Sexual maturity, lack of partner choice and sperm precedence in the promiscuous ladybird beetle Eriopis connexa (Germar): Who is my father?

Ladybird beetles present as key predator of many agricultural pests. Among them, Eriopis connexa stands out due some important traits for pest management programs such as common occurrence, population selected for resistance to pyrethroid insecticides, and possibility to be commercially available by rearing using alternative prey. Despite that, little is known about the role of polyandry and its effect on paternity in this species. Ladybird beetles engage in multiple matings, raising questions about the benefits of polyandry and paternity. We studied the selection of mating pair, sperm precedence, and offspring paternity by performing experiments on (1) the age of sexual maturity, (2) the frequency and refractory mating behavior within a photophase period, (3) the preference of insecticide-susceptible females to mate with either susceptible or resistant male phenotypes; and (4) the effect of multiple matings, on progeny paternity. Sexual maturity in E. connexa was found to begin within 3 days of adult emergence for both sexes, but fully developed after 5 days. The highest frequency of mating exhibited by sexual mature pairs occurred within first hour of pairing and the phenotype for insecticide resistance did not affect the choice of a mating partner. The resistance trait marker in the resistant beetle phenotype indicates that progeny paternity results from a mixture of available sperm and do not depend on mating order. These data suggest that released beetles would have a simple prospect for progeny production for both insecticide resistant and susceptible beetles.

Immature stages of the genus Casignetus MacLeay, 1819 (Coleoptera: Lucanidae: Lucaninae).

The immature stages of Casignetus MacLeay, 1819 (Coleoptera: Lucanidae: Lucaninae: Casignetini) are revised with the description of third instars of males and female of C. humboldti (Gyllenhal, 1817), and C. spixi (Perty, 1830), and female of C. lindei (Boileau, 1899). Pupae of both sexes of C. humboldti, and female of C. lindei are also described for the first time. Casignetus larvae can be recognized by the form of the pars stridens, formed by a slightly arched, longitudinal row of robust, and sclerotized teeth, and by the fusion of the femur and trochanter in prothoracic and mesothoracic legs. Additionally, new characters are proposed for Casignetus species: frontal sutures curvature; epicranial setae; epipharynx and hypopharynx setae; and number and shape of stridulatory teeth.