Observations on the biology and ecology of the chrysomelid genus <i>Haltica</i> Geoff, in Britain

Abstract

Abstract. 1. Ecological observations were made on four species of the genus Haltica and the life cycle described, with particular reference to H.lythri Aubé. 2. The species are usually univoltine although a second egg laying period may occur. 3. Post hibernation aggregation behaviour of adulls occurs in the spring and feeding damage is often localized. First instar larvae of H.lythri feed in groups. 4. Parasitism by Perilitus sp. (Hymenoptera, Braconidae), Degeeria luctuosa Meigen (Diptera, Tachinidae), gregarine protozoa, Nematoda (Mermithidae) and a fungus, Verticillium sp., is reported. 5. Hemiptera are important predators of some Haltica species. Eggs of H.lythri were attacked by the mirid Dicyphus epilobii Reuter. Larvae of H.oleracea and H.lythri were preyed upon by the pentatomid Zicrona coerula (L.). 6. Feeding tests with carabid beetles suggested that Stomis pumpicatus (Pz) may be a potential predator of larvae of H.lythri. 7. Chemical secretions at the tips of spined tubercles of first instar larvae may have a defensive function. Other defence mechanisms are described.