Perhaps「snake with your wife」that inserts pathogens in spread legs so that everyone with contact becomes ill also…BLACK FLIES and MOSQUITOES are virtually unstoppable and will eventually enter any dwelling, and are highly attracted to moist areas such as those「in spread legs.」The modern custom of wearing at least underwear most of the time has had the effect of causing humans to forget how attracted these insects are to a crotch.
　Or possibly「insect like your wife」are female blood-sucking insects, the many species of BLACK FLY:
　「Most black flies gain nourishment by feeding on the blood of mammals, including humans, although the males feed mainly on nectar [sticky dew, a honeypot]. They are usually small, black or gray, with short legs, and antennae. They are a common nuisance for humans…. The larvae use tiny hooks at the ends of their abdomens to hold on…. They have foldable fans surrounding their mouths. The fans expand when feeding, catching passing debris…. The larva scrapes the fan's catch into its mouth every few seconds. Black flies depend on lotic habitats [places where fluids flow] to bring food to them. …Even non-biting clouds of black flies, whether composed of males or of species that do not feed on humans or do not require a blood meal before egg laying, can form a nuisance by swarming into orifices. Bites are shallow and accomplished by first stretching the skin using teeth on the labrum and then abrading it with the maxillae and mandibles, cutting the skin and rupturing its fine capillaries.」
　　[　https://en.wikipedia.org/wiki/Black_fly 2013-09-14　]　
　Some sources also cite WHITE SOCKS, but apparently this reference was to the pathogens or larvae in no-longer-integrated foot binding cloths of service providers (「insect like your wife」as female blood-suckers), and not to actual stockings nor to any baseball team…may have referred to white splats falling onto one's socks,「rod dripping with final thought or sound.」GNATS are especially attracted by moist fructose-laden splats, such as human semen.

Modern definitions (that generally disregard history) …excluding politically incorrect concepts and other meanings deemed offensive today; may list only pigeonholed definitions, euphemisms, or meaningless mnemonics)
Chinese: (mosquito); Simulia lugubris; blackfly
Japanese: black fly, gnat
Unihan extended: gnat, mosquito
EDRDG: gnat; sand fly