BugGuide
Iowa State University Department of Entomology
Community database of photographs and taxonomy for insects, spiders and related arthropods of the United States and Canada, hosted by Iowa State University. Expert editors check the identifications. The taxonomic guide pages and forum can be browsed free and used to get submitted photos identified. The standard free tool for identifying a North American specimen and for connecting book taxonomy to real photographs.
More resources on Entomology
Featured Creatures
Series of about 770 species profiles written by University of Florida entomologists, running since 1996. Each profile covers identification, life cycle, distribution, host plants, economic or medical importance, and management. Coverage centres on agricultural pests, disease vectors, beneficial insects and invasive species. It gives case studies at species level that the textbooks and course cannot.
Borror and DeLong's Introduction to the Study of Insects (7th Edition)
Reference text for identifying North American insects to family level. Order-by-order chapters give illustrated dichotomous keys, morphology and biology, with a chapter on collecting and preserving specimens. The 7th edition revises phylogeny and reclassifies Homoptera into Hemiptera. Where Gullan & Cranston cover how insects work, Borror & DeLong covers how to key specimens to family, which serves the collecting and identification part of the topic note.
The Insects: An Outline of Entomology (5th Edition)
University textbook on insect biology organised by function rather than taxonomy. It covers external and internal anatomy, physiology, development, behaviour, ecology of ground, aquatic, plant and social insects, predation, phylogeny, medical and veterinary entomology, and pest management.
ENT 425 – General Entomology
Public website for NC State's undergraduate General Entomology course. It includes a compendium of insect orders and common families, Kwik-Key identification keys, short lessons on anatomy, physiology, defenses and medical pests, a glossary with flashcards, and instructions for building a specimen collection. It has dichotomous keys by order, family-level coverage and practical collecting guidance, which no MOOC offers.
Bugs 101: Insect-Human Interactions
The best free, structured video introduction to the field. Video course from the University of Alberta, also taught for credit there as ENT 101. It covers arthropod evolution, insect anatomy and diversity, pollination, biological pest control, insect-borne disease, forest pests and conservation. Thirteen modules; no prior background assumed.