Rice Insect Pests and their Arthropod Parasites and Predators


The proper identification of insect pests, and their associated natural enemies, is an important component in developing a holistic system for managing rice insect pests. To assist national rice research programs in the identification of specimens in their rice arthropod collections, the International Rice Research Institute (IRRI) in Los BaƱos, Philippines conducted an international collection program to establish a comprehensive rice insect pest and natural enemy collection. The collection was originally established by the first IRRI entomologist, Dr. Mano D. Pathak, in the early 1960s, and has been maintained over the years, by a series of IRRI entomologists.

Associated with this collection, a key, entitled Taxonomy of Rice Insect Pests and their Arthropod Parasites and Predators, authored by Alberto T. Barrion and James A. Litsinger, was published by IRRI (1994) as chapter 2, page 14-359, in the book, Biology and Management of Rice Insects, edited by E. A. Heinrichs, IRRI Department of Entomology Department Head, 1975-1985, and copy edited by Tom Hargrove and Jan Ray of the IRRI Communications Department. The chapter provides a practical and comprehensive classification of insects and spiders associated with rice worldwide. It includes both rice pests and natural enemies (predators and parasites of rice pests). The keys are based on diagnostic characters for each species and have necessarily had to involve morphological features relevant to each taxonomic group. The richly illustrated keys (1817 superbly produced line drawings by Danny Amalin of the IRRI Entomology Division) can be used by individuals with minimal experience in insect morphology and taxonomy. The authors have maintained technical accuracy by using precise morphological and taxonomic terminology but also provide non-technical synonyms. With the exceptions of leafhoppers and planthoppers, the keys are based primarily on adults which have a greater array of morphological features.

Although the key has a global coverage, it is more complete for Asia than for other rice-growing continents as it was based on specimens in the IRRI reference collection and literature available to the authors. This is the only key that includes all the major insect orders and spiders in the global rice ecosystems. The key includes 12 insect orders: Coleoptera, Dermaptera, Diptera, Hemiptera, Hymenoptera, Isoptera, Lepidoptera, Neuroptera, Odonata, Orthoptera, Strepsiptera, and Thysanoptera. The spider order, Araneae, consists of 11 families: Araneidae, Gnaphosidae, Hahnidae, Linyphiidae, Metidae, Pisauridae, Salticidae, Tetragnathidae, Theridiidae, Theridiosomatidae and Thomisidae.

Since the published book is now out-of-print, the insect and spider keys are no longer available in a published, hard-copy version. However, two recent developments have enabled a digital, interactive version of the key to be developed, and made freely available online. First, the original key is now available in a digital, pdf version of the book, available from the Research Gate site. Second, a recent upgrade of the Lucid software product, for constructing interactive Matrix keys, now includes a program for building dichotomous or pathway keys, including the conversion of paper-based dichotomous keys to interactive, online keys. These two developments have enabled the original key, published in the 1994 book, to be converted to a digital key and made freely available online, courtesy of the International Association for the Plant Protection Sciences (IAPPS). The key can be accessed at https://keys.lucidcentral.org/keys/v4/irri-rice-insects-and-spiders/

Apart from its value for rice plant protection specialists, this online, illustrated, rice insect and spider key, also provides useful training tools for parataxonomists (high school and college graduates without formal training in entomology and taxonomy). The interactive nature of this Lucid edition of the key makes it more user friendly than the book version. This is especially the case with thumbnail and enlarged images being made available as users work through the key to insect and spider species associated with global rice agroecosystems. A glossary provides further assistance in describing the key morphological features of the species in each of the orders.

The insects and spiders, included in the key, have been deposited in the IRRI Global Rice Arthropod collection. While some species of insects and natural enemies found in rice agroecosystems are not in the key, most of the rice insects and spiders occurring in Asian rice agroecosystems are included and the major, and most economically important rice insect species in North America, South America, and Africa, are also included. As a result, we hope that the key will be useful in identifying and understanding the components of the arthropod communities in rice agroecosystems, and lead to the development of effective pest management systems.

E. A. Heinrichs
August 1, 2022
Lincoln, Nebraska