ♂, specimen number BMNH(E)968243, dorsal habitus. Scale bars all 1 mm. © Natural History Museum, London.