Lariophagus distinguendus

Lariophagus distinguendus (Foerster)

(This taxon apparently consists of two genetically distinct lineages, which probably represent separate species).

Systematic position: Insecta, Holometabola, Hymenoptera, Apocryta, Chalcidoidea, Pteromalidae.

Geographical distribution:

Morphology: The body of the adults is shiny black, the legs and the antennae are yellow-brown, except for the terminal segments.

Life history: This species is a solitary ectoparasitoid of the larvae of at least 11 beetle species in five families. It locates hosts mainly on the basis of faeces-borne volatiles, but rejects moldy grains containing larval hosts. The parasitoid then paralyzes them and usually places a single egg onto the body of these hosts. Development requires about 4 weeks, the calculated threshold of development is at 15.1°C and adults live for 1-2 weeks. Fecundity is about 40 progeny/female. It develops best at around 20ºC and is most efficient at this temperature.

Economic importance: Lariophagus distinguendus attacks the larvae of several stored product pests, including Callosobruchus chinensis, Sitophilus zeamais, Stegobium paniceum and others, and may control them. Extent of control depends on the container in which the commodity is stored, ease of entrance therein (wider mesh sizes facilitate penetration) and the depth of the commodity. At depths of 20–45 cm from the surface of jute bags containing maize, infestations by S. zeamais were reduced by 74%, whereas at a depth of 95 to 100 cm, mean reduction was only 34%. Due to the fact that L. distinguendus is best at lower temperatures, wherea Anisopteromalus calandrae performs better at higher temperatures, a combined application of both has been suggested. Due to the different modes of host searching, the 2 parasitoids can coexisted until host-pest populations are suppressed. The parasitoid can locate hosts within and down to a depth of 4 m of pest sites in bulk grain, and it should be released about four weeks after harvest, in fall and spring. The “Hohenheimer Box” refers to a method for mass-rearing beetle hosts and L. distinguendus. This device, from which the parasites can emerge over several months, may be placed in storage sites in order to facilitate continuous pest control.

The company Biologische Beratung Ltd, located in Berlin, produces and sells L. distinguendus (product name: “Lario+”) for the control of several stored product beetles.

The effect of transgenic maize: Significantly fewer L. distinguendus emerged from beetles that had developed in kernels of transgenic maize (Zea mays L.), containing the lepidopteran-specific Bt Cry1Ab toxin.


Adarkwah, C., Obeng-Ofori, D., Buttner, C., Reichmuth, C. and Scholler, M. 2002. Potential of Lariophagus distinguendus (Foerster) (Hymenoptera: Pteromalidae) to suppress the maize weevil Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) in bagged and bulk stored maize. Journal of Stored Products Research 38: 43-53.

Benelli, G., Pacini, N., Conti, B. and Canale, A. 2013. Following a scented beetle: larval faeces as a key olfactory cue in host location of Stegobium paniceum (Coleoptera: Anobiidae) by Lariophagus distinguendus (Hymenoptera: Pteromalidae). Chemoecology 23: 129-136.

Gonen, M. and Kugler, J. 1970. Notes on the biology of Lariophagus distinguendus (Foerster) (Hym. Pteromalidae) as a parasite of Sitophilus oryzae (L.) (Col. Curculionidae). Israel Journal of Entomology 5: 133-140.

Hansen, L.S. 2007. Biocontrol potential of Lariophagus distinguendus (Hymenoptera: Pteromalidae) against Sitophilus granarius (Coleoptera: Curculionidae) at low temperatures: reproduction and parasitoid-induced mortality. Journal of Economic Entomology 100: 1011-1016.

Hansen, L.S., Lövei, G.L. and Székács, A. 2013. Survival and development of a stored-product pest, Sitophilus zeamais (Coleoptera: Curculionidae), and its natural enemy, the parasitoid Lariophagus distinguendus (Hymenoptera: Pteromalidae), on transgenic Bt maize. Pest Management Science 69: 602–606.

Kerstin, K. (and 10 co-authors) 2015. Does early learning drive ecological divergence during speciation processes in parasitoid wasps? Proceedings of the Royal Society B: Biological Sciences 282(1799).

Niedermayer, S., Pollmann, M. and Steidle, J.L.M. 2016. Lariophagus distinguendus (Hymenoptera: Pteromalidae) (Förster)—past, present, and future: The history of a biological control method using L. distinguendus against different storage pests. Insects: 7: 39.

Niedermayer, S. and Steidle, J.L.M. 2013. The Hohenheimer Box – A new way to rear and release Lariophagus distinguendus to control stored product pest insects. Biological Control 64: 263–269.

Ryoo, M.I., Hong, Y.S. and Yoo, C.K. 1991. Relationship between temperature and development of Lariophagus distinguendus (Hymenoptera: Pteromalidae), an ectoparasitoid of Sitophilus oryzae (Coleoptera: Curculionidae). Journal of Economic Entomology 84: 825–829.

Ryoo, M.I., Yoon, T.J. and Shin, S.S. 1996. Intra- and interspecific competition among two parasitoids of the rice weevil (Coleoptera: Curculionidae). Researches on Population Ecology 25: 1101–1108.

Steidle, J.L.M. and Schöller, M. 2002.Fecundity and ability of the parasitoid Lariophagus distinguendus (Hymenoptera: Pteromalidae) to find larvae of the granary weevil Sitophilus granarius (Coleoptera: Curculionidae) in bulk grain. Journal of Stored Products Research 38: 43-53.

Steiner, S., Erdmann, D., Steidle, J.L. and Ruther, J. 2007. Host habitat assessment by a parasitoid using fungal volatiles. Frontiers in Zoology 6: 3.