Four Species of Under-reported Parasitic Arthropods in Mexico and their Potential Role as Vectors of Pathogens.

Numerous arthropod taxa are important in human and veterinary medicine. The salivary secretions and feces of arthropods can cause allergic reactions in host vertebrates or harbor pathogens. Also, bites can be a risk factor for secondary infections. Documenting the diversity of arthropods of medical and veterinary importance remains an important aspect of disease control and prevention. We provide new records of ectoparasitic arthropods from Mexico that are of potential medical or veterinary relevance. Scanning electron microscopy along with amplification and sequencing of a fragment of the mitochondrial gene (16S rRNA) was used to confirm some species identities. We report the cat louse Felicola subrostratus from cats and the chewing louse Heterodoxus spiniger from dogs, which are common ectoparasites but largely not reported in Mexico. The chigger Eutrombicula alfreddugesi is common on wild lizards (Squamata). For the first time, E. alfreddugesi is reported on Hemidactylus frenatus (common house gecko). This reptile has a close relationship with humans and its chiggers can cause dermatitis (i.e., trombiculiasis) or transmit pathogens. In addition, the common bed bug Cimex lectularius is reported for the first time in the state of Yucatan, an atypical area for its natural distribution. Phylogenetic analysis revealed that Cimex lectularius from Yucatan is closely related to genetic sequences of Cimex lectularius from China. Knowing the regional distribution of arthropods allows the design and implementation of prevention strategies for those that have potential roles as reservoirs or vectors.

The chewing lice (Phthiraptera: Ischnocera, Amblycera) of the great cormorant (Phalacrocorax carbo).

The Great Cormorant is a widespread bird species with almost worldwide distribution. Accordingly, its general biology has been investigated thoroughly. Less well known, however, are the chewing lice that live inside the plumage of this diving bird. We examined the two known species of Great Cormorant chewing lice, Eidmanniella pellucida (Rudow, 1869) (Amblycera: Menoponidae) and Pectinopygus gyricornis (Denny, 1842) (Ischnocera: Philopteridae). Taking advantage of the autofluorescence of the cuticle, confocal laser scanning microscopy (CLSM) was used to explore the external morphology of all developmental stages of P. gyricornis. Morphometric analyses revealed a standard increase in body size from first larval instar to the adult. In addition, all instars exhibited increasing body segment differentiation, especially in the abdomen and the head. A total of 277 individuals of Pectinopygus gyricornis and 2 individuals of Eidmanniella pellucida were collected from eleven Great Cormorants from Mecklenburg-Western Pomerania, Germany, in 2015.

Antennal lobe organization in the slender pigeon louse, Columbicola columbae (Phthiraptera: Ischnocera).

This study reports on the structure of the antennal lobe of the pigeon louse, Columbicola columbae. Anterograde staining of antennal receptor neurons revealed an antennal lobe with a few diffuse compartments, an organization distinct from the typical spheroidal glomerular structure found in the olfactory bulb of vertebrates and the antennal lobe of many other insects. This anatomical arrangement of neuronal input is somewhat reminiscent of the aglomerular antennal lobe previously reported in psyllids and aphids. As in psyllids, reports on the odor-mediated behavior of C. columbae suggest that the olfactory sense is important in these animals and indicates that a glomerular organization of the antennal lobe may not be necessary to subtend odor-mediated behaviors in all insects. The diffuse or aglomerular antennal lobe organization found in these two Paraneopteran insect orders might represent an independently evolved reduction due to similar ecological constraints.