ABSTRACT
The egg parasitoid Cleruchoides noackae Lin & Huber, 2007 (Hymenoptera: Mymaridae) is originated from Australia and the main biological control agent of Thaumastocoris peregrinus Carpenter & Dellapé, 2006 (Hemiptera: Thaumastocoridae) on Eucalyptus L'Hér (Myrtaceae). Companies that grow Eucalyptus are in need of a mass rearing protocol to increase the number of individuals produced and improve the quality of this parasitoid. The aim of this study was to define a protocol for mass rearing C. noackae in T. peregrinus eggs, based in the evaluations of the key biological attributes of this parasitoid in the parental and F1 generations, after the cold storage of the parasitised host eggs. Two methods were tested as C. noackae rearing protocols. In the first, parasitised eggs of T. peregrinus by C. noackae were cold stored for 7 days after being left in a climatic chamber at 24 ± 2°C, 60 ± 10% RH and a photoperiod of 12:12 (light:dark) h (standard environmental conditions) for 3, 6, 9 or 12 days. In the second, T. peregrinus eggs parasitised by C. noackae were maintained in a climatic chamber under standard environmental conditions for 6 days, after which these eggs were cold-stored for 0 (control), 7, 14 or 21 days. Parasitism (%), and the development period (parasitism to adult) and female proportion (%) of C. noackae were evaluated. Based on the results (parental generation: parasitism, around 45%; F1 generation: parasitism, around 55%; development period, around 16 days; female proportion, around 60%), eggs should be stored at 5°C on the sixth day after parasitism by C. noackae and maintained at this temperature for 7 days. The cold storage of T. peregrinus eggs, after parasitism, can be included in the mass rearing protocols of the parasitoid C. noackae.
Subject(s)
Eucalyptus , Heteroptera , Hymenoptera , Wasps , Female , Animals , Cold Temperature , Temperature , OvumABSTRACT
The olive fruit fly, Bactrocera oleae, is considered the main olive pest worldwide, and has been the target of biological control programmes through the release of the braconid parasitoid Psyttalia concolor. Laboratory tests were performed to evaluate the influence of distance from the host on parasitisation, placing larvae of the substitute host Ceratitis capitata at seven distances (0, 0.5, 1, 1.5, 2, 2.5, 3 mm) and four different time periods (7, 15, 30, 60 min). Moreover, field collected olives of Ogliarola Barese cultivar infested by B. oleae were exposed to P. concolor females to confirm its ability to parasitise B. oleae in small olives. Psyttalia concolor oviposition was inhibited at 2.5 and 3 mm due to the ovipositor length of the parasitoid females (2.7 mm). Hosts were easily parasitised at distances between 0 and 1.5 mm. The thin fruit pulp (up to 3.5 mm) of field collected olives allowed the parasitisation to occur also in mature fruits. At the best combination distance/time (0 mm, 30 min), tests performed with different larvae/parasitoid female ratio showed an increasing emergence of P. concolor (from 20% to 57%) with larvae/parasitoid ratio increasing from 0.11 to 0.74. The results of the present study might optimise the mass rearing of P. concolor, through a proper setting of its parameters, such as the host/parasitoid ratio, exposure distances, and interaction time.
ABSTRACT
The temperature is among the abiotic factors that directly affect the developmental time and behavior of insects. The adaptability to climatic conditions is a key point for the success of mass-rearing and establishment of parasitoids in biological control programs. The objective of this study was to evaluate the developmental time and parasitism of Lysiphlebus testaceipes (Cresson) on Aphis gossypiiGlover as host in different temperatures. The tests were carried out in climatic chambers at 15, 20, 25 and 30 ± 1°C, 60 ± 10% RH and 10h photophase. Parasitized nymphs of A. gossypii were kept individualized in petri dishes (6 cm of diameter) on a leaf disk (2 cm diameter) of chrysanthemum (Dendranthema grandiflorum Tzvelev) Yellow Snowdon cultivar on a layer of agar. The developmental time of L. testaceipes was 26.9, 14.8, 11.3 and 12.2 days at 15, 20, 25 and 30ºC, respectively. Parasitism rates were 76, 68, 65 and 40% at 15, 20, 25 and 30°C, and emergence rates were 80, 61, 62 and 14% at these temperatures. The combination of a low developmental time (11.3 days) and parasitism and emergency higher than 60% occurred at 25ºC, indicating that this temperature could be the most adequate for reproduction and establishment of L.testaceipes as a biological control agent of A. gossypii in protected cultivation.
A temperatura está entre os fatores abióticos que influenciam o desenvolvimento e o comportamento dos insetos. A adaptabilidade às condições climáticas é um dos pontos chaves para o sucesso da multiplicação e estabelecimento de parasitóides em programas de controle biológico. Estetrabalho teve como objetivo avaliar o desenvolvimento e o parasitismo de Lysiphlebus testaceipes (Cresson) em diferentes temperaturas, tendo como hospedeiro Aphis gossypii Glover. Os testes foram conduzidos em câmaras climáticas nas temperaturas de 15, 20, 25 e 30 ± 1°C, 60 ± 10% UR e fotofase de 10h. Cada ninfa hospedeira parasitada foi individualizada em placa de Petri (6 cm de diâmetro), contendouma camada de agar-água e um disco foliar (2 cm de diâmetro) de crisântemo (Dendranthema grandiflorum Tzvelev) cultivar Yellow Snowdon. O período de desenvolvimento de L. testaceipes foide 26,9; 14,8; 11,3 e 12,2 dias nas temperaturas de 15, 20, 25 e 30ºC, respectivamente, e a porcentagem deemergência foi de 80, 61, 62 e 14% nas mesmas temperaturas. A taxa de parasitismo foi de 76, 68, 65 e 40%nas temperaturas de 15, 20, 25 e 30°C, respectivamente. A combinação do menor período de desenvolvimento e da porcentagem de parasitismo e de emergência maiores que 60%, encontrados a 25ºC, indicam que essa temperatura é a mais indicada para multiplicação e estabelecimento de L.testaceipes como agente de controle biológico de A. gossypii em ambientes protegidos.
ABSTRACT
O objetivo da pesquisa, visando otimizar a criação de Ageniaspis citricola Logvinovskaya (Hymenoptera: Encyrtidae) em laboratório, foi estudar a capacidade de parasitismo e desenvolvimento do parasitóide a 20, 25 e 30°C. Em testes de livre escolha e confinamento o parasitismo foi semelhante em ovos ou lagartas de 1° ínstar de Phyllocnistis citrella Stainton. A capacidade de parasitismo foi semelhante nas três temperaturas, embora tenha havido diferenças nos outros parâmetros principalmente quanto à duração do período ovo-adulto, que foi 23,6 dias a 20°C, 18,1 dias a 25°C e 13,8 dias a 30°C. A temperatura de 25°C foi a mais adequada para criação do inseto em laboratório, por proporcionar maior sobrevivência, e produzir maior número de pupas por ovo parasitado. Embora a 20°C os resultados tenham sido muito próximos, não se recomenda tal temperatura, pois nesta condição há um alongamento do ciclo e, conseqüentemente, menor número de indivíduos produzidos.
In order to optimize rearing of Ageniaspis citricola Logvinovskaya (Hymenoptera: Encyrtidae) in laboratory the parasitism capacity of the parasitoid was evaluated at 20, 25 and 30°C. After determining that the parasitism was similar in eggs and 1st-instar larvae of Phyllocnistis citrella Stainton in free-choice and no choice tests, the study of the development of the parasitoid on eggs was preferred for the readiness of acquiring and handling this stage of the parasitoid development. The parasitism capacity was similar at all three temperatures, although differences occurred in the other parameters especially the duration of the egg-adult period (23.6 days to 20°C, 18.1 days to 25°C and 13.8 days to 30°C), decreasing with the thermal elevation. However, considering the aim of this work, the 25°C temperature is more adequate for rearing the insect in laboratory for providing higher survival and produced a higher number of pupae per parasitized egg. Although the results at 20°C were very close, such temperature is not recommended because the cycle is extended with a consequent lower number of individuals produced.
