 Females are larger than males and live for a year, a time just long enough to produce a brood, whereas the males die in only a few days, just enough time to impregnate a female.In Steven J. Phillips' book "A Natural History of the Sonoran Desert", he referred to them as superficially resembling "huge yellowjackets or hornets" and stated that they are "powerful fliers with compound eyes".On average, males weigh 95mg and females are far heavier, at 256mg, probably because of the additional weight of the ovaries, developing eggs and nutritional reserves.