Among others, he discovered a virus disease of the coconut palm rhinoceros beetle (Oryctes rhinoceros) in Malaysia from a previously unknown group of viruses which provided long-term control of this pest when introduced into islands invaded by the beetle.

In 1957, after completing his studies he joined the Institut für biologische Schädlingsbekämpfung, Biologische Bundesanstalt für Land- und Forstwirtschaft (Institute for Biological Pest Control, Federal Research Centre for Agriculture and Forestry) in Darmstadt, where he worked for his entire professional career.

This beetle is an important pest of coconut palms and was introduced accidentally into Samoa from where it spread to other parts of the South Pacific.

For example, the release of the virus into the islands of the Maldives, reduced the pest population considerably, often to less than a quarter of the level before the introduction.

He first noticed highly unusual symptoms in diseased mealworm larvae (Tenebrio molitor) which turned out to be caused by a new type of Bacillus thuringiensis.

Other bacterial diseases studied by Alois Huger included the mysterious male-killing (or son-killing) trait in some insect groups like parasitic wasps.