Whitefly (Bemisia tabaci) damages field crops by sucking sap and transmitting viral diseases. None of the insecticidal proteins used in genetically modified (GM) crop plants to date are effective against whitefly. We report the identification of a protein (Tma12) from an edible fern, Tectaria macrodonta (Fee) C. Chr., that is insecticidal to whitefly (median lethal concentration = 1.49 μg/ml in in vitro feeding assays) and interferes with its life cycle at sublethal doses. Transgenic cotton lines that express Tma12 at ∼0.01% of total soluble leaf protein were resistant to whitefly infestation in contained field trials, with no detectable yield penalty. The transgenic cotton lines were also protected from whitefly-borne cotton leaf curl viral disease. Rats fed Tma12 showed no detectable histological or biochemical changes, and this, together with the predicted absence of allergenic domains in Tma12, indicates that Tma12 might be well suited for deployment in GM crops to control whitefly and the viruses it carries.

The functional response parameters and patterns of three coccinellid predators, Cheilomenes sexmaculata, Propylea dissecta, and Coccinella transversalis (Coleoptera: Coccinellidae) were evaluated to find out how these predators respond at two different prey species across various prey densities levels. All three predators exhibited a decelerating curve Type II response determined by a logistic regression model. The linear reciprocal transformation of Holling's disc equation was used to further evaluate the parametric values. C. sexmaculata responded maximally, followed by C. transversalis and P. dissecta, in terms of consumption of the aphids, Aphis craccivora and Myzus persicae, with suitable values of coefficient of attack rates and handling times on these prey species. Differences in handling times were found to be significant within and between the predatory species on both prey species indicating that predators respond differentially to prey species. Differences in coefficients of attack rates, however, did not vary significantly in most of the treatments. The potential role of these predators in biocontrol of A. craccivora and M. persicae suggests that C. sexmaculata is the best predator for the management of both prey species, particularly A. craccivora. However, further field based studies are needed to confirm this hypothesis.

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Abstract. The reproductive behaviour of a ladybeetle, Coccinella septempunctata was studied in detail. Males became sexually mature within 8.8 ± 0.3 days at 27°C, while females took 11.2 ± 0.4 days. Males exhibited courtship display in five steps: approach, watch, examine, mount and copulatory attempt. A prominent rejection display was shown by certain females who had not matured sexually, had recently mated or were about to oviposit. Males appeared to recognize females through chemical and some visual cues, such as size and body shape, with the chemical cues possibly playing a more significant role. Multiple matings took place within the same day. There was a gradual decrease with time in reproductive parametres, such as the duration of copulation, the number of copulatory bouts and the latent period from first to subsequent matings on the same day. The interval between mating bouts slightly increased from first to subsequent matings. The sexual status of males and females affected the duration of copulation, which was greatest in the case of unmated males and virgin females. Multiple matings increased the oviposition period, fecundity and percent hatching of eggs.