Negative body size-dependent resource allocation underlies conspicuous sexual ornaments in a territorial damselfly.

Sexual ornaments, signalling individual quality to choosy females or rival males, often show steeper body size scaling compared with non-sexually selected traits. Theory posits such steeper body size scaling is the result of differential resource allocation, reflecting trade-offs between different components of fitness. Yet, the process of resource allocation towards body size-dependent sexual ornaments has been rarely understood empirically.

Tests of search image and learning in the wild: Insights from sexual conflict in damselflies.

Search image formation, a proximal mechanism to maintain genetic polymorphisms by negative frequency-dependent selection, has rarely been tested under natural conditions. Females of many nonterritorial damselflies resemble either conspecific males or background vegetation. Mate-searching males are assumed to form search images of the majority female type, sexually harassing it at rates higher than expected from its frequency, thus selectively favoring the less common morph.

Mechanical and tactile incompatibilities cause reproductive isolation between two young damselfly species.

External male reproductive structures have received considerable attention as a cause of reproductive isolation (RI), because the morphology of these structures often evolves rapidly between populations. This rapid evolution presents the potential for mechanical incompatibilities with heterospecific female structures during mating and could thus prevent interbreeding between nascent species. Although such mechanical incompatibilities have received little empirical support as a common cause of RI, the potential for mismatch of reproductive structures to cause RI due to incompatible species-specific tactile cues has not been tested.

Predation by odonates depresses mosquito abundance in water-filled tree holes in Panama.

In the lowland moist forest of Barro Colorado Island (BCI), Panama, larvae of four common species of odonates, a mosquito, and a tadpole are the major predators in water-filled tree holes. Mosquito larvae are their most common prey. Holes colonized naturally by predators and prey had lower densities of mosquitoes if odonates were present than if they were absent.

Population regulation of a tropical damselfly in the larval stage by food limitation, cannibalism, intraguild predation and habitat drying.

The relative importance of intraspecific, interspecific, and seasonal causes of larval mortality were investigated for aquatic larvae of the giant damselfly Megaloprepus coerulatus in Panama. These larvae live in water-filled holes in fallen and living trees, where they and three other common odonate species are the top predators. By mid wet season, M.

LIFETIME REPRODUCTIVE SUCCESS AND THE OPPORTUNITY FOR SELECTION IN A NONTERRITORIAL DAMSELFLY (ODONATA: COENAGRIONIDAE).

Major components of male and female lifetime reproductive success (LRS) were quantified for a damselfly that exhibits "scramble competition" for mates. The opportunity for selection on male reproduction was potentially 2.9 times that for females.