Scientists from Sun Yat-sen University, China, International Centre for Genetic Engineering and Biotechnology, Delhi, Indian Institute of Rice Research and Agri Biotech Foundation have explored the microbiome or microbes associated with a major rice pest, Asian Rice Gall Midge.

The Asian Rice Gall Midge is an insect about the size of a mosquito and a member of the specialized gall making insect family Cecidomyiidae. It spends most part of its life cycle within the rice plant. Upon hatching, the larva of the midge which is known as the maggot, slides down between leaf sheaths. After reaching the apical meristem, which is the part of the plant at the extremities from where vertical growth occurs, the maggot begins feeding by lacerating the plant tissue. The maggot induces changes in the plant such that a gall can be formed around its body, which contains nutritive nurse cells that can sustain it for the next phases of its life. The successful establishment of the insect in the plant means that the plant cannot bear grains.

Previous studies had explored the plant’s defence mechanisms against the midge, but studies have not explored the role of the insect’s microbiome in its interaction with the plant. An insight into the plant-midge-microbe interactions could provide us with novel strategies to control this infection.

For their latest study the scientists used next generation sequencing (NGS) protocol to identify different bacterial species associated with the midges and the plant.

The microbiome of the Asian Rice Gall Midge was made up of both rare and abundant species. Wolbachia species and Psuedomonas species of bacteria were commonly found in the Asian Rice Gall Midge. Wolbachia sp has been described as a microbe with a capacity to change several traits of its host, while Psuedomonas sp. are also known to be present in other pest species. Most notably, the study shows that the bacterial community structure differed among different host plant and different stages of development of the midge. These variation observed in the microbiome of the Asian Rice Gall Midge with reference to the host from which they were isolated indicate that they might have an influential impact on the midge and plant interaction.