Scientists from the field of biological control of pest insects need insight from ecologists on the concept of economic regulation. These findings help them control destructive organisms by releasing a specific natural enemy of the organisms onto the crop, which reduces the number of pest species. Tutaabsoluta is a pest that was first discovered in 2006 in Europe, and since then, it has rapidly spread worldwide. Chemical control is ineffective on this pest as it requires frequent use of insecticide spray, which could lead to resistance. This makes the whole situation quite tricky, so there is a pressing need to find the most effective natural enemy of a pest applied against all tomato varieties and production systems established globally. In addition, factors like variations in the climate, fertilizer use, and variations in climate also need to be looked at before determining the natural enemy.
Taking a big step towards arriving at a conclusion, a research team provided evidence that could help come to the most effective natural enemy. They suggested that daily kill rates of predatory insect species and parasitoid species could be efficient criteria in determining which natural enemies could be the most useful against the biological control of insect pests. This is an enormous breakthrough for the Pest Control Market as the problem caused by tutaabsoluta (tomato leafminer) worldwide could be countered through this present study.
The team analyzed the ‘kill rates’ of seven parasitoid species and six predatory insect species foraging for the tutaabsoluta (a small moth whose larvae causes damage to tomato leaves and the tomato itself). They concluded that the kill rate of Nesidiocoris tenuis (a predatory bug) and of the parasitoidNecremnustutae showed that both the species could potentially keep the tomato leafminer under control.
The researchers on tutaabsoluta calculated the kill rates of the pesticide insects and parasitoid wasps based on numbers present as per the existing data. Two predators came out to be particularly effective, namely, Tupiocoriscucurbitaceus and N. tenuis. However, there are some other predators as well that have a higher rate than the natural growth rate of the insect pest. Among parasitoids, Trichogrammatoideabactraehad the most acceptable kill rate, while the effectiveness of N. tutae was considered good.
These findings prove that kill rates can help rule out a large number of natural enemies from the list of prospective candidates. These natural enemies' 'kill rates' are not enough to fight against the insect pest population to the economic injury threshold (the density rate wherein the farmer does not have harvest loss of tomato). In the end, what can be done is to assess the effectiveness of the species that remain in different tomato production systems.