Leaf consumption by Diabrotica speciosa (Coleoptera: Chrysomelidade) adults on difFerent host plants

Abstract

Studies related to the feeding behavior of pest insects provide information that will aid the development of control tactics. Leaf consumption by Diabrotica speciosa adults fed on bean, corn, potato and soybean was determined in the laboratory under free-choice (multiple or double-choice) and no-choice (confinement) conditions. In the multiple-choice tests leaf circles were randomly arranged in a circular pattern (arena) inside Petri dishes. The degree of preference for the hosts was determined under double-choice conditions, where common bean was considered the standard host and the remaining plants (soybean, potato and corn) as test hosts. In all trials, two Diabrotica speciosa couples were released and maintained within the dish for 24 hours; the leaf area consumed by the insects was determined after this feeding period. Food type (host) influenced leaf area consumption by D. speciosa adults both in free-choice and in no-choice tests (P < 0.05). Under freechoice conditions, the insects preferred to feed on bean rather than on soybean, potato or corn, with no differences among these last three host plants (P > 0.05). As to the no-choice test, the consumption was higher for corn than for potato, probably to compensate the low nutritional quality of the first host. Key words: insect, root worm, host plant, food preference, food intake CONSUMO FOLIAR POR ADULTOS DE Diabrotica speciosa (COLEOPTERA: CHRYSOMELIDAE) EM DIFERENTES HOSPEDEIROSRESUMO: Estudos relacionados ao comportamento alimentar dos insetos-pragas, podem fornecer informações que auxiliam no desenvolvimento de táticas visando seu controle. Foi determinado, em laboratório, o consumo foliar por adultos de Diabrotica speciosa, quando alimentados com folhas de feijoeiro, milho, batata e soja, sob condições de livre escolha (múltipla e dupla escolha) e sem chance de escolha (confinamento). Nos testes de múltipla escolha, círculos foliares foram dispostos, ao acaso, num arranjo circular (arena) em placas de Petri. O grau de preferência dos hospedeiros foi determinado em condições de dupla escolha, considerandose o feijoeiro a espécie padrão e os demais hospedeiros (soja, batata e milho) como plantas testes. Para todos os testes, dois casais de D. speciosa foram liberados no interior da placa e aí mantidos por 24 horas, determinadose, após esse período, a área foliar consumida pelos insetos. O tipo de alimento (hospedeiro) oferecido aos adultos de D. speciosa influenciou o grau de consumo foliar tanto nos testes de livre escolha como nos de confinamento (P < 0.05). Nos testes de livre escolha, os insetos preferiam se alimentar de folhas de feijoeiro em relação às de batata, soja e milho, sem diferir significativamente entre estas últimas. Em condições de confinamento o consumo foliar é maior em milho do que em batata, provavelmente como compensação pela baixa qualidade nutricional da gramínea em relação às leguminosas.

Biology, Reproductive Capacity, and Foliar Consumption of Diabrotica speciosa (Germar) (Coleoptera: Chrysomelidae) in Different Host Plants

“…On the other hand, in confinement, the insects fed on other plants, but common bean was preferred again only in relation to forage turnip or corn. Similar results were found by Ávila and Parra (2003) who observed that common bean leaves were more consumed by adult of D. speciosa in contrast to those fed on potato, soybean, and corn under free-choice conditions. However, these authors observed that in confinement there was greater consumption of potato than corn, with intermediate values observed for common bean and soybean.…”

“…Nutritional quality, as well as the phenological age of the host available during the larval and adult stages of D. speciosa can interfere in its biology and reproductive capacity and, consequently, in the potential damage caused to crops (Panizzi & Parra, 2009;Ávila & Parra, 2003;Cohen, 2015). Wherefore, studies of this nature may assist in the understanding of factors that determine the population dynamics of insects in crop systems, thus contributing to the enhancement and development of management strategies.…”

“…Many ecological, physiological, and behavioral processes exhibited by the insects are related to the nutritional context (Cohen, 2015). Thus, it is extremely important to know the behavior, food preference, dietary habits, and nutritional needs of these insects and their consequences on growth, survival, longevity, and reproduction (Panizzi & Parra, 2009;Ávila & Parra, 2003). The objective of this paper was to evaluate the influence of different host plants offered during the larval and adult stages of D. speciosa on their development, reproductive capacity, and foliar consumption.…”

Comportamento alimentar de adultos de Diabrotica speciosa na presença de extratos aquosos de Meliaceae

“…Estudos relacionados ao comportamento alimentar dos insetos-praga podem fornecer informações que auxiliam no desenvolvimento de novas formas de controle (ÁVILA & PARRA, 2003).…”

Effect of temperature and species of plant on the consumption of leaves by three species of Orthoptera under laboratory conditions

“…The area of each leaf provided to the insects was measured by scanning the area of the leaf using a computer and software Delta-T SCAN (Version 2.04nc, Delta-T Devices Ltd., Burwell, Cambridge, UK). Insects were permitted to feed for 24 h and then removed and the area of leaf consumed by each individual was determined by measuring the area of the leaf again (Shields et al, 1985;Ávila & Parra, 2003). Insects that became less active during or after testing were replaced and the measurements for these insects were not included in the analysis.…”