Aggregation promotes water conservation during diapause in the tropical fungus beetle, Stenotarsus rotundus

  title={Aggregation promotes water conservation during diapause in the tropical fungus beetle, Stenotarsus rotundus},
  author={Jay A. Yoder and David L. Denlinger and Henk Wolda},
  journal={Entomologia Experimentalis et Applicata},
During diapause adults of the fungus beetle, Stenotarsus rotundus Arrow (Endomychidae, Coleoptera) form huge aggregations (4000070000 individuals) at the base of a palm tree (Oenocarpus mapora) on Barro Colorado Island, Panama (Wolda & Denlinger, 1984; Tanaka etal., 1987a, 1987b). The beetles remain aggregated for 8-10 months, through the rainy season and the ensuing dry season, and disperse for reproduction at the onset of the next rainy season. Formation of an aggregation is fairly common… 

Stenotarsus Subtilis Arrow, the Aggregating Fungus Beetle of Barro Colorado Island Nature Monument, Panama (Coleoptera: Endomychidae)

It is suggested beetles may live more than one year and return to diapause sites after completing the still undocumented mating and reproductive facets of their life cycle.

Seasonal Timing of Diapause Induction Limits the Effective Range of Diorhabda elongata deserticola (Coleoptera: Chrysomelidae) as a Biological Control Agent for Tamarisk (Tamarix spp.)

It is predicted that south of the 38th parallel, premature diapause will increase mortality and disrupt synchrony between the life cycle of the beetle and host plant availability, providing a rationale for testing other populations of D. elongata in the southern range of Tamarix in North America.

Overwintering aggregations are part of Hippodamia undecimnotata’s (Coleoptera: Coccinellidae) mating system

The results suggest that finding sexual mates may have been involved in overwintering aggregations in H. undecimnotata, an aphidophagous species from Southern and Eastern Europe as well as Asia.

Influence of Microclimate Factors on Halyomorpha halys Dehydration

It is demonstrated that microclimate conditions affect H. halys water loss and that transpiration is influenced by feeding regime and sex, and that the first nutritional need of individuals exiting diapause is represented by hydration, likely due to water loss during the diAPause.

Overwintering Sites Might not be Safe Haven for Hippodamia undecimnotata (Schneider) (Coleoptera: Coccinellidae)

It was found that overwintering microsites did not offer direct suitable conditions in terms of temperature for lady beetle survival and/or presented relative humidity and temperature conditions favorable to ectoparasitic fungi and therefore indirectly affected lady beetles survival.

Effects of group size on aggregation against desiccation in woodlice (Isopoda: Oniscidea)

A geometrical explanation is proposed for the nonlinear water losses in woodlice aggregates and results are discussed in relation to the group sizes observed both in the laboratory and the field.

Group influence on water conservation in the giant Madagascar hissing‐cockroach, Gromphadorhina portentosa (Dictyoptera: Blaberidae)

The profound impact exerted by the ‘group’ for water conservation suggests that members of this species live huddled together in nature, particularly during the long tropical dry season in order to conserve water, and adds to previous evidence for the existence of a probable social structure.

Antarctic Collembolans Use Chemical Signals to Promote Aggregation and Egg Laying

Chemicals released by the collembolans appear to induce both aggregation and oviposition in these Antarctic species, including F. grisea and C. antarcticus.

Aggregation effects on anhydrobiotic survival in the tardigrade Richtersius coronifer.

This study experimentally evaluates the effect of aggregation size (number of animals in a group of desiccating animals) on anhydrobiotic survival in the eutardigrade Richtersius coronifer and suggests that aggregation could potentially be an important survival factor for tardigrades living in environments characterized by periods of rapid desiccation.



Abstinence from mating by sexually mature males of the fungus beetle Stenotarsus rotundus, during a tropical dry season

It is suggested that the aggregated beetles remain as virgins until the rains trigger mating and dispersal, and abstinence in sexually mature males during the dry season may be important for conserving energy reserves.

Group size affects the metabolic rate of a tropical beetle

A decrease in metabolic rate can also be achieved by elevating relative humidity, thus suggesting that one function of the aggregation is to increase humidity within the group and thereby decrease metabolic rate.

Dormancy in tropical insects.

  • D. Denlinger
  • Environmental Science
    Annual review of entomology
  • 1986
The primary objective in this review is to dispell this myth by presenting evidence for the widespread existence of diapause among tropical species, and to identify factors implicated in regulation and some of the special problems of diAPause in the tropics.

Diapause in a large aggregation of a tropical beetle

Diapause is described for adults of Stenotarsus rotundus Arrow in the tropical lowland forest on Barro Colorado Island, Panama.

Water Balance in Drosophila pseudoobscura, and its Ecological Implications

Drosophila pseudoobscura Frolova was found to lose weight at all water vapor activities below saturation, suggesting that it is incapable of active sorption of water, and it is postulated that transpiration rate is regulated by the spiracular openings.

Epicuticular Wax Secretion in Diapause and Non-diapause Pupae of the Bertha Army worm

The thicker wax layer in general and the higher content of hydrocarbons in particular protect the diapausing pupae from desiccation during diapause.

Scaling, why is animal size so important?

This book discusses the size of living things, animal activity and metabolic scope, and some important concepts of body temperature and temperature regulation.

Water balance of insects

  • 1985

Daylength and humidity as environmental cues for diapause termination in a tropical beetle

M Males consistently initiated gonad development earlier than females, but both sexes developed flight muscles at the same time, and Beetles showed a graded response to intermediate photoperiods.