Predatory Ability of Adult Diving Beetles on the Japanese Encephalitis Vector Culex tritaeniorhynchus

Abstract

The predatory ability of adult Japanese diving beetles on 4th instars of the Japanese encephalitis vector mosquito, Culex tritaeniorhynchus, was assessed under laboratory conditions. To determine the differences in the predatory ability among 14 beetle species inhabiting rice fields, the following species were introduced to 10 Cx. tritaeniorhynchus 4th instars in a plastic cup: 5 small-bodied species (< 9 mm in body length) comprising Hydroglyphus japonicus, Noterus japonicus, Laccophilus difficilis, Hyphydrus japonicus, and Agabusjaponicus; 7 medium-bodied species (9-20 mm in body length) comprising Hydaticus rhantoides, Hydaticus grammicus, Rhantus suturalis, Eretes griseus, Hydaticus bowringii, Agabus conspicuous, and Graphoderus adamsii; and 2 large-bodied species (> 20 mm) comprising Cybister brevis and C. japonicus. The average 24-h predation rate was highest in medium-bodied species (> 90%), followed by small-bodied species (31%) and large-bodied species (19%). The functional responses to Cx. tritaeniorhynchus larvae of 3 medium-bodied species (H. grammicus, R. suturalis, and E. griseus) were estimated. Eretes griseus exhibited the highest attach rate and shortest prey-handling time, suggesting that medium-bodied diving beetles, especially E. griseus, may be efficient predators of mosquito larvae in rice fields.

Predators of <I>Anopheles gambiae</I> sensu lato (Diptera: Culicidae) Larvae in Wetlands, Western Kenya: Confirmation by Polymerase Chain Reaction Method

“…The diving beetle, Laccophilus spp. (<5 mm in body length, classified into small-bodied species; Ohba and Takagi 2010), was the dominant coleopteran predator in this study.…”

“…Beetles captured in the current study were <9 mm in body length and were classified as a small-bodied species. According to Ohba and Takagi (2010), predation rates are higher in medium-bodied species (9–20 mm in body length) than in small (<9 mm)- and large-bodied (>20 mm) species. In a preliminary field survey in May 2009, the density of medium-bodied predatory diving beetles (Coleoptera, Dytiscidae) in wetland habitats was higher during the high rainy season than during the low rainy season (S.-Y.O., unpublished data).…”

Relationships between predatory aquatic insects and mosquito larvae in residential areas in northern Thailand

“…Most coleopterans were abundant where macrophytes also were abundant, and members of the family Noteridae exhibited the greatest density, followed by members of Hydrophilidae and Dytiscidae. However, in contrast to the Hydrophilidae and Dytiscidae, little is known about the efficiency of Noteridae member predation (Ohba and Takagi , Mogi ), thus warranting further investigation. Meanwhile, members of Odonata exhibited a consistent trend of occurrence with mosquito larvae in habitats with abundant macrophytes (Table ), possibly due to the greater proportion of Zygoptera than Anisoptera, the former of which are considered less efficient mosquito predators (Venkatesh and Tyagi ).…”

Abundance, Diversity, and Seasonal Population Dynamics of Aquatic Coleoptera and Heteroptera in Rice Fields: Effects of Direct Seeding Management

“…This might be attributed to the higher abundance of invertebrate prey associated with DS Þelds. Diving beetles feed on a variety of invertebrates, such as mosquito larvae, Odonata nymphs, backswimmers, diving beetle larvae, and isopods (Kehl andDettner 2003, Ohba 2009a,b;Ohba and Takagi 2010). Numerous invertebrate preys, including water beetles and bugs, may support the high density of diving beetle populations in DS Þelds.…”