0851996884.pdf

Europe, many more aphid and leafminer
parasitoids are marketed, both in total num-
ber as well as in the diversity of species.
Also, the number of E. formosa sold in
Europe is much higher than in the USA. The
reason for this difference is that these natural
enemies are applied in greenhouses, and the
number of large greenhouses for commercial
production of vegetables and ornamentals is
much larger in Europe.

Predatory insects

It seems that, in the USA, Chrysoperlaspp.
are used more often than in Europe. Their
high price and the observation that they are
mainly effective at a high pest density make
them not so attractive for the European
greenhouse market, where only a very low
pest density can be tolerated. Also
Cryptolaemussp. is more popular in the USA
than in Europe, but the use of Oriusspp. is
more prevalent in Europe. Most of the preda-
tory species are available both in the USA

and Europe, so there is less difference in the

predator-species composition than was

found for parasitoids.

Predatory mites and entomophagous

nematodes

The spectrum of available predatory mites

and entomophagous nematode species is

similar in the USA and Europe, with the

exception ofHypoaspis species, which are

used mainly in Europe. The quantity of

predatory mites sold in Europe is much

larger because predatory mites are used pri-

marily in greenhouses.

A final conclusion that we can draw from the

current data on mass production is that in

Europe most natural enemies are used by

professionals, whereas in North America bio-

logical control agents are also often used in

home gardens and can be bought at garden

centres or via garden catalogues (Cranshaw

et al., 1996).

178 J.C. van Lenteren

Spider mites 16

Aphids 13

Others 16

Thrips 22

Whiteflies 33

Fig. 11.2.Investments in money (expressed as percentages) in natural enemies used for control of different
greenhouse pests (after Bolckmans, 1999).

References

Anon. (2000) 2001 directory of least-toxic pest control products. IPM Practitioner22, 1–38.
Bolckmans, K.J.F. (1999) Commercial aspects of biological pest control. In: Albajes, R., Gullino, M.L., van
Lenteren, J.C. and Elad, Y. (eds) Integrated Pest and Disease Management in Greenhouse Crops. Kluwer
Academic Publishers, Dordrecht, pp. 310–338.
Cranshaw, W., Sclar, D.C. and Cooper, D. (1996) A review of 1994 pricing and marketing by suppliers of
organisms for biological control of arthropods in the United States.Biological Control6, 291–296.