Technique for Studying Arthropod and Microbial Communities within Tree Tissues

Abstract

Phloem tissues of pine are habitats for many thousands of organisms. Arthropods and microbes use phloem and cambium tissues to seek mates, lay eggs, rear young, feed, or hide from natural enemies or harsh environmental conditions outside of the tree. Organisms that persist within the phloem habitat are difficult to observe given their location under bark. We provide a technique to preserve intact phloem and prepare it for experimentation with invertebrates and microorganisms. The apparatus is called a 'phloem sandwich' and allows for the introduction and observation of arthropods, microbes, and other organisms. This technique has resulted in a better understanding of the feeding behaviors, lifehistory traits, reproduction, development, and interactions of organisms within tree phloem. The strengths of this technique include the use of inexpensive materials, variability in sandwich size, flexibility to re-open the sandwich or introduce multiple organisms through drilled holes, and the preservation and maintenance of phloem integrity. The phloem sandwich is an excellent educational tool for scientific discovery in both K-12 science courses and university research laboratories.

Artificial diet sandwich reveals subsocial behaviour in the coffee berry borer Hypothenemus hampei (Coleoptera: Curculionidae: Scolytinae)

“…The insect spends most of its life cycle hidden inside the coffee berry, making it impossible to observe its behaviour under natural conditions. A similar situation occurs with bark beetles that live in the phloem of trees, but a technique based on what is known as phloem sandwiches, consisting of placement of phloem between two glass or plastic plates, has been successfully used to study their behaviour (Bedard 1933;Hopping 1961;Beanlands 1966;Kinn and Miller 1981;Salom et al 1986;Grosman et al 1992;Taylor et al 1992;Aflitto et al 2014).…”