New Predator Insects May Help Fight Major Maize Pests

Two newly identified parasitoids promise major benefits as biological control solutions for maize pests in Africa and Europe. Researchers Paul-André Calatayud, senior research scientist at the French Research Institute for Development, and Sevgan Subramanian, principal scientist and insect pathologist at the International Centre of Insect Physiology and Ecology, headquartered in Nairobi, Kenya, wrote about their recent discovery.

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The parasitoid Cotesia icipe may offer biological control against the fall armyworm. DR ROBERT COPELAND

Insect pests, such as maize stem borers and fall armyworm, increasingly challenge food production around the world.

Huge demands for crops have meant agricultural systems have simplified and frequently focused on single crops. In monocropping systems, when fields are full of a single crop, they can easily be found by their insect pests, as opposed to when mixed cropping is practised. Because of this, higher yield losses have more chance to occur in monocropping systems.

Climate change, which is mostly associated with increased temperatures and changes in rainfall patterns, as well as wild habitat reduction by farmers, have added to this by increasing pest pressure and resurgence.

The rapid evolution of pest resistance to chemicals, an increasing organic food market, and the negative effects of chemicals on the health of people and the environment, have increased the need to control insect pests biologically.

Insect predators

Biological control uses live organisms, such as insect predators, to kill or eat insect pests. Insect parasitoids are one form of biological control. These are insects that develop as parasites on other arthropods, mostly insects, causing their death or sterility.

They can target each developmental stage of the insect (eggs, larvae or pupae). These parasitoids have received increased attention because they are efficient, cheaper and offer a management strategy that safeguards human health and the environment.