surface of their food source, primarily apples. The fly extends its proboscis and drops saliva onto the skin of the apple, and the saliva is used as a solvent for substances on the apple. If drier substances are present, the fly dissolves them before sucking up fluid. Larvae use chitinous hooks to cut through pulp just below the skin of the fruit, producing characteristic brown markings, leading to the larvae being called "railroad worms". If the apples are still growing, larvae burrows are difficult to find because they heal quickly. Softened apples allow larvae to grow rapidly and break down pulp, even to the point of feeding at the core. Mating Rhagoletis pomonella adult flies may begin copulation as early as eight days old. Males attempt copulation when females are in oviposition on fruit. The male springs onto the female and positions his forefeet on her abdomen and his second pair of feet on her wings. The male waits and uncoils his spring-like penis, quickly entering the opening of the ovipositor when the female extends it. Mating occurs on the host plant and averages thirty minutes, during which the flies are attached and can fly about. Then, when the flies separate, the ovipositor and penis are quickly retracted. The flies undergo multiple matings, which benefits both sexes. Generally, multiple mating is thought to be a more adaptive strategy for males because of male potential to fertilize many females and the trend of greater female parental investment. However, studies have shown increased female fecundity and fertility from multiple matings. Females have long-term sperm storage, and there is little to no parental investment after she lays eggs. A 2000 study by Opp and Prokopy found that male and female apple maggot flies mated up to six times a day in males and eight times in females, thus there is most likely no mating refractory period, unlike other tephritid species like Mediterranean fruit flies, whose females may mate only after stored sperm is depleted. Threats Predators The apple maggot is not as heavily targeted by predators and parasites as other insects because for most of its lifespan it is inaccessible, living inside apples as larvae and in soil as pupae. Occasionally flies are captured by various species of spiders, such as the Dendryphantes militaris Hentz, which predates on flies in apple trees. Birds may feed on larvae, pupae, or adults. Some full-grown maggots