A new biological method to control Anobium punctatum, by using the parasitoid wasp Spathius exarator

Abstract

AbstractBiological pest control by means of beneficial organisms is for long part of agriculture and Integrated Pest Management (IPM). A new and efficient strategy to control the most common timber pest species in churches and museums, the furniture beetle Anobium punctatum (De Geer) (Coleoptera: Anobiidae), is based on the parasitoid wasp species Spathius exarator (Linnaeus) (Hymenoptera: Braconidae). Once this braconid wasp detects its host species beneath the surface, it pierces the wood with its ovipositor to lay one single egg onto the beetle larva. After hatching, the wasp larva feeds on the beetle larva thereby killing it. Afterwards, it pupates and emerges through a self‐gnawed hole as an adult wasp. The tiny, 0.5‐mm‐wide exit hole can easily be distinguished from the 1‐ to 2‐mm‐wide exit hole of A. punctatum. Laboratory tests revealed that female wasps have an average life span of 85 days and produce a total of 24 offspring, when nutrition is provided. Between 2012 and 2019, braconid wasps were introduced into 54 different A. punctatum infested buildings. Treatment success was monitored by examining exit holes of new beetles and wasps thereby calculating corresponding parasitism rates. After the first year of treatment, parasitism rates were significantly higher with a mean value of 0.15 when compared to untreated objects with a natural parasitism and a mean value of 0.08 (n = 54). Following treatment of three objects over a period of eight years, parasitism rates continuously increased from 0.02 up to 0.31. In a church organ, which was treated during this period, the monitoring revealed a complete suppression of pest activity. These data prove that this biological method of pest control is an efficient, sustainable and non‐toxic option to manage the common furniture beetle.