Toxicity, Sublethal and Low Dose Effects of Imidacloprid and Deltamethrin on the Aphidophagous Predator Ceratomegilla undecimnotata (Coleoptera: Coccinellidae).

Ceratomegilla undecimnotata (Coleoptera: Coccinellidae) is a common aphidophagous coccinellid predator used in biological control against aphid pests. Knowing toxicity, lethal, and sublethal effects of insecticides on natural enemies is essential in order to incorporate them into Integrated Pest Management (IPM). In the present study, the lethal and sublethal effects of imidacloprid and deltamethrin were evaluated on the fourth instar larvae of C. undecimnotata and subsequently on the full life cycle. Our results strongly suggest that sublethal and low doses of imidacloprid and deltamethrin at LD10 and LD30 affected fourth instar larvae duration time, adult preoviposition period, total preoviposition period, and fecundity. Moreover, the intrinsic (r) and finite (λ) rate of increase and the net reproduction rate (R0) significantly decreased in populations treated with imidacloprid compared to the control population. The data clearly suggest that imidacloprid and deltamethrin have a negative influence on population growth parameters of C. undecimnotata at sublethal and low doses and, therefore, these insecticides should be used with caution within the context of IPM.

Lethal and sub-lethal effects of imidacloprid on the aphidophagous coccinellid hippodamia variegata.

Hippodamia variegata is one of the most abundant ladybird species in Greece, preying on several aphid species and other arthropods, of which many are pests of cultivated plants. Imidacloprid, a neonicotinoid insecticide, is commonly used for controlling sucking insects; at the same time, however, it can cause various sub-lethal effects on non-target organisms. The development of IPM programs against pests requires an evaluation of the side effects of insecticides on natural enemies. We evaluated the sub-lethal effects of imidacloprid on H. variegata. Our results demonstrate that imidacloprid at a LC10 (3.92 mg (a.i.) L-1 and LC30 (8.69 mg (a.i.) L-1) decreased adult longevity and survival rate. In addition, demographic parameters, such as the intrinsic rate of increase (r), finite rate of increase (λ) and net reproductive rate (R0), were reduced when exposed to sub-lethal concentrations of imidacloprid. These results demonstrate a negative influence of imidacloprid at sub-lethal concentrations on H. variegata which could reduce biological control services provided by this predator.

Left atrial remodeling in patients younger than 70 years with diastolic and systolic heart failure.

OBJECTIVE: We sought to determine left atrial (LA) volume and systolic function (LA remodeling) in younger (<70 years) patients with systolic and diastolic heart failure (HF). METHODS: In all, 32 patients with diastolic HF (left ventricular [LV] ejection fraction > or = 0.50), 26 patients with systolic HF (LV ejection fraction < 0.50), and 48 control subjects were studied. LAlpha volume (cm(3)/m(2)) was echocardiographically determined at mitral valve opening (maximal), mitral valve closure (minimal), and atrial systole (electrocardiographic Rho wave) using the biplane area-length method. The LA active emptying fraction (%) and ejection force (kdyne/m(2)) served as indices of LA systolic function. RESULTS: LA maximal volume was greater in systolic HF than diastolic HF and in the latter greater than control (68.6 +/- 13.8 vs 52 +/- 11.6 vs 42.9 +/- 14.4, respectively, P < .0001). Active emptying fraction was similar between diastolic HF and control, and greater than systolic HF (31.5 +/- 8.1 vs 36.3 +/- 7 vs 26.6 +/- 6.2, respectively, P < .0001), whereas LA ejection force was similar in diastolic and systolic HF and greater than control (5.05 +/- 1.3 vs 4.98 +/- 2.17 vs 3.63 +/- 2.05, respectively, P = .001). Vmax was related to body surface area, brain natriuretic peptide, and LV mass in diastolic HF (multiple R2 = 0.74) and to diastolic blood pressure, LV mass, and early to late transmitral flow velocity ratio in systolic HF (multiple R2 = 0.96). CONCLUSIONS: LA remodeling is more severe in systolic HF than diastolic HF and governed by different mechanisms. This may be of significant clinical relevance regarding the morbidity and mortality of these two conditions.