Status of pigeonpea as an alternative host of Piezodorus guildinii (Hemiptera: Pentatomidae), a pest of soybean

• Published in: The Florida entomologist 2000-09, Vol.83 (3), p.334-342
• Main Authors: Panizzi, A.R, Cardoso, S.R, Oliveira, E.D.M
• Format: Article
• Language: English
• Subjects: Adult insects; alternative hosts; biological development; body weight; Brazil; Cajanus cajan; fecundity; feeding preferences; Female animals; Food; Glycine max; host plants; Immatures; Instars; Legumes; Longevity; mortality; Nymphs; oviposition; Pentatomidae; Piezodorus guildinii; population density; reproduction; seasonal abundance; seasonal variation; Soybeans; Stink bugs
• ISSN: 0015-4040; 1938-5102
• DOI: 10.2307/3496352

Pigeonpea, Cajanus cajan (L.) Millsp. (Leguminosae), was found hosting Piezodorus guildinii (Westwood) (Hemiptera: Pentatomidae) in Paraná State, Brazil. In the laboratory, nymphs performed better on immature pods of soybean, Glycine max (L.) Merrill (Leguminosae), than on immature pods of pigeonpea. Although nymphs required similar time to complete development, and attained similar weights at adult emergence, mortality was much lower on soybean (57.7%) than on pigeonpea (94.4%). Adult P. guildinii also performed better on soybean than on pigeonpea. Females and males showed similar longevity on both foods, but 34.5% of females oviposited on soybean compared to 10.3% on pigeonpea, with an oviposition delay of 26 days on pigeonpea compared to soybean. Fecundity (eggs/females) was 6.5× greater on soybean than on pigeonpea, and adult body weight gain after 14 and 28 days was 13-23% greater on soybean than on pigeonpea. P. guildinii also showed greater feeding activity on, and greater feeding preference for, soybean than pigeonpea. Bugs colonized soybean during summer and early autumn (January-March), and pigeonpea during autumn, early winter (April-July), and spring (October-November). These results indicate that pigeonpea, although a less preferred and less suitable plant food source of P. guildinii in Brazil, plays an important role to the bug's life history by serving as a temporary host. /// O guandu, Cajanus cajan (L.) Millsp. (Leguminosae) foi encontrado abrigando Piezodorus guildinii (Westwood) (Hemiptera: Pentatomidae) no Estado do Paraná, Brasil. Em laboratório, as ninfas tiveram um desempenho melhor quando alimentadas com vagens imaturas de soja, Glycine max (L.) Merrill (Leguminosae), do que quando alimentadas com vagens de guandu. Embora as ninfas tenham requerido um tempo semelhante para completar o desenvolvimento e obtido pesos semelhantes na emergência, a mortalidade foi menor em soja (57,7%) do que em guandu (94,4%). Os adultos de P. guildinii mostraram um desempenho melhor em soja do que em guandu. Fêmeas e machos tiveram longevidades semelhantes em ambos alimentos; 34,5% das fêmeas ovipositaram em soja e 10,3% em guandu, com um atrazo na oviposição de 26 dias no guandu em comparação com a soja. A fecundidade (ovos/fêmeas) foi 6,5× maior em soja do que em guandu, e o ganho de peso dos adultos após 14 e 28 dias foi de 13 a 23% maior em soja do que em guandu. P. guildinii também mostrou maior atividade alimentar em, e maior preferência alimenta