He long honeydew ribbons or tubes away from their bodies (Figs. 1C, D 3A, D). These setae were described earlier by light microscopy in ACP nymphs as `lanceolate setae’ by Husain and Nath [5], who also indicated that they were covered with narrow tubular sheaths of waxy secretion, produced by glands situated around their bases. Second, we observed that most of the nymphs feeding on the upper side of the leaf usually leave their long honeydew tubes or ribbons behind attached to the exuvia during molting (Fig. 1E). In the field, honeydew tubes or ribbons are infrequently noticeable (unpublished observations), perhaps due to wind or wind-induced movement of citrus leaves. In addition to reducing contamination with honeydew, it has been suggested that waxy secretions inPsyllid Honeydew: Behavior, Structure Compositionaphids may also provide `a microclimate coat’ or afford some protection against fungus, parasite or predator attacks [39]. But this may be true mainly with insects that produce wax filaments on larger areas of their cuticle, not just their circumanal ring or circumabdominal setae, like mealybugs, scale insects, some aphids and planthoppers [33,34,39,41,42]. The phloem feeding scale insects and mealybugs are known to posses several mechanisms to limit contamination from their own sticky honeydew excretions [34,41,42]: 1. filaments of wax often coat the insect body so that honeydew droplets do not adhere to it; 2. the anal opening is surrounded by an anal ring that usually bears setae and pores, wax from these pores coats the anal ring setae and prevents honeydew droplets from sticking to them; and 3. the anal ring has certain ways by which it can propel the honeydew away from the inset body. Our study shows that ACP nymphs may have mechanisms similar to the first two mentioned above, but the wax produced is on the surface of honeydew excretions and circumabdominal setae rather than on the insect body itself. We also show that ACP females posses something similar to the third mechanism, i.e. propelling their wax-covered excretions to the side away from their bodies. To our knowledge, this behavioral difference between males and females has not been described earlier for ACP or other psyllid species. We hope that this investigation furthers our understanding of the 23148522 biology, adaptations and survival of this group of hemipteran insects that is economically important on many field and Title Loaded From File horticultural crops worldwide.Supporting InformationVideo S1 Anal (honeydew) excretion behavior of Asian citrus psyllid males and females. This video (1 min 52 sec. long) is composed of 4 short clips showing one male producing two consecutive, clear, honeydew drops, one on top of the other (2 separate clips), followed by one Title Loaded From File female producing one, yellowish/ whitish, honeydew pellet (one clip), and finally another female (at lower right) producing another pellet (one clip). All clips were recorded at real time (normal speed); the male clips are played back at normal speed, whereas the female clips are played back at a much slower speed (1/16th their actual speed). (WMV)AcknowledgmentsWe thank Kathy Moulton and Monty Watson for excellent technical assistance, Dr. L. R. Nault (Ohio State University) and Dr. Astri Wayadande (Oklahoma State University) for their valuable comments on an earlier version of the manuscript. This article reports the results of research only. Mention of a trademark or proprietary product is solely for the purpose of providing.He long honeydew ribbons or tubes away from their bodies (Figs. 1C, D 3A, D). These setae were described earlier by light microscopy in ACP nymphs as `lanceolate setae’ by Husain and Nath [5], who also indicated that they were covered with narrow tubular sheaths of waxy secretion, produced by glands situated around their bases. Second, we observed that most of the nymphs feeding on the upper side of the leaf usually leave their long honeydew tubes or ribbons behind attached to the exuvia during molting (Fig. 1E). In the field, honeydew tubes or ribbons are infrequently noticeable (unpublished observations), perhaps due to wind or wind-induced movement of citrus leaves. In addition to reducing contamination with honeydew, it has been suggested that waxy secretions inPsyllid Honeydew: Behavior, Structure Compositionaphids may also provide `a microclimate coat’ or afford some protection against fungus, parasite or predator attacks [39]. But this may be true mainly with insects that produce wax filaments on larger areas of their cuticle, not just their circumanal ring or circumabdominal setae, like mealybugs, scale insects, some aphids and planthoppers [33,34,39,41,42]. The phloem feeding scale insects and mealybugs are known to posses several mechanisms to limit contamination from their own sticky honeydew excretions [34,41,42]: 1. filaments of wax often coat the insect body so that honeydew droplets do not adhere to it; 2. the anal opening is surrounded by an anal ring that usually bears setae and pores, wax from these pores coats the anal ring setae and prevents honeydew droplets from sticking to them; and 3. the anal ring has certain ways by which it can propel the honeydew away from the inset body. Our study shows that ACP nymphs may have mechanisms similar to the first two mentioned above, but the wax produced is on the surface of honeydew excretions and circumabdominal setae rather than on the insect body itself. We also show that ACP females posses something similar to the third mechanism, i.e. propelling their wax-covered excretions to the side away from their bodies. To our knowledge, this behavioral difference between males and females has not been described earlier for ACP or other psyllid species. We hope that this investigation furthers our understanding of the 23148522 biology, adaptations and survival of this group of hemipteran insects that is economically important on many field and horticultural crops worldwide.Supporting InformationVideo S1 Anal (honeydew) excretion behavior of Asian citrus psyllid males and females. This video (1 min 52 sec. long) is composed of 4 short clips showing one male producing two consecutive, clear, honeydew drops, one on top of the other (2 separate clips), followed by one female producing one, yellowish/ whitish, honeydew pellet (one clip), and finally another female (at lower right) producing another pellet (one clip). All clips were recorded at real time (normal speed); the male clips are played back at normal speed, whereas the female clips are played back at a much slower speed (1/16th their actual speed). (WMV)AcknowledgmentsWe thank Kathy Moulton and Monty Watson for excellent technical assistance, Dr. L. R. Nault (Ohio State University) and Dr. Astri Wayadande (Oklahoma State University) for their valuable comments on an earlier version of the manuscript. This article reports the results of research only. Mention of a trademark or proprietary product is solely for the purpose of providing.
