Finding a “worm” inside an apple is a common experience. While colloquially called worms, these are typically the larval stages of certain insects. Identifying them involves observing both the appearance of the larva itself and the specific signs of damage left on and within the apple.
The Worm’s Appearance
The larvae found in apples are generally small, soft-bodied, and cylindrical, showing some segmentation. Their size can vary, typically ranging from a few millimeters when newly hatched to over a centimeter as they mature. Most often, these larvae appear in shades of creamy white or yellowish. Some may exhibit a slight pinkish tint. A darker head capsule, often brown or black, is a distinguishing feature for some types of apple larvae, while others appear to have no distinct head or legs.
Signs on the Apple
The presence of larvae in an apple is often indicated by specific visual cues on the fruit’s surface and inside its flesh. Small, dark holes, sometimes accompanied by a slight depression or discoloration, can mark entry or exit points. These openings might also show sticky substances or a slight browning around the edges.
Internally, infested apples typically reveal tunneling or galleries, which are discolored paths within the fruit’s flesh. These tunnels can appear brown or black, indicating where the larva has fed. The surrounding apple flesh might also become softened or discolored around these damaged areas. Another clear sign of infestation is the presence of frass, which is the larva’s excrement. This granular material resembles sawdust or coffee grounds and is often found near entry or exit holes, or packed within the tunnels inside the apple.
Common Apple Pests
The two most frequently encountered larvae in apples are those of the codling moth and the apple maggot.
Codling moth larvae are often described as having a creamy white to pinkish body with a noticeable brown or black head. These larvae typically tunnel directly towards the apple’s core, where they feed on the seeds. Their tunnels are often filled with crumbly, reddish-brown frass.
Apple maggot larvae, in contrast, are entirely white or creamy and lack visible legs, tapering slightly at one end. Instead of heading for the core, these larvae create winding, irregular tunnels throughout the apple’s flesh. This tunneling often leads to soft, brown decay within the fruit, differentiating their damage from that of codling moth larvae.