Female Oviposition Decisions and Their Impact on Progeny Life-History Traits

Abstract

An important factor affecting the life-history of an organism is parental investment in reproduction: reproductive decisions are almost invariably costly. Therefore, reproductive decisions should be beneficial in terms of increased offspring number or fitness. For example, egg laying decisions in many insects can influence resource availability of the offspring through changes in the larval density, and resource availability will have effects on many life-history traits. Here we studied whether female reproductive decisions affect offspring fitness in Callosobruchus maculatus seed beetles. Females laid more eggs on black-eye beans than on mung beans. However, when the difference in the surface area of the beans was accounted for, the number of eggs was not higher in black-eye beans. This together with the poisson distribution of eggs on each of the bean types suggests that females tend to lay their eggs randomly. We found that development time was longer, larval mortality lower and adult survival higher in black-eye beans. We also found interactions between bean type and larval density on size of the offspring such that in mung beans the emergence mass and pronotum width decreased with increasing larval density, but in black-eye beans larval density did not affect the size measures. We conclude that when there is a risk that larval denisty will become high within a bean and there is variable resources available, there exist clear benefits that females might obtain by choosing black-eye beans as a resource for their offspring. However, in contrast to many earlier studies, our results suggest that females may not be making any active oviposition decisions. Therefore, to unequivocally determine whether females do capitalise the potential benefits by active decision making, some further experimentation is required.

The Large Seed Size of Domesticated Lima Beans Mitigates Intraspecific Competition among Seed Beetle Larvae

“…Earlier studies with Phaseolus beans and various species of Bruchinae beetles, support our findings that seed size largely explains the observed patterns of oviposition and larval performance (Paukku and Kotiaho, 2008;Moreira et al, 2015;Oliveira et al, 2015;Hernandez-Cumplido et al, 2016). In a study aimed at examining the role of cyanogenic glycosides of Lima bean seeds on beetle performance, Shlichta et al (unpublished data) conducted an experiment similar to the one described here but allowing only one larva of Z. subfasciatus to develop in each seed.…”

Electrophysiological and behavioral responses of pea weevil Bruchus pisorum L. (Coleóptera: Bruchidae) to volatiles collected from its host Pisum sativum L

“…In contrast, female EAG responses between phenological stages of pea were not significant each other. This behavior may be founded on the insect female's need to find a suitable host that provides food and safety for the progeny (Paukku and Kotiaho, 2008). Our results permit to establish the olfactive perception of B. pisorum for its host, and several studies have support the hypothesis that the characteristic blend of volatile compounds produced by host plants are fundamental for species-specific attraction of herbivorous insects (Webster et al, 2010;Hare, 2011;Scala et al, 2013).…”

Attractant Effect of Eucalyptus globulus (Labill) and Foeniculum vulgare (Mill.) Essential Oils on Aegorhinus superciliosus (Guérin) (Coleoptera: Curculionidae)

“…Similarly, this response has been described for the bruchid C. maculatus when stimulated with the seed-extract of their host plant Vigna unguiculata (Linnaeus) Walp. The higher antennal response in females could be related with their oviposition behavior (Adhikari et al 2002;Paukku and Kotiaho 2008). In agreement with our results, anethole produced a dose-dependent (0.6 to 4.4 mV) response and an attractant behavioral response on Proagopertha lucidula (Faldermann) (Coleoptera: Scarabaeidae) at 10 μg μL −1 , which is a concentration higher than the three-dose tested in our study (Chang-Kuan et al 2009).…”