Revista Brasileira de Entomologia Revista Brasileira de Entomologia
Rev Bras Entomol 2017;61:257-61 - Vol. 61 Núm.3 DOI: 10.1016/j.rbe.2017.05.003
Biology, Ecology and Diversity
Biology of Blepyrus clavicornis (Compere) (Hymenoptera: Encyrtidae), a parasitoid of Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae)
Vitor Pacheco da Silvaa,b,, , Mauro Garciaa, Marcos Bottonb
a Universidade Federal de Pelotas, Pós-Graduação em Fitossanidade, Departamento de Fitossanidade, Pelotas, RS, Brazil
b Embrapa Uva e Vinho, Bento Gonçalves, RS, Brazil
Recebido 28 Novembro 2016, Aceitaram 24 Maio 2017
Abstract

Encyrtids (Hymenoptera: Encyrtidae) are the most important and diverse group of natural enemies of mealybugs (Hemiptera: Pseudococcidae). Blepyrus clavicornis (Compere) is the most common parasitoid associated with Pseudococcus viburni (Signoret) in the Serra Gaúcha region, Brazil. We conducted laboratory studies to assess the development time, sex ratio, adult longevity, host stage selection for parasitism, and effect of food on the longevity of adult females of B. clavicornis. The experiments were conducted in a climate chamber at 25±1°C, 70±10% RH and 12:12 L:D photoperiod. The solitary parasitoid B. clavicornis parasitized third-instar and adult female stages of P. viburni. The development time was more than 30 days (31.75±0.38 for females and 30.02±0.34 for males) when B. clavicornis laid eggs in adult mealybug females, and 35 days (36.50±0.50 for females and 34.24±0.43 for males) on third-instar mealybug nymphs. The wasps did not survive longer than four days when they were fed only water, while females survived for about 30 days when fed with honey. The lifespan of females is about 20 days longer than the lifespan of males. Although B. clavicornis can provide significant natural control, reducing the number of individuals in the next generation by parasitizing advanced mealybug instars, we consider it unpromising for use in applied biological-control programs. Furthermore, the predominance of males in the progeny observed here suggests that P. viburni may not be the most suitable or preferred host for B. clavicornis.

Keywords
Biological control, Chalcidoidea, Obscure mealybug, Parasitism
Rev Bras Entomol 2017;61:257-61 - Vol. 61 Núm.3 DOI: 10.1016/j.rbe.2017.05.003