First cases of exclusive paternal care in stink bugs (Hemiptera: Pentatomidae)

We describe paternal care in two pentatomid bugs, Lopadusa (Lopadusa) augur Stål, 1860 and Edessa nigropunctata Berg, 1884. Field and laboratory observations showed that males remain with their eggs and early hatched nymphs, while females abandon the eggs after oviposition. Guarding males defensive behaviors towards their clutches were similar to those described for guarding females of pentatomids. Since there is no detailed information on the internal phylogeny of Pentatomidae, it is not possible to make a robust inference on whether paternal care in L. augur and E. nigropunctata has arisen independently or not. If the latter, the two new cases of paternal care we describe here represent the fifth event of independent evolution of this rare behavioral trait in Heteroptera.FAPESPCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)CNP

Egg Production Constrains Chemical Defenses in a Neotropical Arachnid.

Female investment in large eggs increases the demand for fatty acids, which are allocated for yolk production. Since the biosynthetic pathway leading to fatty acids uses the same precursors used in the formation of polyketides, allocation trade-offs are expected to emerge. Therefore, egg production should constrain the investment in chemical defenses based on polyketides, such as benzoquinones. We tested this hypothesis using the harvestman Acutiosoma longipes, which produces large eggs and releases benzoquinones as chemical defense. We predicted that the amount of secretion released by ovigerous females (OFs) would be smaller than that of non-ovigerous females (NOF). We also conducted a series of bioassays in the field and in the laboratory to test whether egg production renders OFs more vulnerable to predation. OFs produce less secretion than NOFs, which is congruent with the hypothesis that egg production constrains the investment in chemical defenses. Results of the bioassays show that the secretion released by OFs is less effective in deterring potential predators (ants and spiders) than the secretion released by NOFs. In conclusion, females allocate resources to chemical defenses in a way that preserves a primary biological function related to reproduction. However, the trade-off between egg and secretion production makes OFs vulnerable to predators. We suggest that egg production is a critical moment in the life of harvestman females, representing perhaps the highest cost of reproduction in the group

Results of the field experiment in which the number of ants tending sugar baits was counted before and after stimulation with one of the three experimental groups: (1) secretion of one non-ovigerous female of <i>Acutisoma longipes</i>, (2) secretion of one ovigerous female of <i>A</i>. <i>longipes</i>, and (3) distilled water (control).

<p>Different letters indicate significant differences (post-hoc test, p < 0.05).</p

Mean (± SE) number of workers of the ants <i>Odontomachus chelifer</i> and <i>Pachycondyla striata</i> tending three types of baits: (1) sugar solution + secretion of one non-ovigerous female of <i>Acutisoma longipes</i>, (2) sugar solution + secretion of one ovigerous female of <i>A</i>. <i>longipes</i>. and (3) sugar solution (control).

<p>The photo illustrates the experimental setup of an <i>O</i>. <i>chelifer</i> colony at 14 min of experiment.</p

Mass of defensive secretion (mean ± SE) released by egg-guarding, non-ovigerous, and ovigerous females of the harvestman <i>Acutisoma longipes</i>.

<p>Different letters indicate significant differences (post-hoc test, p < 0.05).</p

Results of the GLM testing the effect of body size and reproductive phase on the mass of defensive gland secretion and concentration of total benzoquinones released by females of the harvestman <i>Acutisoma longipes</i>.

<p>Significant p-values are shown in bold.</p