ABSTRACT Sugarcane-associated nematodes (Saccharum spp.) can reduce productivity up to 50%. Through the survey, it was possible to identify the main nematodes that occur in a certain region as a tool for designing the best management and control strategies. The aim of this study was to characterize the population of nematodes associated with sugarcane in the North Central, North Pioneiro and Northwest mesoregion of the state of Paraná, Brazil, quantify the nematode genera associated with the crop and identify the species of Pratylenchus and Meloidogyne. A total amount of 89 soil and root composite samples were collected in nine municipalities. Nematodes were extracted and counted in a Peters counting chamber under an optical light microscope. Morphological description followed identification keys. Pratylenchus spp. were identified by morphological characteristics; Meloidogyne spp. were identified by morphological characteristics and isoenzyme electrophoresis. Twelve genera of nematodes associated with sugarcane were identified: Pratylenchus, Meloidogyne, Helicotylenchus, Xiphinema, Mesocriconema, Trichodorus, Aphelenchus, Hoplolaimus, Tylenchus, Tylenchorhynchus, Ditylenchus, and Paratrichodorus. The genera Pratylenchus and Meloidogyne were found with the highest frequencies in the roots. Among the species of Pratylenchus, P. zeae and P. brachyurus were found, with P. zeae being the most frequent. Among the Meloidogyne species, only M. javanica was found. These results are essential to aid decision making in the management of phytonematodes, mainly in the development of new control strategies and in directing genetic breeding programs for development of sugarcane cultivars for the Paraná state.

A influência da temperatura sobre parâmetros biológicos de Trichogramma pretiosum Riley e Trichogrammatoidea annulata De Santis (Hymenoptera: Trichogrammatidae) foi avaliada à 15, 20, 25 e 30° C. Foi usado como hospedeiro ovos de Anagasta kuehniella (Lepidoptera: Pyralidae). A progênie de ambos parasitóidesapresentou um desenvolvimento similar quando submetidas a 20, 25 ou 30º C. T. annulata, contudo, apresentou um desenvolvimento ligeiramente mais rápido que T. pretiosum à 15° C. A porcentagem de emergência foi elevada para ambas espécies em todas as temperaturas, não havendo influência destas sobre o número de parasitóides emergindo por hospedeiro. O número de graus dia para desenvolvimento de T. pretiosum e T. annulata foi 126,9 e 122,3, respectivamente, e a temperatura base de desenvolvimento 11° C. A taxa de parasitismo aumentou com o aumento da temperatura, sendo máxima a 25° C. Fêmeas de T. annulata,entretanto, parasitaram um número significativamente maior de hospedeiros que T. pretiosum nas quatro temperaturas. A progênie de T. annulata foi constuída principalmente por machos, exceto a 15° C, enquanto que a de T. pretiosum por fêmeas, exceto a 30° C. A longevidade de ambas espécies de parasitóides diminuiu com o aumento da temperatura sendo que as fêmeas viveram por um periodo significativamente maior que os machos.

The influence of temperature on lifetime attributes of Trichogramma pretiosum Riley and Trichogrammatoidea annulata De Santis (Hymenoptera: Trichogrammatidae) was evaluated at four constant temperatures (15, 20, 25, and 30º C), RH 70 ± 10%, photophase 14 h. Anagasta kuehniella (Lepidoptera: Pyralidae) eggs were used as hosts. Developmental times of both parasitoid species were similar when exposed to 20, 25, or 30º C. T. annulata, however, developed slightly faster than T. pretiosum at 15º C. Emergence rates of both species were above 89%. The temperature threshold for T. pretiosum and T. annulata was 11º C and the number of degree-days required for their development was 126.9 and 122.3, respectively. Parasitization was maximal at 25º C. T. annulata, however, parasitized significantly more hosts than T. pretiosum in the entire temperature range. Temperature had no effect in brood size.T. annulata progeny consisted predominantly of males, except at 15º C, whereas in T.pretiosumitconsisted predominantly of females, except at 30º C. Parental females lived longer than males.