DIVERSITY AND RELATIONSHIP BETWEEN WATER BUGS (HEMIPTERA) AND WATER BEETLES (COLEOPTERA) IN DIFFERENT HABITATS AT SOME NATIONAL PARKS IN NORTH VIETNAM

The research on water insect biodiversity (Hemiptera, Coleoptera) in Vietnam was very limited and mainly focused on taxonomy. In this study, the diversity index and relationships between the number of individuals of water bugs (Hemiptera) and water beetles (Coleoptera) in primary forest habitats, secondary forest habitats, agricultural crop habitats and shrub habitats in Ba Be National Park, Bac Kan Province, Vu Quang National Park, Ha Tinh Province, Hoang Lien National Park, Lao Cai, Lai Chau Provinces were studied and evaluated. From 75 sampling sites in four habitats in three National Park were collected 1892 individuals of the water bugs (Hemiptera) and water beetles (Coleoptera) representing 73 species of 48 genera of 14 families. Among them, 42 species of water bugs (Hemiptera) with 27 genera of 10 families, 31 species of water beetles (Coleoptera) with 21 genera of 4 families. The number of species in the family Nepidae, Gerridae (Hemiptera), Dytiscidae, Hydrophilidae (Coleoptera) were highest in secondary forest habitats, shrub habitats and lowest in agricultural crop habitats, shrub habitats. The diversity index (Dominance_D, Simpson_1-D, Shannon_H, Evenness_e^H/S, Brillouin, Menhinick, Margalef, Equitability_J, Fisher_alpha, Berger-Parker, Chao-1) in different habitats did differ between water bugs (Hemiptera) and water beetles (Coleoptera). The Simpson_1-D, Shannon_H, Margalef indexes of water bugs (Hemiptera) have value in primary forest habitat> secondary forest habitat> agricultural crop habitats> shrub habitats. Meanwhile, water beetles (Coleoptera) have value in agricultural crop habitats> shrub habitats> secondary forest habitats> primary forest habitats. The relationship between the number of individuals of water bugs (Hemiptera) and water beetles (Coleoptera) in different habitats in three National Parks was weak and different. In primary forest habitats, this relationship showed a positive, weak correlation. The analysis model species packing in the primary forest habitat was a parabolic curve with a downward concavity, showing the co-increase and co-decrease of water bugs and water beetles. In secondary forest habitats, this relationship showed a positive, very weak correlation. The analysis model species packing in the secondary forest habitats was a curve, showing the co-increase of water bugs and water beetles. In agricultural crop habitats and shrub habitats, the relationship showed a negative, very weak correlation. The analysis model species packing in the agricultural crop habitats and shrub habitats is a straight line and did not show the contrasting increase and decrease of water beetles and water beetles.