<P> Predatory and parasitoidal wasps subdue their prey by stinging it . They hunt a wide variety of prey, mainly other insects (including other Hymenoptera), both larvae and adults . The Pompilidae specialize in catching spiders to provision their nests . </P> <P> Some social wasps are omnivorous, feeding on fallen fruit, nectar, and carrion such as dead insects . Adult male wasps sometimes visit flowers to obtain nectar . Some wasps, such as Polistes fuscatus, commonly return to locations where they previously found prey to forage . In many social species, the larvae exude copious amounts of salivary secretions that are avidly consumed by the adults . These include both sugars and amino acids, and may provide essential protein - building nutrients that are otherwise unavailable to the adults (who cannot digest proteins). </P> <P> In wasps, as in other Hymenoptera, sex is determined by a haplodiploid system, which means that females are unusually closely related to their sisters, enabling kin selection to favour the evolution of eusocial behaviour . Females are diploid, meaning that they have 2n chromosomes and develop from fertilized eggs . Males, called drones, have a haploid (n) number of chromosomes and develop from an unfertilized egg . Wasps store sperm inside their body and control its release for each individual egg as it is laid; if a female wishes to produce a male egg, she simply lays the egg without fertilizing it . Therefore, under most conditions in most species, wasps have complete voluntary control over the sex of their offspring . Experimental infection of Muscidifurax uniraptor with the bacterium Wolbachia induced thelytokous reproduction and an inability to produce fertile, viable male offspring . </P> <P> Females of the solitary wasp parasitoid Venturia canescens can avoid mating with their brothers through kin recognition . In experimental comparisons, the probability that a female will mate with an unrelated male was about twice as high as the chance of her mating with brothers . Female wasps appear to recognize siblings on the basis of a chemical signature carried or emitted by males . Sibling - mating avoidance reduces inbreeding depression that is largely due to the expression of homozygous deleterious recessive mutations . </P>

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