Current Comments” EUGENE GARFIELD INSTITUTE FOR SCIENTIFIC lNFORMATION!B I 3501 MARKET ST PHILAOELFI+A, PA 19104 The Cockroach Connection—Ancient, Seemingly Indestructible Pest. Part 1, Morphology, Behavior, and the I Relationship to Allergies and Disease Number 45 November 5, 1990 This two-part essay provides a brief overview of the cc&roach literature. Pan 1 looks at the insect’s capabdities, distribution, morphology, evolutional link with humans, and the connection between roaches and allergies and disease. Anyone growing up in a city, especially in Cockroaches do surface from time to time tenements, has encountered cockroaches. in the popular consciousness. Two exam- From childhood I remember my mother ples that come to mind: the folk song that clobbering them with a shoe or a newspaper. became popular during the Mexican revolu- Looking back, I marvel at how mothers in tion (19 10-1940) that we all fondly know as slums managed to keep apartments free of “La Cucaracha,” and the famous scene from them. Even in modem high rises, these in- the film Pupil/on where a starving Steve seets are indefatigable--often outwitting McQueen captures a cockroach in his jail regulas extermination squads. However, cell and eats it on camera! However, for what I encountered as a child was nothing many years, cockroaches escaped such compared to my Army experiences. When prominence in the popular media—but that my outfit transferred from Colorado to all changed in the mid- 1980s. Texas, we were installed in barracks so full of cmkroaches, gas bombs had to be used to clean them out! I vividly recall a pile of Invasion of the Flying Roaches dead roaches that was literally two feet high. Like many other insects inhabiting the 1[began in late spring 1986. Anew immi- urban environment (like flies and silver- grant arrived in central Florida by boat. fish), cockroaches generally conjure up neg- This may not appear to be unusual, but this ative images in the US. 1 But unlike other was a newcomer with a difference-a one- insects, cockroaches seem to be associated inch fellow known to entomologists as with taboo topics. You don’t talk about Blatfella asahinai, or more commonly, the them in polite company. But this has never Asian cockroach. deterred us in selecting topics for essays in Previously, this insect had been virtually Current Contents @ I was curious to learn unknown in the New World. Indeed, the more about these ancient, well-adapted Asian roach had been described formafly by creatures. insect researchers only four years before its We’ve pulled together an interesting re- appearance in the US. This cockroach’s nat- view that demonstrates once again that even ural range is from southern India through the most practical and elemental of human Southeast Asia. Its introduction into central problems is closely intertwined with basic Florida was seemingly inauspicious---in research in entomology. Several years ago, June 1986 the species was limited to spo- in 1984, we reviewed entomology joumals,z radic infestations within 60 square miles of and that same year I published a tribute to Lakekmd-and was barely noticed.q my good friend Miriam Rothschild.3 Her But a year later, this changed. A major specialty is the flea, but it is not a big jump pandemic infestation was faced by Florida to talk about cockroaches. offtcials, By day, nothing seemed out of the 407 ordinary; but at dusk, things became quite crease your knowledge abut this fascinat- different. The Asian roaches came out of ing insect. hiding, and with a vengeance. In 1987 their density was estimated at up to 100,000 per acre+-or slightly more than two per square An Adaptable, Successful Living Fossil foot—and they infested nearly 500 square miles in three central Florida counties. Cockroaches are among the most primi- Telephone calls from distressed residents tive living winged insects-they have re- began to pour into public offices. The twi- mained essentially unchanged for more than light behavior of the insects was like a 300 million years. Cockroach fossils found cheap horror movie come frighteningly in coal and amber deposits show virtually alive. The roaches reprtedly flew in clouds no morphological differences in size or like locusts. Unlike other cockroach spe- shape from those inhabiting our cupboards cies, they were attracted to illumination— today. The oldest known cockroach fossil is street lights, trat%c Iights, porch lights, tele- Paleoblatta douvillei, found in Carbonifer- vision screens, and lights in houses. Even ous deposits of the Devonian period. Its more disturbing, the insects landed on peo- preferred habitat was among ferns in low, ple without hesitation. As the roaches en- moist areas along banks of rivers and tered homes, they were attracted to well-lit marshes.a rooms andlanded onthe brightest walls. As But today, roaches can be found just about interior lighting changed in rooms, the anywhere. Whh more than 3,500 identified roaches moved accordingly. During the cockroach species (ranging in size from 8 day, they acted just like their roach millimeters [3/1O of an inch] to nearly 70 brethren-scurrying into cracks and crev- [3 inches]), these insects are distributed ices in the walls and flows, often “hanging fairly generally throughout most continents, out” in kitchens, bathrooms, and potted with perhaps the most species residing in plants until dusks tropical America and western Africa. Of the In just three years, the Asian roach ex- total number of species, only 50 are re- panded itsterntory from 3 Florida counties garded as “pests’’—that is, an insect viewed to 18. Theentomology expexls’fears of the as detrimental or annoying to human beings. roaches hitchhiking in cars, trucks, and As a general rule, cockroaches have been trains to other parts of the country were found to survive comfortably at tempera- soon realized-an outbreak of the Asian tures between 19 and 1I6 degrees Fahren- roach appeared in Michigan in 1988, the heit, making the insects adaptable to most insects arriving by way of a travel trailer.G areas that humans inhabit.g (p. 10) The story at this point became a national The three widest spread species are the media event. American cockroach (Per-iplaneta Ameri- Unlike other insects (such as “killer bees” cana); the German cockroach (B. ,qer- or ticks carrying Lyme disease7), cock- manica), the most common insect pest roaches have not been proven to be life worldwide; and the Oriental cockroach threatening. Yet roaches seem to be espe- (Blafta orientalis), also known as the “water cially—perhaps irrationally-reviled. Last bug,” considered one of the filthiest of year US consumers spent $1.5 billion on household pests. IIJ commercial insecticides to rid their homes Cockroaches are very adaptable and virtu- of cockroaches-almost twice as much as ally indestructible. Some species can swim the Federal government spent on AIDS re- rapidly underwater for up to 2 minutes and search (about $790 million).g remain submerged for as long as 15 min- In this two-part essay, we’ll briefly review utes; the Asian roach has been collected in the cockroach literature, as well as focus on mountainous regions and even in areas of research specialties on this insect. Although intermittent snow.’t Roaches inhabit TVs, we may not be able to explain the irrational microwave ovens, and even submarines. 11 behavior of many humans in response to They have been found in hospital laundry these lowly creatures, hopefully we may in- baskets, incubators for premature babies, 408 and beauty salons in department stores.g Cockroaches have a well-defined court- (p. 11) Some 20 species have been found ship prior to actual mating. The mating rit- on aircraft. These were recovered from air- ual itself can take up to an hour. Male planes at airports in the US, Kenya, and roaches are attracted to virgin females in a New Zealand, suggesting that this may be a receptive condition. Such females fre- significant method of species migration. quently secrete pheromones, chemical sub- German and American roaches are the most stances that influence the behavior of other “frequent flyers.”g (p. 12) individuals of the same species. In Ameri- Speaking of transportation, some of the can roaches, on detection of the odor, the earliest records of cockroaches as pests can male initiates searching movements, first be found in ship logs. These insects are with antennae, then with wings fluttering, found in the reports of Sir Francis Drake actively searching the female out. (Scien- (sixteenth century) and William Bligh (eigh- tists have been vigorously pursuing the arti- teenth century). Drake reported one cap- ficial creation of the cockroach pheromone, tured Spanish ship to be overrun with cock- but more about this later.) roaches. Bligh recorded in the Bounty’s logs During the courtship ritual, the male a description of a successful method of kill- backs up into the female, depositing a sperm ing the cc&roach population–-using boil- packet that the female retains for four to five ing water. Centuries later, the insects are months while continually producing egg still a nuisance to shlppirtg-the German sacks, each holding 16 to 35 tiny roaches. roach appears to & the most successful spe- When the eggs are ready to hatch, the fe- cies, especially associated with galleys, cab- male deposits the ootheca. Soft white ins, and mess rooms.q (p. 12) nymphs emerge, hardening and turning brown in color on ex~sure to the air. Be- Cockroach Morphology and Behavior: fore becoming mature adults, the nymphs Like Roach, Like Human? go through several immature stages with molts in-between before a sexually mature For every cockroach one sees in the aver- adult is produced.