ABSTRACT
ABSTRACT: In order to manipulate the mass rearing of natural enemies, temperature variations can be used. The effects are widely studied for their survival and developmental duration; however, there is little information about their reproductive system in the literature. Therefore, the purpose of this study was to evaluate the effects of different temperatures on the reproductive system of the predator Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae). The predator was kept at temperature conditions of 17, 21, 25, and 29 °C until reaching 15 days of age, the adult stage. The insects were then killed, measured for both weight and size, dissected, and then evaluated for the following parameters: length of the most developed ovariole; number of ovarioles per ovary; number of oocytes per the more developed ovarioles; number of oocytes per P. nigrispinus female; and the total area of the testicles was measured in the male insects. Results showed that as the temperature increased, the parameters were positively affected. These temperature variations can be used to manipulate the mass rearing of P. nigrispinus under controlled conditions.
RESUMO: As variações de temperatura podem ser utilizadas para manipular a criação massal de inimigos naturais e seus efeitos são amplamente estudados para a sobrevivência e duração de desenvolvimento, porém, existem poucas informações sobre o sistema reprodutivo na literatura. Por isso, o objetivo desse trabalho foi avaliar os efeitos de diferentes temperaturas sobre o aparelho reprodutivo do predador Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae). O predador foi mantido nas temperaturas de 17, 21, 25 e 29 °C até atingir 15 dias de idade na fase adulta. Esses insetos foram mortos, medido o peso e tamanho, dissecados e avaliados nos seguintes parâmetros: comprimento do ovaríolo mais desenvolvido; número de ovaríolo por ovário; números de ovócitos por ovaríolo mais desenvolvidos; número de ovócitos por fêmea; e, nos machos, área total do testículo. Os resultados evidenciaram que a medida que aumenta a temperatura os parâmetros foram afetados positivamente. Essas variações de temperatura podem ser utilizadas para manipular a criação massal de P. nigrispinus em condições controladas.
ABSTRACT
Cryopreservation protocols have been developed for eggs of Diptera, Lepidoptera, and Hymenoptera; however, for Heteroptera, such as Podisus nigrispinus Dallas, 1851 (Pentatomidae), no procedures have been described yet. The objective of this study was to evaluate the processes of dechorionation and permeabilization on the viability of eggs of P. nigrispinus with different embryonic ages. In the laboratory, embryos of 24, 48, 72, and 96 h of age were submitted to sodium hydroxide, sodium hypochlorite, isopropyl, and hexane solutions for dechorionation and permeabilization. The experiment was carried out in a 4 × 8 factorial scheme. Sodium hydroxide affects embryo viability; however, 96-h-old embryos showed higher viability when compared with 24, 48, and 72-h-old embryos. Microscope observations showed that, after the treatments, the chorion of P. nigrispinus eggs was reduced to 5.11 ± 0.30 µm. These solutions for dechorionation and permeabilization of P. nigrispinus eggs together with embryonic age affect the viability of embryos to be cryopreserved.
Subject(s)
Cryopreservation/methods , Heteroptera/physiology , Ovum , Pest Control, Biological , 2-Propanol/chemistry , Animals , Hexanes/chemistry , Insect Control , Sodium Hydroxide/chemistry , Sodium Hypochlorite/chemistryABSTRACT
Heraclides anchisiades capys (Hübner, [1809]) (Lepidoptera: Papilionidae) is an abundant insect pest on crops of Citrus spp. (Rutaceae) in Brazil and pupae of this defoliator could be used for the mass rearing of parasitoids. The aim of this study was to evaluate the parasitism of Palmistichus elaeisis Delvare & LaSalle, 1993 (Hymenoptera: Eulophidae) on H. anchisiades capys pupae in the laboratory. Twenty 1-day-old H. anchisiades capys pupae were individualized in test tubes (14 cm length x 2.2 cm diameter) with a drop of honey as food and with ten mated P. elaeisis females for ten days. The duration of the life cycle (egg to adult), emergence rate, total individuals emerged per pupa, sex ratio, size of the body and longevity of P. elaeisis males and females emerged from H. anchisiades capys pupae were evaluated. The duration of the life cycle of P. elaeisis was 21.15 +/- 0.15 days. Forty percent of H. anchisiades capys pupae showed emergence of parasitoids, with an average of 323 +/- 38 individuals from each one and a sex ratio of 0.95 +/- 0.02. The total number of parasitoids emerged was 2,584 individuals. The size of the body and the head capsule (mm) of female and male P. elaeisis progeny were 1.92 +/- 0.04; 0.52 +/- 0.02 and 1.28 +/- 0.04; 0.40 +/- 0.02, respectively. The average longevity was 23.72 +/- 1.15 days for females and 30.1 +/- 2.42 days for males of P. elaeisis. Heraclides anchisiades capys, abundant on crops of Citrus spp. in Brazil, has potential to be used as a host for mass rearing of P. elaeisis in the laboratory for biological control programs.
