Adult feeding and host type modulate the life history traits of the capital breeder Zabrotes subfasciatus

Abstract

Income breeding animals support reproduction by the intake of energy and molecular building blocks during adulthood. Capital breeders, in contrast, fuel reproduction by the intake of materials during the larval stage. There exists, however, some controversy as to whether adult feeding in capital breeders actually increases fitness. We tested whether individuals feed as adults in the weevil Zabrotes subfasciatus Boheman, whether they equally accept carbohydrate‐ or nitrogen‐rich food (sugar or yeast), whether food ingestion varies with the available host type and whether feeding as adults alters life history traits. The hosts tested were three varieties of Phaseolus vulgaris, Carioca, Jalo, and Preto; Vigna unguiculata Frade; and Vicia faba. We also tested whether sugar ingestion affects life history traits differently in the presence of different host types. We found that Z. subfasciatus feed as adults and equally accept sugar and yeast, and food ingestion depends on host type. Sugar and yeast significantly promote oviposition of larger eggs on Carioca seeds and enhance adult emergence, and sugar ingestion increases longevity. Moreover, the insects avoid feeding when on V. faba seeds, on which they did not oviposit. Mean fitness values showed the following hierarchy: Carioca = Jalo > Frade > Preto > V. faba. These results show that the capital breeder Z. subfasciatus feed as adults, which increases life history traits and suggests the existence of a hierarchy of performance on different hosts, with the P. vulgaris varieties Carioca and Jalo offering the best conditions.

Life history trait response to ambient temperature and food availability variations in the bean weevil Zabrotes subfasciatus

“…Our results confirmed our previous work showing that Z. subfasciatus feed as adults (Corrêa et al, 2020) and showed that ingestion is influenced by temperature with a maximum at 25 ∘ C (at 30 and 35 ∘ C we found a smaller effect). This might simply reflect the conditions weevils face while living in stored grains, which are maintained at approximately 16 to 33 ∘ C (Eliud et al, 2010) and contain grinded seed fragments (crumbs, originated from the immature-infested seeds) which are eventually consumed.…”

“…The seed weevil Zabrotes subfasciatus (Boheman, 1833) (Coleoptera; Polyphaga; Cucujiformia; Chrysomeloidea; Chrysomelidae; Bruchinae; Amblycerini) feeds on stored grains during the larval stage, in particular, on seeds of the common bean ( Phaseolus vulgaris L.) (Teixeira et al ., 2008), which is an important source of protein in more than 75% of developing countries, including those in Latin America and Africa (Cardona, 2004). During the adult life, these insects may consume carbohydrate‐ and nitrogen‐rich food, which modulates components of fitness (Corrêa et al ., 2020). Particularly, adult weevils' food consumption positively alters egg size and enhance adult emergence, and sugar ingestion increases longevity.…”

“…Considering its pattern of worldwide distribution (https:// www.plantwise.org/KnowledgeBank/datasheet/57289), we hypothesized Z. subfasciatus would perform better at high temperatures and since we have previously demonstrated that this species feeds as adults (Corrêa et al, 2020), we expected carbohydrate intake would counterbalance the decreasing effects of low temperatures on life history traits. This would have practical implications for the management of warehouses, where different types of seeds are usually maintained, which also include seed crumbs (a by-product of seed infestation) along with other materials, including sugar.…”

Transcriptional signature of host shift in the seed beetle Zabrotes subfasciatus

“…The larva that hatches after embryonic development pierces the tegument and develops inside the seed, feeding on the cotyledons and embryonic regions. After pupal development, adults emerge (after 26 days of development at 30-35 °C, Corrêa et al, 2021 ), look for host seeds, mate, and the cycle resumes, without the need to ingest food or water, which appears to be facultative ( Howe and Currie, 1964 ; Southgate, 1979 ; Kingsolver, 2004 ; Corrêa et al , 2020 , 2021 ).…”

“…Research on the biology of host use by Z. subfasciatus shows that this species can grow on several Fabaceae species, but prefers bean ( Phaseolus vulgaris ) varieties, where it shows high fitness ​​( Meik and Dobie, 1986 ; Teixeira and Zucoloto, 2003 , Teixeira et al , 2008 , Corrêa et al, 2020 ). In Cicer arietinum (chickpea), for example, Z. subfasciatus has the worst fitness values ​​( Teixeira and Zucoloto, 2003 ), and the seeds of this host are the least chosen in behavioral tests (unpublished material from our laboratory).…”