Deer predation on leaf miners via leaf abscission

Area of Science:

• Ecology
• Entomology
• Zoology

Background:

• Evergreen oaks (Quercus gilva) shed leaves containing leaf miner (Stigmella sp.) mines earlier than unmined leaves.
• Leaf abscission timing can influence insect survival and interactions with other species.

Purpose of the Study:

• To investigate the impact of leaf abscission on the survival of the leaf miner Stigmella sp.
• To determine the role of sika deer (Cervus nippon centralis) predation in leaf miner mortality through leaf fall.

Main Methods:

• Laboratory experiments comparing eclosion rates of leaf miners from abscised and retained leaves.
• Field observations of sika deer feeding behavior on fallen oak leaves.

Main Results:

• Leaf miners successfully eclosed from both fallen and retained leaves in laboratory settings.
• Sika deer were observed consuming fallen leaves containing leaf miner mines.
• Significant mortality of leaf miners is suggested due to deer predation on fallen leaves.

Conclusions:

• Leaf abscission by Quercus gilva accelerates the exposure of Stigmella sp. larvae to predation.
• Sika deer predation on fallen mined leaves represents a previously undocumented mortality factor for leaf miners.
• This interaction highlights a novel ecological relationship mediated by leaf abscission between an insect herbivore and a mammalian herbivore.