In the news today I came across this rather strange report from the Associated Press:
MIAMI — U.S. Customs and Border Protection officials say they have intercepted a rare and dangerous insect found in a shipment of flowers at a Miami airport that could cause significant damage.
Officials said Saturday they were examining a box of flowers last week at Miami International airport when they found Hemiptera. Hemiptera's are typically aphids, cicadas, and leaf hoppers and comprise about 80,000 different species. They feed on the seed heads of grasses and sedges. The insect is found in South America.
Officials believe it is the first time the insect has been found in the U.S.
The report is inaccurate in several ways. The insect actually comes from South Africa, which is different from South America. There is no indication that it is rare. The fact that it isn't found in the United States doesn't make it rare. We don't say that tsetse flies are rare because they aren't found in the United States. Nor is there any reason to believe that it is dangerous. It may be destructive of plants, which is why this discovery is of interest, but even that isn't known. It isn't considered a pest in South Africa and it isn't known what would happen if it got loose and survived in Florida.
Several points are of linguistic interest. One is the reference to "Hemiptera". Hemiptera is the name of the order to which the insect, a member of the species Uttaris pallidipennis Stal belongs. A member of this order is a Hemipteran.
More interesting is the statement that "Hemipteras are typically aphids, cicadas, and leaf hoppers", which is not well-formed. What the author presumably meant is: "Typical members of the order Hemiptera are aphids, cicadas, and leaf hoppers". When you say that "Hemipterans are typically X", X must describe a characteristic; it can't list examples.
I suspect that there's a reason for the erroneous description of this insect as "dangerous". The usage of this word is rather interesting. Anything that can injure or destroy something can be described as "dangerous" to it. One can say, for example, that "Aphids are dangerous to roses.". But this only works if you specify what is subject to the danger. If we remove "to roses" and just say "Aphids are dangerous", the sentence becomes false. It seems that "dangerous" comes with a default bearer of the danger, namely human beings. When you say that something is dangerous without specifying to what, you mean that it is dangerous to people. Furthermore, it seems that a non-human bearer of the danger must be linguistically overt. Although we can felicitously say "Owls are dangerous to mice", even if the topic of conversation is predators of mice, it is not felicitous to say "Owls are dangerous." without adding "to mice". My guess is that someone said or thought that the insect in question might be "dangerous to crops" or something along those lines, and then, without thinking, removed "to crops".
The actual facts can be found in the much better report in the Miami Herald. The odd wording appears to have originated with Customs, in this press release. (Customs is now part of the "Department of Homeland Security" but I avoid using this name. Whenever I see it, I hear "Reichsicherheitshauptamt". )