Photographs of left elytra of Harmonia axyridis parasitised by Hesperomyces virescens

Photographs of 80 left elytra of Harmonia axyridis specimens, collected from the South and West walls of William James Hall, Cambridge, Massachusetts in October–November 2016. All 80 specimens were parasitized by Hesperomyces virescens (Laboulbeniales). Photographs made using an Olympus XC50 camera and cellSens Standard 1.14 software (Olympus). <br>From Haelewaters D, Hiller T, Gorczak M &amp; Pfister DH. 2018. Influence of elytral color pattern, size, and sex of Harmonia axyridis (Coleoptera, Coccinellidae) on parasite prevalence and intensity of Hesperomyces virescens (Ascomycota, Laboulbeniales). <em>Insects</em> 9 (2): 67. doi:10.3390/insects9020067.<br><b>Abstract:</b> <i>Harmonia axyridis</i> is an invasive ladybird (Coleoptera, Coccinellidae) with the potential to outcompete native ladybird species in its invasive distribution area. It was introduced as a biological control agent in many countries but has also spread unintentionally in many others. <i>Hesperomyces virescens</i> (Ascomycota, Laboulbeniales) is a minute (200–400 µm in size) biotrophic fungus that infects over 30 species of ladybirds. The aim of this study was to evaluate whether the elytral color pattern, size, and sex of <i>Ha. axyridis</i> affect infection by <i>H. virescens</i>. Coloration in <i>Ha. axyridis</i> has been linked to the presence of an antimicrobial alkaloid (harmonine). In fall 2016, we collected 763 <i>Ha. axyridis</i> individuals in Cambridge, Massaschusetts, of which 119 (16%) bore <i>H. virescens</i> fruiting bodies. We analyzed 160 individuals (80 infected, 80 uninfected) concerning the intensity of infection by <i>H. virescens</i>. Elytral sizes and coloration patterns were quantified using digital photography and analytical methods. Smaller ladybirds had a higher prevalence and higher intensity of parasitism. Additionally, male ladybirds bore more thalli compared to female ladybirds. Elytral color patterns had an effect on neither prevalence nor intensity of infection by Laboulbeniales in our dataset, although we found a slight trend to higher intensity of parasitism in more melanic males. This suggests that the development of Laboulbeniales might be affected by certain insect alkaloids.<br><b>Keywords: </b>biotrophic interactions, invasive species, color polymorphism, harlequin ladybird, harmonine