Abstract
The effectiveness of maternal care in the bug Elasmucha putoni feeding on wild mulberry was studied by individual marking of females and their egg masses in the suburbs of Kanazawa from early June to middle July in 1981. When disturbed, females standing over the eggs and young larvae showed a characteristic guarding behaviour. Of 57 guarding females, 6 (10.5%) deserted their eggs before hatching, 6 disappeared while the larvae were in the first instar and 45 (78.9%) still guarded the second instar larvae. Loss rate from egg to second instar was 25.3% when egg masses were guarded by the females until the 2nd instar, while the rate was 74.3% when the females were removed from the egg masses. The increased loss rate in the unguarded egg masses was due to the increase of egg predation and dispersal of first instar larvae. The ant, Lasius niger, was frequently seen attacking the egg masses, but no parasitization of eggs occurred. The eggs and larvae were lost in an “all or none” manner in the unguarded groups, while a small number of individuals were lost randomly in the guarded groups.
