Ammar El-Desouky, Hentz Matthew, Hall David G, Shatters Robert G
United States Department of Agriculture-Agricultural Research Service, Horticultural Research Laboratory, Fort Pierce, Florida, United States of America.
PLoS One. 2015 Mar 20;10(3):e0121354. doi: 10.1371/journal.pone.0121354. eCollection 2015.
The melaleuca psyllid, Boreioglycaspis melaleucae (Hemiptera: Psyllidae), was introduced to Florida as a biological control agent against Melaleuca quinquenervia, an invasive evergreen tree that has invaded large areas of Florida Everglades. Colonies of B. melaleucae nymphs are normally covered by white waxy secretions, and nymphs of various instars produce long bundles of white waxy filaments extending laterally and posteriorly from their abdomen. Scanning electron microscopy of 'naturally waxed' and 'dewaxed' nymphs (cleaned from wax) revealed two types of wax pore plates located dorsally and laterally on the integument of posterior abdominal segments starting with the 4th segment. Type-1 wax pore plates, with raised rim, peripheral groove, slits and pits, produce long ribbons and filaments of waxy secretions that are wound together forming long wax bundles, whereas type-2 wax pore plates, with slits only, produce shorter wax curls. Additionally, in both nymphs and adult females, the circumanal ring contained ornate rows of wax pores that produce wax filaments covering their honeydew excretions. Video recordings with stereomicroscopy showed that adult females produce whitish honeydew balls, powerfully propelled away from their body, probably to get these sticky excretions away from their eggs and newly hatched nymphs. Adult males, however, produce clear droplets of honeydew immediately behind them, simply by bending the posterior end of the abdomen downward. The possible role(s) of waxy secretions by nymphs and adults of B. melaleucae in reducing contamination of their colonies with honeydew, among other possibilities, are discussed.
白千层木虱（Boreioglycaspis melaleucae，半翅目：木虱科）作为一种生物防治剂被引入佛罗里达州，用于防治千层金（Melaleuca quinquenervia），这是一种入侵性常绿树，已侵入佛罗里达大沼泽地的大片区域。白千层木虱若虫群体通常被白色蜡质分泌物覆盖，不同龄期的若虫会从腹部向侧面和后方伸出长长的白色蜡质细丝束。对“自然有蜡”和“脱蜡”（去除蜡质）的若虫进行扫描电子显微镜观察发现，从第4腹节开始，在腹部后段的体表背侧和侧面有两种蜡孔板。1型蜡孔板有凸起的边缘、周边凹槽、狭缝和凹坑，能产生长长的蜡质分泌物带和细丝，它们缠绕在一起形成长长的蜡束，而2型蜡孔板只有狭缝，产生较短的蜡卷。此外，在若虫和成年雌虫中，肛门环都有排列精美的蜡孔排，能产生覆盖其蜜露排泄物的蜡丝。体视显微镜的视频记录显示，成年雌虫会产生白色的蜜露球，并有力地将其从身体推开，可能是为了使这些粘性排泄物远离它们的卵和新孵化的若虫。然而，成年雄虫只是通过将腹部后端向下弯曲，在其身后立即产生清澈的蜜露滴。本文讨论了白千层木虱若虫和成虫的蜡质分泌物在减少蜜露对其群体的污染等方面可能发挥的作用。
