Biological Control with Trichogramma: Advances, Successes, and Potential of Their Use

Abstract

Major contributions to the release of Trichogramma for biological control of lepidopterous pests have been made in the past 20 years. Most trials have used only five species of Trichogramma against two pests; Ostrinia in corn is considered the most universally feasible. All Trichogramma programs must address the following four aspects to be successful commercially. Selection of the appropriate population is based on inter- and intraspecific variation, as well as on current definitions of parasitoid quality. Mass rearing is comprised of both host and parasitoid components, although major emphasis is now on developing artificial systems. Effective distribution of Trichogramma requires supportive extension and advanced technology. Strategies for use in the field vary according to the approach desired (inundative or inoculative), the timing, frequency and rate of release, and the multiple factors that affect release, such as the weather, crop, host, predation, pesticides, and dispersal. The past difficulty in assessing the efficacy of Trichogramma should be improved with new guidelines for standardizing terminology and measurements.

Biological control with Trichogramma pretiosum increases organic maize productivity by 19.4%

“…According to Smith (1996), the effectiveness of Trichogramma releases has been often inconsistent due to the model adopted for assessment and suggests that the crop yield is one of the parameters to be used to validate the effect of this biological control agent. The action limit, based on the capture of moths in traps, was calculated from data on the biology and ecology of S. frugiperda, considering periods of life including incubation, larval development, and ability to cause economic damage.…”

Efficacy assessment of some Trichogramma species (Hymenoptera: Trichogrammatidae) in controlling the potato tuber moth Phthorimaea operculella Zell. (Lepidoptera: Gelechiidae)

“…To overcome or at least minimize the use of pesticides, renewed interest in expanding the use of biological control agents acquires special significance. The releases of oophagous hymenopterous parasitoids such as Trichogramma for lepidopterous biological control has been proposed as an important component in insect-pest management programs (with >32 million ha of agricultural and forestland worldwide treated annually) (Li 1994;Smith 1996).…”

Biological Control of Parasites

“…Most insect parasitoids are wasps or flies and may have a very narrow host range. The most important groups are the ichneumonid wasps, which prey mainly on caterpillars of butterflies and moths; braconid wasps, which attack caterpillars and a wide range of other insects including greenfly; chalcid wasps, which parasitize eggs and larvae of greenfly, whitefly [40], cabbage caterpillars and scale insects and tachinid flies, which parasitize a wide range of insects including caterpillars, adult and larval beetles and true bugs [37,[41][42][43][44].…”