We investigated the patterns of total lipid, glycogen, hemolymph carbohydrate, and trichloroacetic acid-precipitable protein contents starting 8 h before puparium formation and throughout the whole metamorphosis of the Medfly, Ceratitis capitata (Wiedemann). In addition, during the early stages of metamorphosis, we measured the activity of acid proteinases and glutamate dehydrogenase (GDH), an important enzymatic link between amino acids and the tricarboxylic acid cycle. Lipids accumulate during the larval-dispersal phase and the first 20 h of the prepupal stage. Thereafter, levels decline slightly throughout the pupal stage and first half of the pharate-adult stage, and drastically decline toward the last hours of metamorphosis. Glycogen and hemolymph carbohydrates are highly used from the moment the larvae leave the diet until the mid-pupal stage, then glycogen increases toward the mid pharate-adult and decreases again to low levels at the moment of adult emergence. Protein levels decrease during the prepupal stage (coinciding with a rise in acid proteinase activity) recovering toward the pharate-adult stage. GDH activity increases during the prepupal stage, attaining maximal activity at the onset of the pupal stage and then declines to low levels. This high GDH activity may be linked to the conversion of glutamate to α-ketoglutarate while proteins are being broken during tissue histolysis. Our results are discussed in view of the differential utilization of metabolites during metamorphosis.

Varroa destructor is an ectoparasitic mite of Asian or Eastern honeybees Apis cerana (A. cerana) which has become a serious threat to European subspecies of Western honeybees Apis mellifera (A. mellifera) within the last century. V. destructor and its vectored honeybee viruses became serious threats for colony survival. This is a short period for pathogen- and host-populations to adapt. To look for possible variation in the composition of viral populations we performed RNA metagenomic analysis of the Western honeybee subspecies A. m. ligustica, A. m. syriaca, A. m. intermissa, and A. cerana and their respective V. destructor mites. The analysis revealed two novel viruses: Varroa orthomyxovirus-1 (VOV-1) in A. mellifera and V. destructor and a Hubei like-virga virus-14 homolog in V. destructor. VOV-1 was more prevalent in V. destructor than in A. mellifera and we found evidence for viral replication in both hosts. Interestingly, we found differences in viral loads of A. cerana and their V. destructor, A. m. intermissa, and its V. destructor showed partial similarity, while A. m. ligustica and A. m. syriaca and their varroa where very similar. Deformed wing virus exhibited 82.20%, 99.20%, 97.90%, and 0.76% of total viral reads in A. m. ligustica, A. m. syriaca, A. m. intermissa, and A. cerana, respectively. This is the first report of a complete segmented-single-stranded negative-sense RNA virus genome in honeybees and V. destructor mites.