Animal behaviours often dependent on age. In many insect species, walking shows an age-dependent decline, and food intake may also be dependent on age. However, few studies have investigated the relationship between age and walking or food intake. In the present study, we compared walking traits and food intake among individuals of different ages in the assassin bug Amphibolus venator (Hemiptera, Reduviidae). The present results showed an age-dependent decline in walking, similar to findings in many animal species. On the other hand, food intake showed a positive correlation with age. Therefore, the decline in walking did not lead to a decline in feeding. The positive relationship between food intake and age may be related to the type of predation, sit-and-wait, used by A. venator via alterations in investment in reproductive traits with age.

20Animal behaviors are often affected by aging. In many insect species, 21 locomotor activity decreases with aging. Foraging ability may also decrease 22 with aging. However, few studies have investigated the effects of aging on 23 both locomotor activity and foraging ability. In the present study, we tested 24 the aging effect on locomotor activity and foraging ability in the assassin bug 25 Amphibolus venator. The present results showed that locomotor activity 26 decreased with age, similar to findings in many other animal species. 27However, foraging ability increased with age. Namely, the decline in 28 locomotor activity with age did not lead to a decline in foraging ability. The 29 positive relationship between foraging ability and age may be related to the 30 type of predation, sit-and-wait, used by A. venator via alterations in 31 investment in reproductive traits with age. 32 33