Which species of biting arthropod is known for producing an obnoxiously sweet odor?

Bed bugs are specifically noted for producing an obnoxiously sweet odor, which can often be described as similar to that of ripe raspberries. This sweet smell is due to the pheromones they release, particularly when they are disturbed, during mating, or when they are in a crowded environment.

In contrast, ticks, fleas, and lice do not typically emit such distinct odors. Ticks are generally known for their blood-feeding behaviors and can transmit diseases but do not have a noteworthy odor associated with them. Fleas, while they can produce some scent, are not known for a sweet odor and are often identified more by their jumping ability and the irritation caused by their bites. Lice are primarily recognized for their presence on the scalp or body and the itching associated with infestations, without any prominent odor characteristic.

Thus, the defining feature of bed bugs is their ability to produce this unique sweet odor, setting them apart from the other listed biting arthropods.