Direct and indirect effects of a predatory backswimmer (Notonecta maculata) on community structure of desert temporary pools
Article first published online: 14 MAR 2008
Volume 20, Issue 4, pages 311–318, November 1995
How to Cite
BLAUSTEIN, L., KOTLER, B. P. and WARD, D. (1995), Direct and indirect effects of a predatory backswimmer (Notonecta maculata) on community structure of desert temporary pools. Ecological Entomology, 20: 311–318. doi: 10.1111/j.1365-2311.1995.tb00462.x
- Issue published online: 14 MAR 2008
- Article first published online: 14 MAR 2008
- Accepted 12 July 1995
- Culiseta longiareolata;
- mosquito larvae;
- temporary pools;
- trophic cascade
- 1We assessed experimentally the effects of the predatory backswimmer, Notonecta maculata, on naturally colonizing mosquito populations in artificial outdoor pools in the Negev Desert, Israel. A single Notonecta adult per pool (8–15 litres water) had a very large negative impact on populations of Culiseta longiareolata, the most common species found in natural local pools. Notonecta caused large reductions of Culiseta egg rafts and early-instar larvae (instars I and II) and virtually 100% reductions of late-instar Culiseta larvae (instars III and IV) and pupae.
- 2Notonecta also caused a trophic cascade in the experimental pools; by preying on periphyton-feeding Culiseta larvae, Notonecta indirectly caused significantly higher densities of diatoms, the major component of the periphyton.
- 3Surveys of nearby natural pools taken between March and May supported the experimental results: a strong negative association between Notonecta and Culiseta among pools occurred as Notonecta increased in numbers and became more widely distributed. Anopheles (occurring only in May) and Culex mosquito immatures were not negatively associated with Notonecta. Culiseta was not associated with surface vegetation whereas both Culex and Anopheles showed strong positive associations with surface vegetation both among and within pools. We attribute the negative association between the predator and Culiseta to local prey extinctions caused by Notonecta in individual pools. Culiseta, being an open water species, is apparently more prone to predation by Notonecta than the vegetation-dwelling Culex and Anopheles.