The vast numbers of alien arthropods across the world collectively impose major conservation concerns. Many insect invaders are presumed to be pests but, even for acknowledged pest species, debates can become divisive both in (1) assessing severity of impacts beyond an immediate pest context and (2) the remedial actions needed. The Australian Light brown apple moth (Epiphyas postvittana, Tortricidae) in California, where it was recorded first in 2007, is highly polyphagous with its larvae reported to feed on more than 200 plant species, including many crops. This discovery led to a massive eradication campaign. However, as discussed by Chen (2010), some entomologists doubt that it is really a recent invader but may have been in California for several decades over which it did not come to notice through any significant damage to crops. In that case, a highly expensive eradication campaign would not be needed, and is highly unlikely to succeed. E. postvittana, as a well-known and economically significant insect, simply indicates the problems that arise in seeking sound information on impacts and any remedial steps in a new, or previously undetected, environment where, essentially, the history and reality of invasion is unknown. Pest management, to a large extent founded on invasive insects of economic, social or ecological importance, continues to provide examples of the diverse impacts of invasive taxa, and parallels with conservation management – albeit often from different ‘directions’ of suppression or encouragement.