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The mouthparts of female Corethrella brakeleyi and C. wirthi were studied using light and electron microscopy. Mandibles, hypopharynx and labium are highly sclerotized and are modified for obtaining blood meals. All structures were larger in C. brakeleyi than in C. wirthi except mandibular and hypopharyngeal teeth; these were smaller and more numerous in C. brakeleyi. The labium of both species terminates in peg-like structures which are similar to those reported from several genera of mosquitoes. Sensillae on the second segment of the maxillary palps appear to be identical to those described in both biting and nonbiting male and female blackflies., (Copyright © 1979 Wiley-Liss, Inc.)

Single esophageal and paired cheliceral, palpal, pedal (I-IV), and opisthosomal nerves enter the synganglion and form specific neuropilar ganglia. The ganglia are integrated by a complex series of commissures and connectives. Eighteen paraldehyde-fuchsin-positive neurosecretory regions, which vary greatly in size and amount of granular neurosecretory material, are each associated (one or more) with neuropilar ganglia. Presumably transport of neurosecretory materials to target tissues occurs through axonal pathways, perineurial-neural lamella associations, and the neurohemal retrocerebral organ complex., (Copyright © 1982 Wiley-Liss, Inc.)

Sperm induction pores, tubuli annulati, rami sacculi, sacculus foemineus, cornu sacculus and acantho-membranous hood in female Dermanyssus gallinae support the probability of coxal insemination as reported for some other mesostigmatid species. Development of the circular testis in males (from fusion of two anterolaterally projecting protonymphal testicular arms) and formation of haploid (n = 3) spermatids from haploid (n = 3) spermatogonial cells is entirely mitotic. Spermatogenesis begins within one hour after protonymphal feeding and continues through adult ecdysis in normally fed individuals. Nutritional deficit causes cessation of spermatogenic divisions in deutonymphs starved 23 days, but is rapidly rejuvenated upon feeding. No rejuvenation of division was observed in adult males given the opportunity to feed, thus adult males might not feed., (Copyright © 1976 Wiley-Liss, Inc.)