Biologia de Hippodamia convergens Guerin-Meneville, 1824 e Coleomegilla maculata (DeGeer, 1775) (Coleoptera: Coccinellidae) sobre ovos de Anagasta kuehniella (Zeller, 1879) (Lepidoptera: Pyralidae) e sobre os pulgoes Schizaphis graminum (Rondani, 1852) e Brachycaudus (Appelia) schwartzi Borner, 1931 (Homoptera: Aphididae)

Abstract

The work aimed to invetigate the biology ofHippodamia convergem and ColeomegiUa maculata on the three preys type. The experiment was set in the Laboratory of Insect Biology (temperature 25 ± 1°C; 70 ± 10% RH; 12 hour photoperiod) at Plant Protection Departament at Universidade Federal de Lavras, Minas Gerais State, Brazil. As food for larvae, wereused eggs of Anagasta kuehnieüa and the aphids Schizaphis graminum and Brachycaudus (Appelia) schwartzi. As food for the adults was used aphid S graminum. The larvae of H. convergem and C maculata were reared on the tested foods showed four larval instars. The aphid 5. graminum provided for H. convergem the shortest lenght ofthe Ia, 2nd and 3*0 instar, ofthe larval phase, and in the duration ofthe period oflarva to adult and biological cycle. This result, however, it only was observed in third instar larval, larval phase, and inthe duration ofthe period from larva to adult and the biological cycle of C maculata reared on A. kuehnüla eggs. The viability ofeggs, Ia, 2a* , 3™1 and 4ainstar, pre-pupa, pupa and the period from larva to adult, of H convergem and C maculata was not effectedby the type offood on which they were reared. The aphid S. graminum, as a food for larvae ofH convergens, maked them to bear adults with larger average weight. The preys given the larvae of C maculata did not show any influence on the average weight ofthe adults. There were no influence ofthe foods utilized in larvae rearing to both coccinellid H convergem and C maculata, at the sex ratio, in the period of preoviposition, oviposition, post-oviposition and embryonic, also on longevity and fecundity. In this study, larvae feeding didnot affect the adultphase ofH convergem and C maculata. Therefore the A kuehnieüa eggs can be used as a substitute food, regarding the aphids & graminum and R schwartzifood for rearing oflarvae of H. convergem and C. maculata. Tested preys can be considered as a suitable food for the larval development, and the aphid & graminum can be utilized in rearing adults of H. convergens and C maculata. at least in the fírst generation, as observed in this study.