Development and testing of a standardized method to estimate honeydew production

Abstract

Honeydew production by Hemiptera is an ecologically important process that facilitates mutualisms and increases nutrient cycling. Accurate estimates of the amount of honeydew available in a system are essential for quantifying food web dynamics, energy flow, and the potential growth of sooty mould that inhibits plant growth. Despite the importance of honeydew, there is no standardized method to estimate its production when intensive laboratory testing is not feasible. We developed two new models to predict honeydew production, one based on insect body mass and taxonomic family, and one based on body mass and life stage. We tested the accuracy of both models’ predictions for a diverse range of honeydew-producing hemipteran families (Aphididae, Pseudococcidae, Coccidae, Psyllidae, Aleyrodidae, Delphacidae, Cicadellidae). The method based on body mass and family provided more accurate estimates of honeydew production, due to large variation in honeydew production among families. We apply our methodology to a case study, the recalculation of honeydew available to invasive red imported fire ant (Solenopsis invicta) in the United States. We find that the amount of honeydew may be an order of magnitude lower than that previously estimated (2.16 versus 21.6 grams of honeydew per day) and discuss possible reasons for the difference. We anticipate that being able to estimate honeydew production based on minimal biological information will have applications to agriculture, invasion biology, forestry, and carbon farming.

Previous diet affects the amount but not the type of bait consumed by an invasive ant

“…We wrapped the bases of the cane stalks in moist paper towel covered with plastic wrap and secured it with bent paper clips. There are no standard models for estimating honeydew production for Aleyrodidae so we based estimates on the measured honeydew production of the confamilial Bemisia argentifolii Bellows and Perring. Based on estimated average sugar production rates of 15.2 ± 11.8 µg (mean ± SD) per 10 h for B. argentifolii nymphs, we conservatively estimate that on average over the 4 days each honeydew fed colony received a total of 564 ± 436 mg (mean ± SD) sugars (see Supplementary material for calculations).…”

Native and non-native sources of carbohydrate correlate with abundance of an invasive ant

“…We calculated honeydew production over 24 hours at each site using the standardized method of (Moir et al 2018). We did this by weighing and identifying each specimen collected in the field to the lowest taxonomic rank possible.…”

“…For Coccoidea species we used the power equation y = 0.785× 0.672 , for Psyllidae we used the null model y = 7.99, for Aphididae we used the power equation y = 3.46× 0.3156 , and for both Cicadellidae and Membracidae we used the power model of Delphacidae y = 1.229× 0.7692 (table 2 in Moir et al 2018). For the latter two families we did not use the exponential model of Cicadellidae from Moir et al (2018) because the species in our study were phloem-, rather than xylem-, feeders and we would therefore not expect them to have the high levels of honeydew excretion as the larger-bodied xylem-feeders incorporated into the models of Moir et al (2018). After calculating individual specimen honeydew production rates, we pooled the rates across all tended hemipterans for each site over 24 hours.…”

The Probing Behavior Component of Disease Transmission in Insect-Transmitted Bacterial Plant Pathogens

“…The bacterial load within a few micrometers of the growing point may not be sufficient to reliably infect the early instars. It is expected that the total volume of fluid ingested by early instars is less than for later instars or adults [46]. If bacteria are present at low concentrations and the early instar ingests a lesser volume before molting, then there is less opportunity for acquisition.…”