ABSTRACT:Corn rootworm Diabrotica speciosa is an important pest in several crops. The aim of this work was to study the biology of adult D. speciosa and build a fertility life table in the natural diet based on beans, and beans, sliced carrots and honey solution at 10%. The following parameters were: duration of pre-oviposition, oviposition and post-oviposition, total fertility, adult longevity and egg viability. For the fertility life table parameters, the following were determined: generation interval (T), net reproductive rate (Ro), intrinsic rate of increase (rm) and finite rate of increase (λ). From the results obtained, it can be observed that there was an influence of food offered to adults for the duration of pre-oviposition and oviposition, and also in total fertility and viability of eggs. Adult longevity was influenced by diet consisting of bean leaflets. Among the treatments, a diet consisting of beans, carrot and honey provided higher significant longevity of males compared to those fed with beans. The results in the fertility table indicated that the reproductive potential of D. speciosa significantly increases in two successive generations when females are fed on beans, carrots and honey, showing there is improved mass rearing for this insect under laboratory conditions. KEYWORDS: corn rootworm; reproduction rate; host plant. RESUMO:A vaquinha Diabrotica speciosa é uma importante praga em diversas culturas. O objetivo deste trabalho foi estudar a biologia de adultos de D. speciosa e construir a tabela de vida de fertilidade em dieta natural à base de feijão, e à base de feijão, rodelas de cenoura e solução de mel a 10%. Os parâmetros biológicos avaliados foram: duração dos períodos de pré-oviposição, oviposição e pós-oviposição, fecundidade total, longevidade de adultos e viabilidade dos ovos. Para a tabela de vida de fertilidade, os parâmetros determinados foram: intervalo entre gerações (T), taxa líquida de reprodução (Ro), taxa intrínseca de crescimento (rm) e taxa finita de aumento (λ). A partir dos resultados obtidos, pode-se constatar que houve influência do alimento oferecido aos adultos para os períodos de pré-oviposição e oviposição, e também na fecundidade total e na viabilidade dos ovos. A longevidade dos adultos foi influenciada pela dieta constituída de folíolos de feijão. A dieta constituída de feijão, cenoura e mel propiciou maior longevidade significativa dos machos em relação àqueles alimentados com feijão. Os resultados da tabela de fertilidade indicaram que o potencial de reprodução de D. speciosa aumenta significativamente em duas gerações sucessivas quando as fêmeas são alimentadas com feijão, cenoura e mel, demonstrando que há melhoria na criação massal desse inseto em condições de laboratório.

The potato a crop is attacked by many pests, among which the Diabrotica speciosa (Coleoptera: Chrysomelidae) is considered the main one. Because of chemical control failures associated with the requirements of integrated potato production (IPP) requiring sustainable measures, aimed to characterize advanced clones breeding program of Embrapa for resistance to insect infestation in artificial conditions. Tests were performed in a greenhouse without choice of plants and tubers of four clones of Embrapa (C2337-06-02, C2337-18-02, C2342-1-02, C2362-02-02), a standard-resistant clone (NYL 235-4) and a susceptible standard cultivar (Asterix). Results of susceptibility of 'Asterix' and resistance of 'NYL 235-4' and 'C2342-1-02', both in shoots and in tubers, predominated. Thus indicating a typical behavior of tolerance of 'NYL 235-4' and 'C2337-06-02' to insect attack, both in the shoots and in the tubers. Clones C2337-06-02 and C2362-02-02 which expressed resistance to the attack of the young stage of the insect in the tubers. Three potato genotypes derived from the wild species Solanum berthaultii (NYL 235-4, C2337-06-02, C2362-02-02) even under infestation of D. speciosa, showed agronomic traits determinants of greater commercial acceptance of tubers such as maintaining productivity, elongated, skin smoothness and shallower depth of the eye (vegetative bud).

No abstract

The Diabrotica speciosa (Germar) (Coleoptera: Chrysomelidae) is an important pest for several crops. The purpose of this work was to improve the method of rearing corn rootworm in lab conditions. Four systems were compared for rearing larvae, two with transference and two without transferring the larvae, constituted by maize seedling kept in peat and vermiculite. The following biological parameters were assessed: duration and feasibility in the adult-larva period, pre-oviposition and oviposition periods, males and females longevity, fertility and feasibility, net reproduction rate (Ro), average duration of a generation in weeks (T), innate capacity to increase in number (rm) and increase finite rate (λ) of D. speciosa adults. Based on the results obtained, it could be noticed that there was no influence of the substrates and rearing techniques used in the pre-oviposition and oviposition periods, males and females longevity and also in the whole fertility. However, there was effect on larval feasibility, where a higher feasibility was obtained in the treatment without transferring and with transference when peat and vermiculite were used as substrates, respectively; a bigger duration of the adult-larva period when the insects were reared in vermiculite substrate, regardless the transference; and in the feasibility of the eggs, which was higher in the treatment without transference for the two substrates. The results of the fertility table indicated that the reproduction potential of the D. speciosa significantly increases when the larvae are reared in peat without transference and vermiculite with transference.